blob: dbdf9c301b0215a7a3fbbac771e1df3fdaee85d6 [file] [log] [blame]
Peter Maydell3c95fde2020-03-06 17:17:44 +00001HXCOMM Use DEFHEADING() to define headings in both help text and rST.
2HXCOMM Text between SRST and ERST is copied to the rST version and
3HXCOMM discarded from C version.
Blue Swirlad960902010-03-29 19:23:52 +00004HXCOMM DEF(option, HAS_ARG/0, opt_enum, opt_help, arch_mask) is used to
5HXCOMM construct option structures, enums and help message for specified
6HXCOMM architectures.
Peter Maydell3c95fde2020-03-06 17:17:44 +00007HXCOMM HXCOMM can be used for comments, discarded from both rST and C.
blueswir15824d652009-03-28 06:44:27 +00008
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02009DEFHEADING(Standard options:)
blueswir15824d652009-03-28 06:44:27 +000010
11DEF("help", 0, QEMU_OPTION_h,
Blue Swirlad960902010-03-29 19:23:52 +000012 "-h or -help display this help and exit\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +000013SRST
14``-h``
15 Display help and exit
16ERST
blueswir15824d652009-03-28 06:44:27 +000017
pbrook9bd7e6d2009-04-07 22:58:45 +000018DEF("version", 0, QEMU_OPTION_version,
Blue Swirlad960902010-03-29 19:23:52 +000019 "-version display version information and exit\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +000020SRST
21``-version``
22 Display version information and exit
23ERST
pbrook9bd7e6d2009-04-07 22:58:45 +000024
Jan Kiszka80f52a62011-07-23 12:39:46 +020025DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
26 "-machine [type=]name[,prop[=value][,...]]\n"
Peter Maydell585f6032012-10-04 16:22:01 +010027 " selects emulated machine ('-machine help' for list)\n"
Jan Kiszka80f52a62011-07-23 12:39:46 +020028 " property accel=accel1[:accel2[:...]] selects accelerator\n"
Reinoud Zandijk74a414a2021-04-02 22:25:32 +020029 " supported accelerators are kvm, xen, hax, hvf, nvmm, whpx or tcg (default: tcg)\n"
Don Slutzd1048be2014-11-21 11:18:52 -050030 " vmport=on|off|auto controls emulation of vmport (default: auto)\n"
Luiz Capitulino8490fc72012-09-05 16:50:16 -030031 " dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
Le Tana52a7fd2014-08-16 13:55:40 +080032 " mem-merge=on|off controls memory merge support (default: on)\n"
Tony Krowiak2eb1cd02015-03-12 13:53:51 +010033 " aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
Alexander Graf9850c602015-02-23 13:56:42 +010034 " dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
Xiao Guangrong87252e12015-12-02 15:20:58 +080035 " suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
Greg Kurz902c0532016-02-18 12:32:25 +010036 " nvdimm=on|off controls NVDIMM support (default=off)\n"
Tao Xu244b3f42019-12-13 09:19:22 +080037 " memory-encryption=@var{} memory encryption object to use (default=none)\n"
Igor Mammedov8db0b202021-01-21 11:15:04 -050038 " hmat=on|off controls ACPI HMAT support (default=off)\n"
Jonathan Cameron03b39fc2022-06-08 15:54:33 +010039 " memory-backend='backend-id' specifies explicitly provided backend for main RAM (default=none)\n"
Matthew Rosato59d1ce42022-09-02 13:27:37 -040040 " cxl-fmw.0.targets.0=firsttarget,cxl-fmw.0.targets.1=secondtarget,cxl-fmw.0.size=size[,cxl-fmw.0.interleave-granularity=granularity]\n"
41 " zpcii-disable=on|off disables zPCI interpretation facilities (default=off)\n",
Jan Kiszka80f52a62011-07-23 12:39:46 +020042 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +000043SRST
44``-machine [type=]name[,prop=value[,...]]``
45 Select the emulated machine by name. Use ``-machine help`` to list
46 available machines.
47
48 For architectures which aim to support live migration compatibility
49 across releases, each release will introduce a new versioned machine
50 type. For example, the 2.8.0 release introduced machine types
51 "pc-i440fx-2.8" and "pc-q35-2.8" for the x86\_64/i686 architectures.
52
53 To allow live migration of guests from QEMU version 2.8.0, to QEMU
54 version 2.9.0, the 2.9.0 version must support the "pc-i440fx-2.8"
55 and "pc-q35-2.8" machines too. To allow users live migrating VMs to
56 skip multiple intermediate releases when upgrading, new releases of
57 QEMU will support machine types from many previous versions.
58
59 Supported machine properties are:
60
61 ``accel=accels1[:accels2[:...]]``
62 This is used to enable an accelerator. Depending on the target
Reinoud Zandijk74a414a2021-04-02 22:25:32 +020063 architecture, kvm, xen, hax, hvf, nvmm, whpx or tcg can be available.
Peter Maydelle2fcbf42020-03-06 10:07:14 +000064 By default, tcg is used. If there is more than one accelerator
65 specified, the next one is used if the previous one fails to
66 initialize.
67
68 ``vmport=on|off|auto``
69 Enables emulation of VMWare IO port, for vmmouse etc. auto says
70 to select the value based on accel. For accel=xen the default is
71 off otherwise the default is on.
72
73 ``dump-guest-core=on|off``
74 Include guest memory in a core dump. The default is on.
75
76 ``mem-merge=on|off``
77 Enables or disables memory merge support. This feature, when
78 supported by the host, de-duplicates identical memory pages
79 among VMs instances (enabled by default).
80
81 ``aes-key-wrap=on|off``
82 Enables or disables AES key wrapping support on s390-ccw hosts.
83 This feature controls whether AES wrapping keys will be created
84 to allow execution of AES cryptographic functions. The default
85 is on.
86
87 ``dea-key-wrap=on|off``
88 Enables or disables DEA key wrapping support on s390-ccw hosts.
89 This feature controls whether DEA wrapping keys will be created
90 to allow execution of DEA cryptographic functions. The default
91 is on.
92
93 ``nvdimm=on|off``
94 Enables or disables NVDIMM support. The default is off.
95
Peter Maydelle2fcbf42020-03-06 10:07:14 +000096 ``memory-encryption=``
97 Memory encryption object to use. The default is none.
98
99 ``hmat=on|off``
100 Enables or disables ACPI Heterogeneous Memory Attribute Table
101 (HMAT) support. The default is off.
Igor Mammedov8db0b202021-01-21 11:15:04 -0500102
Peter Maydell95355822021-07-19 11:52:57 +0100103 ``memory-backend='id'``
Igor Mammedov8db0b202021-01-21 11:15:04 -0500104 An alternative to legacy ``-mem-path`` and ``mem-prealloc`` options.
105 Allows to use a memory backend as main RAM.
106
107 For example:
108 ::
Peter Maydell95355822021-07-19 11:52:57 +0100109
110 -object memory-backend-file,id=pc.ram,size=512M,mem-path=/hugetlbfs,prealloc=on,share=on
111 -machine memory-backend=pc.ram
112 -m 512M
Igor Mammedov8db0b202021-01-21 11:15:04 -0500113
114 Migration compatibility note:
Peter Maydell95355822021-07-19 11:52:57 +0100115
116 * as backend id one shall use value of 'default-ram-id', advertised by
117 machine type (available via ``query-machines`` QMP command), if migration
118 to/from old QEMU (<5.0) is expected.
119 * for machine types 4.0 and older, user shall
120 use ``x-use-canonical-path-for-ramblock-id=off`` backend option
121 if migration to/from old QEMU (<5.0) is expected.
122
Igor Mammedov8db0b202021-01-21 11:15:04 -0500123 For example:
124 ::
Peter Maydell95355822021-07-19 11:52:57 +0100125
126 -object memory-backend-ram,id=pc.ram,size=512M,x-use-canonical-path-for-ramblock-id=off
127 -machine memory-backend=pc.ram
128 -m 512M
Jonathan Cameron03b39fc2022-06-08 15:54:33 +0100129
130 ``cxl-fmw.0.targets.0=firsttarget,cxl-fmw.0.targets.1=secondtarget,cxl-fmw.0.size=size[,cxl-fmw.0.interleave-granularity=granularity]``
131 Define a CXL Fixed Memory Window (CFMW).
132
133 Described in the CXL 2.0 ECN: CEDT CFMWS & QTG _DSM.
134
135 They are regions of Host Physical Addresses (HPA) on a system which
136 may be interleaved across one or more CXL host bridges. The system
137 software will assign particular devices into these windows and
138 configure the downstream Host-managed Device Memory (HDM) decoders
139 in root ports, switch ports and devices appropriately to meet the
140 interleave requirements before enabling the memory devices.
141
142 ``targets.X=target`` provides the mapping to CXL host bridges
143 which may be identified by the id provied in the -device entry.
144 Multiple entries are needed to specify all the targets when
145 the fixed memory window represents interleaved memory. X is the
146 target index from 0.
147
148 ``size=size`` sets the size of the CFMW. This must be a multiple of
149 256MiB. The region will be aligned to 256MiB but the location is
150 platform and configuration dependent.
151
152 ``interleave-granularity=granularity`` sets the granularity of
153 interleave. Default 256KiB. Only 256KiB, 512KiB, 1024KiB, 2048KiB
154 4096KiB, 8192KiB and 16384KiB granularities supported.
155
156 Example:
157
158 ::
159
160 -machine cxl-fmw.0.targets.0=cxl.0,cxl-fmw.0.targets.1=cxl.1,cxl-fmw.0.size=128G,cxl-fmw.0.interleave-granularity=512k
Matthew Rosato59d1ce42022-09-02 13:27:37 -0400161
162 ``zpcii-disable=on|off``
163 Disables zPCI interpretation facilties on s390-ccw hosts.
164 This feature can be used to disable hardware virtual assists
165 related to zPCI devices. The default is off.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000166ERST
blueswir15824d652009-03-28 06:44:27 +0000167
Sean Christophersondfce81f2021-09-28 10:40:58 +0200168DEF("M", HAS_ARG, QEMU_OPTION_M,
Yang Zhong11058122021-11-01 12:20:05 -0400169 " sgx-epc.0.memdev=memid,sgx-epc.0.node=numaid\n",
Sean Christophersondfce81f2021-09-28 10:40:58 +0200170 QEMU_ARCH_ALL)
171
172SRST
Yang Zhong11058122021-11-01 12:20:05 -0400173``sgx-epc.0.memdev=@var{memid},sgx-epc.0.node=@var{numaid}``
Sean Christophersondfce81f2021-09-28 10:40:58 +0200174 Define an SGX EPC section.
175ERST
Jan Kiszka80f52a62011-07-23 12:39:46 +0200176
blueswir15824d652009-03-28 06:44:27 +0000177DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
Peter Maydell585f6032012-10-04 16:22:01 +0100178 "-cpu cpu select CPU ('-cpu help' for list)\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000179SRST
180``-cpu model``
181 Select CPU model (``-cpu help`` for list and additional feature
182 selection)
183ERST
blueswir15824d652009-03-28 06:44:27 +0000184
KONRAD Frederic8d4e9142017-02-23 18:29:08 +0000185DEF("accel", HAS_ARG, QEMU_OPTION_accel,
Paolo Bonzinife174132019-11-13 15:16:44 +0100186 "-accel [accel=]accelerator[,prop[=value][,...]]\n"
Reinoud Zandijk74a414a2021-04-02 22:25:32 +0200187 " select accelerator (kvm, xen, hax, hvf, nvmm, whpx or tcg; use 'help' for a list)\n"
Paolo Bonzini46472d82019-11-13 10:56:53 +0100188 " igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n"
Paolo Bonzini11bc4a12019-11-13 10:56:53 +0100189 " kernel-irqchip=on|off|split controls accelerated irqchip support (default=on)\n"
Paolo Bonzini23b08982019-11-13 10:56:53 +0100190 " kvm-shadow-mem=size of KVM shadow MMU in bytes\n"
Richard Hendersona35b3e12020-10-28 20:50:29 -0700191 " split-wx=on|off (enable TCG split w^x mapping)\n"
Paolo Bonzinife174132019-11-13 15:16:44 +0100192 " tb-size=n (TCG translation block cache size)\n"
Peter Xu2ea5cb02021-05-06 12:05:47 -0400193 " dirty-ring-size=n (KVM dirty ring GFN count, default 0)\n"
Chenyi Qiange2e69f62022-09-29 15:20:14 +0800194 " notify-vmexit=run|internal-error|disable,notify-window=n (enable notify VM exit and set notify window, x86 only)\n"
Eduardo Habkost0b3c5c82018-06-11 16:56:07 -0300195 " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000196SRST
197``-accel name[,prop=value[,...]]``
198 This is used to enable an accelerator. Depending on the target
Reinoud Zandijk74a414a2021-04-02 22:25:32 +0200199 architecture, kvm, xen, hax, hvf, nvmm, whpx or tcg can be available. By
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000200 default, tcg is used. If there is more than one accelerator
201 specified, the next one is used if the previous one fails to
202 initialize.
203
204 ``igd-passthru=on|off``
205 When Xen is in use, this option controls whether Intel
206 integrated graphics devices can be passed through to the guest
207 (default=off)
208
209 ``kernel-irqchip=on|off|split``
210 Controls KVM in-kernel irqchip support. The default is full
211 acceleration of the interrupt controllers. On x86, split irqchip
212 reduces the kernel attack surface, at a performance cost for
213 non-MSI interrupts. Disabling the in-kernel irqchip completely
214 is not recommended except for debugging purposes.
215
216 ``kvm-shadow-mem=size``
217 Defines the size of the KVM shadow MMU.
218
Richard Hendersona35b3e12020-10-28 20:50:29 -0700219 ``split-wx=on|off``
220 Controls the use of split w^x mapping for the TCG code generation
221 buffer. Some operating systems require this to be enabled, and in
222 such a case this will default on. On other operating systems, this
223 will default off, but one may enable this for testing or debugging.
224
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000225 ``tb-size=n``
226 Controls the size (in MiB) of the TCG translation block cache.
227
228 ``thread=single|multi``
229 Controls number of TCG threads. When the TCG is multi-threaded
Michael Tokarevcba42d62021-03-09 14:15:10 +0300230 there will be one thread per vCPU therefore taking advantage of
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000231 additional host cores. The default is to enable multi-threading
232 where both the back-end and front-ends support it and no
233 incompatible TCG features have been enabled (e.g.
234 icount/replay).
Peter Xu2ea5cb02021-05-06 12:05:47 -0400235
236 ``dirty-ring-size=n``
237 When the KVM accelerator is used, it controls the size of the per-vCPU
238 dirty page ring buffer (number of entries for each vCPU). It should
239 be a value that is power of two, and it should be 1024 or bigger (but
240 still less than the maximum value that the kernel supports). 4096
241 could be a good initial value if you have no idea which is the best.
242 Set this value to 0 to disable the feature. By default, this feature
243 is disabled (dirty-ring-size=0). When enabled, KVM will instead
244 record dirty pages in a bitmap.
245
Chenyi Qiange2e69f62022-09-29 15:20:14 +0800246 ``notify-vmexit=run|internal-error|disable,notify-window=n``
247 Enables or disables notify VM exit support on x86 host and specify
248 the corresponding notify window to trigger the VM exit if enabled.
249 ``run`` option enables the feature. It does nothing and continue
250 if the exit happens. ``internal-error`` option enables the feature.
251 It raises a internal error. ``disable`` option doesn't enable the feature.
252 This feature can mitigate the CPU stuck issue due to event windows don't
253 open up for a specified of time (i.e. notify-window).
254 Default: notify-vmexit=run,notify-window=0.
255
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000256ERST
KONRAD Frederic8d4e9142017-02-23 18:29:08 +0000257
blueswir15824d652009-03-28 06:44:27 +0000258DEF("smp", HAS_ARG, QEMU_OPTION_smp,
Yanan Wang864c3b52021-12-28 17:22:09 +0800259 "-smp [[cpus=]n][,maxcpus=maxcpus][,sockets=sockets][,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]\n"
Yanan Wang0d871782021-12-28 17:22:08 +0800260 " set the number of initial CPUs to 'n' [default=1]\n"
Daniel P. Berrangéce8ee7c2021-06-22 15:30:43 +0100261 " maxcpus= maximum number of total CPUs, including\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -0700262 " offline CPUs for hotplug, etc\n"
Yanan Wang0d871782021-12-28 17:22:08 +0800263 " sockets= number of sockets on the machine board\n"
264 " dies= number of dies in one socket\n"
Yanan Wang864c3b52021-12-28 17:22:09 +0800265 " clusters= number of clusters in one die\n"
266 " cores= number of cores in one cluster\n"
Yanan Wang0d871782021-12-28 17:22:08 +0800267 " threads= number of threads in one core\n"
268 "Note: Different machines may have different subsets of the CPU topology\n"
269 " parameters supported, so the actual meaning of the supported parameters\n"
270 " will vary accordingly. For example, for a machine type that supports a\n"
271 " three-level CPU hierarchy of sockets/cores/threads, the parameters will\n"
272 " sequentially mean as below:\n"
273 " sockets means the number of sockets on the machine board\n"
274 " cores means the number of cores in one socket\n"
275 " threads means the number of threads in one core\n"
276 " For a particular machine type board, an expected CPU topology hierarchy\n"
277 " can be defined through the supported sub-option. Unsupported parameters\n"
278 " can also be provided in addition to the sub-option, but their values\n"
279 " must be set as 1 in the purpose of correct parsing.\n",
280 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000281SRST
Yanan Wang864c3b52021-12-28 17:22:09 +0800282``-smp [[cpus=]n][,maxcpus=maxcpus][,sockets=sockets][,dies=dies][,clusters=clusters][,cores=cores][,threads=threads]``
Daniel P. Berrangé80d78352021-06-22 16:17:09 +0100283 Simulate a SMP system with '\ ``n``\ ' CPUs initially present on
284 the machine type board. On boards supporting CPU hotplug, the optional
285 '\ ``maxcpus``\ ' parameter can be set to enable further CPUs to be
Yanan Wang7d8c5a32021-09-29 10:58:05 +0800286 added at runtime. When both parameters are omitted, the maximum number
287 of CPUs will be calculated from the provided topology members and the
288 initial CPU count will match the maximum number. When only one of them
289 is given then the omitted one will be set to its counterpart's value.
290 Both parameters may be specified, but the maximum number of CPUs must
Yanan Wang0d871782021-12-28 17:22:08 +0800291 be equal to or greater than the initial CPU count. Product of the
292 CPU topology hierarchy must be equal to the maximum number of CPUs.
293 Both parameters are subject to an upper limit that is determined by
294 the specific machine type chosen.
Daniel P. Berrangé80d78352021-06-22 16:17:09 +0100295
Yanan Wang0d871782021-12-28 17:22:08 +0800296 To control reporting of CPU topology information, values of the topology
297 parameters can be specified. Machines may only support a subset of the
298 parameters and different machines may have different subsets supported
299 which vary depending on capacity of the corresponding CPU targets. So
300 for a particular machine type board, an expected topology hierarchy can
301 be defined through the supported sub-option. Unsupported parameters can
302 also be provided in addition to the sub-option, but their values must be
303 set as 1 in the purpose of correct parsing.
Daniel P. Berrangé80d78352021-06-22 16:17:09 +0100304
305 Either the initial CPU count, or at least one of the topology parameters
Yanan Wangc2511b12021-09-29 10:58:02 +0800306 must be specified. The specified parameters must be greater than zero,
307 explicit configuration like "cpus=0" is not allowed. Values for any
308 omitted parameters will be computed from those which are given.
Yanan Wang0d871782021-12-28 17:22:08 +0800309
310 For example, the following sub-option defines a CPU topology hierarchy
311 (2 sockets totally on the machine, 2 cores per socket, 2 threads per
312 core) for a machine that only supports sockets/cores/threads.
313 Some members of the option can be omitted but their values will be
314 automatically computed:
315
316 ::
317
318 -smp 8,sockets=2,cores=2,threads=2,maxcpus=8
319
320 The following sub-option defines a CPU topology hierarchy (2 sockets
321 totally on the machine, 2 dies per socket, 2 cores per die, 2 threads
322 per core) for PC machines which support sockets/dies/cores/threads.
323 Some members of the option can be omitted but their values will be
324 automatically computed:
325
326 ::
327
328 -smp 16,sockets=2,dies=2,cores=2,threads=2,maxcpus=16
329
Yanan Wangd55c3162022-01-07 16:32:27 +0800330 The following sub-option defines a CPU topology hierarchy (2 sockets
331 totally on the machine, 2 clusters per socket, 2 cores per cluster,
332 2 threads per core) for ARM virt machines which support sockets/clusters
333 /cores/threads. Some members of the option can be omitted but their values
334 will be automatically computed:
335
336 ::
337
338 -smp 16,sockets=2,clusters=2,cores=2,threads=2,maxcpus=16
339
Yanan Wangc2511b12021-09-29 10:58:02 +0800340 Historically preference was given to the coarsest topology parameters
341 when computing missing values (ie sockets preferred over cores, which
342 were preferred over threads), however, this behaviour is considered
Yanan Wang4a0af292021-09-29 10:58:09 +0800343 liable to change. Prior to 6.2 the preference was sockets over cores
344 over threads. Since 6.2 the preference is cores over sockets over threads.
Yanan Wang0d871782021-12-28 17:22:08 +0800345
346 For example, the following option defines a machine board with 2 sockets
347 of 1 core before 6.2 and 1 socket of 2 cores after 6.2:
348
349 ::
350
351 -smp 2
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000352ERST
blueswir15824d652009-03-28 06:44:27 +0000353
aliguori268a3622009-04-21 22:30:27 +0000354DEF("numa", HAS_ARG, QEMU_OPTION_numa,
Tao Xu244b3f42019-12-13 09:19:22 +0800355 "-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n"
356 "-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=node]\n"
Igor Mammedov2d19c652017-11-28 15:53:58 +0100357 "-numa dist,src=source,dst=destination,val=distance\n"
Liu Jingqi9b12dfa2019-12-13 09:19:23 +0800358 "-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]\n"
Liu Jingqic412a482019-12-13 09:19:24 +0800359 "-numa hmat-lb,initiator=node,target=node,hierarchy=memory|first-level|second-level|third-level,data-type=access-latency|read-latency|write-latency[,latency=lat][,bandwidth=bw]\n"
360 "-numa hmat-cache,node-id=node,size=size,level=level[,associativity=none|direct|complex][,policy=none|write-back|write-through][,line=size]\n",
Igor Mammedov2d19c652017-11-28 15:53:58 +0100361 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000362SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +0000363``-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]``
364 \
365``-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node][,initiator=initiator]``
366 \
367``-numa dist,src=source,dst=destination,val=distance``
368 \
369``-numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]``
370 \
371``-numa hmat-lb,initiator=node,target=node,hierarchy=hierarchy,data-type=tpye[,latency=lat][,bandwidth=bw]``
372 \
373``-numa hmat-cache,node-id=node,size=size,level=level[,associativity=str][,policy=str][,line=size]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000374 Define a NUMA node and assign RAM and VCPUs to it. Set the NUMA
375 distance from a source node to a destination node. Set the ACPI
376 Heterogeneous Memory Attributes for the given nodes.
377
378 Legacy VCPU assignment uses '\ ``cpus``\ ' option where firstcpu and
379 lastcpu are CPU indexes. Each '\ ``cpus``\ ' option represent a
380 contiguous range of CPU indexes (or a single VCPU if lastcpu is
381 omitted). A non-contiguous set of VCPUs can be represented by
382 providing multiple '\ ``cpus``\ ' options. If '\ ``cpus``\ ' is
383 omitted on all nodes, VCPUs are automatically split between them.
384
385 For example, the following option assigns VCPUs 0, 1, 2 and 5 to a
386 NUMA node:
387
388 ::
389
390 -numa node,cpus=0-2,cpus=5
391
392 '\ ``cpu``\ ' option is a new alternative to '\ ``cpus``\ ' option
393 which uses '\ ``socket-id|core-id|thread-id``\ ' properties to
394 assign CPU objects to a node using topology layout properties of
395 CPU. The set of properties is machine specific, and depends on used
396 machine type/'\ ``smp``\ ' options. It could be queried with
397 '\ ``hotpluggable-cpus``\ ' monitor command. '\ ``node-id``\ '
398 property specifies node to which CPU object will be assigned, it's
399 required for node to be declared with '\ ``node``\ ' option before
400 it's used with '\ ``cpu``\ ' option.
401
402 For example:
403
404 ::
405
406 -M pc \
407 -smp 1,sockets=2,maxcpus=2 \
408 -numa node,nodeid=0 -numa node,nodeid=1 \
409 -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1
410
Igor Mammedov32a354d2020-06-09 09:56:35 -0400411 Legacy '\ ``mem``\ ' assigns a given RAM amount to a node (not supported
412 for 5.1 and newer machine types). '\ ``memdev``\ ' assigns RAM from
413 a given memory backend device to a node. If '\ ``mem``\ ' and
414 '\ ``memdev``\ ' are omitted in all nodes, RAM is split equally between them.
415
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000416
417 '\ ``mem``\ ' and '\ ``memdev``\ ' are mutually exclusive.
418 Furthermore, if one node uses '\ ``memdev``\ ', all of them have to
419 use it.
420
421 '\ ``initiator``\ ' is an additional option that points to an
422 initiator NUMA node that has best performance (the lowest latency or
423 largest bandwidth) to this NUMA node. Note that this option can be
424 set only when the machine property 'hmat' is set to 'on'.
425
426 Following example creates a machine with 2 NUMA nodes, node 0 has
427 CPU. node 1 has only memory, and its initiator is node 0. Note that
428 because node 0 has CPU, by default the initiator of node 0 is itself
429 and must be itself.
430
431 ::
432
433 -machine hmat=on \
434 -m 2G,slots=2,maxmem=4G \
435 -object memory-backend-ram,size=1G,id=m0 \
436 -object memory-backend-ram,size=1G,id=m1 \
437 -numa node,nodeid=0,memdev=m0 \
438 -numa node,nodeid=1,memdev=m1,initiator=0 \
439 -smp 2,sockets=2,maxcpus=2 \
440 -numa cpu,node-id=0,socket-id=0 \
441 -numa cpu,node-id=0,socket-id=1
442
443 source and destination are NUMA node IDs. distance is the NUMA
444 distance from source to destination. The distance from a node to
445 itself is always 10. If any pair of nodes is given a distance, then
446 all pairs must be given distances. Although, when distances are only
447 given in one direction for each pair of nodes, then the distances in
448 the opposite directions are assumed to be the same. If, however, an
449 asymmetrical pair of distances is given for even one node pair, then
450 all node pairs must be provided distance values for both directions,
451 even when they are symmetrical. When a node is unreachable from
452 another node, set the pair's distance to 255.
453
454 Note that the -``numa`` option doesn't allocate any of the specified
455 resources, it just assigns existing resources to NUMA nodes. This
456 means that one still has to use the ``-m``, ``-smp`` options to
457 allocate RAM and VCPUs respectively.
458
459 Use '\ ``hmat-lb``\ ' to set System Locality Latency and Bandwidth
460 Information between initiator and target NUMA nodes in ACPI
461 Heterogeneous Attribute Memory Table (HMAT). Initiator NUMA node can
462 create memory requests, usually it has one or more processors.
463 Target NUMA node contains addressable memory.
464
465 In '\ ``hmat-lb``\ ' option, node are NUMA node IDs. hierarchy is
466 the memory hierarchy of the target NUMA node: if hierarchy is
467 'memory', the structure represents the memory performance; if
468 hierarchy is 'first-level\|second-level\|third-level', this
469 structure represents aggregated performance of memory side caches
470 for each domain. type of 'data-type' is type of data represented by
471 this structure instance: if 'hierarchy' is 'memory', 'data-type' is
472 'access\|read\|write' latency or 'access\|read\|write' bandwidth of
473 the target memory; if 'hierarchy' is
474 'first-level\|second-level\|third-level', 'data-type' is
475 'access\|read\|write' hit latency or 'access\|read\|write' hit
476 bandwidth of the target memory side cache.
477
478 lat is latency value in nanoseconds. bw is bandwidth value, the
479 possible value and units are NUM[M\|G\|T], mean that the bandwidth
480 value are NUM byte per second (or MB/s, GB/s or TB/s depending on
481 used suffix). Note that if latency or bandwidth value is 0, means
482 the corresponding latency or bandwidth information is not provided.
483
484 In '\ ``hmat-cache``\ ' option, node-id is the NUMA-id of the memory
485 belongs. size is the size of memory side cache in bytes. level is
486 the cache level described in this structure, note that the cache
487 level 0 should not be used with '\ ``hmat-cache``\ ' option.
488 associativity is the cache associativity, the possible value is
489 'none/direct(direct-mapped)/complex(complex cache indexing)'. policy
490 is the write policy. line is the cache Line size in bytes.
491
492 For example, the following options describe 2 NUMA nodes. Node 0 has
493 2 cpus and a ram, node 1 has only a ram. The processors in node 0
494 access memory in node 0 with access-latency 5 nanoseconds,
495 access-bandwidth is 200 MB/s; The processors in NUMA node 0 access
496 memory in NUMA node 1 with access-latency 10 nanoseconds,
497 access-bandwidth is 100 MB/s. And for memory side cache information,
498 NUMA node 0 and 1 both have 1 level memory cache, size is 10KB,
499 policy is write-back, the cache Line size is 8 bytes:
500
501 ::
502
503 -machine hmat=on \
504 -m 2G \
505 -object memory-backend-ram,size=1G,id=m0 \
506 -object memory-backend-ram,size=1G,id=m1 \
Yanan Wang848dd262021-09-28 20:11:34 +0800507 -smp 2,sockets=2,maxcpus=2 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000508 -numa node,nodeid=0,memdev=m0 \
509 -numa node,nodeid=1,memdev=m1,initiator=0 \
510 -numa cpu,node-id=0,socket-id=0 \
511 -numa cpu,node-id=0,socket-id=1 \
512 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=5 \
513 -numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=200M \
514 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=10 \
515 -numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=100M \
516 -numa hmat-cache,node-id=0,size=10K,level=1,associativity=direct,policy=write-back,line=8 \
517 -numa hmat-cache,node-id=1,size=10K,level=1,associativity=direct,policy=write-back,line=8
518ERST
aliguori268a3622009-04-21 22:30:27 +0000519
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100520DEF("add-fd", HAS_ARG, QEMU_OPTION_add_fd,
521 "-add-fd fd=fd,set=set[,opaque=opaque]\n"
522 " Add 'fd' to fd 'set'\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000523SRST
524``-add-fd fd=fd,set=set[,opaque=opaque]``
525 Add a file descriptor to an fd set. Valid options are:
526
527 ``fd=fd``
528 This option defines the file descriptor of which a duplicate is
529 added to fd set. The file descriptor cannot be stdin, stdout, or
530 stderr.
531
532 ``set=set``
533 This option defines the ID of the fd set to add the file
534 descriptor to.
535
536 ``opaque=opaque``
537 This option defines a free-form string that can be used to
538 describe fd.
539
540 You can open an image using pre-opened file descriptors from an fd
541 set:
542
543 .. parsed-literal::
544
Laszlo Ersek353a06b2020-09-08 19:21:11 +0200545 |qemu_system| \\
546 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\
547 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000548 -drive file=/dev/fdset/2,index=0,media=disk
549ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100550
551DEF("set", HAS_ARG, QEMU_OPTION_set,
552 "-set group.id.arg=value\n"
553 " set <arg> parameter for item <id> of type <group>\n"
554 " i.e. -set drive.$id.file=/path/to/image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000555SRST
556``-set group.id.arg=value``
557 Set parameter arg for item id of type group
558ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100559
560DEF("global", HAS_ARG, QEMU_OPTION_global,
Paolo Bonzini3751d7c2015-04-09 14:16:19 +0200561 "-global driver.property=value\n"
562 "-global driver=driver,property=property,value=value\n"
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100563 " set a global default for a driver property\n",
564 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000565SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +0000566``-global driver.prop=value``
567 \
568``-global driver=driver,property=property,value=value``
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000569 Set default value of driver's property prop to value, e.g.:
570
571 .. parsed-literal::
572
573 |qemu_system_x86| -global ide-hd.physical_block_size=4096 disk-image.img
574
575 In particular, you can use this to set driver properties for devices
576 which are created automatically by the machine model. To create a
577 device which is not created automatically and set properties on it,
578 use -``device``.
579
580 -global driver.prop=value is shorthand for -global
581 driver=driver,property=prop,value=value. The longhand syntax works
582 even when driver contains a dot.
583ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100584
585DEF("boot", HAS_ARG, QEMU_OPTION_boot,
586 "-boot [order=drives][,once=drives][,menu=on|off]\n"
Amos Kongc8a6ae82013-03-19 14:23:27 +0800587 " [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100588 " 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n"
589 " 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n"
590 " 'sp_time': the period that splash picture last if menu=on, unit is ms\n"
591 " 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n",
592 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000593SRST
594``-boot [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_timeout][,strict=on|off]``
595 Specify boot order drives as a string of drive letters. Valid drive
596 letters depend on the target architecture. The x86 PC uses: a, b
597 (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p
598 (Etherboot from network adapter 1-4), hard disk boot is the default.
599 To apply a particular boot order only on the first startup, specify
600 it via ``once``. Note that the ``order`` or ``once`` parameter
601 should not be used together with the ``bootindex`` property of
602 devices, since the firmware implementations normally do not support
603 both at the same time.
604
605 Interactive boot menus/prompts can be enabled via ``menu=on`` as far
606 as firmware/BIOS supports them. The default is non-interactive boot.
607
608 A splash picture could be passed to bios, enabling user to show it
609 as logo, when option splash=sp\_name is given and menu=on, If
610 firmware/BIOS supports them. Currently Seabios for X86 system
611 support it. limitation: The splash file could be a jpeg file or a
612 BMP file in 24 BPP format(true color). The resolution should be
613 supported by the SVGA mode, so the recommended is 320x240, 640x480,
614 800x640.
615
616 A timeout could be passed to bios, guest will pause for rb\_timeout
617 ms when boot failed, then reboot. If rb\_timeout is '-1', guest will
618 not reboot, qemu passes '-1' to bios by default. Currently Seabios
619 for X86 system support it.
620
621 Do strict boot via ``strict=on`` as far as firmware/BIOS supports
622 it. This only effects when boot priority is changed by bootindex
623 options. The default is non-strict boot.
624
Peter Maydell09ce5f22020-02-28 15:36:13 +0000625 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000626
627 # try to boot from network first, then from hard disk
628 |qemu_system_x86| -boot order=nc
629 # boot from CD-ROM first, switch back to default order after reboot
630 |qemu_system_x86| -boot once=d
631 # boot with a splash picture for 5 seconds.
632 |qemu_system_x86| -boot menu=on,splash=/root/boot.bmp,splash-time=5000
633
634 Note: The legacy format '-boot drives' is still supported but its
635 use is discouraged as it may be removed from future versions.
636ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100637
638DEF("m", HAS_ARG, QEMU_OPTION_m,
Michael Tokarev89f3ea22016-11-10 17:51:32 +0300639 "-m [size=]megs[,slots=n,maxmem=size]\n"
Igor Mammedov6e1d3c12013-11-27 01:27:35 +0100640 " configure guest RAM\n"
Alexander Graf0daba1f2015-06-05 11:05:03 +0200641 " size: initial amount of guest memory\n"
Igor Mammedovc270fb92014-06-02 15:25:02 +0200642 " slots: number of hotplug slots (default: none)\n"
Matthew Rosatob6fe0122014-08-28 11:25:33 -0400643 " maxmem: maximum amount of guest memory (default: none)\n"
644 "NOTE: Some architectures might enforce a specific granularity\n",
Igor Mammedov6e1d3c12013-11-27 01:27:35 +0100645 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000646SRST
647``-m [size=]megs[,slots=n,maxmem=size]``
648 Sets guest startup RAM size to megs megabytes. Default is 128 MiB.
649 Optionally, a suffix of "M" or "G" can be used to signify a value in
650 megabytes or gigabytes respectively. Optional pair slots, maxmem
651 could be used to set amount of hotpluggable memory slots and maximum
652 amount of memory. Note that maxmem must be aligned to the page size.
653
654 For example, the following command-line sets the guest startup RAM
655 size to 1GB, creates 3 slots to hotplug additional memory and sets
656 the maximum memory the guest can reach to 4GB:
657
658 .. parsed-literal::
659
660 |qemu_system| -m 1G,slots=3,maxmem=4G
661
662 If slots and maxmem are not specified, memory hotplug won't be
663 enabled and the guest startup RAM will never increase.
664ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100665
666DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
667 "-mem-path FILE provide backing storage for guest RAM\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000668SRST
669``-mem-path path``
670 Allocate guest RAM from a temporarily created file in path.
671ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100672
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100673DEF("mem-prealloc", 0, QEMU_OPTION_mem_prealloc,
674 "-mem-prealloc preallocate guest memory (use with -mem-path)\n",
675 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000676SRST
677``-mem-prealloc``
678 Preallocate memory when using -mem-path.
679ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100680
681DEF("k", HAS_ARG, QEMU_OPTION_k,
682 "-k language use keyboard layout (for example 'fr' for French)\n",
683 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000684SRST
685``-k language``
686 Use keyboard layout language (for example ``fr`` for French). This
687 option is only needed where it is not easy to get raw PC keycodes
688 (e.g. on Macs, with some X11 servers or with a VNC or curses
689 display). You don't normally need to use it on PC/Linux or
690 PC/Windows hosts.
691
692 The available layouts are:
693
694 ::
695
696 ar de-ch es fo fr-ca hu ja mk no pt-br sv
697 da en-gb et fr fr-ch is lt nl pl ru th
698 de en-us fi fr-be hr it lv nl-be pt sl tr
699
700 The default is ``en-us``.
701ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100702
703
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100704HXCOMM Deprecated by -audiodev
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100705DEF("audio-help", 0, QEMU_OPTION_audio_help,
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100706 "-audio-help show -audiodev equivalent of the currently specified audio settings\n",
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100707 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000708SRST
709``-audio-help``
710 Will show the -audiodev equivalent of the currently specified
711 (deprecated) environment variables.
712ERST
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100713
Paolo Bonzini039a6832022-04-27 12:27:46 +0200714DEF("audio", HAS_ARG, QEMU_OPTION_audio,
715 "-audio [driver=]driver,model=value[,prop[=value][,...]]\n"
716 " specifies the audio backend and device to use;\n"
717 " apart from 'model', options are the same as for -audiodev.\n"
718 " use '-audio model=help' to show possible devices.\n",
719 QEMU_ARCH_ALL)
720SRST
721``-audio [driver=]driver,model=value[,prop[=value][,...]]``
722 This option is a shortcut for configuring both the guest audio
723 hardware and the host audio backend in one go.
Claudio Fontana5e03b6d2022-09-08 10:14:41 +0200724 The driver option is the same as with the corresponding ``-audiodev`` option below.
725 The guest hardware model can be set with ``model=modelname``.
726
727 Use ``driver=help`` to list the available drivers,
728 and ``model=help`` to list the available device types.
Paolo Bonzini039a6832022-04-27 12:27:46 +0200729
730 The following two example do exactly the same, to show how ``-audio``
731 can be used to shorten the command line length:
732
733 .. parsed-literal::
734
735 |qemu_system| -audiodev pa,id=pa -device sb16,audiodev=pa
736 |qemu_system| -audio pa,model=sb16
737ERST
738
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100739DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev,
740 "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n"
741 " specifies the audio backend to use\n"
Claudio Fontana5e03b6d2022-09-08 10:14:41 +0200742 " Use ``-audiodev help`` to list the available drivers\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100743 " id= identifier of the backend\n"
744 " timer-period= timer period in microseconds\n"
Kővágó, Zoltán8efac072019-10-13 21:57:58 +0200745 " in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100746 " in|out.fixed-settings= use fixed settings for host audio\n"
747 " in|out.frequency= frequency to use with fixed settings\n"
748 " in|out.channels= number of channels to use with fixed settings\n"
749 " in|out.format= sample format to use with fixed settings\n"
Volker RĂĽmelin49f77e62020-03-08 20:33:21 +0100750 " valid values: s8, s16, s32, u8, u16, u32, f32\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100751 " in|out.voices= number of voices to use\n"
Stefan Hajnoczi86247252019-09-18 10:53:33 +0100752 " in|out.buffer-length= length of buffer in microseconds\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100753 "-audiodev none,id=id,[,prop[=value][,...]]\n"
754 " dummy driver that discards all output\n"
755#ifdef CONFIG_AUDIO_ALSA
756 "-audiodev alsa,id=id[,prop[=value][,...]]\n"
757 " in|out.dev= name of the audio device to use\n"
Stefan Hajnoczidfc54342019-09-18 10:53:35 +0100758 " in|out.period-length= length of period in microseconds\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100759 " in|out.try-poll= attempt to use poll mode\n"
760 " threshold= threshold (in microseconds) when playback starts\n"
761#endif
762#ifdef CONFIG_AUDIO_COREAUDIO
763 "-audiodev coreaudio,id=id[,prop[=value][,...]]\n"
764 " in|out.buffer-count= number of buffers\n"
765#endif
766#ifdef CONFIG_AUDIO_DSOUND
767 "-audiodev dsound,id=id[,prop[=value][,...]]\n"
768 " latency= add extra latency to playback in microseconds\n"
769#endif
770#ifdef CONFIG_AUDIO_OSS
771 "-audiodev oss,id=id[,prop[=value][,...]]\n"
772 " in|out.dev= path of the audio device to use\n"
773 " in|out.buffer-count= number of buffers\n"
774 " in|out.try-poll= attempt to use poll mode\n"
775 " try-mmap= try using memory mapped access\n"
776 " exclusive= open device in exclusive mode\n"
777 " dsp-policy= set timing policy (0..10), -1 to use fragment mode\n"
778#endif
779#ifdef CONFIG_AUDIO_PA
780 "-audiodev pa,id=id[,prop[=value][,...]]\n"
781 " server= PulseAudio server address\n"
782 " in|out.name= source/sink device name\n"
Stefan Hajnoczi14d4f012019-10-04 13:56:41 +0100783 " in|out.latency= desired latency in microseconds\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100784#endif
785#ifdef CONFIG_AUDIO_SDL
786 "-audiodev sdl,id=id[,prop[=value][,...]]\n"
Volker RĂĽmelin5a0926c2021-01-10 11:02:19 +0100787 " in|out.buffer-count= number of buffers\n"
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100788#endif
Alexandre Ratchov663df1c2022-09-07 15:23:42 +0200789#ifdef CONFIG_AUDIO_SNDIO
790 "-audiodev sndio,id=id[,prop[=value][,...]]\n"
791#endif
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100792#ifdef CONFIG_SPICE
793 "-audiodev spice,id=id[,prop[=value][,...]]\n"
794#endif
Marc-André Lureau739362d2021-03-09 17:15:28 +0400795#ifdef CONFIG_DBUS_DISPLAY
796 "-audiodev dbus,id=id[,prop[=value][,...]]\n"
797#endif
Kővágó, Zoltánf0b3d812019-03-08 23:34:14 +0100798 "-audiodev wav,id=id[,prop[=value][,...]]\n"
799 " path= path of wav file to record\n",
800 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000801SRST
802``-audiodev [driver=]driver,id=id[,prop[=value][,...]]``
803 Adds a new audio backend driver identified by id. There are global
804 and driver specific properties. Some values can be set differently
805 for input and output, they're marked with ``in|out.``. You can set
806 the input's property with ``in.prop`` and the output's property with
807 ``out.prop``. For example:
808
809 ::
810
811 -audiodev alsa,id=example,in.frequency=44110,out.frequency=8000
812 -audiodev alsa,id=example,out.channels=1 # leaves in.channels unspecified
813
814 NOTE: parameter validation is known to be incomplete, in many cases
815 specifying an invalid option causes QEMU to print an error message
816 and continue emulation without sound.
817
818 Valid global options are:
819
820 ``id=identifier``
821 Identifies the audio backend.
822
823 ``timer-period=period``
824 Sets the timer period used by the audio subsystem in
825 microseconds. Default is 10000 (10 ms).
826
827 ``in|out.mixing-engine=on|off``
828 Use QEMU's mixing engine to mix all streams inside QEMU and
829 convert audio formats when not supported by the backend. When
830 off, fixed-settings must be off too. Note that disabling this
831 option means that the selected backend must support multiple
832 streams and the audio formats used by the virtual cards,
833 otherwise you'll get no sound. It's not recommended to disable
834 this option unless you want to use 5.1 or 7.1 audio, as mixing
835 engine only supports mono and stereo audio. Default is on.
836
837 ``in|out.fixed-settings=on|off``
838 Use fixed settings for host audio. When off, it will change
839 based on how the guest opens the sound card. In this case you
840 must not specify frequency, channels or format. Default is on.
841
842 ``in|out.frequency=frequency``
843 Specify the frequency to use when using fixed-settings. Default
844 is 44100Hz.
845
846 ``in|out.channels=channels``
847 Specify the number of channels to use when using fixed-settings.
848 Default is 2 (stereo).
849
850 ``in|out.format=format``
851 Specify the sample format to use when using fixed-settings.
852 Valid values are: ``s8``, ``s16``, ``s32``, ``u8``, ``u16``,
Volker RĂĽmelin49f77e62020-03-08 20:33:21 +0100853 ``u32``, ``f32``. Default is ``s16``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000854
855 ``in|out.voices=voices``
856 Specify the number of voices to use. Default is 1.
857
858 ``in|out.buffer-length=usecs``
859 Sets the size of the buffer in microseconds.
860
861``-audiodev none,id=id[,prop[=value][,...]]``
862 Creates a dummy backend that discards all outputs. This backend has
863 no backend specific properties.
864
865``-audiodev alsa,id=id[,prop[=value][,...]]``
866 Creates backend using the ALSA. This backend is only available on
867 Linux.
868
869 ALSA specific options are:
870
871 ``in|out.dev=device``
872 Specify the ALSA device to use for input and/or output. Default
873 is ``default``.
874
875 ``in|out.period-length=usecs``
876 Sets the period length in microseconds.
877
878 ``in|out.try-poll=on|off``
879 Attempt to use poll mode with the device. Default is on.
880
881 ``threshold=threshold``
882 Threshold (in microseconds) when playback starts. Default is 0.
883
884``-audiodev coreaudio,id=id[,prop[=value][,...]]``
885 Creates a backend using Apple's Core Audio. This backend is only
886 available on Mac OS and only supports playback.
887
888 Core Audio specific options are:
889
890 ``in|out.buffer-count=count``
891 Sets the count of the buffers.
892
893``-audiodev dsound,id=id[,prop[=value][,...]]``
894 Creates a backend using Microsoft's DirectSound. This backend is
895 only available on Windows and only supports playback.
896
897 DirectSound specific options are:
898
899 ``latency=usecs``
900 Add extra usecs microseconds latency to playback. Default is
901 10000 (10 ms).
902
903``-audiodev oss,id=id[,prop[=value][,...]]``
904 Creates a backend using OSS. This backend is available on most
905 Unix-like systems.
906
907 OSS specific options are:
908
909 ``in|out.dev=device``
910 Specify the file name of the OSS device to use. Default is
911 ``/dev/dsp``.
912
913 ``in|out.buffer-count=count``
914 Sets the count of the buffers.
915
916 ``in|out.try-poll=on|of``
917 Attempt to use poll mode with the device. Default is on.
918
919 ``try-mmap=on|off``
920 Try using memory mapped device access. Default is off.
921
922 ``exclusive=on|off``
923 Open the device in exclusive mode (vmix won't work in this
924 case). Default is off.
925
926 ``dsp-policy=policy``
927 Sets the timing policy (between 0 and 10, where smaller number
928 means smaller latency but higher CPU usage). Use -1 to use
929 buffer sizes specified by ``buffer`` and ``buffer-count``. This
930 option is ignored if you do not have OSS 4. Default is 5.
931
932``-audiodev pa,id=id[,prop[=value][,...]]``
933 Creates a backend using PulseAudio. This backend is available on
934 most systems.
935
936 PulseAudio specific options are:
937
938 ``server=server``
939 Sets the PulseAudio server to connect to.
940
941 ``in|out.name=sink``
942 Use the specified source/sink for recording/playback.
943
944 ``in|out.latency=usecs``
945 Desired latency in microseconds. The PulseAudio server will try
946 to honor this value but actual latencies may be lower or higher.
947
948``-audiodev sdl,id=id[,prop[=value][,...]]``
949 Creates a backend using SDL. This backend is available on most
950 systems, but you should use your platform's native backend if
Volker RĂĽmelin5a0926c2021-01-10 11:02:19 +0100951 possible.
952
953 SDL specific options are:
954
955 ``in|out.buffer-count=count``
956 Sets the count of the buffers.
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000957
Alexandre Ratchov663df1c2022-09-07 15:23:42 +0200958``-audiodev sndio,id=id[,prop[=value][,...]]``
959 Creates a backend using SNDIO. This backend is available on
960 OpenBSD and most other Unix-like systems.
961
962 Sndio specific options are:
963
964 ``in|out.dev=device``
965 Specify the sndio device to use for input and/or output. Default
966 is ``default``.
967
968 ``in|out.latency=usecs``
969 Sets the desired period length in microseconds.
970
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000971``-audiodev spice,id=id[,prop[=value][,...]]``
972 Creates a backend that sends audio through SPICE. This backend
973 requires ``-spice`` and automatically selected in that case, so
974 usually you can ignore this option. This backend has no backend
975 specific properties.
976
977``-audiodev wav,id=id[,prop[=value][,...]]``
978 Creates a backend that writes audio to a WAV file.
979
980 Backend specific options are:
981
982 ``path=path``
983 Write recorded audio into the specified file. Default is
984 ``qemu.wav``.
985ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100986
Markus Armbruster10adb8b2013-02-13 19:49:43 +0100987DEF("device", HAS_ARG, QEMU_OPTION_device,
988 "-device driver[,prop[=value][,...]]\n"
989 " add device (based on driver)\n"
990 " prop=value,... sets driver properties\n"
991 " use '-device help' to print all possible drivers\n"
992 " use '-device driver,help' to print all possible properties\n",
993 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +0000994SRST
995``-device driver[,prop[=value][,...]]``
996 Add device driver. prop=value sets driver properties. Valid
997 properties depend on the driver. To get help on possible drivers and
998 properties, use ``-device help`` and ``-device driver,help``.
999
1000 Some drivers are:
1001
Corey Minyard789101b2020-07-17 11:37:02 -05001002``-device ipmi-bmc-sim,id=id[,prop[=value][,...]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001003 Add an IPMI BMC. This is a simulation of a hardware management
1004 interface processor that normally sits on a system. It provides a
1005 watchdog and the ability to reset and power control the system. You
1006 need to connect this to an IPMI interface to make it useful
1007
1008 The IPMI slave address to use for the BMC. The default is 0x20. This
1009 address is the BMC's address on the I2C network of management
1010 controllers. If you don't know what this means, it is safe to ignore
1011 it.
1012
1013 ``id=id``
1014 The BMC id for interfaces to use this device.
1015
1016 ``slave_addr=val``
1017 Define slave address to use for the BMC. The default is 0x20.
1018
1019 ``sdrfile=file``
1020 file containing raw Sensor Data Records (SDR) data. The default
1021 is none.
1022
1023 ``fruareasize=val``
1024 size of a Field Replaceable Unit (FRU) area. The default is
1025 1024.
1026
1027 ``frudatafile=file``
1028 file containing raw Field Replaceable Unit (FRU) inventory data.
1029 The default is none.
1030
1031 ``guid=uuid``
1032 value for the GUID for the BMC, in standard UUID format. If this
1033 is set, get "Get GUID" command to the BMC will return it.
1034 Otherwise "Get GUID" will return an error.
1035
1036``-device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]``
1037 Add a connection to an external IPMI BMC simulator. Instead of
1038 locally emulating the BMC like the above item, instead connect to an
1039 external entity that provides the IPMI services.
1040
1041 A connection is made to an external BMC simulator. If you do this,
1042 it is strongly recommended that you use the "reconnect=" chardev
1043 option to reconnect to the simulator if the connection is lost. Note
1044 that if this is not used carefully, it can be a security issue, as
1045 the interface has the ability to send resets, NMIs, and power off
1046 the VM. It's best if QEMU makes a connection to an external
1047 simulator running on a secure port on localhost, so neither the
1048 simulator nor QEMU is exposed to any outside network.
1049
1050 See the "lanserv/README.vm" file in the OpenIPMI library for more
1051 details on the external interface.
1052
1053``-device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]``
Stefan Weil1e458f12022-10-30 11:59:44 +01001054 Add a KCS IPMI interface on the ISA bus. This also adds a
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001055 corresponding ACPI and SMBIOS entries, if appropriate.
1056
1057 ``bmc=id``
1058 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern
1059 above.
1060
1061 ``ioport=val``
1062 Define the I/O address of the interface. The default is 0xca0
1063 for KCS.
1064
1065 ``irq=val``
1066 Define the interrupt to use. The default is 5. To disable
1067 interrupts, set this to 0.
1068
1069``-device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]``
1070 Like the KCS interface, but defines a BT interface. The default port
1071 is 0xe4 and the default interrupt is 5.
Corey Minyard323679d2019-09-23 13:50:33 -05001072
1073``-device pci-ipmi-kcs,bmc=id``
Stefan Weil1e458f12022-10-30 11:59:44 +01001074 Add a KCS IPMI interface on the PCI bus.
Corey Minyard323679d2019-09-23 13:50:33 -05001075
1076 ``bmc=id``
1077 The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern above.
1078
1079``-device pci-ipmi-bt,bmc=id``
1080 Like the KCS interface, but defines a BT interface on the PCI bus.
Peter Xu7395b3e2021-07-07 11:41:14 -04001081
1082``-device intel-iommu[,option=...]``
1083 This is only supported by ``-machine q35``, which will enable Intel VT-d
1084 emulation within the guest. It supports below options:
1085
1086 ``intremap=on|off`` (default: auto)
1087 This enables interrupt remapping feature. It's required to enable
1088 complete x2apic. Currently it only supports kvm kernel-irqchip modes
1089 ``off`` or ``split``, while full kernel-irqchip is not yet supported.
1090 The default value is "auto", which will be decided by the mode of
1091 kernel-irqchip.
1092
1093 ``caching-mode=on|off`` (default: off)
1094 This enables caching mode for the VT-d emulated device. When
1095 caching-mode is enabled, each guest DMA buffer mapping will generate an
1096 IOTLB invalidation from the guest IOMMU driver to the vIOMMU device in
1097 a synchronous way. It is required for ``-device vfio-pci`` to work
1098 with the VT-d device, because host assigned devices requires to setup
1099 the DMA mapping on the host before guest DMA starts.
1100
1101 ``device-iotlb=on|off`` (default: off)
1102 This enables device-iotlb capability for the emulated VT-d device. So
1103 far virtio/vhost should be the only real user for this parameter,
1104 paired with ats=on configured for the device.
1105
1106 ``aw-bits=39|48`` (default: 39)
1107 This decides the address width of IOVA address space. The address
1108 space has 39 bits width for 3-level IOMMU page tables, and 48 bits for
1109 4-level IOMMU page tables.
1110
1111 Please also refer to the wiki page for general scenarios of VT-d
1112 emulation in QEMU: https://wiki.qemu.org/Features/VT-d.
1113
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001114ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001115
1116DEF("name", HAS_ARG, QEMU_OPTION_name,
Dr. David Alan Gilbert8f480de2014-01-30 10:20:31 +00001117 "-name string1[,process=string2][,debug-threads=on|off]\n"
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001118 " set the name of the guest\n"
Roman Bolshakov479a5742018-12-17 23:26:01 +03001119 " string1 sets the window title and string2 the process name\n"
1120 " When debug-threads is enabled, individual threads are given a separate name\n"
Dr. David Alan Gilbert8f480de2014-01-30 10:20:31 +00001121 " NOTE: The thread names are for debugging and not a stable API.\n",
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001122 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001123SRST
1124``-name name``
1125 Sets the name of the guest. This name will be displayed in the SDL
1126 window caption. The name will also be used for the VNC server. Also
1127 optionally set the top visible process name in Linux. Naming of
1128 individual threads can also be enabled on Linux to aid debugging.
1129ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001130
1131DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
1132 "-uuid %08x-%04x-%04x-%04x-%012x\n"
1133 " specify machine UUID\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001134SRST
1135``-uuid uuid``
1136 Set system UUID.
1137ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001138
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001139DEFHEADING()
1140
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02001141DEFHEADING(Block device options:)
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001142
Alex Bennée5af2b0f2022-08-22 17:56:08 +01001143SRST
1144The QEMU block device handling options have a long history and
1145have gone through several iterations as the feature set and complexity
1146of the block layer have grown. Many online guides to QEMU often
1147reference older and deprecated options, which can lead to confusion.
1148
1149The recommended modern way to describe disks is to use a combination of
1150``-device`` to specify the hardware device and ``-blockdev`` to
1151describe the backend. The device defines what the guest sees and the
1152backend describes how QEMU handles the data.
1153
1154ERST
1155
blueswir15824d652009-03-28 06:44:27 +00001156DEF("fda", HAS_ARG, QEMU_OPTION_fda,
Blue Swirlad960902010-03-29 19:23:52 +00001157 "-fda/-fdb file use 'file' as floppy disk 0/1 image\n", QEMU_ARCH_ALL)
1158DEF("fdb", HAS_ARG, QEMU_OPTION_fdb, "", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001159SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00001160``-fda file``
1161 \
1162``-fdb file``
Thomas Huth923e9312020-11-16 15:47:36 +01001163 Use file as floppy disk 0/1 image (see the :ref:`disk images` chapter in
1164 the System Emulation Users Guide).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001165ERST
blueswir15824d652009-03-28 06:44:27 +00001166
1167DEF("hda", HAS_ARG, QEMU_OPTION_hda,
Blue Swirlad960902010-03-29 19:23:52 +00001168 "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
1169DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00001170DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
Blue Swirlad960902010-03-29 19:23:52 +00001171 "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
1172DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001173SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00001174``-hda file``
1175 \
1176``-hdb file``
1177 \
1178``-hdc file``
1179 \
1180``-hdd file``
Thomas Huth923e9312020-11-16 15:47:36 +01001181 Use file as hard disk 0, 1, 2 or 3 image (see the :ref:`disk images`
1182 chapter in the System Emulation Users Guide).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001183ERST
blueswir15824d652009-03-28 06:44:27 +00001184
1185DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
Blue Swirlad960902010-03-29 19:23:52 +00001186 "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
1187 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001188SRST
1189``-cdrom file``
1190 Use file as CD-ROM image (you cannot use ``-hdc`` and ``-cdrom`` at
1191 the same time). You can use the host CD-ROM by using ``/dev/cdrom``
1192 as filename.
1193ERST
blueswir15824d652009-03-28 06:44:27 +00001194
Markus Armbruster42e5f392017-02-28 22:27:07 +01001195DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
1196 "-blockdev [driver=]driver[,node-name=N][,discard=ignore|unmap]\n"
1197 " [,cache.direct=on|off][,cache.no-flush=on|off]\n"
Kevin Wolfc9b749d2019-10-15 12:29:58 +02001198 " [,read-only=on|off][,auto-read-only=on|off]\n"
1199 " [,force-share=on|off][,detect-zeroes=on|off|unmap]\n"
Markus Armbruster42e5f392017-02-28 22:27:07 +01001200 " [,driver specific parameters...]\n"
1201 " configure a block backend\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001202SRST
1203``-blockdev option[,option[,option[,...]]]``
1204 Define a new block driver node. Some of the options apply to all
1205 block drivers, other options are only accepted for a specific block
1206 driver. See below for a list of generic options and options for the
1207 most common block drivers.
1208
1209 Options that expect a reference to another node (e.g. ``file``) can
1210 be given in two ways. Either you specify the node name of an already
1211 existing node (file=node-name), or you define a new node inline,
1212 adding options for the referenced node after a dot
1213 (file.filename=path,file.aio=native).
1214
1215 A block driver node created with ``-blockdev`` can be used for a
1216 guest device by specifying its node name for the ``drive`` property
1217 in a ``-device`` argument that defines a block device.
1218
1219 ``Valid options for any block driver node:``
1220 ``driver``
1221 Specifies the block driver to use for the given node.
1222
1223 ``node-name``
1224 This defines the name of the block driver node by which it
1225 will be referenced later. The name must be unique, i.e. it
1226 must not match the name of a different block driver node, or
1227 (if you use ``-drive`` as well) the ID of a drive.
1228
1229 If no node name is specified, it is automatically generated.
1230 The generated node name is not intended to be predictable
1231 and changes between QEMU invocations. For the top level, an
1232 explicit node name must be specified.
1233
1234 ``read-only``
1235 Open the node read-only. Guest write attempts will fail.
1236
1237 Note that some block drivers support only read-only access,
1238 either generally or in certain configurations. In this case,
1239 the default value ``read-only=off`` does not work and the
1240 option must be specified explicitly.
1241
1242 ``auto-read-only``
1243 If ``auto-read-only=on`` is set, QEMU may fall back to
1244 read-only usage even when ``read-only=off`` is requested, or
1245 even switch between modes as needed, e.g. depending on
1246 whether the image file is writable or whether a writing user
1247 is attached to the node.
1248
1249 ``force-share``
1250 Override the image locking system of QEMU by forcing the
1251 node to utilize weaker shared access for permissions where
1252 it would normally request exclusive access. When there is
1253 the potential for multiple instances to have the same file
1254 open (whether this invocation of QEMU is the first or the
1255 second instance), both instances must permit shared access
1256 for the second instance to succeed at opening the file.
1257
1258 Enabling ``force-share=on`` requires ``read-only=on``.
1259
1260 ``cache.direct``
1261 The host page cache can be avoided with ``cache.direct=on``.
1262 This will attempt to do disk IO directly to the guest's
1263 memory. QEMU may still perform an internal copy of the data.
1264
1265 ``cache.no-flush``
1266 In case you don't care about data integrity over host
1267 failures, you can use ``cache.no-flush=on``. This option
1268 tells QEMU that it never needs to write any data to the disk
1269 but can instead keep things in cache. If anything goes
1270 wrong, like your host losing power, the disk storage getting
1271 disconnected accidentally, etc. your image will most
1272 probably be rendered unusable.
1273
1274 ``discard=discard``
1275 discard is one of "ignore" (or "off") or "unmap" (or "on")
1276 and controls whether ``discard`` (also known as ``trim`` or
1277 ``unmap``) requests are ignored or passed to the filesystem.
1278 Some machine types may not support discard requests.
1279
1280 ``detect-zeroes=detect-zeroes``
1281 detect-zeroes is "off", "on" or "unmap" and enables the
1282 automatic conversion of plain zero writes by the OS to
1283 driver specific optimized zero write commands. You may even
1284 choose "unmap" if discard is set to "unmap" to allow a zero
1285 write to be converted to an ``unmap`` operation.
1286
1287 ``Driver-specific options for file``
1288 This is the protocol-level block driver for accessing regular
1289 files.
1290
1291 ``filename``
1292 The path to the image file in the local filesystem
1293
1294 ``aio``
Stefano Garzarellaad1e6912020-09-24 17:15:11 +02001295 Specifies the AIO backend (threads/native/io_uring,
1296 default: threads)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001297
1298 ``locking``
1299 Specifies whether the image file is protected with Linux OFD
1300 / POSIX locks. The default is to use the Linux Open File
1301 Descriptor API if available, otherwise no lock is applied.
1302 (auto/on/off, default: auto)
1303
1304 Example:
1305
1306 ::
1307
1308 -blockdev driver=file,node-name=disk,filename=disk.img
1309
1310 ``Driver-specific options for raw``
1311 This is the image format block driver for raw images. It is
1312 usually stacked on top of a protocol level block driver such as
1313 ``file``.
1314
1315 ``file``
1316 Reference to or definition of the data source block driver
1317 node (e.g. a ``file`` driver node)
1318
1319 Example 1:
1320
1321 ::
1322
1323 -blockdev driver=file,node-name=disk_file,filename=disk.img
1324 -blockdev driver=raw,node-name=disk,file=disk_file
1325
1326 Example 2:
1327
1328 ::
1329
1330 -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img
1331
1332 ``Driver-specific options for qcow2``
1333 This is the image format block driver for qcow2 images. It is
1334 usually stacked on top of a protocol level block driver such as
1335 ``file``.
1336
1337 ``file``
1338 Reference to or definition of the data source block driver
1339 node (e.g. a ``file`` driver node)
1340
1341 ``backing``
1342 Reference to or definition of the backing file block device
1343 (default is taken from the image file). It is allowed to
1344 pass ``null`` here in order to disable the default backing
1345 file.
1346
1347 ``lazy-refcounts``
1348 Whether to enable the lazy refcounts feature (on/off;
1349 default is taken from the image file)
1350
1351 ``cache-size``
1352 The maximum total size of the L2 table and refcount block
1353 caches in bytes (default: the sum of l2-cache-size and
1354 refcount-cache-size)
1355
1356 ``l2-cache-size``
1357 The maximum size of the L2 table cache in bytes (default: if
1358 cache-size is not specified - 32M on Linux platforms, and 8M
1359 on non-Linux platforms; otherwise, as large as possible
1360 within the cache-size, while permitting the requested or the
1361 minimal refcount cache size)
1362
1363 ``refcount-cache-size``
1364 The maximum size of the refcount block cache in bytes
1365 (default: 4 times the cluster size; or if cache-size is
1366 specified, the part of it which is not used for the L2
1367 cache)
1368
1369 ``cache-clean-interval``
1370 Clean unused entries in the L2 and refcount caches. The
1371 interval is in seconds. The default value is 600 on
1372 supporting platforms, and 0 on other platforms. Setting it
1373 to 0 disables this feature.
1374
1375 ``pass-discard-request``
1376 Whether discard requests to the qcow2 device should be
1377 forwarded to the data source (on/off; default: on if
1378 discard=unmap is specified, off otherwise)
1379
1380 ``pass-discard-snapshot``
1381 Whether discard requests for the data source should be
1382 issued when a snapshot operation (e.g. deleting a snapshot)
1383 frees clusters in the qcow2 file (on/off; default: on)
1384
1385 ``pass-discard-other``
1386 Whether discard requests for the data source should be
1387 issued on other occasions where a cluster gets freed
1388 (on/off; default: off)
1389
1390 ``overlap-check``
1391 Which overlap checks to perform for writes to the image
1392 (none/constant/cached/all; default: cached). For details or
1393 finer granularity control refer to the QAPI documentation of
1394 ``blockdev-add``.
1395
1396 Example 1:
1397
1398 ::
1399
1400 -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
1401 -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216
1402
1403 Example 2:
1404
1405 ::
1406
1407 -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2
1408
1409 ``Driver-specific options for other drivers``
1410 Please refer to the QAPI documentation of the ``blockdev-add``
1411 QMP command.
1412ERST
Markus Armbruster42e5f392017-02-28 22:27:07 +01001413
blueswir15824d652009-03-28 06:44:27 +00001414DEF("drive", HAS_ARG, QEMU_OPTION_drive,
1415 "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
Stefan Hajnoczi92196b22011-08-04 12:26:52 +01001416 " [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
Kevin Wolf572023f2018-06-13 11:01:30 +02001417 " [,snapshot=on|off][,rerror=ignore|stop|report]\n"
Stefano Garzarellaad1e6912020-09-24 17:15:11 +02001418 " [,werror=ignore|stop|report|enospc][,id=name]\n"
1419 " [,aio=threads|native|io_uring]\n"
Stefan Hajnoczifb0490f2011-11-17 13:40:32 +00001420 " [,readonly=on|off][,copy-on-read=on|off]\n"
Peter Lieven2f7133b2014-07-28 21:53:02 +02001421 " [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
Benoît Canet3e9fab62013-09-02 14:14:40 +02001422 " [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
1423 " [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
1424 " [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
1425 " [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
Benoît Canet2024c1d2013-09-02 14:14:41 +02001426 " [[,iops_size=is]]\n"
Alberto Garcia76f4afb2015-06-08 18:17:44 +02001427 " [[,group=g]]\n"
Blue Swirlad960902010-03-29 19:23:52 +00001428 " use 'file' as a drive image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001429SRST
1430``-drive option[,option[,option[,...]]]``
1431 Define a new drive. This includes creating a block driver node (the
1432 backend) as well as a guest device, and is mostly a shortcut for
1433 defining the corresponding ``-blockdev`` and ``-device`` options.
1434
1435 ``-drive`` accepts all options that are accepted by ``-blockdev``.
1436 In addition, it knows the following options:
1437
1438 ``file=file``
Thomas Huth923e9312020-11-16 15:47:36 +01001439 This option defines which disk image (see the :ref:`disk images`
1440 chapter in the System Emulation Users Guide) to use with this drive.
1441 If the filename contains comma, you must double it (for instance,
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001442 "file=my,,file" to use file "my,file").
1443
1444 Special files such as iSCSI devices can be specified using
1445 protocol specific URLs. See the section for "Device URL Syntax"
1446 for more information.
1447
1448 ``if=interface``
1449 This option defines on which type on interface the drive is
1450 connected. Available types are: ide, scsi, sd, mtd, floppy,
1451 pflash, virtio, none.
1452
1453 ``bus=bus,unit=unit``
1454 These options define where is connected the drive by defining
1455 the bus number and the unit id.
1456
1457 ``index=index``
Laurent Vivier35aab302022-02-02 15:34:22 +01001458 This option defines where the drive is connected by using an
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001459 index in the list of available connectors of a given interface
1460 type.
1461
1462 ``media=media``
1463 This option defines the type of the media: disk or cdrom.
1464
1465 ``snapshot=snapshot``
1466 snapshot is "on" or "off" and controls snapshot mode for the
1467 given drive (see ``-snapshot``).
1468
1469 ``cache=cache``
1470 cache is "none", "writeback", "unsafe", "directsync" or
1471 "writethrough" and controls how the host cache is used to access
1472 block data. This is a shortcut that sets the ``cache.direct``
1473 and ``cache.no-flush`` options (as in ``-blockdev``), and
1474 additionally ``cache.writeback``, which provides a default for
1475 the ``write-cache`` option of block guest devices (as in
1476 ``-device``). The modes correspond to the following settings:
1477
Peter Maydell09ce5f22020-02-28 15:36:13 +00001478 ============= =============== ============ ==============
1479 \ cache.writeback cache.direct cache.no-flush
1480 ============= =============== ============ ==============
1481 writeback on off off
1482 none on on off
1483 writethrough off off off
1484 directsync off on off
1485 unsafe on off on
1486 ============= =============== ============ ==============
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001487
1488 The default mode is ``cache=writeback``.
1489
1490 ``aio=aio``
Stefano Garzarellaad1e6912020-09-24 17:15:11 +02001491 aio is "threads", "native", or "io_uring" and selects between pthread
1492 based disk I/O, native Linux AIO, or Linux io_uring API.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001493
1494 ``format=format``
1495 Specify which disk format will be used rather than detecting the
1496 format. Can be used to specify format=raw to avoid interpreting
1497 an untrusted format header.
1498
1499 ``werror=action,rerror=action``
1500 Specify which action to take on write and read errors. Valid
1501 actions are: "ignore" (ignore the error and try to continue),
1502 "stop" (pause QEMU), "report" (report the error to the guest),
1503 "enospc" (pause QEMU only if the host disk is full; report the
1504 error to the guest otherwise). The default setting is
1505 ``werror=enospc`` and ``rerror=report``.
1506
1507 ``copy-on-read=copy-on-read``
1508 copy-on-read is "on" or "off" and enables whether to copy read
1509 backing file sectors into the image file.
1510
1511 ``bps=b,bps_rd=r,bps_wr=w``
1512 Specify bandwidth throttling limits in bytes per second, either
1513 for all request types or for reads or writes only. Small values
1514 can lead to timeouts or hangs inside the guest. A safe minimum
1515 for disks is 2 MB/s.
1516
1517 ``bps_max=bm,bps_rd_max=rm,bps_wr_max=wm``
1518 Specify bursts in bytes per second, either for all request types
1519 or for reads or writes only. Bursts allow the guest I/O to spike
1520 above the limit temporarily.
1521
1522 ``iops=i,iops_rd=r,iops_wr=w``
1523 Specify request rate limits in requests per second, either for
1524 all request types or for reads or writes only.
1525
1526 ``iops_max=bm,iops_rd_max=rm,iops_wr_max=wm``
1527 Specify bursts in requests per second, either for all request
1528 types or for reads or writes only. Bursts allow the guest I/O to
1529 spike above the limit temporarily.
1530
1531 ``iops_size=is``
1532 Let every is bytes of a request count as a new request for iops
1533 throttling purposes. Use this option to prevent guests from
1534 circumventing iops limits by sending fewer but larger requests.
1535
1536 ``group=g``
1537 Join a throttling quota group with given name g. All drives that
1538 are members of the same group are accounted for together. Use
1539 this option to prevent guests from circumventing throttling
1540 limits by using many small disks instead of a single larger
1541 disk.
1542
1543 By default, the ``cache.writeback=on`` mode is used. It will report
1544 data writes as completed as soon as the data is present in the host
1545 page cache. This is safe as long as your guest OS makes sure to
1546 correctly flush disk caches where needed. If your guest OS does not
1547 handle volatile disk write caches correctly and your host crashes or
1548 loses power, then the guest may experience data corruption.
1549
1550 For such guests, you should consider using ``cache.writeback=off``.
1551 This means that the host page cache will be used to read and write
1552 data, but write notification will be sent to the guest only after
1553 QEMU has made sure to flush each write to the disk. Be aware that
1554 this has a major impact on performance.
1555
1556 When using the ``-snapshot`` option, unsafe caching is always used.
1557
1558 Copy-on-read avoids accessing the same backing file sectors
1559 repeatedly and is useful when the backing file is over a slow
1560 network. By default copy-on-read is off.
1561
1562 Instead of ``-cdrom`` you can use:
1563
1564 .. parsed-literal::
1565
1566 |qemu_system| -drive file=file,index=2,media=cdrom
1567
1568 Instead of ``-hda``, ``-hdb``, ``-hdc``, ``-hdd``, you can use:
1569
1570 .. parsed-literal::
1571
1572 |qemu_system| -drive file=file,index=0,media=disk
1573 |qemu_system| -drive file=file,index=1,media=disk
1574 |qemu_system| -drive file=file,index=2,media=disk
1575 |qemu_system| -drive file=file,index=3,media=disk
1576
1577 You can open an image using pre-opened file descriptors from an fd
1578 set:
1579
1580 .. parsed-literal::
1581
Laszlo Ersek353a06b2020-09-08 19:21:11 +02001582 |qemu_system| \\
1583 -add-fd fd=3,set=2,opaque="rdwr:/path/to/file" \\
1584 -add-fd fd=4,set=2,opaque="rdonly:/path/to/file" \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001585 -drive file=/dev/fdset/2,index=0,media=disk
1586
1587 You can connect a CDROM to the slave of ide0:
1588
1589 .. parsed-literal::
1590
1591 |qemu_system_x86| -drive file=file,if=ide,index=1,media=cdrom
1592
1593 If you don't specify the "file=" argument, you define an empty
1594 drive:
1595
1596 .. parsed-literal::
1597
1598 |qemu_system_x86| -drive if=ide,index=1,media=cdrom
1599
1600 Instead of ``-fda``, ``-fdb``, you can use:
1601
1602 .. parsed-literal::
1603
1604 |qemu_system_x86| -drive file=file,index=0,if=floppy
1605 |qemu_system_x86| -drive file=file,index=1,if=floppy
1606
1607 By default, interface is "ide" and index is automatically
1608 incremented:
1609
1610 .. parsed-literal::
1611
1612 |qemu_system_x86| -drive file=a -drive file=b"
1613
1614 is interpreted like:
1615
1616 .. parsed-literal::
1617
1618 |qemu_system_x86| -hda a -hdb b
1619ERST
blueswir15824d652009-03-28 06:44:27 +00001620
1621DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock,
Blue Swirlad960902010-03-29 19:23:52 +00001622 "-mtdblock file use 'file' as on-board Flash memory image\n",
1623 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001624SRST
1625``-mtdblock file``
1626 Use file as on-board Flash memory image.
1627ERST
blueswir15824d652009-03-28 06:44:27 +00001628
1629DEF("sd", HAS_ARG, QEMU_OPTION_sd,
Blue Swirlad960902010-03-29 19:23:52 +00001630 "-sd file use 'file' as SecureDigital card image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001631SRST
1632``-sd file``
1633 Use file as SecureDigital card image.
1634ERST
blueswir15824d652009-03-28 06:44:27 +00001635
blueswir15824d652009-03-28 06:44:27 +00001636DEF("snapshot", 0, QEMU_OPTION_snapshot,
Blue Swirlad960902010-03-29 19:23:52 +00001637 "-snapshot write to temporary files instead of disk image files\n",
1638 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001639SRST
1640``-snapshot``
1641 Write to temporary files instead of disk image files. In this case,
1642 the raw disk image you use is not written back. You can however
Thomas Huth923e9312020-11-16 15:47:36 +01001643 force the write back by pressing C-a s (see the :ref:`disk images`
1644 chapter in the System Emulation Users Guide).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001645ERST
blueswir15824d652009-03-28 06:44:27 +00001646
Gautham R Shenoy74db9202010-04-29 17:44:43 +05301647DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
Greg Kurzb44a6b02019-05-17 17:34:49 +02001648 "-fsdev local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n"
Paolo Bonzini991c1802020-11-13 03:10:52 -05001649 " [,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode]\n"
Pradeep Jagadeeshb8bbdb82017-02-28 10:31:46 +01001650 " [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
1651 " [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
1652 " [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
1653 " [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
Greg Kurzb44a6b02019-05-17 17:34:49 +02001654 " [[,throttling.iops-size=is]]\n"
Paolo Bonzini991c1802020-11-13 03:10:52 -05001655 "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly=on]\n"
1656 "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly=on]\n"
Greg Kurzb44a6b02019-05-17 17:34:49 +02001657 "-fsdev synth,id=id\n",
Gautham R Shenoy74db9202010-04-29 17:44:43 +05301658 QEMU_ARCH_ALL)
1659
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001660SRST
Paolo Bonzini991c1802020-11-13 03:10:52 -05001661``-fsdev local,id=id,path=path,security_model=security_model [,writeout=writeout][,readonly=on][,fmode=fmode][,dmode=dmode] [,throttling.option=value[,throttling.option=value[,...]]]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00001662 \
Paolo Bonzini991c1802020-11-13 03:10:52 -05001663``-fsdev proxy,id=id,socket=socket[,writeout=writeout][,readonly=on]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00001664 \
Paolo Bonzini991c1802020-11-13 03:10:52 -05001665``-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=writeout][,readonly=on]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00001666 \
Paolo Bonzini991c1802020-11-13 03:10:52 -05001667``-fsdev synth,id=id[,readonly=on]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001668 Define a new file system device. Valid options are:
1669
1670 ``local``
1671 Accesses to the filesystem are done by QEMU.
1672
1673 ``proxy``
1674 Accesses to the filesystem are done by virtfs-proxy-helper(1).
1675
1676 ``synth``
1677 Synthetic filesystem, only used by QTests.
1678
1679 ``id=id``
1680 Specifies identifier for this device.
1681
1682 ``path=path``
1683 Specifies the export path for the file system device. Files
1684 under this path will be available to the 9p client on the guest.
1685
1686 ``security_model=security_model``
1687 Specifies the security model to be used for this export path.
1688 Supported security models are "passthrough", "mapped-xattr",
1689 "mapped-file" and "none". In "passthrough" security model, files
1690 are stored using the same credentials as they are created on the
1691 guest. This requires QEMU to run as root. In "mapped-xattr"
1692 security model, some of the file attributes like uid, gid, mode
1693 bits and link target are stored as file attributes. For
1694 "mapped-file" these attributes are stored in the hidden
1695 .virtfs\_metadata directory. Directories exported by this
1696 security model cannot interact with other unix tools. "none"
1697 security model is same as passthrough except the sever won't
1698 report failures if it fails to set file attributes like
1699 ownership. Security model is mandatory only for local fsdriver.
1700 Other fsdrivers (like proxy) don't take security model as a
1701 parameter.
1702
1703 ``writeout=writeout``
1704 This is an optional argument. The only supported value is
1705 "immediate". This means that host page cache will be used to
1706 read and write data but write notification will be sent to the
1707 guest only when the data has been reported as written by the
1708 storage subsystem.
1709
Paolo Bonzini991c1802020-11-13 03:10:52 -05001710 ``readonly=on``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001711 Enables exporting 9p share as a readonly mount for guests. By
1712 default read-write access is given.
1713
1714 ``socket=socket``
1715 Enables proxy filesystem driver to use passed socket file for
1716 communicating with virtfs-proxy-helper(1).
1717
1718 ``sock_fd=sock_fd``
1719 Enables proxy filesystem driver to use passed socket descriptor
1720 for communicating with virtfs-proxy-helper(1). Usually a helper
1721 like libvirt will create socketpair and pass one of the fds as
1722 sock\_fd.
1723
1724 ``fmode=fmode``
1725 Specifies the default mode for newly created files on the host.
1726 Works only with security models "mapped-xattr" and
1727 "mapped-file".
1728
1729 ``dmode=dmode``
1730 Specifies the default mode for newly created directories on the
1731 host. Works only with security models "mapped-xattr" and
1732 "mapped-file".
1733
1734 ``throttling.bps-total=b,throttling.bps-read=r,throttling.bps-write=w``
1735 Specify bandwidth throttling limits in bytes per second, either
1736 for all request types or for reads or writes only.
1737
1738 ``throttling.bps-total-max=bm,bps-read-max=rm,bps-write-max=wm``
1739 Specify bursts in bytes per second, either for all request types
1740 or for reads or writes only. Bursts allow the guest I/O to spike
1741 above the limit temporarily.
1742
1743 ``throttling.iops-total=i,throttling.iops-read=r, throttling.iops-write=w``
1744 Specify request rate limits in requests per second, either for
1745 all request types or for reads or writes only.
1746
1747 ``throttling.iops-total-max=im,throttling.iops-read-max=irm, throttling.iops-write-max=iwm``
1748 Specify bursts in requests per second, either for all request
1749 types or for reads or writes only. Bursts allow the guest I/O to
1750 spike above the limit temporarily.
1751
1752 ``throttling.iops-size=is``
1753 Let every is bytes of a request count as a new request for iops
1754 throttling purposes.
1755
1756 -fsdev option is used along with -device driver "virtio-9p-...".
1757
1758``-device virtio-9p-type,fsdev=id,mount_tag=mount_tag``
1759 Options for virtio-9p-... driver are:
1760
1761 ``type``
1762 Specifies the variant to be used. Supported values are "pci",
1763 "ccw" or "device", depending on the machine type.
1764
1765 ``fsdev=id``
1766 Specifies the id value specified along with -fsdev option.
1767
1768 ``mount_tag=mount_tag``
1769 Specifies the tag name to be used by the guest to mount this
1770 export point.
1771ERST
Gautham R Shenoy74db9202010-04-29 17:44:43 +05301772
Gautham R Shenoy3d54abc2010-04-29 17:45:03 +05301773DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
Greg Kurzb44a6b02019-05-17 17:34:49 +02001774 "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n"
Paolo Bonzini991c1802020-11-13 03:10:52 -05001775 " [,id=id][,writeout=immediate][,readonly=on][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n"
1776 "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly=on]\n"
1777 "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly=on]\n"
1778 "-virtfs synth,mount_tag=tag[,id=id][,readonly=on]\n",
Gautham R Shenoy3d54abc2010-04-29 17:45:03 +05301779 QEMU_ARCH_ALL)
1780
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001781SRST
Paolo Bonzini991c1802020-11-13 03:10:52 -05001782``-virtfs local,path=path,mount_tag=mount_tag ,security_model=security_model[,writeout=writeout][,readonly=on] [,fmode=fmode][,dmode=dmode][,multidevs=multidevs]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00001783 \
Paolo Bonzini991c1802020-11-13 03:10:52 -05001784``-virtfs proxy,socket=socket,mount_tag=mount_tag [,writeout=writeout][,readonly=on]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00001785 \
Paolo Bonzini991c1802020-11-13 03:10:52 -05001786``-virtfs proxy,sock_fd=sock_fd,mount_tag=mount_tag [,writeout=writeout][,readonly=on]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00001787 \
1788``-virtfs synth,mount_tag=mount_tag``
Christian Schoenebeck65abaa02020-05-14 08:06:43 +02001789 Define a new virtual filesystem device and expose it to the guest using
1790 a virtio-9p-device (a.k.a. 9pfs), which essentially means that a certain
1791 directory on host is made directly accessible by guest as a pass-through
1792 file system by using the 9P network protocol for communication between
1793 host and guests, if desired even accessible, shared by several guests
1794 simultaniously.
1795
1796 Note that ``-virtfs`` is actually just a convenience shortcut for its
1797 generalized form ``-fsdev -device virtio-9p-pci``.
1798
1799 The general form of pass-through file system options are:
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001800
1801 ``local``
1802 Accesses to the filesystem are done by QEMU.
1803
1804 ``proxy``
1805 Accesses to the filesystem are done by virtfs-proxy-helper(1).
1806
1807 ``synth``
1808 Synthetic filesystem, only used by QTests.
1809
1810 ``id=id``
1811 Specifies identifier for the filesystem device
1812
1813 ``path=path``
1814 Specifies the export path for the file system device. Files
1815 under this path will be available to the 9p client on the guest.
1816
1817 ``security_model=security_model``
1818 Specifies the security model to be used for this export path.
1819 Supported security models are "passthrough", "mapped-xattr",
1820 "mapped-file" and "none". In "passthrough" security model, files
1821 are stored using the same credentials as they are created on the
1822 guest. This requires QEMU to run as root. In "mapped-xattr"
1823 security model, some of the file attributes like uid, gid, mode
1824 bits and link target are stored as file attributes. For
1825 "mapped-file" these attributes are stored in the hidden
1826 .virtfs\_metadata directory. Directories exported by this
1827 security model cannot interact with other unix tools. "none"
1828 security model is same as passthrough except the sever won't
1829 report failures if it fails to set file attributes like
1830 ownership. Security model is mandatory only for local fsdriver.
1831 Other fsdrivers (like proxy) don't take security model as a
1832 parameter.
1833
1834 ``writeout=writeout``
1835 This is an optional argument. The only supported value is
1836 "immediate". This means that host page cache will be used to
1837 read and write data but write notification will be sent to the
1838 guest only when the data has been reported as written by the
1839 storage subsystem.
1840
Paolo Bonzini991c1802020-11-13 03:10:52 -05001841 ``readonly=on``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001842 Enables exporting 9p share as a readonly mount for guests. By
1843 default read-write access is given.
1844
1845 ``socket=socket``
1846 Enables proxy filesystem driver to use passed socket file for
1847 communicating with virtfs-proxy-helper(1). Usually a helper like
1848 libvirt will create socketpair and pass one of the fds as
1849 sock\_fd.
1850
1851 ``sock_fd``
1852 Enables proxy filesystem driver to use passed 'sock\_fd' as the
1853 socket descriptor for interfacing with virtfs-proxy-helper(1).
1854
1855 ``fmode=fmode``
1856 Specifies the default mode for newly created files on the host.
1857 Works only with security models "mapped-xattr" and
1858 "mapped-file".
1859
1860 ``dmode=dmode``
1861 Specifies the default mode for newly created directories on the
1862 host. Works only with security models "mapped-xattr" and
1863 "mapped-file".
1864
1865 ``mount_tag=mount_tag``
1866 Specifies the tag name to be used by the guest to mount this
1867 export point.
1868
1869 ``multidevs=multidevs``
1870 Specifies how to deal with multiple devices being shared with a
1871 9p export. Supported behaviours are either "remap", "forbid" or
1872 "warn". The latter is the default behaviour on which virtfs 9p
1873 expects only one device to be shared with the same export, and
1874 if more than one device is shared and accessed via the same 9p
1875 export then only a warning message is logged (once) by qemu on
1876 host side. In order to avoid file ID collisions on guest you
1877 should either create a separate virtfs export for each device to
1878 be shared with guests (recommended way) or you might use "remap"
1879 instead which allows you to share multiple devices with only one
1880 export instead, which is achieved by remapping the original
1881 inode numbers from host to guest in a way that would prevent
1882 such collisions. Remapping inodes in such use cases is required
1883 because the original device IDs from host are never passed and
1884 exposed on guest. Instead all files of an export shared with
1885 virtfs always share the same device id on guest. So two files
1886 with identical inode numbers but from actually different devices
1887 on host would otherwise cause a file ID collision and hence
1888 potential misbehaviours on guest. "forbid" on the other hand
1889 assumes like "warn" that only one device is shared by the same
1890 export, however it will not only log a warning message but also
1891 deny access to additional devices on guest. Note though that
1892 "forbid" does currently not block all possible file access
1893 operations (e.g. readdir() would still return entries from other
1894 devices).
1895ERST
Gautham R Shenoy3d54abc2010-04-29 17:45:03 +05301896
Markus Armbruster61d70482017-10-02 16:03:03 +02001897DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
1898 "-iscsi [user=user][,password=password]\n"
1899 " [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"
1900 " [,initiator-name=initiator-iqn][,id=target-iqn]\n"
1901 " [,timeout=timeout]\n"
1902 " iSCSI session parameters\n", QEMU_ARCH_ALL)
1903
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001904SRST
1905``-iscsi``
1906 Configure iSCSI session parameters.
1907ERST
Markus Armbruster44743142017-10-02 16:03:04 +02001908
blueswir15824d652009-03-28 06:44:27 +00001909DEFHEADING()
1910
Thomas Huthc2a34ab2021-03-10 18:33:23 +01001911DEFHEADING(USB convenience options:)
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001912
1913DEF("usb", 0, QEMU_OPTION_usb,
Stefan Hajnoczi73f46fe2019-08-15 15:14:28 +01001914 "-usb enable on-board USB host controller (if not enabled by default)\n",
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001915 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001916SRST
1917``-usb``
1918 Enable USB emulation on machine types with an on-board USB host
1919 controller (if not enabled by default). Note that on-board USB host
1920 controllers may not support USB 3.0. In this case
1921 ``-device qemu-xhci`` can be used instead on machines with PCI.
1922ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001923
1924DEF("usbdevice", HAS_ARG, QEMU_OPTION_usbdevice,
1925 "-usbdevice name add the host or guest USB device 'name'\n",
1926 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001927SRST
1928``-usbdevice devname``
Thomas Huthc2a34ab2021-03-10 18:33:23 +01001929 Add the USB device devname, and enable an on-board USB controller
1930 if possible and necessary (just like it can be done via
1931 ``-machine usb=on``). Note that this option is mainly intended for
1932 the user's convenience only. More fine-grained control can be
1933 achieved by selecting a USB host controller (if necessary) and the
1934 desired USB device via the ``-device`` option instead. For example,
1935 instead of using ``-usbdevice mouse`` it is possible to use
1936 ``-device qemu-xhci -device usb-mouse`` to connect the USB mouse
1937 to a USB 3.0 controller instead (at least on machines that support
1938 PCI and do not have an USB controller enabled by default yet).
1939 For more details, see the chapter about
Thomas Huth923e9312020-11-16 15:47:36 +01001940 :ref:`Connecting USB devices` in the System Emulation Users Guide.
Thomas Huthc2a34ab2021-03-10 18:33:23 +01001941 Possible devices for devname are:
1942
1943 ``braille``
1944 Braille device. This will use BrlAPI to display the braille
1945 output on a real or fake device (i.e. it also creates a
1946 corresponding ``braille`` chardev automatically beside the
1947 ``usb-braille`` USB device).
1948
Thomas Huthc2a34ab2021-03-10 18:33:23 +01001949 ``keyboard``
1950 Standard USB keyboard. Will override the PS/2 keyboard (if present).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001951
1952 ``mouse``
1953 Virtual Mouse. This will override the PS/2 mouse emulation when
1954 activated.
1955
1956 ``tablet``
1957 Pointer device that uses absolute coordinates (like a
1958 touchscreen). This means QEMU is able to report the mouse
1959 position without having to grab the mouse. Also overrides the
1960 PS/2 mouse emulation when activated.
1961
Thomas Huthc2a34ab2021-03-10 18:33:23 +01001962 ``wacom-tablet``
1963 Wacom PenPartner USB tablet.
1964
1965
Peter Maydelle2fcbf42020-03-06 10:07:14 +00001966ERST
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001967
Markus Armbruster10adb8b2013-02-13 19:49:43 +01001968DEFHEADING()
1969
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02001970DEFHEADING(Display options:)
blueswir15824d652009-03-28 06:44:27 +00001971
Jes Sorensen1472a952011-03-16 13:33:31 +01001972DEF("display", HAS_ARG, QEMU_OPTION_display,
Thomas Huth88b40c62019-10-23 14:01:28 +02001973#if defined(CONFIG_SPICE)
Marc-André Lureaud8aec9d2019-02-21 12:07:03 +01001974 "-display spice-app[,gl=on|off]\n"
Thomas Huth88b40c62019-10-23 14:01:28 +02001975#endif
1976#if defined(CONFIG_SDL)
Thomas Hutha743d602022-05-19 17:56:23 +02001977 "-display sdl[,gl=on|core|es|off][,grab-mod=<mod>][,show-cursor=on|off]\n"
1978 " [,window-close=on|off]\n"
Thomas Huth88b40c62019-10-23 14:01:28 +02001979#endif
Robert Hof04ec5a2016-07-26 18:17:11 +08001980#if defined(CONFIG_GTK)
Thomas Huth95f439b2021-06-30 18:32:31 +02001981 "-display gtk[,full-screen=on|off][,gl=on|off][,grab-on-hover=on|off]\n"
Felix xq QueiĂźnerc34a9332022-07-12 15:37:53 +02001982 " [,show-tabs=on|off][,show-cursor=on|off][,window-close=on|off]\n"
Bryce Millsdbccb1a2022-10-11 13:58:21 +00001983 " [,show-menubar=on|off]\n"
Thomas Huth88b40c62019-10-23 14:01:28 +02001984#endif
1985#if defined(CONFIG_VNC)
1986 "-display vnc=<display>[,<optargs>]\n"
1987#endif
1988#if defined(CONFIG_CURSES)
1989 "-display curses[,charset=<encoding>]\n"
1990#endif
Gustavo Noronha Silvaf844cdb2022-03-06 21:11:18 +09001991#if defined(CONFIG_COCOA)
Gustavo Noronha Silva4797adc2022-03-06 21:11:19 +09001992 "-display cocoa[,full-grab=on|off][,swap-opt-cmd=on|off]\n"
Gustavo Noronha Silvaf844cdb2022-03-06 21:11:18 +09001993#endif
Thomas Huth88b40c62019-10-23 14:01:28 +02001994#if defined(CONFIG_OPENGL)
1995 "-display egl-headless[,rendernode=<file>]\n"
1996#endif
Marc-André Lureau142ca622021-07-15 11:53:53 +04001997#if defined(CONFIG_DBUS_DISPLAY)
1998 "-display dbus[,addr=<dbusaddr>]\n"
1999 " [,gl=on|core|es|off][,rendernode=<file>]\n"
2000#endif
Carwyn Ellis48941a52022-01-02 17:41:52 +00002001#if defined(CONFIG_COCOA)
2002 "-display cocoa[,show-cursor=on|off][,left-command-key=on|off]\n"
2003#endif
Thomas Huth88b40c62019-10-23 14:01:28 +02002004 "-display none\n"
2005 " select display backend type\n"
2006 " The default display is equivalent to\n "
2007#if defined(CONFIG_GTK)
2008 "\"-display gtk\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002009#elif defined(CONFIG_SDL)
Thomas Huth88b40c62019-10-23 14:01:28 +02002010 "\"-display sdl\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002011#elif defined(CONFIG_COCOA)
Thomas Huth88b40c62019-10-23 14:01:28 +02002012 "\"-display cocoa\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002013#elif defined(CONFIG_VNC)
Thomas Huth88b40c62019-10-23 14:01:28 +02002014 "\"-vnc localhost:0,to=99,id=default\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002015#else
Thomas Huth88b40c62019-10-23 14:01:28 +02002016 "\"-display none\"\n"
Robert Hof04ec5a2016-07-26 18:17:11 +08002017#endif
2018 , QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002019SRST
2020``-display type``
Thomas Huth707d93d2022-05-19 17:56:25 +02002021 Select type of display to use. Use ``-display help`` to list the available
2022 display types. Valid values for type are
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002023
Ahmed Abouziedddc71752021-06-01 19:41:18 +02002024 ``spice-app[,gl=on|off]``
2025 Start QEMU as a Spice server and launch the default Spice client
2026 application. The Spice server will redirect the serial consoles
2027 and QEMU monitors. (Since 4.0)
2028
Marc-André Lureau142ca622021-07-15 11:53:53 +04002029 ``dbus``
2030 Export the display over D-Bus interfaces. (Since 7.0)
2031
2032 The connection is registered with the "org.qemu" name (and queued when
2033 already owned).
2034
2035 ``addr=<dbusaddr>`` : D-Bus bus address to connect to.
2036
Marc-André Lureau99997822021-10-10 00:16:57 +04002037 ``p2p=yes|no`` : Use peer-to-peer connection, accepted via QMP ``add_client``.
2038
2039 ``gl=on|off|core|es`` : Use OpenGL for rendering (the D-Bus interface
2040 will share framebuffers with DMABUF file descriptors).
Marc-André Lureau142ca622021-07-15 11:53:53 +04002041
Thomas Huth95f439b2021-06-30 18:32:31 +02002042 ``sdl``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002043 Display video output via SDL (usually in a separate graphics
2044 window; see the SDL documentation for other possibilities).
Thomas Huth95f439b2021-06-30 18:32:31 +02002045 Valid parameters are:
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002046
Thomas Huth8e8e8442021-08-25 11:20:21 +02002047 ``grab-mod=<mods>`` : Used to select the modifier keys for toggling
John Snow450e0f22021-10-04 17:52:36 -04002048 the mouse grabbing in conjunction with the "g" key. ``<mods>`` can be
2049 either ``lshift-lctrl-lalt`` or ``rctrl``.
Thomas Huth8e8e8442021-08-25 11:20:21 +02002050
Thomas Huth95f439b2021-06-30 18:32:31 +02002051 ``gl=on|off|core|es`` : Use OpenGL for displaying
2052
2053 ``show-cursor=on|off`` : Force showing the mouse cursor
2054
2055 ``window-close=on|off`` : Allow to quit qemu with window close button
2056
2057 ``gtk``
Ahmed Abouziedddc71752021-06-01 19:41:18 +02002058 Display video output in a GTK window. This interface provides
2059 drop-down menus and other UI elements to configure and control
Thomas Huth95f439b2021-06-30 18:32:31 +02002060 the VM during runtime. Valid parameters are:
Ahmed Abouziedddc71752021-06-01 19:41:18 +02002061
Thomas Huth95f439b2021-06-30 18:32:31 +02002062 ``full-screen=on|off`` : Start in fullscreen mode
2063
2064 ``gl=on|off`` : Use OpenGL for displaying
2065
2066 ``grab-on-hover=on|off`` : Grab keyboard input on mouse hover
2067
Felix xq QueiĂźnerc34a9332022-07-12 15:37:53 +02002068 ``show-tabs=on|off`` : Display the tab bar for switching between the
2069 various graphical interfaces (e.g. VGA and
2070 virtual console character devices) by default.
2071
Thomas Huth95f439b2021-06-30 18:32:31 +02002072 ``show-cursor=on|off`` : Force showing the mouse cursor
2073
2074 ``window-close=on|off`` : Allow to quit qemu with window close button
2075
Bryce Millsdbccb1a2022-10-11 13:58:21 +00002076 ``show-menubar=on|off`` : Display the main window menubar, defaults to "on"
2077
Thomas Huth95f439b2021-06-30 18:32:31 +02002078 ``curses[,charset=<encoding>]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002079 Display video output via curses. For graphics device models
2080 which support a text mode, QEMU can display this output using a
2081 curses/ncurses interface. Nothing is displayed when the graphics
2082 device is in graphical mode or if the graphics device does not
2083 support a text mode. Generally only the VGA device models
2084 support text mode. The font charset used by the guest can be
2085 specified with the ``charset`` option, for example
2086 ``charset=CP850`` for IBM CP850 encoding. The default is
2087 ``CP437``.
2088
Carwyn Ellis48941a52022-01-02 17:41:52 +00002089 ``cocoa``
2090 Display video output in a Cocoa window. Mac only. This interface
2091 provides drop-down menus and other UI elements to configure and
2092 control the VM during runtime. Valid parameters are:
2093
2094 ``show-cursor=on|off`` : Force showing the mouse cursor
2095
2096 ``left-command-key=on|off`` : Disable forwarding left command key to host
2097
Thomas Huth95f439b2021-06-30 18:32:31 +02002098 ``egl-headless[,rendernode=<file>]``
Ahmed Abouziedddc71752021-06-01 19:41:18 +02002099 Offload all OpenGL operations to a local DRI device. For any
2100 graphical display, this display needs to be paired with either
2101 VNC or SPICE displays.
2102
Thomas Huth95f439b2021-06-30 18:32:31 +02002103 ``vnc=<display>``
2104 Start a VNC server on display <display>
2105
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002106 ``none``
2107 Do not display video output. The guest will still see an
2108 emulated graphics card, but its output will not be displayed to
2109 the QEMU user. This option differs from the -nographic option in
2110 that it only affects what is done with video output; -nographic
2111 also changes the destination of the serial and parallel port
2112 data.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002113ERST
Jes Sorensen1472a952011-03-16 13:33:31 +01002114
blueswir15824d652009-03-28 06:44:27 +00002115DEF("nographic", 0, QEMU_OPTION_nographic,
Blue Swirlad960902010-03-29 19:23:52 +00002116 "-nographic disable graphical output and redirect serial I/Os to console\n",
2117 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002118SRST
2119``-nographic``
2120 Normally, if QEMU is compiled with graphical window support, it
2121 displays output such as guest graphics, guest console, and the QEMU
2122 monitor in a window. With this option, you can totally disable
2123 graphical output so that QEMU is a simple command line application.
2124 The emulated serial port is redirected on the console and muxed with
2125 the monitor (unless redirected elsewhere explicitly). Therefore, you
2126 can still use QEMU to debug a Linux kernel with a serial console.
2127 Use C-a h for help on switching between the console and monitor.
2128ERST
blueswir15824d652009-03-28 06:44:27 +00002129
Marc-André Lureau5324e3e2021-09-09 12:44:11 +04002130#ifdef CONFIG_SPICE
Gerd Hoffmann29b00402010-03-11 11:13:27 -03002131DEF("spice", HAS_ARG, QEMU_OPTION_spice,
Yonit Halperin27af7782012-08-21 13:54:20 +03002132 "-spice [port=port][,tls-port=secured-port][,x509-dir=<dir>]\n"
2133 " [,x509-key-file=<file>][,x509-key-password=<file>]\n"
2134 " [,x509-cert-file=<file>][,x509-cacert-file=<file>]\n"
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002135 " [,x509-dh-key-file=<file>][,addr=addr]\n"
2136 " [,ipv4=on|off][,ipv6=on|off][,unix=on|off]\n"
Yonit Halperin27af7782012-08-21 13:54:20 +03002137 " [,tls-ciphers=<list>]\n"
2138 " [,tls-channel=[main|display|cursor|inputs|record|playback]]\n"
2139 " [,plaintext-channel=[main|display|cursor|inputs|record|playback]]\n"
Daniel P. Berrangé99522f62021-03-11 11:43:42 +00002140 " [,sasl=on|off][,disable-ticketing=on|off]\n"
2141 " [,password=<string>][,password-secret=<secret-id>]\n"
Yonit Halperin27af7782012-08-21 13:54:20 +03002142 " [,image-compression=[auto_glz|auto_lz|quic|glz|lz|off]]\n"
2143 " [,jpeg-wan-compression=[auto|never|always]]\n"
2144 " [,zlib-glz-wan-compression=[auto|never|always]]\n"
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002145 " [,streaming-video=[off|all|filter]][,disable-copy-paste=on|off]\n"
2146 " [,disable-agent-file-xfer=on|off][,agent-mouse=[on|off]]\n"
Hans de Goede5ad24e52013-06-08 15:37:27 +02002147 " [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
Marc-André Lureau7b525502017-02-12 15:21:18 +04002148 " [,gl=[on|off]][,rendernode=<file>]\n"
Yonit Halperin27af7782012-08-21 13:54:20 +03002149 " enable spice\n"
2150 " at least one of {port, tls-port} is mandatory\n",
2151 QEMU_ARCH_ALL)
Marc-André Lureau5324e3e2021-09-09 12:44:11 +04002152#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002153SRST
2154``-spice option[,option[,...]]``
2155 Enable the spice remote desktop protocol. Valid options are
2156
2157 ``port=<nr>``
2158 Set the TCP port spice is listening on for plaintext channels.
2159
2160 ``addr=<addr>``
2161 Set the IP address spice is listening on. Default is any
2162 address.
2163
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002164 ``ipv4=on|off``; \ ``ipv6=on|off``; \ ``unix=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002165 Force using the specified IP version.
2166
Daniel P. Berrangé99522f62021-03-11 11:43:42 +00002167 ``password=<string>``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002168 Set the password you need to authenticate.
2169
Daniel P. Berrangéc47c0bc2021-03-11 11:43:43 +00002170 This option is deprecated and insecure because it leaves the
2171 password visible in the process listing. Use ``password-secret``
2172 instead.
2173
Daniel P. Berrangé99522f62021-03-11 11:43:42 +00002174 ``password-secret=<secret-id>``
2175 Set the ID of the ``secret`` object containing the password
2176 you need to authenticate.
2177
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002178 ``sasl=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002179 Require that the client use SASL to authenticate with the spice.
2180 The exact choice of authentication method used is controlled
2181 from the system / user's SASL configuration file for the 'qemu'
2182 service. This is typically found in /etc/sasl2/qemu.conf. If
2183 running QEMU as an unprivileged user, an environment variable
2184 SASL\_CONF\_PATH can be used to make it search alternate
2185 locations for the service config. While some SASL auth methods
2186 can also provide data encryption (eg GSSAPI), it is recommended
2187 that SASL always be combined with the 'tls' and 'x509' settings
2188 to enable use of SSL and server certificates. This ensures a
2189 data encryption preventing compromise of authentication
2190 credentials.
2191
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002192 ``disable-ticketing=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002193 Allow client connects without authentication.
2194
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002195 ``disable-copy-paste=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002196 Disable copy paste between the client and the guest.
2197
Daniel P. Berrangéa9daa362021-02-16 19:10:20 +00002198 ``disable-agent-file-xfer=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002199 Disable spice-vdagent based file-xfer between the client and the
2200 guest.
2201
2202 ``tls-port=<nr>``
2203 Set the TCP port spice is listening on for encrypted channels.
2204
2205 ``x509-dir=<dir>``
2206 Set the x509 file directory. Expects same filenames as -vnc
2207 $display,x509=$dir
2208
2209 ``x509-key-file=<file>``; \ ``x509-key-password=<file>``; \ ``x509-cert-file=<file>``; \ ``x509-cacert-file=<file>``; \ ``x509-dh-key-file=<file>``
2210 The x509 file names can also be configured individually.
2211
2212 ``tls-ciphers=<list>``
2213 Specify which ciphers to use.
2214
2215 ``tls-channel=[main|display|cursor|inputs|record|playback]``; \ ``plaintext-channel=[main|display|cursor|inputs|record|playback]``
2216 Force specific channel to be used with or without TLS
2217 encryption. The options can be specified multiple times to
2218 configure multiple channels. The special name "default" can be
2219 used to set the default mode. For channels which are not
2220 explicitly forced into one mode the spice client is allowed to
2221 pick tls/plaintext as he pleases.
2222
2223 ``image-compression=[auto_glz|auto_lz|quic|glz|lz|off]``
2224 Configure image compression (lossless). Default is auto\_glz.
2225
2226 ``jpeg-wan-compression=[auto|never|always]``; \ ``zlib-glz-wan-compression=[auto|never|always]``
2227 Configure wan image compression (lossy for slow links). Default
2228 is auto.
2229
2230 ``streaming-video=[off|all|filter]``
2231 Configure video stream detection. Default is off.
2232
2233 ``agent-mouse=[on|off]``
2234 Enable/disable passing mouse events via vdagent. Default is on.
2235
2236 ``playback-compression=[on|off]``
2237 Enable/disable audio stream compression (using celt 0.5.1).
2238 Default is on.
2239
2240 ``seamless-migration=[on|off]``
2241 Enable/disable spice seamless migration. Default is off.
2242
2243 ``gl=[on|off]``
2244 Enable/disable OpenGL context. Default is off.
2245
2246 ``rendernode=<file>``
2247 DRM render node for OpenGL rendering. If not specified, it will
2248 pick the first available. (Since 2.9)
2249ERST
Gerd Hoffmann29b00402010-03-11 11:13:27 -03002250
blueswir15824d652009-03-28 06:44:27 +00002251DEF("portrait", 0, QEMU_OPTION_portrait,
Blue Swirlad960902010-03-29 19:23:52 +00002252 "-portrait rotate graphical output 90 deg left (only PXA LCD)\n",
2253 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002254SRST
2255``-portrait``
2256 Rotate graphical output 90 deg left (only PXA LCD).
2257ERST
blueswir15824d652009-03-28 06:44:27 +00002258
Vasily Khoruzhick93128052011-06-17 13:04:36 +03002259DEF("rotate", HAS_ARG, QEMU_OPTION_rotate,
2260 "-rotate <deg> rotate graphical output some deg left (only PXA LCD)\n",
2261 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002262SRST
2263``-rotate deg``
2264 Rotate graphical output some deg left (only PXA LCD).
2265ERST
Vasily Khoruzhick93128052011-06-17 13:04:36 +03002266
blueswir15824d652009-03-28 06:44:27 +00002267DEF("vga", HAS_ARG, QEMU_OPTION_vga,
Gerd Hoffmanna94f0c52014-09-10 14:28:48 +02002268 "-vga [std|cirrus|vmware|qxl|xenfb|tcx|cg3|virtio|none]\n"
Blue Swirlad960902010-03-29 19:23:52 +00002269 " select video card type\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002270SRST
2271``-vga type``
2272 Select type of VGA card to emulate. Valid values for type are
2273
2274 ``cirrus``
2275 Cirrus Logic GD5446 Video card. All Windows versions starting
2276 from Windows 95 should recognize and use this graphic card. For
2277 optimal performances, use 16 bit color depth in the guest and
2278 the host OS. (This card was the default before QEMU 2.2)
2279
2280 ``std``
2281 Standard VGA card with Bochs VBE extensions. If your guest OS
2282 supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if
2283 you want to use high resolution modes (>= 1280x1024x16) then you
2284 should use this option. (This card is the default since QEMU
2285 2.2)
2286
2287 ``vmware``
2288 VMWare SVGA-II compatible adapter. Use it if you have
2289 sufficiently recent XFree86/XOrg server or Windows guest with a
2290 driver for this card.
2291
2292 ``qxl``
2293 QXL paravirtual graphic card. It is VGA compatible (including
2294 VESA 2.0 VBE support). Works best with qxl guest drivers
2295 installed though. Recommended choice when using the spice
2296 protocol.
2297
2298 ``tcx``
2299 (sun4m only) Sun TCX framebuffer. This is the default
2300 framebuffer for sun4m machines and offers both 8-bit and 24-bit
2301 colour depths at a fixed resolution of 1024x768.
2302
2303 ``cg3``
2304 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit
2305 framebuffer for sun4m machines available in both 1024x768
2306 (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people
2307 wishing to run older Solaris versions.
2308
2309 ``virtio``
2310 Virtio VGA card.
2311
2312 ``none``
2313 Disable VGA card.
2314ERST
blueswir15824d652009-03-28 06:44:27 +00002315
2316DEF("full-screen", 0, QEMU_OPTION_full_screen,
Blue Swirlad960902010-03-29 19:23:52 +00002317 "-full-screen start in full screen\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002318SRST
2319``-full-screen``
2320 Start in full screen.
2321ERST
blueswir15824d652009-03-28 06:44:27 +00002322
John Snow60f9a4e2020-02-04 11:56:38 -05002323DEF("g", HAS_ARG, QEMU_OPTION_g ,
Blue Swirlad960902010-03-29 19:23:52 +00002324 "-g WxH[xDEPTH] Set the initial graphical resolution and depth\n",
Laurent Vivier8ac919a2019-10-26 18:45:43 +02002325 QEMU_ARCH_PPC | QEMU_ARCH_SPARC | QEMU_ARCH_M68K)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002326SRST
Peter Maydell09ce5f22020-02-28 15:36:13 +00002327``-g`` *width*\ ``x``\ *height*\ ``[x``\ *depth*\ ``]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002328 Set the initial graphical resolution and depth (PPC, SPARC only).
2329
2330 For PPC the default is 800x600x32.
2331
2332 For SPARC with the TCX graphics device, the default is 1024x768x8
2333 with the option of 1024x768x24. For cgthree, the default is
2334 1024x768x8 with the option of 1152x900x8 for people who wish to use
2335 OBP.
2336ERST
blueswir15824d652009-03-28 06:44:27 +00002337
2338DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
Robert Hof04ec5a2016-07-26 18:17:11 +08002339 "-vnc <display> shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002340SRST
2341``-vnc display[,option[,option[,...]]]``
2342 Normally, if QEMU is compiled with graphical window support, it
2343 displays output such as guest graphics, guest console, and the QEMU
2344 monitor in a window. With this option, you can have QEMU listen on
2345 VNC display display and redirect the VGA display over the VNC
2346 session. It is very useful to enable the usb tablet device when
2347 using this option (option ``-device usb-tablet``). When using the
2348 VNC display, you must use the ``-k`` parameter to set the keyboard
2349 layout if you are not using en-us. Valid syntax for the display is
2350
2351 ``to=L``
2352 With this option, QEMU will try next available VNC displays,
2353 until the number L, if the origianlly defined "-vnc display" is
2354 not available, e.g. port 5900+display is already used by another
2355 application. By default, to=0.
2356
2357 ``host:d``
2358 TCP connections will only be allowed from host on display d. By
2359 convention the TCP port is 5900+d. Optionally, host can be
2360 omitted in which case the server will accept connections from
2361 any host.
2362
2363 ``unix:path``
2364 Connections will be allowed over UNIX domain sockets where path
2365 is the location of a unix socket to listen for connections on.
2366
2367 ``none``
2368 VNC is initialized but not started. The monitor ``change``
2369 command can be used to later start the VNC server.
2370
2371 Following the display value there may be one or more option flags
2372 separated by commas. Valid options are
2373
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002374 ``reverse=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002375 Connect to a listening VNC client via a "reverse" connection.
2376 The client is specified by the display. For reverse network
2377 connections (host:d,``reverse``), the d argument is a TCP port
2378 number, not a display number.
2379
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002380 ``websocket=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002381 Opens an additional TCP listening port dedicated to VNC
2382 Websocket connections. If a bare websocket option is given, the
2383 Websocket port is 5700+display. An alternative port can be
2384 specified with the syntax ``websocket``\ =port.
2385
2386 If host is specified connections will only be allowed from this
2387 host. It is possible to control the websocket listen address
2388 independently, using the syntax ``websocket``\ =host:port.
2389
2390 If no TLS credentials are provided, the websocket connection
2391 runs in unencrypted mode. If TLS credentials are provided, the
2392 websocket connection requires encrypted client connections.
2393
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002394 ``password=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002395 Require that password based authentication is used for client
2396 connections.
2397
2398 The password must be set separately using the ``set_password``
Thomas Huth923e9312020-11-16 15:47:36 +01002399 command in the :ref:`QEMU monitor`. The
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002400 syntax to change your password is:
2401 ``set_password <protocol> <password>`` where <protocol> could be
2402 either "vnc" or "spice".
2403
2404 If you would like to change <protocol> password expiration, you
2405 should use ``expire_password <protocol> <expiration-time>``
2406 where expiration time could be one of the following options:
2407 now, never, +seconds or UNIX time of expiration, e.g. +60 to
2408 make password expire in 60 seconds, or 1335196800 to make
2409 password expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for
2410 this date and time).
2411
2412 You can also use keywords "now" or "never" for the expiration
2413 time to allow <protocol> password to expire immediately or never
2414 expire.
2415
Daniel P. Berrangé6c6840e2021-03-11 11:43:41 +00002416 ``password-secret=<secret-id>``
2417 Require that password based authentication is used for client
2418 connections, using the password provided by the ``secret``
2419 object identified by ``secret-id``.
2420
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002421 ``tls-creds=ID``
2422 Provides the ID of a set of TLS credentials to use to secure the
2423 VNC server. They will apply to both the normal VNC server socket
2424 and the websocket socket (if enabled). Setting TLS credentials
2425 will cause the VNC server socket to enable the VeNCrypt auth
2426 mechanism. The credentials should have been previously created
2427 using the ``-object tls-creds`` argument.
2428
2429 ``tls-authz=ID``
2430 Provides the ID of the QAuthZ authorization object against which
2431 the client's x509 distinguished name will validated. This object
2432 is only resolved at time of use, so can be deleted and recreated
2433 on the fly while the VNC server is active. If missing, it will
2434 default to denying access.
2435
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002436 ``sasl=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002437 Require that the client use SASL to authenticate with the VNC
2438 server. The exact choice of authentication method used is
2439 controlled from the system / user's SASL configuration file for
2440 the 'qemu' service. This is typically found in
2441 /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user,
2442 an environment variable SASL\_CONF\_PATH can be used to make it
2443 search alternate locations for the service config. While some
2444 SASL auth methods can also provide data encryption (eg GSSAPI),
2445 it is recommended that SASL always be combined with the 'tls'
2446 and 'x509' settings to enable use of SSL and server
2447 certificates. This ensures a data encryption preventing
2448 compromise of authentication credentials. See the
Thomas Huth923e9312020-11-16 15:47:36 +01002449 :ref:`VNC security` section in the System Emulation Users Guide
2450 for details on using SASL authentication.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002451
2452 ``sasl-authz=ID``
2453 Provides the ID of the QAuthZ authorization object against which
2454 the client's SASL username will validated. This object is only
2455 resolved at time of use, so can be deleted and recreated on the
2456 fly while the VNC server is active. If missing, it will default
2457 to denying access.
2458
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002459 ``acl=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002460 Legacy method for enabling authorization of clients against the
2461 x509 distinguished name and SASL username. It results in the
2462 creation of two ``authz-list`` objects with IDs of
2463 ``vnc.username`` and ``vnc.x509dname``. The rules for these
2464 objects must be configured with the HMP ACL commands.
2465
2466 This option is deprecated and should no longer be used. The new
2467 ``sasl-authz`` and ``tls-authz`` options are a replacement.
2468
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002469 ``lossy=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002470 Enable lossy compression methods (gradient, JPEG, ...). If this
2471 option is set, VNC client may receive lossy framebuffer updates
2472 depending on its encoding settings. Enabling this option can
2473 save a lot of bandwidth at the expense of quality.
2474
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002475 ``non-adaptive=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002476 Disable adaptive encodings. Adaptive encodings are enabled by
2477 default. An adaptive encoding will try to detect frequently
2478 updated screen regions, and send updates in these regions using
2479 a lossy encoding (like JPEG). This can be really helpful to save
2480 bandwidth when playing videos. Disabling adaptive encodings
2481 restores the original static behavior of encodings like Tight.
2482
2483 ``share=[allow-exclusive|force-shared|ignore]``
2484 Set display sharing policy. 'allow-exclusive' allows clients to
2485 ask for exclusive access. As suggested by the rfb spec this is
2486 implemented by dropping other connections. Connecting multiple
2487 clients in parallel requires all clients asking for a shared
2488 session (vncviewer: -shared switch). This is the default.
2489 'force-shared' disables exclusive client access. Useful for
2490 shared desktop sessions, where you don't want someone forgetting
2491 specify -shared disconnect everybody else. 'ignore' completely
2492 ignores the shared flag and allows everybody connect
2493 unconditionally. Doesn't conform to the rfb spec but is
2494 traditional QEMU behavior.
2495
2496 ``key-delay-ms``
2497 Set keyboard delay, for key down and key up events, in
2498 milliseconds. Default is 10. Keyboards are low-bandwidth
2499 devices, so this slowdown can help the device and guest to keep
2500 up and not lose events in case events are arriving in bulk.
2501 Possible causes for the latter are flaky network connections, or
2502 scripts for automated testing.
2503
2504 ``audiodev=audiodev``
2505 Use the specified audiodev when the VNC client requests audio
2506 transmission. When not using an -audiodev argument, this option
2507 must be omitted, otherwise is must be present and specify a
2508 valid audiodev.
Daniel P. Berrangé7b5fa0b2020-12-11 16:08:25 +00002509
Daniel P. Berrangé82a17d12021-02-16 19:10:23 +00002510 ``power-control=on|off``
Daniel P. Berrangé7b5fa0b2020-12-11 16:08:25 +00002511 Permit the remote client to issue shutdown, reboot or reset power
2512 control requests.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002513ERST
blueswir15824d652009-03-28 06:44:27 +00002514
Michael Ellermana3adb7a2011-12-19 17:19:31 +11002515ARCHHEADING(, QEMU_ARCH_I386)
blueswir15824d652009-03-28 06:44:27 +00002516
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002517ARCHHEADING(i386 target only:, QEMU_ARCH_I386)
blueswir15824d652009-03-28 06:44:27 +00002518
blueswir15824d652009-03-28 06:44:27 +00002519DEF("win2k-hack", 0, QEMU_OPTION_win2k_hack,
Blue Swirlad960902010-03-29 19:23:52 +00002520 "-win2k-hack use it when installing Windows 2000 to avoid a disk full bug\n",
2521 QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002522SRST
2523``-win2k-hack``
2524 Use it when installing Windows 2000 to avoid a disk full bug. After
2525 Windows 2000 is installed, you no longer need this option (this
2526 option slows down the IDE transfers).
2527ERST
blueswir15824d652009-03-28 06:44:27 +00002528
blueswir15824d652009-03-28 06:44:27 +00002529DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
Blue Swirlad960902010-03-29 19:23:52 +00002530 "-no-fd-bootchk disable boot signature checking for floppy disks\n",
2531 QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002532SRST
2533``-no-fd-bootchk``
2534 Disable boot signature checking for floppy disks in BIOS. May be
2535 needed to boot from old floppy disks.
2536ERST
blueswir15824d652009-03-28 06:44:27 +00002537
blueswir15824d652009-03-28 06:44:27 +00002538DEF("no-acpi", 0, QEMU_OPTION_no_acpi,
Shannon Zhaof5d8c8c2015-05-29 11:28:54 +01002539 "-no-acpi disable ACPI\n", QEMU_ARCH_I386 | QEMU_ARCH_ARM)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002540SRST
2541``-no-acpi``
2542 Disable ACPI (Advanced Configuration and Power Interface) support.
2543 Use it if your guest OS complains about ACPI problems (PC target
2544 machine only).
2545ERST
blueswir15824d652009-03-28 06:44:27 +00002546
blueswir15824d652009-03-28 06:44:27 +00002547DEF("no-hpet", 0, QEMU_OPTION_no_hpet,
Blue Swirlad960902010-03-29 19:23:52 +00002548 "-no-hpet disable HPET\n", QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002549SRST
2550``-no-hpet``
2551 Disable HPET support.
2552ERST
blueswir15824d652009-03-28 06:44:27 +00002553
blueswir15824d652009-03-28 06:44:27 +00002554DEF("acpitable", HAS_ARG, QEMU_OPTION_acpitable,
Michael Tokarev104bf022011-05-12 18:44:17 +04002555 "-acpitable [sig=str][,rev=n][,oem_id=str][,oem_table_id=str][,oem_rev=n][,asl_compiler_id=str][,asl_compiler_rev=n][,{data|file}=file1[:file2]...]\n"
Blue Swirlad960902010-03-29 19:23:52 +00002556 " ACPI table description\n", QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002557SRST
2558``-acpitable [sig=str][,rev=n][,oem_id=str][,oem_table_id=str][,oem_rev=n] [,asl_compiler_id=str][,asl_compiler_rev=n][,data=file1[:file2]...]``
2559 Add ACPI table with specified header fields and context from
2560 specified files. For file=, take whole ACPI table from the specified
2561 files, including all ACPI headers (possible overridden by other
2562 options). For data=, only data portion of the table is used, all
2563 header information is specified in the command line. If a SLIC table
2564 is supplied to QEMU, then the SLIC's oem\_id and oem\_table\_id
2565 fields will override the same in the RSDT and the FADT (a.k.a.
2566 FACP), in order to ensure the field matches required by the
2567 Microsoft SLIC spec and the ACPI spec.
2568ERST
blueswir15824d652009-03-28 06:44:27 +00002569
aliguorib6f6e3d2009-04-17 18:59:56 +00002570DEF("smbios", HAS_ARG, QEMU_OPTION_smbios,
2571 "-smbios file=binary\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002572 " load SMBIOS entry from binary file\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002573 "-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]\n"
2574 " [,uefi=on|off]\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002575 " specify SMBIOS type 0 fields\n"
aliguorib6f6e3d2009-04-17 18:59:56 +00002576 "-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
2577 " [,uuid=uuid][,sku=str][,family=str]\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002578 " specify SMBIOS type 1 fields\n"
2579 "-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str]\n"
2580 " [,asset=str][,location=str]\n"
2581 " specify SMBIOS type 2 fields\n"
2582 "-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str]\n"
2583 " [,sku=str]\n"
2584 " specify SMBIOS type 3 fields\n"
2585 "-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str]\n"
Ying Fangc906e032020-08-06 11:56:33 +08002586 " [,asset=str][,part=str][,max-speed=%d][,current-speed=%d]\n"
Patrick Venturecb5fb042022-01-25 08:31:18 -08002587 " [,processor-id=%d]\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002588 " specify SMBIOS type 4 fields\n"
Hal Martinfd8caa22022-08-12 15:51:53 +02002589 "-smbios type=8[,external_reference=str][,internal_reference=str][,connector_type=%d][,port_type=%d]\n"
2590 " specify SMBIOS type 8 fields\n"
Daniel P. Berrangé48a7ff42020-09-23 14:38:04 +01002591 "-smbios type=11[,value=str][,path=filename]\n"
2592 " specify SMBIOS type 11 fields\n"
Gabriel L. Somlob155eb12015-02-05 11:45:30 -05002593 "-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str]\n"
Gabriel L. Somlo3ebd6cc2015-03-11 13:58:01 -04002594 " [,asset=str][,part=str][,speed=%d]\n"
Vincent Bernat05dfb442021-04-01 19:11:38 +02002595 " specify SMBIOS type 17 fields\n"
2596 "-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]\n"
2597 " specify SMBIOS type 41 fields\n",
Wei Huangc30e1562015-09-07 10:39:29 +01002598 QEMU_ARCH_I386 | QEMU_ARCH_ARM)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002599SRST
2600``-smbios file=binary``
2601 Load SMBIOS entry from binary file.
2602
2603``-smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]``
2604 Specify SMBIOS type 0 fields
2605
2606``-smbios type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]``
2607 Specify SMBIOS type 1 fields
2608
2609``-smbios type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str]``
2610 Specify SMBIOS type 2 fields
2611
2612``-smbios type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]``
2613 Specify SMBIOS type 3 fields
2614
Patrick Venturecb5fb042022-01-25 08:31:18 -08002615``-smbios type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str][,processor-id=%d]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002616 Specify SMBIOS type 4 fields
2617
Daniel P. Berrangé48a7ff42020-09-23 14:38:04 +01002618``-smbios type=11[,value=str][,path=filename]``
2619 Specify SMBIOS type 11 fields
2620
2621 This argument can be repeated multiple times, and values are added in the order they are parsed.
2622 Applications intending to use OEM strings data are encouraged to use their application name as
2623 a prefix for the value string. This facilitates passing information for multiple applications
2624 concurrently.
2625
2626 The ``value=str`` syntax provides the string data inline, while the ``path=filename`` syntax
2627 loads data from a file on disk. Note that the file is not permitted to contain any NUL bytes.
2628
2629 Both the ``value`` and ``path`` options can be repeated multiple times and will be added to
2630 the SMBIOS table in the order in which they appear.
2631
2632 Note that on the x86 architecture, the total size of all SMBIOS tables is limited to 65535
2633 bytes. Thus the OEM strings data is not suitable for passing large amounts of data into the
2634 guest. Instead it should be used as a indicator to inform the guest where to locate the real
2635 data set, for example, by specifying the serial ID of a block device.
2636
2637 An example passing three strings is
2638
2639 .. parsed-literal::
2640
2641 -smbios type=11,value=cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/,\\
2642 value=anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os,\\
2643 path=/some/file/with/oemstringsdata.txt
2644
2645 In the guest OS this is visible with the ``dmidecode`` command
2646
2647 .. parsed-literal::
2648
2649 $ dmidecode -t 11
2650 Handle 0x0E00, DMI type 11, 5 bytes
2651 OEM Strings
2652 String 1: cloud-init:ds=nocloud-net;s=http://10.10.0.1:8000/
2653 String 2: anaconda:method=http://dl.fedoraproject.org/pub/fedora/linux/releases/25/x86_64/os
2654 String 3: myapp:some extra data
2655
2656
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002657``-smbios type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]``
2658 Specify SMBIOS type 17 fields
Vincent Bernat05dfb442021-04-01 19:11:38 +02002659
2660``-smbios type=41[,designation=str][,kind=str][,instance=%d][,pcidev=str]``
2661 Specify SMBIOS type 41 fields
2662
2663 This argument can be repeated multiple times. Its main use is to allow network interfaces be created
2664 as ``enoX`` on Linux, with X being the instance number, instead of the name depending on the interface
2665 position on the PCI bus.
2666
2667 Here is an example of use:
2668
2669 .. parsed-literal::
2670
2671 -netdev user,id=internet \\
2672 -device virtio-net-pci,mac=50:54:00:00:00:42,netdev=internet,id=internet-dev \\
2673 -smbios type=41,designation='Onboard LAN',instance=1,kind=ethernet,pcidev=internet-dev
2674
2675 In the guest OS, the device should then appear as ``eno1``:
2676
2677 ..parsed-literal::
2678
2679 $ ip -brief l
2680 lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP>
2681 eno1 UP 50:54:00:00:00:42 <BROADCAST,MULTICAST,UP,LOWER_UP>
2682
2683 Currently, the PCI device has to be attached to the root bus.
2684
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002685ERST
aliguorib6f6e3d2009-04-17 18:59:56 +00002686
Markus Armbrusterc70a01e2013-02-13 19:49:40 +01002687DEFHEADING()
blueswir15824d652009-03-28 06:44:27 +00002688
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02002689DEFHEADING(Network options:)
blueswir15824d652009-03-28 06:44:27 +00002690
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002691DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
blueswir15824d652009-03-28 06:44:27 +00002692#ifdef CONFIG_SLIRP
Daniel P. Berrangé8b0dc242021-02-16 19:10:21 +00002693 "-netdev user,id=str[,ipv4=on|off][,net=addr[/mask]][,host=addr]\n"
2694 " [,ipv6=on|off][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
Samuel Thibault0b11c032016-03-20 12:29:54 +01002695 " [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
Benjamin Drungf18d1372018-02-27 17:06:01 +01002696 " [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n"
Fam Zheng0fca92b2018-09-14 15:26:16 +08002697 " [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
Jan Kiszkaad196a92009-06-24 14:42:28 +02002698#ifndef _WIN32
Jan Kiszkac92ef6a2009-06-24 14:42:28 +02002699 "[,smb=dir[,smbserver=addr]]\n"
Jan Kiszkaad196a92009-06-24 14:42:28 +02002700#endif
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002701 " configure a user mode network backend with ID 'str',\n"
2702 " its DHCP server and optional services\n"
blueswir15824d652009-03-28 06:44:27 +00002703#endif
2704#ifdef _WIN32
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002705 "-netdev tap,id=str,ifname=name\n"
2706 " configure a host TAP network backend with ID 'str'\n"
blueswir15824d652009-03-28 06:44:27 +00002707#else
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002708 "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n"
Alexey Kardashevskiy584613e2016-09-13 17:11:54 +10002709 " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002710 " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
Jason Wang69e87b32016-07-06 09:57:55 +08002711 " [,poll-us=n]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002712 " configure a host TAP network backend with ID 'str'\n"
Alexey Kardashevskiy584613e2016-09-13 17:11:54 +10002713 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002714 " use network scripts 'file' (default=" DEFAULT_NETWORK_SCRIPT ")\n"
2715 " to configure it and 'dfile' (default=" DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
2716 " to deconfigure it\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002717 " use '[down]script=no' to disable script execution\n"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002718 " use network helper 'helper' (default=" DEFAULT_BRIDGE_HELPER ") to\n"
2719 " configure it\n"
blueswir15824d652009-03-28 06:44:27 +00002720 " use 'fd=h' to connect to an already opened TAP interface\n"
Jason Wang2ca81ba2013-02-20 18:04:01 +08002721 " use 'fds=x:y:...:z' to connect to already opened multiqueue capable TAP interfaces\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002722 " use 'sndbuf=nbytes' to limit the size of the send buffer (the\n"
Michael S. Tsirkinf157ed22011-02-01 14:25:40 +02002723 " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n"
Bruce Rogersca1a8a02010-01-06 12:33:57 -07002724 " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n"
2725 " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n"
Michael S. Tsirkin82b0d802010-03-17 13:08:24 +02002726 " use vhost=on to enable experimental in kernel accelerator\n"
mst@redhat.com5430a282011-02-01 22:13:42 +02002727 " (only has effect for virtio guests which use MSIX)\n"
2728 " use vhostforce=on to force vhost on for non-MSIX virtio guests\n"
Michael S. Tsirkin82b0d802010-03-17 13:08:24 +02002729 " use 'vhostfd=h' to connect to an already opened vhost net device\n"
Jason Wang2ca81ba2013-02-20 18:04:01 +08002730 " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n"
Jason Wangec396012013-02-22 22:57:52 +08002731 " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n"
Michael Tokarevcba42d62021-03-09 14:15:10 +03002732 " use 'poll-us=n' to specify the maximum number of microseconds that could be\n"
Jason Wang69e87b32016-07-06 09:57:55 +08002733 " spent on busy polling for vhost net\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002734 "-netdev bridge,id=str[,br=bridge][,helper=helper]\n"
2735 " configure a host TAP network backend with ID 'str' that is\n"
2736 " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n"
2737 " using the program 'helper (default=" DEFAULT_BRIDGE_HELPER ")\n"
Mark McLoughlin0df0ff62009-06-18 18:21:34 +01002738#endif
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002739#ifdef __linux__
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002740 "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
Daniel P. Berrangé8b0dc242021-02-16 19:10:21 +00002741 " [,rxsession=rxsession],txsession=txsession[,ipv6=on|off][,udp=on|off]\n"
2742 " [,cookie64=on|off][,counter][,pincounter][,txcookie=txcookie]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002743 " [,rxcookie=rxcookie][,offset=offset]\n"
2744 " configure a network backend with ID 'str' connected to\n"
2745 " an Ethernet over L2TPv3 pseudowire.\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002746 " Linux kernel 3.3+ as well as most routers can talk\n"
Michael Tokarev2f47b402014-07-24 20:10:17 +04002747 " L2TPv3. This transport allows connecting a VM to a VM,\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002748 " VM to a router and even VM to Host. It is a nearly-universal\n"
Stefan Hajnoczi21843dc2020-02-29 11:17:27 +00002749 " standard (RFC3931). Note - this implementation uses static\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002750 " pre-configured tunnels (same as the Linux kernel).\n"
2751 " use 'src=' to specify source address\n"
2752 " use 'dst=' to specify destination address\n"
2753 " use 'udp=on' to specify udp encapsulation\n"
Gonglei39526512014-08-14 14:35:48 +08002754 " use 'srcport=' to specify source udp port\n"
Anton Ivanov3fb69aa2014-06-20 10:34:41 +01002755 " use 'dstport=' to specify destination udp port\n"
2756 " use 'ipv6=on' to force v6\n"
2757 " L2TPv3 uses cookies to prevent misconfiguration as\n"
2758 " well as a weak security measure\n"
2759 " use 'rxcookie=0x012345678' to specify a rxcookie\n"
2760 " use 'txcookie=0x012345678' to specify a txcookie\n"
2761 " use 'cookie64=on' to set cookie size to 64 bit, otherwise 32\n"
2762 " use 'counter=off' to force a 'cut-down' L2TPv3 with no counter\n"
2763 " use 'pincounter=on' to work around broken counter handling in peer\n"
2764 " use 'offset=X' to add an extra offset between header and data\n"
2765#endif
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002766 "-netdev socket,id=str[,fd=h][,listen=[host]:port][,connect=host:port]\n"
2767 " configure a network backend to connect to another network\n"
2768 " using a socket connection\n"
2769 "-netdev socket,id=str[,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
2770 " configure a network backend to connect to a multicast maddr and port\n"
Mike Ryan3a75e742010-12-01 11:16:47 -08002771 " use 'localaddr=addr' to specify the host address to send packets from\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002772 "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
2773 " configure a network backend to connect to another network\n"
2774 " using an UDP tunnel\n"
Laurent Vivier1f9c8902022-10-21 11:09:20 +02002775 "-netdev stream,id=str[,server=on|off],addr.type=inet,addr.host=host,addr.port=port[,to=maxport][,numeric=on|off][,keep-alive=on|off][,mptcp=on|off][,addr.ipv4=on|off][,addr.ipv6=on|off]\n"
2776 "-netdev stream,id=str[,server=on|off],addr.type=unix,addr.path=path[,abstract=on|off][,tight=on|off]\n"
Laurent Vivier5166fe02022-10-21 11:09:11 +02002777 "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor\n"
2778 " configure a network backend to connect to another network\n"
2779 " using a socket connection in stream mode.\n"
2780 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]\n"
2781 "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=file-descriptor]\n"
2782 " configure a network backend to connect to a multicast maddr and port\n"
2783 " use ``local.host=addr`` to specify the host address to send packets from\n"
2784 "-netdev dgram,id=str,local.type=inet,local.host=addr,local.port=port[,remote.type=inet,remote.host=addr,remote.port=port]\n"
Laurent Vivier784e7a22022-10-21 11:09:17 +02002785 "-netdev dgram,id=str,local.type=unix,local.path=path[,remote.type=unix,remote.path=path]\n"
Laurent Vivier5166fe02022-10-21 11:09:11 +02002786 "-netdev dgram,id=str,local.type=fd,local.str=file-descriptor\n"
2787 " configure a network backend to connect to another network\n"
2788 " using an UDP tunnel\n"
blueswir15824d652009-03-28 06:44:27 +00002789#ifdef CONFIG_VDE
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002790 "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
2791 " configure a network backend to connect to port 'n' of a vde switch\n"
2792 " running on host and listening for incoming connections on 'socketpath'.\n"
blueswir15824d652009-03-28 06:44:27 +00002793 " Use group 'groupname' and mode 'octalmode' to change default\n"
2794 " ownership and permissions for communication port.\n"
2795#endif
Vincenzo Maffione58952132013-11-06 11:44:06 +01002796#ifdef CONFIG_NETMAP
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002797 "-netdev netmap,id=str,ifname=name[,devname=nmname]\n"
Vincenzo Maffione58952132013-11-06 11:44:06 +01002798 " attach to the existing netmap-enabled network interface 'name', or to a\n"
2799 " VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
2800 " netmap device, defaults to '/dev/netmap')\n"
2801#endif
Thomas Huth253dc142018-02-21 11:18:32 +01002802#ifdef CONFIG_POSIX
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002803 "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
2804 " configure a vhost-user network, backed by a chardev 'dev'\n"
Thomas Huth253dc142018-02-21 11:18:32 +01002805#endif
Cindy Lu108a6482020-07-01 22:55:37 +08002806#ifdef __linux__
Si-Wei Liu8801ccd2022-10-08 00:58:58 -07002807 "-netdev vhost-vdpa,id=str[,vhostdev=/path/to/dev][,vhostfd=h]\n"
Cindy Lu108a6482020-07-01 22:55:37 +08002808 " configure a vhost-vdpa network,Establish a vhost-vdpa netdev\n"
Si-Wei Liu8801ccd2022-10-08 00:58:58 -07002809 " use 'vhostdev=/path/to/dev' to open a vhost vdpa device\n"
2810 " use 'vhostfd=h' to connect to an already opened vhost vdpa device\n"
Cindy Lu108a6482020-07-01 22:55:37 +08002811#endif
Vladislav Yaroshchukb0290db2022-03-17 20:28:38 +03002812#ifdef CONFIG_VMNET
2813 "-netdev vmnet-host,id=str[,isolated=on|off][,net-uuid=uuid]\n"
2814 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n"
2815 " configure a vmnet network backend in host mode with ID 'str',\n"
2816 " isolate this interface from others with 'isolated',\n"
2817 " configure the address range and choose a subnet mask,\n"
2818 " specify network UUID 'uuid' to disable DHCP and interact with\n"
2819 " vmnet-host interfaces within this isolated network\n"
2820 "-netdev vmnet-shared,id=str[,isolated=on|off][,nat66-prefix=addr]\n"
2821 " [,start-address=addr,end-address=addr,subnet-mask=mask]\n"
2822 " configure a vmnet network backend in shared mode with ID 'str',\n"
2823 " configure the address range and choose a subnet mask,\n"
2824 " set IPv6 ULA prefix (of length 64) to use for internal network,\n"
2825 " isolate this interface from others with 'isolated'\n"
2826 "-netdev vmnet-bridged,id=str,ifname=name[,isolated=on|off]\n"
2827 " configure a vmnet network backend in bridged mode with ID 'str',\n"
2828 " use 'ifname=name' to select a physical network interface to be bridged,\n"
2829 " isolate this interface from others with 'isolated'\n"
2830#endif
Thomas Huth18d65d22018-01-15 20:50:55 +01002831 "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002832 " configure a hub port on the hub with ID 'n'\n", QEMU_ARCH_ALL)
Thomas Huth78cd6f72018-02-21 11:18:36 +01002833DEF("nic", HAS_ARG, QEMU_OPTION_nic,
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02002834 "-nic [tap|bridge|"
Thomas Huth78cd6f72018-02-21 11:18:36 +01002835#ifdef CONFIG_SLIRP
2836 "user|"
2837#endif
2838#ifdef __linux__
2839 "l2tpv3|"
2840#endif
2841#ifdef CONFIG_VDE
2842 "vde|"
2843#endif
2844#ifdef CONFIG_NETMAP
2845 "netmap|"
2846#endif
2847#ifdef CONFIG_POSIX
2848 "vhost-user|"
2849#endif
Vladislav Yaroshchukb0290db2022-03-17 20:28:38 +03002850#ifdef CONFIG_VMNET
2851 "vmnet-host|vmnet-shared|vmnet-bridged|"
2852#endif
Thomas Huth78cd6f72018-02-21 11:18:36 +01002853 "socket][,option][,...][mac=macaddr]\n"
2854 " initialize an on-board / default host NIC (using MAC address\n"
2855 " macaddr) and connect it to the given host network backend\n"
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02002856 "-nic none use it alone to have zero network devices (the default is to\n"
Thomas Huth78cd6f72018-02-21 11:18:36 +01002857 " provided a 'user' network connection)\n",
2858 QEMU_ARCH_ALL)
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002859DEF("net", HAS_ARG, QEMU_OPTION_net,
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002860 "-net nic[,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
Thomas Huth0e60a822017-12-19 16:28:55 +01002861 " configure or create an on-board (or machine default) NIC and\n"
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002862 " connect it to hub 0 (please use -nic unless you need a hub)\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002863 "-net ["
Mark McLoughlina1ea4582009-10-08 19:58:26 +01002864#ifdef CONFIG_SLIRP
2865 "user|"
2866#endif
2867 "tap|"
Corey Bryanta7c36ee2012-01-26 09:42:27 -05002868 "bridge|"
Mark McLoughlina1ea4582009-10-08 19:58:26 +01002869#ifdef CONFIG_VDE
2870 "vde|"
2871#endif
Vincenzo Maffione58952132013-11-06 11:44:06 +01002872#ifdef CONFIG_NETMAP
2873 "netmap|"
2874#endif
Vladislav Yaroshchukb0290db2022-03-17 20:28:38 +03002875#ifdef CONFIG_VMNET
2876 "vmnet-host|vmnet-shared|vmnet-bridged|"
2877#endif
Thomas Huthaf1a5c32018-04-30 20:02:23 +02002878 "socket][,option][,option][,...]\n"
Thomas Huth6a8b4a52015-05-15 16:58:24 +02002879 " old way to initialize a host network interface\n"
2880 " (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002881SRST
2882``-nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]``
2883 This option is a shortcut for configuring both the on-board
2884 (default) guest NIC hardware and the host network backend in one go.
2885 The host backend options are the same as with the corresponding
2886 ``-netdev`` options below. The guest NIC model can be set with
2887 ``model=modelname``. Use ``model=help`` to list the available device
2888 types. The hardware MAC address can be set with ``mac=macaddr``.
2889
2890 The following two example do exactly the same, to show how ``-nic``
2891 can be used to shorten the command line length:
2892
2893 .. parsed-literal::
2894
2895 |qemu_system| -netdev user,id=n1,ipv6=off -device e1000,netdev=n1,mac=52:54:98:76:54:32
2896 |qemu_system| -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32
2897
2898``-nic none``
2899 Indicate that no network devices should be configured. It is used to
2900 override the default configuration (default NIC with "user" host
2901 network backend) which is activated if no other networking options
2902 are provided.
2903
2904``-netdev user,id=id[,option][,option][,...]``
2905 Configure user mode host network backend which requires no
2906 administrator privilege to run. Valid options are:
2907
2908 ``id=id``
2909 Assign symbolic name for use in monitor commands.
2910
2911 ``ipv4=on|off and ipv6=on|off``
2912 Specify that either IPv4 or IPv6 must be enabled. If neither is
2913 specified both protocols are enabled.
2914
2915 ``net=addr[/mask]``
2916 Set IP network address the guest will see. Optionally specify
2917 the netmask, either in the form a.b.c.d or as number of valid
2918 top-most bits. Default is 10.0.2.0/24.
2919
2920 ``host=addr``
2921 Specify the guest-visible address of the host. Default is the
2922 2nd IP in the guest network, i.e. x.x.x.2.
2923
2924 ``ipv6-net=addr[/int]``
2925 Set IPv6 network address the guest will see (default is
2926 fec0::/64). The network prefix is given in the usual hexadecimal
2927 IPv6 address notation. The prefix size is optional, and is given
2928 as the number of valid top-most bits (default is 64).
2929
2930 ``ipv6-host=addr``
2931 Specify the guest-visible IPv6 address of the host. Default is
2932 the 2nd IPv6 in the guest network, i.e. xxxx::2.
2933
2934 ``restrict=on|off``
2935 If this option is enabled, the guest will be isolated, i.e. it
2936 will not be able to contact the host and no guest IP packets
2937 will be routed over the host to the outside. This option does
2938 not affect any explicitly set forwarding rules.
2939
2940 ``hostname=name``
2941 Specifies the client hostname reported by the built-in DHCP
2942 server.
2943
2944 ``dhcpstart=addr``
2945 Specify the first of the 16 IPs the built-in DHCP server can
2946 assign. Default is the 15th to 31st IP in the guest network,
2947 i.e. x.x.x.15 to x.x.x.31.
2948
2949 ``dns=addr``
2950 Specify the guest-visible address of the virtual nameserver. The
2951 address must be different from the host address. Default is the
2952 3rd IP in the guest network, i.e. x.x.x.3.
2953
2954 ``ipv6-dns=addr``
2955 Specify the guest-visible address of the IPv6 virtual
2956 nameserver. The address must be different from the host address.
2957 Default is the 3rd IP in the guest network, i.e. xxxx::3.
2958
2959 ``dnssearch=domain``
2960 Provides an entry for the domain-search list sent by the
2961 built-in DHCP server. More than one domain suffix can be
2962 transmitted by specifying this option multiple times. If
2963 supported, this will cause the guest to automatically try to
2964 append the given domain suffix(es) in case a domain name can not
2965 be resolved.
2966
2967 Example:
2968
2969 .. parsed-literal::
2970
2971 |qemu_system| -nic user,dnssearch=mgmt.example.org,dnssearch=example.org
2972
2973 ``domainname=domain``
2974 Specifies the client domain name reported by the built-in DHCP
2975 server.
2976
2977 ``tftp=dir``
2978 When using the user mode network stack, activate a built-in TFTP
2979 server. The files in dir will be exposed as the root of a TFTP
2980 server. The TFTP client on the guest must be configured in
2981 binary mode (use the command ``bin`` of the Unix TFTP client).
2982
2983 ``tftp-server-name=name``
2984 In BOOTP reply, broadcast name as the "TFTP server name"
2985 (RFC2132 option 66). This can be used to advise the guest to
2986 load boot files or configurations from a different server than
2987 the host address.
2988
2989 ``bootfile=file``
2990 When using the user mode network stack, broadcast file as the
2991 BOOTP filename. In conjunction with ``tftp``, this can be used
2992 to network boot a guest from a local directory.
2993
2994 Example (using pxelinux):
2995
2996 .. parsed-literal::
2997
Laszlo Ersek353a06b2020-09-08 19:21:11 +02002998 |qemu_system| -hda linux.img -boot n -device e1000,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00002999 -netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
3000
3001 ``smb=dir[,smbserver=addr]``
3002 When using the user mode network stack, activate a built-in SMB
3003 server so that Windows OSes can access to the host files in
3004 ``dir`` transparently. The IP address of the SMB server can be
3005 set to addr. By default the 4th IP in the guest network is used,
3006 i.e. x.x.x.4.
3007
3008 In the guest Windows OS, the line:
3009
3010 ::
3011
3012 10.0.2.4 smbserver
3013
3014 must be added in the file ``C:\WINDOWS\LMHOSTS`` (for windows
3015 9x/Me) or ``C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS`` (Windows
3016 NT/2000).
3017
3018 Then ``dir`` can be accessed in ``\\smbserver\qemu``.
3019
3020 Note that a SAMBA server must be installed on the host OS.
3021
3022 ``hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport``
3023 Redirect incoming TCP or UDP connections to the host port
3024 hostport to the guest IP address guestaddr on guest port
3025 guestport. If guestaddr is not specified, its value is x.x.x.15
3026 (default first address given by the built-in DHCP server). By
3027 specifying hostaddr, the rule can be bound to a specific host
3028 interface. If no connection type is set, TCP is used. This
3029 option can be given multiple times.
3030
3031 For example, to redirect host X11 connection from screen 1 to
3032 guest screen 0, use the following:
3033
Peter Maydell09ce5f22020-02-28 15:36:13 +00003034 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003035
3036 # on the host
3037 |qemu_system| -nic user,hostfwd=tcp:127.0.0.1:6001-:6000
3038 # this host xterm should open in the guest X11 server
3039 xterm -display :1
3040
3041 To redirect telnet connections from host port 5555 to telnet
3042 port on the guest, use the following:
3043
Peter Maydell09ce5f22020-02-28 15:36:13 +00003044 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003045
3046 # on the host
3047 |qemu_system| -nic user,hostfwd=tcp::5555-:23
3048 telnet localhost 5555
3049
3050 Then when you use on the host ``telnet localhost 5555``, you
3051 connect to the guest telnet server.
3052
3053 ``guestfwd=[tcp]:server:port-dev``; \ ``guestfwd=[tcp]:server:port-cmd:command``
3054 Forward guest TCP connections to the IP address server on port
3055 port to the character device dev or to a program executed by
3056 cmd:command which gets spawned for each connection. This option
3057 can be given multiple times.
3058
3059 You can either use a chardev directly and have that one used
3060 throughout QEMU's lifetime, like in the following example:
3061
Peter Maydell09ce5f22020-02-28 15:36:13 +00003062 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003063
3064 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
3065 # the guest accesses it
3066 |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321
3067
3068 Or you can execute a command on every TCP connection established
3069 by the guest, so that QEMU behaves similar to an inetd process
3070 for that virtual server:
3071
Peter Maydell09ce5f22020-02-28 15:36:13 +00003072 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003073
3074 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
3075 # and connect the TCP stream to its stdin/stdout
3076 |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
3077
3078``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]``
3079 Configure a host TAP network backend with ID id.
3080
3081 Use the network script file to configure it and the network script
3082 dfile to deconfigure it. If name is not provided, the OS
3083 automatically provides one. The default network configure script is
3084 ``/etc/qemu-ifup`` and the default network deconfigure script is
3085 ``/etc/qemu-ifdown``. Use ``script=no`` or ``downscript=no`` to
3086 disable script execution.
3087
3088 If running QEMU as an unprivileged user, use the network helper
Tianjia Zhang8d73ec82020-07-27 12:59:25 +08003089 to configure the TAP interface and attach it to the bridge.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003090 The default network helper executable is
3091 ``/path/to/qemu-bridge-helper`` and the default bridge device is
3092 ``br0``.
3093
3094 ``fd``\ =h can be used to specify the handle of an already opened
3095 host TAP interface.
3096
3097 Examples:
3098
Peter Maydell09ce5f22020-02-28 15:36:13 +00003099 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003100
3101 #launch a QEMU instance with the default network script
3102 |qemu_system| linux.img -nic tap
3103
Peter Maydell09ce5f22020-02-28 15:36:13 +00003104 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003105
3106 #launch a QEMU instance with two NICs, each one connected
3107 #to a TAP device
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003108 |qemu_system| linux.img \\
3109 -netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003110 -netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1
3111
Peter Maydell09ce5f22020-02-28 15:36:13 +00003112 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003113
3114 #launch a QEMU instance with the default network helper to
3115 #connect a TAP device to bridge br0
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003116 |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003117 -netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
3118
3119``-netdev bridge,id=id[,br=bridge][,helper=helper]``
3120 Connect a host TAP network interface to a host bridge device.
3121
3122 Use the network helper helper to configure the TAP interface and
3123 attach it to the bridge. The default network helper executable is
3124 ``/path/to/qemu-bridge-helper`` and the default bridge device is
3125 ``br0``.
3126
3127 Examples:
3128
Peter Maydell09ce5f22020-02-28 15:36:13 +00003129 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003130
3131 #launch a QEMU instance with the default network helper to
3132 #connect a TAP device to bridge br0
3133 |qemu_system| linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1
3134
Peter Maydell09ce5f22020-02-28 15:36:13 +00003135 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003136
3137 #launch a QEMU instance with the default network helper to
3138 #connect a TAP device to bridge qemubr0
3139 |qemu_system| linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1
3140
3141``-netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]``
3142 This host network backend can be used to connect the guest's network
3143 to another QEMU virtual machine using a TCP socket connection. If
3144 ``listen`` is specified, QEMU waits for incoming connections on port
3145 (host is optional). ``connect`` is used to connect to another QEMU
3146 instance using the ``listen`` option. ``fd``\ =h specifies an
3147 already opened TCP socket.
3148
3149 Example:
3150
Peter Maydell09ce5f22020-02-28 15:36:13 +00003151 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003152
3153 # launch a first QEMU instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003154 |qemu_system| linux.img \\
3155 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003156 -netdev socket,id=n1,listen=:1234
3157 # connect the network of this instance to the network of the first instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003158 |qemu_system| linux.img \\
3159 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003160 -netdev socket,id=n2,connect=127.0.0.1:1234
3161
3162``-netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]``
3163 Configure a socket host network backend to share the guest's network
3164 traffic with another QEMU virtual machines using a UDP multicast
3165 socket, effectively making a bus for every QEMU with same multicast
3166 address maddr and port. NOTES:
3167
3168 1. Several QEMU can be running on different hosts and share same bus
3169 (assuming correct multicast setup for these hosts).
3170
3171 2. mcast support is compatible with User Mode Linux (argument
3172 ``ethN=mcast``), see http://user-mode-linux.sf.net.
3173
3174 3. Use ``fd=h`` to specify an already opened UDP multicast socket.
3175
3176 Example:
3177
Peter Maydell09ce5f22020-02-28 15:36:13 +00003178 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003179
3180 # launch one QEMU instance
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003181 |qemu_system| linux.img \\
3182 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003183 -netdev socket,id=n1,mcast=230.0.0.1:1234
3184 # launch another QEMU instance on same "bus"
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003185 |qemu_system| linux.img \\
3186 -device e1000,netdev=n2,mac=52:54:00:12:34:57 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003187 -netdev socket,id=n2,mcast=230.0.0.1:1234
3188 # launch yet another QEMU instance on same "bus"
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003189 |qemu_system| linux.img \\
3190 -device e1000,netdev=n3,mac=52:54:00:12:34:58 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003191 -netdev socket,id=n3,mcast=230.0.0.1:1234
3192
3193 Example (User Mode Linux compat.):
3194
Peter Maydell09ce5f22020-02-28 15:36:13 +00003195 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003196
3197 # launch QEMU instance (note mcast address selected is UML's default)
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003198 |qemu_system| linux.img \\
3199 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003200 -netdev socket,id=n1,mcast=239.192.168.1:1102
3201 # launch UML
3202 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
3203
3204 Example (send packets from host's 1.2.3.4):
3205
3206 .. parsed-literal::
3207
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003208 |qemu_system| linux.img \\
3209 -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003210 -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
3211
Daniel P. Berrangé8b0dc242021-02-16 19:10:21 +00003212``-netdev l2tpv3,id=id,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6=on|off][,udp=on|off][,cookie64][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003213 Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931)
3214 is a popular protocol to transport Ethernet (and other Layer 2) data
3215 frames between two systems. It is present in routers, firewalls and
3216 the Linux kernel (from version 3.3 onwards).
3217
3218 This transport allows a VM to communicate to another VM, router or
3219 firewall directly.
3220
3221 ``src=srcaddr``
3222 source address (mandatory)
3223
3224 ``dst=dstaddr``
3225 destination address (mandatory)
3226
3227 ``udp``
3228 select udp encapsulation (default is ip).
3229
3230 ``srcport=srcport``
3231 source udp port.
3232
3233 ``dstport=dstport``
3234 destination udp port.
3235
3236 ``ipv6``
3237 force v6, otherwise defaults to v4.
3238
3239 ``rxcookie=rxcookie``; \ ``txcookie=txcookie``
3240 Cookies are a weak form of security in the l2tpv3 specification.
3241 Their function is mostly to prevent misconfiguration. By default
3242 they are 32 bit.
3243
3244 ``cookie64``
3245 Set cookie size to 64 bit instead of the default 32
3246
3247 ``counter=off``
3248 Force a 'cut-down' L2TPv3 with no counter as in
3249 draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00
3250
3251 ``pincounter=on``
3252 Work around broken counter handling in peer. This may also help
3253 on networks which have packet reorder.
3254
3255 ``offset=offset``
3256 Add an extra offset between header and data
3257
3258 For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to
3259 the bridge br-lan on the remote Linux host 1.2.3.4:
3260
Peter Maydell09ce5f22020-02-28 15:36:13 +00003261 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003262
3263 # Setup tunnel on linux host using raw ip as encapsulation
3264 # on 1.2.3.4
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003265 ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003266 encap udp udp_sport 16384 udp_dport 16384
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003267 ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003268 0xFFFFFFFF peer_session_id 0xFFFFFFFF
3269 ifconfig vmtunnel0 mtu 1500
3270 ifconfig vmtunnel0 up
3271 brctl addif br-lan vmtunnel0
3272
3273
3274 # on 4.3.2.1
3275 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
3276
Laszlo Ersek353a06b2020-09-08 19:21:11 +02003277 |qemu_system| linux.img -device e1000,netdev=n1 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003278 -netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
3279
3280``-netdev vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]``
3281 Configure VDE backend to connect to PORT n of a vde switch running
3282 on host and listening for incoming connections on socketpath. Use
3283 GROUP groupname and MODE octalmode to change default ownership and
3284 permissions for communication port. This option is only available if
3285 QEMU has been compiled with vde support enabled.
3286
3287 Example:
3288
Peter Maydell09ce5f22020-02-28 15:36:13 +00003289 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003290
3291 # launch vde switch
3292 vde_switch -F -sock /tmp/myswitch
3293 # launch QEMU instance
3294 |qemu_system| linux.img -nic vde,sock=/tmp/myswitch
3295
3296``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]``
3297 Establish a vhost-user netdev, backed by a chardev id. The chardev
3298 should be a unix domain socket backed one. The vhost-user uses a
3299 specifically defined protocol to pass vhost ioctl replacement
3300 messages to an application on the other end of the socket. On
3301 non-MSIX guests, the feature can be forced with vhostforce. Use
3302 'queues=n' to specify the number of queues to be created for
3303 multiqueue vhost-user.
3304
3305 Example:
3306
3307 ::
3308
3309 qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
3310 -numa node,memdev=mem \
3311 -chardev socket,id=chr0,path=/path/to/socket \
3312 -netdev type=vhost-user,id=net0,chardev=chr0 \
3313 -device virtio-net-pci,netdev=net0
3314
Si-Wei Liu8801ccd2022-10-08 00:58:58 -07003315``-netdev vhost-vdpa[,vhostdev=/path/to/dev][,vhostfd=h]``
Cindy Lu108a6482020-07-01 22:55:37 +08003316 Establish a vhost-vdpa netdev.
3317
3318 vDPA device is a device that uses a datapath which complies with
3319 the virtio specifications with a vendor specific control path.
3320 vDPA devices can be both physically located on the hardware or
3321 emulated by software.
3322
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003323``-netdev hubport,id=id,hubid=hubid[,netdev=nd]``
3324 Create a hub port on the emulated hub with ID hubid.
3325
3326 The hubport netdev lets you connect a NIC to a QEMU emulated hub
3327 instead of a single netdev. Alternatively, you can also connect the
3328 hubport to another netdev with ID nd by using the ``netdev=nd``
3329 option.
3330
3331``-net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]``
3332 Legacy option to configure or create an on-board (or machine
3333 default) Network Interface Card(NIC) and connect it either to the
3334 emulated hub with ID 0 (i.e. the default hub), or to the netdev nd.
3335 If model is omitted, then the default NIC model associated with the
3336 machine type is used. Note that the default NIC model may change in
3337 future QEMU releases, so it is highly recommended to always specify
3338 a model. Optionally, the MAC address can be changed to mac, the
3339 device address set to addr (PCI cards only), and a name can be
3340 assigned for use in monitor commands. Optionally, for PCI cards, you
3341 can specify the number v of MSI-X vectors that the card should have;
3342 this option currently only affects virtio cards; set v = 0 to
3343 disable MSI-X. If no ``-net`` option is specified, a single NIC is
3344 created. QEMU can emulate several different models of network card.
3345 Use ``-net nic,model=help`` for a list of available devices for your
3346 target.
3347
3348``-net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]``
3349 Configure a host network backend (with the options corresponding to
3350 the same ``-netdev`` option) and connect it to the emulated hub 0
3351 (the default hub). Use name to specify the name of the hub port.
3352ERST
blueswir15824d652009-03-28 06:44:27 +00003353
Matthew Booth7273a2d2009-10-30 13:41:12 +00003354DEFHEADING()
3355
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02003356DEFHEADING(Character device options:)
Matthew Booth7273a2d2009-10-30 13:41:12 +00003357
3358DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
Lin Ma517b3d42016-08-17 01:13:52 +08003359 "-chardev help\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003360 "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Markus Armbrusterba858d12021-09-28 09:14:49 +02003361 "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]\n"
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003362 " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off]\n"
Daniel P. Berrangefd4a5fd2019-03-08 15:21:50 +00003363 " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n"
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003364 "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds]\n"
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003365 " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003366 "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003367 " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003368 " [,logfile=PATH][,logappend=on|off]\n"
3369 "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003370 "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n"
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003371 " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3372 "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n"
3373 "-chardev file,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3374 "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003375#ifdef _WIN32
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003376 "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3377 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003378#else
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003379 "-chardev pty,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3380 "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003381#endif
3382#ifdef CONFIG_BRLAPI
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003383 "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003384#endif
3385#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
3386 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003387 "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3388 "-chardev tty,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003389#endif
3390#if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003391 "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
3392 "-chardev parport,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
Matthew Booth7273a2d2009-10-30 13:41:12 +00003393#endif
Alon Levycbcc6332011-01-19 10:49:50 +02003394#if defined(CONFIG_SPICE)
Daniel P. Berranged0d77082016-01-11 12:44:41 +00003395 "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
3396 "-chardev spiceport,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n"
Alon Levycbcc6332011-01-19 10:49:50 +02003397#endif
Blue Swirlad960902010-03-29 19:23:52 +00003398 , QEMU_ARCH_ALL
Matthew Booth7273a2d2009-10-30 13:41:12 +00003399)
3400
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003401SRST
3402The general form of a character device option is:
3403
3404``-chardev backend,id=id[,mux=on|off][,options]``
3405 Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``,
3406 ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``,
3407 ``pty``, ``stdio``, ``braille``, ``tty``, ``parallel``, ``parport``,
3408 ``spicevmc``, ``spiceport``. The specific backend will determine the
3409 applicable options.
3410
3411 Use ``-chardev help`` to print all available chardev backend types.
3412
3413 All devices must have an id, which can be any string up to 127
3414 characters long. It is used to uniquely identify this device in
3415 other command line directives.
3416
3417 A character device may be used in multiplexing mode by multiple
3418 front-ends. Specify ``mux=on`` to enable this mode. A multiplexer is
3419 a "1:N" device, and here the "1" end is your specified chardev
3420 backend, and the "N" end is the various parts of QEMU that can talk
3421 to a chardev. If you create a chardev with ``id=myid`` and
3422 ``mux=on``, QEMU will create a multiplexer with your specified ID,
3423 and you can then configure multiple front ends to use that chardev
3424 ID for their input/output. Up to four different front ends can be
3425 connected to a single multiplexed chardev. (Without multiplexing
3426 enabled, a chardev can only be used by a single front end.) For
3427 instance you could use this to allow a single stdio chardev to be
3428 used by two serial ports and the QEMU monitor:
3429
3430 ::
3431
3432 -chardev stdio,mux=on,id=char0 \
3433 -mon chardev=char0,mode=readline \
3434 -serial chardev:char0 \
3435 -serial chardev:char0
3436
3437 You can have more than one multiplexer in a system configuration;
3438 for instance you could have a TCP port multiplexed between UART 0
3439 and UART 1, and stdio multiplexed between the QEMU monitor and a
3440 parallel port:
3441
3442 ::
3443
3444 -chardev stdio,mux=on,id=char0 \
3445 -mon chardev=char0,mode=readline \
3446 -parallel chardev:char0 \
3447 -chardev tcp,...,mux=on,id=char1 \
3448 -serial chardev:char1 \
3449 -serial chardev:char1
3450
3451 When you're using a multiplexed character device, some escape
Thomas Huth923e9312020-11-16 15:47:36 +01003452 sequences are interpreted in the input. See the chapter about
3453 :ref:`keys in the character backend multiplexer` in the
3454 System Emulation Users Guide for more details.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003455
3456 Note that some other command line options may implicitly create
3457 multiplexed character backends; for instance ``-serial mon:stdio``
3458 creates a multiplexed stdio backend connected to the serial port and
3459 the QEMU monitor, and ``-nographic`` also multiplexes the console
3460 and the monitor to stdio.
3461
3462 There is currently no support for multiplexing in the other
3463 direction (where a single QEMU front end takes input and output from
3464 multiple chardevs).
3465
3466 Every backend supports the ``logfile`` option, which supplies the
3467 path to a file to record all data transmitted via the backend. The
3468 ``logappend`` option controls whether the log file will be truncated
3469 or appended to when opened.
3470
3471The available backends are:
3472
3473``-chardev null,id=id``
3474 A void device. This device will not emit any data, and will drop any
3475 data it receives. The null backend does not take any options.
3476
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003477``-chardev socket,id=id[,TCP options or unix options][,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,tls-creds=id][,tls-authz=id]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003478 Create a two-way stream socket, which can be either a TCP or a unix
3479 socket. A unix socket will be created if ``path`` is specified.
3480 Behaviour is undefined if TCP options are specified for a unix
3481 socket.
3482
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003483 ``server=on|off`` specifies that the socket shall be a listening socket.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003484
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003485 ``wait=on|off`` specifies that QEMU should not block waiting for a client
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003486 to connect to a listening socket.
3487
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003488 ``telnet=on|off`` specifies that traffic on the socket should interpret
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003489 telnet escape sequences.
3490
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003491 ``websocket=on|off`` specifies that the socket uses WebSocket protocol for
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003492 communication.
3493
3494 ``reconnect`` sets the timeout for reconnecting on non-server
3495 sockets when the remote end goes away. qemu will delay this many
3496 seconds and then attempt to reconnect. Zero disables reconnecting,
3497 and is the default.
3498
3499 ``tls-creds`` requests enablement of the TLS protocol for
3500 encryption, and specifies the id of the TLS credentials to use for
3501 the handshake. The credentials must be previously created with the
3502 ``-object tls-creds`` argument.
3503
3504 ``tls-auth`` provides the ID of the QAuthZ authorization object
3505 against which the client's x509 distinguished name will be
3506 validated. This object is only resolved at time of use, so can be
3507 deleted and recreated on the fly while the chardev server is active.
3508 If missing, it will default to denying access.
3509
3510 TCP and unix socket options are given below:
3511
Paolo Bonzinia9b13152021-02-25 11:47:52 +01003512 ``TCP options: port=port[,host=host][,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003513 ``host`` for a listening socket specifies the local address to
3514 be bound. For a connecting socket species the remote host to
3515 connect to. ``host`` is optional for listening sockets. If not
3516 specified it defaults to ``0.0.0.0``.
3517
3518 ``port`` for a listening socket specifies the local port to be
3519 bound. For a connecting socket specifies the port on the remote
3520 host to connect to. ``port`` can be given as either a port
3521 number or a service name. ``port`` is required.
3522
3523 ``to`` is only relevant to listening sockets. If it is
3524 specified, and ``port`` cannot be bound, QEMU will attempt to
3525 bind to subsequent ports up to and including ``to`` until it
3526 succeeds. ``to`` must be specified as a port number.
3527
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003528 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4
3529 or IPv6 must be used. If neither is specified the socket may
3530 use either protocol.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003531
Paolo Bonzinia9b13152021-02-25 11:47:52 +01003532 ``nodelay=on|off`` disables the Nagle algorithm.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003533
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003534 ``unix options: path=path[,abstract=on|off][,tight=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003535 ``path`` specifies the local path of the unix socket. ``path``
3536 is required.
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003537 ``abstract=on|off`` specifies the use of the abstract socket namespace,
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003538 rather than the filesystem. Optional, defaults to false.
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003539 ``tight=on|off`` sets the socket length of abstract sockets to their minimum,
xiaoqiang zhaoe3392732020-05-16 11:13:27 +08003540 rather than the full sun_path length. Optional, defaults to true.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003541
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003542``-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr][,localport=localport][,ipv4=on|off][,ipv6=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003543 Sends all traffic from the guest to a remote host over UDP.
3544
3545 ``host`` specifies the remote host to connect to. If not specified
3546 it defaults to ``localhost``.
3547
3548 ``port`` specifies the port on the remote host to connect to.
3549 ``port`` is required.
3550
3551 ``localaddr`` specifies the local address to bind to. If not
3552 specified it defaults to ``0.0.0.0``.
3553
3554 ``localport`` specifies the local port to bind to. If not specified
3555 any available local port will be used.
3556
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00003557 ``ipv4=on|off`` and ``ipv6=on|off`` specify that either IPv4 or IPv6 must be used.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003558 If neither is specified the device may use either protocol.
3559
3560``-chardev msmouse,id=id``
3561 Forward QEMU's emulated msmouse events to the guest. ``msmouse``
3562 does not take any options.
3563
3564``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]``
3565 Connect to a QEMU text console. ``vc`` may optionally be given a
3566 specific size.
3567
3568 ``width`` and ``height`` specify the width and height respectively
3569 of the console, in pixels.
3570
3571 ``cols`` and ``rows`` specify that the console be sized to fit a
3572 text console with the given dimensions.
3573
3574``-chardev ringbuf,id=id[,size=size]``
3575 Create a ring buffer with fixed size ``size``. size must be a power
3576 of two and defaults to ``64K``.
3577
3578``-chardev file,id=id,path=path``
3579 Log all traffic received from the guest to a file.
3580
3581 ``path`` specifies the path of the file to be opened. This file will
3582 be created if it does not already exist, and overwritten if it does.
3583 ``path`` is required.
3584
3585``-chardev pipe,id=id,path=path``
3586 Create a two-way connection to the guest. The behaviour differs
3587 slightly between Windows hosts and other hosts:
3588
3589 On Windows, a single duplex pipe will be created at
3590 ``\\.pipe\path``.
3591
3592 On other hosts, 2 pipes will be created called ``path.in`` and
3593 ``path.out``. Data written to ``path.in`` will be received by the
3594 guest. Data written by the guest can be read from ``path.out``. QEMU
3595 will not create these fifos, and requires them to be present.
3596
3597 ``path`` forms part of the pipe path as described above. ``path`` is
3598 required.
3599
3600``-chardev console,id=id``
3601 Send traffic from the guest to QEMU's standard output. ``console``
3602 does not take any options.
3603
3604 ``console`` is only available on Windows hosts.
3605
3606``-chardev serial,id=id,path=path``
3607 Send traffic from the guest to a serial device on the host.
3608
3609 On Unix hosts serial will actually accept any tty device, not only
3610 serial lines.
3611
3612 ``path`` specifies the name of the serial device to open.
3613
3614``-chardev pty,id=id``
3615 Create a new pseudo-terminal on the host and connect to it. ``pty``
3616 does not take any options.
3617
3618 ``pty`` is not available on Windows hosts.
3619
3620``-chardev stdio,id=id[,signal=on|off]``
3621 Connect to standard input and standard output of the QEMU process.
3622
3623 ``signal`` controls if signals are enabled on the terminal, that
3624 includes exiting QEMU with the key sequence Control-c. This option
3625 is enabled by default, use ``signal=off`` to disable it.
3626
3627``-chardev braille,id=id``
3628 Connect to a local BrlAPI server. ``braille`` does not take any
3629 options.
3630
3631``-chardev tty,id=id,path=path``
3632 ``tty`` is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD
3633 and DragonFlyBSD hosts. It is an alias for ``serial``.
3634
3635 ``path`` specifies the path to the tty. ``path`` is required.
3636
Peter Maydell09ce5f22020-02-28 15:36:13 +00003637``-chardev parallel,id=id,path=path``
3638 \
3639``-chardev parport,id=id,path=path``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003640 ``parallel`` is only available on Linux, FreeBSD and DragonFlyBSD
3641 hosts.
3642
3643 Connect to a local parallel port.
3644
3645 ``path`` specifies the path to the parallel port device. ``path`` is
3646 required.
3647
3648``-chardev spicevmc,id=id,debug=debug,name=name``
3649 ``spicevmc`` is only available when spice support is built in.
3650
3651 ``debug`` debug level for spicevmc
3652
3653 ``name`` name of spice channel to connect to
3654
3655 Connect to a spice virtual machine channel, such as vdiport.
3656
3657``-chardev spiceport,id=id,debug=debug,name=name``
3658 ``spiceport`` is only available when spice support is built in.
3659
3660 ``debug`` debug level for spicevmc
3661
3662 ``name`` name of spice port to connect to
3663
3664 Connect to a spice port, allowing a Spice client to handle the
3665 traffic identified by a name (preferably a fqdn).
3666ERST
Matthew Booth7273a2d2009-10-30 13:41:12 +00003667
3668DEFHEADING()
3669
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003670#ifdef CONFIG_TPM
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02003671DEFHEADING(TPM device options:)
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003672
3673DEF("tpmdev", HAS_ARG, QEMU_OPTION_tpmdev, \
Stefan Berger92dcc232013-02-27 12:47:54 -05003674 "-tpmdev passthrough,id=id[,path=path][,cancel-path=path]\n"
3675 " use path to provide path to a character device; default is /dev/tpm0\n"
3676 " use cancel-path to provide path to TPM's cancel sysfs entry; if\n"
Amarnath Vallurif4ede812017-09-29 14:10:20 +03003677 " not provided it will be searched for in /sys/class/misc/tpm?/device\n"
3678 "-tpmdev emulator,id=id,chardev=dev\n"
3679 " configure the TPM device using chardev backend\n",
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003680 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003681SRST
3682The general form of a TPM device option is:
3683
3684``-tpmdev backend,id=id[,options]``
3685 The specific backend type will determine the applicable options. The
3686 ``-tpmdev`` option creates the TPM backend and requires a
3687 ``-device`` option that specifies the TPM frontend interface model.
3688
3689 Use ``-tpmdev help`` to print all available TPM backend types.
3690
3691The available backends are:
3692
3693``-tpmdev passthrough,id=id,path=path,cancel-path=cancel-path``
3694 (Linux-host only) Enable access to the host's TPM using the
3695 passthrough driver.
3696
3697 ``path`` specifies the path to the host's TPM device, i.e., on a
3698 Linux host this would be ``/dev/tpm0``. ``path`` is optional and by
3699 default ``/dev/tpm0`` is used.
3700
3701 ``cancel-path`` specifies the path to the host TPM device's sysfs
3702 entry allowing for cancellation of an ongoing TPM command.
3703 ``cancel-path`` is optional and by default QEMU will search for the
3704 sysfs entry to use.
3705
3706 Some notes about using the host's TPM with the passthrough driver:
3707
3708 The TPM device accessed by the passthrough driver must not be used
3709 by any other application on the host.
3710
3711 Since the host's firmware (BIOS/UEFI) has already initialized the
3712 TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize
3713 the TPM again and may therefore not show a TPM-specific menu that
3714 would otherwise allow the user to configure the TPM, e.g., allow the
3715 user to enable/disable or activate/deactivate the TPM. Further, if
3716 TPM ownership is released from within a VM then the host's TPM will
3717 get disabled and deactivated. To enable and activate the TPM again
3718 afterwards, the host has to be rebooted and the user is required to
3719 enter the firmware's menu to enable and activate the TPM. If the TPM
3720 is left disabled and/or deactivated most TPM commands will fail.
3721
3722 To create a passthrough TPM use the following two options:
3723
3724 ::
3725
3726 -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0
3727
3728 Note that the ``-tpmdev`` id is ``tpm0`` and is referenced by
3729 ``tpmdev=tpm0`` in the device option.
3730
3731``-tpmdev emulator,id=id,chardev=dev``
3732 (Linux-host only) Enable access to a TPM emulator using Unix domain
3733 socket based chardev backend.
3734
3735 ``chardev`` specifies the unique ID of a character device backend
3736 that provides connection to the software TPM server.
3737
3738 To create a TPM emulator backend device with chardev socket backend:
3739
3740 ::
3741
3742 -chardev socket,id=chrtpm,path=/tmp/swtpm-sock -tpmdev emulator,id=tpm0,chardev=chrtpm -device tpm-tis,tpmdev=tpm0
3743ERST
Stefan Bergerd1a0cf72013-02-27 12:47:49 -05003744
3745DEFHEADING()
3746
3747#endif
3748
Alex Bennée1235cf72022-07-25 15:05:20 +01003749DEFHEADING(Boot Image or Kernel specific:)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003750SRST
Alex Bennée1235cf72022-07-25 15:05:20 +01003751There are broadly 4 ways you can boot a system with QEMU.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003752
Alex Bennée1235cf72022-07-25 15:05:20 +01003753 - specify a firmware and let it control finding a kernel
3754 - specify a firmware and pass a hint to the kernel to boot
3755 - direct kernel image boot
3756 - manually load files into the guest's address space
3757
3758The third method is useful for quickly testing kernels but as there is
3759no firmware to pass configuration information to the kernel the
3760hardware must either be probeable, the kernel built for the exact
3761configuration or passed some configuration data (e.g. a DTB blob)
3762which tells the kernel what drivers it needs. This exact details are
3763often hardware specific.
3764
3765The final method is the most generic way of loading images into the
3766guest address space and used mostly for ``bare metal`` type
3767development where the reset vectors of the processor are taken into
3768account.
3769
3770ERST
3771
3772SRST
3773
3774For x86 machines and some other architectures ``-bios`` will generally
3775do the right thing with whatever it is given. For other machines the
3776more strict ``-pflash`` option needs an image that is sized for the
3777flash device for the given machine type.
3778
3779Please see the :ref:`system-targets-ref` section of the manual for
3780more detailed documentation.
3781
3782ERST
3783
3784DEF("bios", HAS_ARG, QEMU_OPTION_bios, \
3785 "-bios file set the filename for the BIOS\n", QEMU_ARCH_ALL)
3786SRST
3787``-bios file``
3788 Set the filename for the BIOS.
3789ERST
3790
3791DEF("pflash", HAS_ARG, QEMU_OPTION_pflash,
3792 "-pflash file use 'file' as a parallel flash image\n", QEMU_ARCH_ALL)
3793SRST
3794``-pflash file``
3795 Use file as a parallel flash image.
3796ERST
3797
3798SRST
3799
3800The kernel options were designed to work with Linux kernels although
3801other things (like hypervisors) can be packaged up as a kernel
3802executable image. The exact format of a executable image is usually
3803architecture specific.
3804
3805The way in which the kernel is started (what address it is loaded at,
3806what if any information is passed to it via CPU registers, the state
3807of the hardware when it is started, and so on) is also architecture
3808specific. Typically it follows the specification laid down by the
3809Linux kernel for how kernels for that architecture must be started.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003810
3811ERST
blueswir15824d652009-03-28 06:44:27 +00003812
3813DEF("kernel", HAS_ARG, QEMU_OPTION_kernel, \
Blue Swirlad960902010-03-29 19:23:52 +00003814 "-kernel bzImage use 'bzImage' as kernel image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003815SRST
3816``-kernel bzImage``
3817 Use bzImage as kernel image. The kernel can be either a Linux kernel
3818 or in multiboot format.
3819ERST
blueswir15824d652009-03-28 06:44:27 +00003820
3821DEF("append", HAS_ARG, QEMU_OPTION_append, \
Blue Swirlad960902010-03-29 19:23:52 +00003822 "-append cmdline use 'cmdline' as kernel command line\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003823SRST
3824``-append cmdline``
3825 Use cmdline as kernel command line
3826ERST
blueswir15824d652009-03-28 06:44:27 +00003827
3828DEF("initrd", HAS_ARG, QEMU_OPTION_initrd, \
Blue Swirlad960902010-03-29 19:23:52 +00003829 "-initrd file use 'file' as initial ram disk\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003830SRST
3831``-initrd file``
3832 Use file as initial ram disk.
3833
3834``-initrd "file1 arg=foo,file2"``
3835 This syntax is only available with multiboot.
3836
3837 Use file1 and file2 as modules and pass arg=foo as parameter to the
3838 first module.
3839ERST
blueswir15824d652009-03-28 06:44:27 +00003840
Grant Likely412beee2012-03-02 11:56:38 +00003841DEF("dtb", HAS_ARG, QEMU_OPTION_dtb, \
Peter A. G. Crosthwaite379b5c72012-03-04 21:03:54 +10003842 "-dtb file use 'file' as device tree image\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003843SRST
3844``-dtb file``
3845 Use file as a device tree binary (dtb) image and pass it to the
3846 kernel on boot.
3847ERST
Grant Likely412beee2012-03-02 11:56:38 +00003848
Alex Bennée1235cf72022-07-25 15:05:20 +01003849SRST
3850
3851Finally you can also manually load images directly into the address
3852space of the guest. This is most useful for developers who already
3853know the layout of their guest and take care to ensure something sane
3854will happen when the reset vector executes.
3855
3856The generic loader can be invoked by using the loader device:
3857
3858``-device loader,addr=<addr>,data=<data>,data-len=<data-len>[,data-be=<data-be>][,cpu-num=<cpu-num>]``
3859
3860there is also the guest loader which operates in a similar way but
3861tweaks the DTB so a hypervisor loaded via ``-kernel`` can find where
3862the guest image is:
3863
3864``-device guest-loader,addr=<addr>[,kernel=<path>,[bootargs=<arguments>]][,initrd=<path>]``
3865
3866ERST
3867
blueswir15824d652009-03-28 06:44:27 +00003868DEFHEADING()
3869
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02003870DEFHEADING(Debug/Expert options:)
blueswir15824d652009-03-28 06:44:27 +00003871
Markus Armbruster6dd75472021-03-18 16:55:10 +01003872DEF("compat", HAS_ARG, QEMU_OPTION_compat,
Markus Armbrusterdbb675c2021-03-18 16:55:19 +01003873 "-compat [deprecated-input=accept|reject|crash][,deprecated-output=accept|hide]\n"
Markus Armbruster57df0df2021-10-28 12:25:20 +02003874 " Policy for handling deprecated management interfaces\n"
3875 "-compat [unstable-input=accept|reject|crash][,unstable-output=accept|hide]\n"
3876 " Policy for handling unstable management interfaces\n",
Markus Armbruster6dd75472021-03-18 16:55:10 +01003877 QEMU_ARCH_ALL)
3878SRST
3879``-compat [deprecated-input=@var{input-policy}][,deprecated-output=@var{output-policy}]``
3880 Set policy for handling deprecated management interfaces (experimental):
3881
3882 ``deprecated-input=accept`` (default)
3883 Accept deprecated commands and arguments
3884 ``deprecated-input=reject``
3885 Reject deprecated commands and arguments
Markus Armbrusterdbb675c2021-03-18 16:55:19 +01003886 ``deprecated-input=crash``
3887 Crash on deprecated commands and arguments
Markus Armbruster6dd75472021-03-18 16:55:10 +01003888 ``deprecated-output=accept`` (default)
3889 Emit deprecated command results and events
3890 ``deprecated-output=hide``
3891 Suppress deprecated command results and events
3892
3893 Limitation: covers only syntactic aspects of QMP.
Markus Armbruster57df0df2021-10-28 12:25:20 +02003894
3895``-compat [unstable-input=@var{input-policy}][,unstable-output=@var{output-policy}]``
3896 Set policy for handling unstable management interfaces (experimental):
3897
3898 ``unstable-input=accept`` (default)
3899 Accept unstable commands and arguments
3900 ``unstable-input=reject``
3901 Reject unstable commands and arguments
3902 ``unstable-input=crash``
3903 Crash on unstable commands and arguments
3904 ``unstable-output=accept`` (default)
3905 Emit unstable command results and events
3906 ``unstable-output=hide``
3907 Suppress unstable command results and events
3908
3909 Limitation: covers only syntactic aspects of QMP.
Markus Armbruster6dd75472021-03-18 16:55:10 +01003910ERST
3911
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04003912DEF("fw_cfg", HAS_ARG, QEMU_OPTION_fwcfg,
3913 "-fw_cfg [name=]<name>,file=<file>\n"
Markus Armbruster63d31452016-04-18 18:29:50 +02003914 " add named fw_cfg entry with contents from file\n"
Gabriel L. Somlo6407d762015-09-29 12:29:01 -04003915 "-fw_cfg [name=]<name>,string=<str>\n"
Markus Armbruster63d31452016-04-18 18:29:50 +02003916 " add named fw_cfg entry with contents from string\n",
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04003917 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003918SRST
3919``-fw_cfg [name=]name,file=file``
3920 Add named fw\_cfg entry with contents from file file.
3921
3922``-fw_cfg [name=]name,string=str``
3923 Add named fw\_cfg entry with contents from string str.
3924
3925 The terminating NUL character of the contents of str will not be
3926 included as part of the fw\_cfg item data. To insert contents with
3927 embedded NUL characters, you have to use the file parameter.
3928
3929 The fw\_cfg entries are passed by QEMU through to the guest.
3930
3931 Example:
3932
3933 ::
3934
3935 -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin
3936
3937 creates an fw\_cfg entry named opt/com.mycompany/blob with contents
3938 from ./my\_blob.bin.
3939ERST
Gabriel L. Somlo81b2b812015-04-29 11:21:53 -04003940
blueswir15824d652009-03-28 06:44:27 +00003941DEF("serial", HAS_ARG, QEMU_OPTION_serial, \
Blue Swirlad960902010-03-29 19:23:52 +00003942 "-serial dev redirect the serial port to char device 'dev'\n",
3943 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00003944SRST
3945``-serial dev``
3946 Redirect the virtual serial port to host character device dev. The
3947 default device is ``vc`` in graphical mode and ``stdio`` in non
3948 graphical mode.
3949
3950 This option can be used several times to simulate up to 4 serial
3951 ports.
3952
3953 Use ``-serial none`` to disable all serial ports.
3954
3955 Available character devices are:
3956
3957 ``vc[:WxH]``
3958 Virtual console. Optionally, a width and height can be given in
3959 pixel with
3960
3961 ::
3962
3963 vc:800x600
3964
3965 It is also possible to specify width or height in characters:
3966
3967 ::
3968
3969 vc:80Cx24C
3970
3971 ``pty``
3972 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
3973
3974 ``none``
3975 No device is allocated.
3976
3977 ``null``
3978 void device
3979
3980 ``chardev:id``
3981 Use a named character device defined with the ``-chardev``
3982 option.
3983
3984 ``/dev/XXX``
3985 [Linux only] Use host tty, e.g. ``/dev/ttyS0``. The host serial
3986 port parameters are set according to the emulated ones.
3987
3988 ``/dev/parportN``
3989 [Linux only, parallel port only] Use host parallel port N.
3990 Currently SPP and EPP parallel port features can be used.
3991
3992 ``file:filename``
3993 Write output to filename. No character can be read.
3994
3995 ``stdio``
3996 [Unix only] standard input/output
3997
3998 ``pipe:filename``
3999 name pipe filename
4000
4001 ``COMn``
4002 [Windows only] Use host serial port n
4003
4004 ``udp:[remote_host]:remote_port[@[src_ip]:src_port]``
4005 This implements UDP Net Console. When remote\_host or src\_ip
4006 are not specified they default to ``0.0.0.0``. When not using a
4007 specified src\_port a random port is automatically chosen.
4008
4009 If you just want a simple readonly console you can use
4010 ``netcat`` or ``nc``, by starting QEMU with:
4011 ``-serial udp::4555`` and nc as: ``nc -u -l -p 4555``. Any time
4012 QEMU writes something to that port it will appear in the
4013 netconsole session.
4014
4015 If you plan to send characters back via netconsole or you want
4016 to stop and start QEMU a lot of times, you should have QEMU use
4017 the same source port each time by using something like ``-serial
4018 udp::4555@:4556`` to QEMU. Another approach is to use a patched
4019 version of netcat which can listen to a TCP port and send and
4020 receive characters via udp. If you have a patched version of
4021 netcat which activates telnet remote echo and single char
4022 transfer, then you can use the following options to set up a
4023 netcat redirector to allow telnet on port 5555 to access the
4024 QEMU port.
4025
4026 ``QEMU Options:``
4027 -serial udp::4555@:4556
4028
4029 ``netcat options:``
4030 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
4031
4032 ``telnet options:``
4033 localhost 5555
4034
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004035 ``tcp:[host]:port[,server=on|off][,wait=on|off][,nodelay=on|off][,reconnect=seconds]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004036 The TCP Net Console has two modes of operation. It can send the
4037 serial I/O to a location or wait for a connection from a
4038 location. By default the TCP Net Console is sent to host at the
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004039 port. If you use the ``server=on`` option QEMU will wait for a client
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004040 socket application to connect to the port before continuing,
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004041 unless the ``wait=on|off`` option was specified. The ``nodelay=on|off``
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004042 option disables the Nagle buffering algorithm. The ``reconnect=on``
4043 option only applies if ``server=no`` is set, if the connection goes
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004044 down it will attempt to reconnect at the given interval. If host
4045 is omitted, 0.0.0.0 is assumed. Only one TCP connection at a
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004046 time is accepted. You can use ``telnet=on`` to connect to the
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004047 corresponding character device.
4048
4049 ``Example to send tcp console to 192.168.0.2 port 4444``
4050 -serial tcp:192.168.0.2:4444
4051
4052 ``Example to listen and wait on port 4444 for connection``
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004053 -serial tcp::4444,server=on
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004054
4055 ``Example to not wait and listen on ip 192.168.0.100 port 4444``
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004056 -serial tcp:192.168.0.100:4444,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004057
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004058 ``telnet:host:port[,server=on|off][,wait=on|off][,nodelay=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004059 The telnet protocol is used instead of raw tcp sockets. The
4060 options work the same as if you had specified ``-serial tcp``.
4061 The difference is that the port acts like a telnet server or
4062 client using telnet option negotiation. This will also allow you
4063 to send the MAGIC\_SYSRQ sequence if you use a telnet that
4064 supports sending the break sequence. Typically in unix telnet
4065 you do it with Control-] and then type "send break" followed by
4066 pressing the enter key.
4067
Paolo Bonzinia9b13152021-02-25 11:47:52 +01004068 ``websocket:host:port,server=on[,wait=on|off][,nodelay=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004069 The WebSocket protocol is used instead of raw tcp socket. The
4070 port acts as a WebSocket server. Client mode is not supported.
4071
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004072 ``unix:path[,server=on|off][,wait=on|off][,reconnect=seconds]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004073 A unix domain socket is used instead of a tcp socket. The option
4074 works the same as if you had specified ``-serial tcp`` except
4075 the unix domain socket path is used for connections.
4076
4077 ``mon:dev_string``
4078 This is a special option to allow the monitor to be multiplexed
4079 onto another serial port. The monitor is accessed with key
4080 sequence of Control-a and then pressing c. dev\_string should be
4081 any one of the serial devices specified above. An example to
4082 multiplex the monitor onto a telnet server listening on port
4083 4444 would be:
4084
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00004085 ``-serial mon:telnet::4444,server=on,wait=off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004086
4087 When the monitor is multiplexed to stdio in this way, Ctrl+C
4088 will not terminate QEMU any more but will be passed to the guest
4089 instead.
4090
4091 ``braille``
4092 Braille device. This will use BrlAPI to display the braille
4093 output on a real or fake device.
4094
4095 ``msmouse``
4096 Three button serial mouse. Configure the guest to use Microsoft
4097 protocol.
4098ERST
blueswir15824d652009-03-28 06:44:27 +00004099
4100DEF("parallel", HAS_ARG, QEMU_OPTION_parallel, \
Blue Swirlad960902010-03-29 19:23:52 +00004101 "-parallel dev redirect the parallel port to char device 'dev'\n",
4102 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004103SRST
4104``-parallel dev``
4105 Redirect the virtual parallel port to host device dev (same devices
4106 as the serial port). On Linux hosts, ``/dev/parportN`` can be used
4107 to use hardware devices connected on the corresponding host parallel
4108 port.
4109
4110 This option can be used several times to simulate up to 3 parallel
4111 ports.
4112
4113 Use ``-parallel none`` to disable all parallel ports.
4114ERST
blueswir15824d652009-03-28 06:44:27 +00004115
4116DEF("monitor", HAS_ARG, QEMU_OPTION_monitor, \
Blue Swirlad960902010-03-29 19:23:52 +00004117 "-monitor dev redirect the monitor to char device 'dev'\n",
4118 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004119SRST
4120``-monitor dev``
4121 Redirect the monitor to host device dev (same devices as the serial
4122 port). The default device is ``vc`` in graphical mode and ``stdio``
4123 in non graphical mode. Use ``-monitor none`` to disable the default
4124 monitor.
4125ERST
Gerd Hoffmann6ca55822009-12-08 13:11:52 +01004126DEF("qmp", HAS_ARG, QEMU_OPTION_qmp, \
Blue Swirlad960902010-03-29 19:23:52 +00004127 "-qmp dev like -monitor but opens in 'control' mode\n",
4128 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004129SRST
4130``-qmp dev``
4131 Like -monitor but opens in 'control' mode.
4132ERST
Max Reitz4821cd42014-11-17 13:31:04 +01004133DEF("qmp-pretty", HAS_ARG, QEMU_OPTION_qmp_pretty, \
4134 "-qmp-pretty dev like -qmp but uses pretty JSON formatting\n",
4135 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004136SRST
4137``-qmp-pretty dev``
4138 Like -qmp but uses pretty JSON formatting.
4139ERST
blueswir15824d652009-03-28 06:44:27 +00004140
Gerd Hoffmann22a0e042009-12-08 13:11:51 +01004141DEF("mon", HAS_ARG, QEMU_OPTION_mon, \
Vicente Jimenez Aguilaref670722017-11-14 09:11:27 +01004142 "-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004143SRST
4144``-mon [chardev=]name[,mode=readline|control][,pretty[=on|off]]``
Ali Shirvani16b3f3b2021-05-19 11:41:45 +04304145 Setup monitor on chardev name. ``mode=control`` configures
4146 a QMP monitor (a JSON RPC-style protocol) and it is not the
4147 same as HMP, the human monitor that has a "(qemu)" prompt.
4148 ``pretty`` is only valid when ``mode=control``,
4149 turning on JSON pretty printing to ease
Daniel P. Berrangé283d8452021-02-19 17:56:13 +00004150 human reading and debugging.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004151ERST
Gerd Hoffmann22a0e042009-12-08 13:11:51 +01004152
H. Peter Anvinc9f398e2009-12-29 13:51:36 -08004153DEF("debugcon", HAS_ARG, QEMU_OPTION_debugcon, \
Blue Swirlad960902010-03-29 19:23:52 +00004154 "-debugcon dev redirect the debug console to char device 'dev'\n",
4155 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004156SRST
4157``-debugcon dev``
4158 Redirect the debug console to host device dev (same devices as the
4159 serial port). The debug console is an I/O port which is typically
4160 port 0xe9; writing to that I/O port sends output to this device. The
4161 default device is ``vc`` in graphical mode and ``stdio`` in non
4162 graphical mode.
4163ERST
H. Peter Anvinc9f398e2009-12-29 13:51:36 -08004164
blueswir15824d652009-03-28 06:44:27 +00004165DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
Blue Swirlad960902010-03-29 19:23:52 +00004166 "-pidfile file write PID to 'file'\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004167SRST
4168``-pidfile file``
4169 Store the QEMU process PID in file. It is useful if you launch QEMU
4170 from a script.
4171ERST
blueswir15824d652009-03-28 06:44:27 +00004172
aurel321b530a62009-04-05 20:08:59 +00004173DEF("singlestep", 0, QEMU_OPTION_singlestep, \
Blue Swirlad960902010-03-29 19:23:52 +00004174 "-singlestep always run in singlestep mode\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004175SRST
4176``-singlestep``
4177 Run the emulation in single step mode.
4178ERST
aurel321b530a62009-04-05 20:08:59 +00004179
Igor Mammedov047f7032018-05-11 19:24:43 +02004180DEF("preconfig", 0, QEMU_OPTION_preconfig, \
Markus Armbruster361ac942018-07-05 11:14:02 +02004181 "--preconfig pause QEMU before machine is initialized (experimental)\n",
Igor Mammedov047f7032018-05-11 19:24:43 +02004182 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004183SRST
4184``--preconfig``
4185 Pause QEMU for interactive configuration before the machine is
4186 created, which allows querying and configuring properties that will
4187 affect machine initialization. Use QMP command 'x-exit-preconfig' to
4188 exit the preconfig state and move to the next state (i.e. run guest
4189 if -S isn't used or pause the second time if -S is used). This
4190 option is experimental.
4191ERST
Igor Mammedov047f7032018-05-11 19:24:43 +02004192
blueswir15824d652009-03-28 06:44:27 +00004193DEF("S", 0, QEMU_OPTION_S, \
Blue Swirlad960902010-03-29 19:23:52 +00004194 "-S freeze CPU at startup (use 'c' to start execution)\n",
4195 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004196SRST
4197``-S``
4198 Do not start CPU at startup (you must type 'c' in the monitor).
4199ERST
blueswir15824d652009-03-28 06:44:27 +00004200
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03004201DEF("overcommit", HAS_ARG, QEMU_OPTION_overcommit,
BALATON Zoltandfaa7d52018-07-16 21:12:08 +02004202 "-overcommit [mem-lock=on|off][cpu-pm=on|off]\n"
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03004203 " run qemu with overcommit hints\n"
4204 " mem-lock=on|off controls memory lock support (default: off)\n"
4205 " cpu-pm=on|off controls cpu power management (default: off)\n",
4206 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004207SRST
4208``-overcommit mem-lock=on|off``
Peter Maydell09ce5f22020-02-28 15:36:13 +00004209 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004210``-overcommit cpu-pm=on|off``
4211 Run qemu with hints about host resource overcommit. The default is
4212 to assume that host overcommits all resources.
4213
4214 Locking qemu and guest memory can be enabled via ``mem-lock=on``
4215 (disabled by default). This works when host memory is not
Thomas Huthc8c9dc42020-12-10 16:58:07 +01004216 overcommitted and reduces the worst-case latency for guest.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004217
4218 Guest ability to manage power state of host cpus (increasing latency
4219 for other processes on the same host cpu, but decreasing latency for
4220 guest) can be enabled via ``cpu-pm=on`` (disabled by default). This
4221 works best when host CPU is not overcommitted. When used, host
4222 estimates of CPU cycle and power utilization will be incorrect, not
4223 taking into account guest idle time.
4224ERST
Michael S. Tsirkin6f131f12018-06-22 22:22:05 +03004225
aliguori59030a82009-04-05 18:43:41 +00004226DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
Peter Maydelle5910d42020-04-03 10:40:14 +01004227 "-gdb dev accept gdb connection on 'dev'. (QEMU defaults to starting\n"
4228 " the guest without waiting for gdb to connect; use -S too\n"
4229 " if you want it to not start execution.)\n",
4230 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004231SRST
4232``-gdb dev``
Thomas Huth923e9312020-11-16 15:47:36 +01004233 Accept a gdb connection on device dev (see the :ref:`GDB usage` chapter
4234 in the System Emulation Users Guide). Note that this option does not pause QEMU
Peter Maydelle5910d42020-04-03 10:40:14 +01004235 execution -- if you want QEMU to not start the guest until you
4236 connect with gdb and issue a ``continue`` command, you will need to
4237 also pass the ``-S`` option to QEMU.
4238
4239 The most usual configuration is to listen on a local TCP socket::
4240
4241 -gdb tcp::3117
4242
4243 but you can specify other backends; UDP, pseudo TTY, or even stdio
4244 are all reasonable use cases. For example, a stdio connection
4245 allows you to start QEMU from within gdb and establish the
4246 connection via a pipe:
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004247
Peter Maydell09ce5f22020-02-28 15:36:13 +00004248 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004249
4250 (gdb) target remote | exec |qemu_system| -gdb stdio ...
4251ERST
blueswir15824d652009-03-28 06:44:27 +00004252
aliguori59030a82009-04-05 18:43:41 +00004253DEF("s", 0, QEMU_OPTION_s, \
Blue Swirlad960902010-03-29 19:23:52 +00004254 "-s shorthand for -gdb tcp::" DEFAULT_GDBSTUB_PORT "\n",
4255 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004256SRST
4257``-s``
4258 Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234
Thomas Huth923e9312020-11-16 15:47:36 +01004259 (see the :ref:`GDB usage` chapter in the System Emulation Users Guide).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004260ERST
blueswir15824d652009-03-28 06:44:27 +00004261
4262DEF("d", HAS_ARG, QEMU_OPTION_d, \
Peter Maydell989b6972013-02-26 17:52:40 +00004263 "-d item1,... enable logging of specified items (use '-d help' for a list of log items)\n",
Blue Swirlad960902010-03-29 19:23:52 +00004264 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004265SRST
4266``-d item1[,...]``
4267 Enable logging of specified items. Use '-d help' for a list of log
4268 items.
4269ERST
blueswir15824d652009-03-28 06:44:27 +00004270
Matthew Fernandezc235d732011-06-07 16:32:40 +00004271DEF("D", HAS_ARG, QEMU_OPTION_D, \
Peter Maydell989b6972013-02-26 17:52:40 +00004272 "-D logfile output log to logfile (default stderr)\n",
Matthew Fernandezc235d732011-06-07 16:32:40 +00004273 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004274SRST
4275``-D logfile``
4276 Output log in logfile instead of to stderr
4277ERST
Matthew Fernandezc235d732011-06-07 16:32:40 +00004278
Alex Bennée35145522016-03-15 14:30:20 +00004279DEF("dfilter", HAS_ARG, QEMU_OPTION_DFILTER, \
4280 "-dfilter range,.. filter debug output to range of addresses (useful for -d cpu,exec,etc..)\n",
4281 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004282SRST
4283``-dfilter range1[,...]``
4284 Filter debug output to that relevant to a range of target addresses.
4285 The filter spec can be either start+size, start-size or start..end
4286 where start end and size are the addresses and sizes required. For
4287 example:
4288
4289 ::
4290
4291 -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000
4292
4293 Will dump output for any code in the 0x1000 sized block starting at
4294 0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and
4295 another 0x1000 sized block starting at 0xffffffc00005f000.
4296ERST
Alex Bennée35145522016-03-15 14:30:20 +00004297
Richard Henderson9c09a252019-03-14 13:06:29 -07004298DEF("seed", HAS_ARG, QEMU_OPTION_seed, \
4299 "-seed number seed the pseudo-random number generator\n",
4300 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004301SRST
4302``-seed number``
4303 Force the guest to use a deterministic pseudo-random number
4304 generator, seeded with number. This does not affect crypto routines
4305 within the host.
4306ERST
Richard Henderson9c09a252019-03-14 13:06:29 -07004307
blueswir15824d652009-03-28 06:44:27 +00004308DEF("L", HAS_ARG, QEMU_OPTION_L, \
Blue Swirlad960902010-03-29 19:23:52 +00004309 "-L path set the directory for the BIOS, VGA BIOS and keymaps\n",
4310 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004311SRST
4312``-L path``
4313 Set the directory for the BIOS, VGA BIOS and keymaps.
4314
4315 To list all the data directories, use ``-L help``.
4316ERST
blueswir15824d652009-03-28 06:44:27 +00004317
blueswir15824d652009-03-28 06:44:27 +00004318DEF("enable-kvm", 0, QEMU_OPTION_enable_kvm, \
Thomas Huth21abf012022-04-27 15:49:06 +02004319 "-enable-kvm enable KVM full virtualization support\n",
4320 QEMU_ARCH_ARM | QEMU_ARCH_I386 | QEMU_ARCH_MIPS | QEMU_ARCH_PPC |
4321 QEMU_ARCH_RISCV | QEMU_ARCH_S390X)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004322SRST
4323``-enable-kvm``
4324 Enable KVM full virtualization support. This option is only
4325 available if KVM support is enabled when compiling.
4326ERST
blueswir15824d652009-03-28 06:44:27 +00004327
aliguorie37630c2009-04-22 15:19:10 +00004328DEF("xen-domid", HAS_ARG, QEMU_OPTION_xen_domid,
Thomas Hutheeb36472022-04-27 15:31:56 +02004329 "-xen-domid id specify xen guest domain id\n",
4330 QEMU_ARCH_ARM | QEMU_ARCH_I386)
aliguorie37630c2009-04-22 15:19:10 +00004331DEF("xen-attach", 0, QEMU_OPTION_xen_attach,
4332 "-xen-attach attach to existing xen domain\n"
Anthony PERARD1077bca2018-09-14 12:18:30 +01004333 " libxl will use this when starting QEMU\n",
Thomas Hutheeb36472022-04-27 15:31:56 +02004334 QEMU_ARCH_ARM | QEMU_ARCH_I386)
Paul Durrant1c599472017-03-22 09:39:15 +00004335DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,
4336 "-xen-domid-restrict restrict set of available xen operations\n"
4337 " to specified domain id. (Does not affect\n"
4338 " xenpv machine type).\n",
Thomas Hutheeb36472022-04-27 15:31:56 +02004339 QEMU_ARCH_ARM | QEMU_ARCH_I386)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004340SRST
4341``-xen-domid id``
4342 Specify xen guest domain id (XEN only).
4343
4344``-xen-attach``
4345 Attach to existing xen domain. libxl will use this when starting
4346 QEMU (XEN only). Restrict set of available xen operations to
4347 specified domain id (XEN only).
4348ERST
aliguorie37630c2009-04-22 15:19:10 +00004349
blueswir15824d652009-03-28 06:44:27 +00004350DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \
Blue Swirlad960902010-03-29 19:23:52 +00004351 "-no-reboot exit instead of rebooting\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004352SRST
4353``-no-reboot``
4354 Exit instead of rebooting.
4355ERST
blueswir15824d652009-03-28 06:44:27 +00004356
4357DEF("no-shutdown", 0, QEMU_OPTION_no_shutdown, \
Blue Swirlad960902010-03-29 19:23:52 +00004358 "-no-shutdown stop before shutdown\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004359SRST
4360``-no-shutdown``
4361 Don't exit QEMU on guest shutdown, but instead only stop the
4362 emulation. This allows for instance switching to monitor to commit
4363 changes to the disk image.
4364ERST
blueswir15824d652009-03-28 06:44:27 +00004365
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004366DEF("action", HAS_ARG, QEMU_OPTION_action,
Paolo Bonzinic27025e2021-01-20 14:30:27 +01004367 "-action reboot=reset|shutdown\n"
4368 " action when guest reboots [default=reset]\n"
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004369 "-action shutdown=poweroff|pause\n"
4370 " action when guest shuts down [default=poweroff]\n"
Ilya Leoshkevich0882caf2022-07-26 00:37:45 +02004371 "-action panic=pause|shutdown|exit-failure|none\n"
Paolo Bonzinic27025e2021-01-20 14:30:27 +01004372 " action when guest panics [default=shutdown]\n"
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004373 "-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n"
4374 " action when watchdog fires [default=reset]\n",
4375 QEMU_ARCH_ALL)
4376SRST
4377``-action event=action``
4378 The action parameter serves to modify QEMU's default behavior when
4379 certain guest events occur. It provides a generic method for specifying the
4380 same behaviors that are modified by the ``-no-reboot`` and ``-no-shutdown``
4381 parameters.
4382
4383 Examples:
4384
Alejandro Jimenezc753e8e2020-12-11 17:31:52 -05004385 ``-action panic=none``
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004386 ``-action reboot=shutdown,shutdown=pause``
Paolo Bonzini5433af72022-09-10 13:44:47 +02004387 ``-device i6300esb -action watchdog=pause``
Alejandro Jimenez2a5ad602020-12-11 11:52:41 -05004388
4389ERST
4390
blueswir15824d652009-03-28 06:44:27 +00004391DEF("loadvm", HAS_ARG, QEMU_OPTION_loadvm, \
4392 "-loadvm [tag|id]\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004393 " start right away with a saved state (loadvm in monitor)\n",
4394 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004395SRST
4396``-loadvm file``
4397 Start right away with a saved state (``loadvm`` in monitor)
4398ERST
blueswir15824d652009-03-28 06:44:27 +00004399
4400#ifndef _WIN32
4401DEF("daemonize", 0, QEMU_OPTION_daemonize, \
Blue Swirlad960902010-03-29 19:23:52 +00004402 "-daemonize daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00004403#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004404SRST
4405``-daemonize``
4406 Daemonize the QEMU process after initialization. QEMU will not
4407 detach from standard IO until it is ready to receive connections on
4408 any of its devices. This option is a useful way for external
4409 programs to launch QEMU without having to cope with initialization
4410 race conditions.
4411ERST
blueswir15824d652009-03-28 06:44:27 +00004412
4413DEF("option-rom", HAS_ARG, QEMU_OPTION_option_rom, \
Blue Swirlad960902010-03-29 19:23:52 +00004414 "-option-rom rom load a file, rom, into the option ROM space\n",
4415 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004416SRST
4417``-option-rom file``
4418 Load the contents of file as an option ROM. This option is useful to
4419 load things like EtherBoot.
4420ERST
blueswir15824d652009-03-28 06:44:27 +00004421
Jan Kiszka1ed2fc12009-09-15 13:36:04 +02004422DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
Artem Pisarenko238d1242018-10-18 13:12:52 +06004423 "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004424 " set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
4425 QEMU_ARCH_ALL)
Jan Kiszka1ed2fc12009-09-15 13:36:04 +02004426
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004427SRST
4428``-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]``
4429 Specify ``base`` as ``utc`` or ``localtime`` to let the RTC start at
4430 the current UTC or local time, respectively. ``localtime`` is
4431 required for correct date in MS-DOS or Windows. To start at a
4432 specific point in time, provide datetime in the format
4433 ``2006-06-17T16:01:21`` or ``2006-06-17``. The default base is UTC.
4434
4435 By default the RTC is driven by the host system time. This allows
4436 using of the RTC as accurate reference clock inside the guest,
4437 specifically if the host time is smoothly following an accurate
4438 external reference clock, e.g. via NTP. If you want to isolate the
4439 guest time from the host, you can set ``clock`` to ``rt`` instead,
4440 which provides a host monotonic clock if host support it. To even
4441 prevent the RTC from progressing during suspension, you can set
4442 ``clock`` to ``vm`` (virtual clock). '\ ``clock=vm``\ ' is
4443 recommended especially in icount mode in order to preserve
4444 determinism; however, note that in icount mode the speed of the
4445 virtual clock is variable and can in general differ from the host
4446 clock.
4447
4448 Enable ``driftfix`` (i386 targets only) if you experience time drift
4449 problems, specifically with Windows' ACPI HAL. This option will try
4450 to figure out how many timer interrupts were not processed by the
4451 Windows guest and will re-inject them.
4452ERST
blueswir15824d652009-03-28 06:44:27 +00004453
4454DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
Peter Maydellfa647902020-11-21 21:35:06 +00004455 "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=<filename>[,rrsnapshot=<snapshot>]]\n" \
aliguoribc14ca22009-04-05 18:43:37 +00004456 " enable virtual instruction counter with 2^N clock ticks per\n" \
Victor CLEMENTf1f4b572015-05-29 17:14:05 +02004457 " instruction, enable aligning the host and virtual clocks\n" \
Peter Maydellfa647902020-11-21 21:35:06 +00004458 " or disable real time cpu sleeping, and optionally enable\n" \
4459 " record-and-replay mode\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004460SRST
Peter Maydellfa647902020-11-21 21:35:06 +00004461``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004462 Enable virtual instruction counter. The virtual cpu will execute one
4463 instruction every 2^N ns of virtual time. If ``auto`` is specified
4464 then the virtual cpu speed will be automatically adjusted to keep
4465 virtual time within a few seconds of real time.
4466
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004467 Note that while this option can give deterministic behavior, it does
4468 not provide cycle accurate emulation. Modern CPUs contain
4469 superscalar out of order cores with complex cache hierarchies. The
4470 number of instructions executed often has little or no correlation
4471 with actual performance.
4472
Peter Maydellfa647902020-11-21 21:35:06 +00004473 When the virtual cpu is sleeping, the virtual time will advance at
4474 default speed unless ``sleep=on`` is specified. With
4475 ``sleep=on``, the virtual time will jump to the next timer
4476 deadline instantly whenever the virtual cpu goes to sleep mode and
4477 will not advance if no timer is enabled. This behavior gives
4478 deterministic execution times from the guest point of view.
4479 The default if icount is enabled is ``sleep=off``.
4480 ``sleep=on`` cannot be used together with either ``shift=auto``
4481 or ``align=on``.
4482
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004483 ``align=on`` will activate the delay algorithm which will try to
4484 synchronise the host clock and the virtual clock. The goal is to
4485 have a guest running at the real frequency imposed by the shift
4486 option. Whenever the guest clock is behind the host clock and if
4487 ``align=on`` is specified then we print a message to the user to
4488 inform about the delay. Currently this option does not work when
4489 ``shift`` is ``auto``. Note: The sync algorithm will work for those
4490 shift values for which the guest clock runs ahead of the host clock.
4491 Typically this happens when the shift value is high (how high
Peter Maydellfa647902020-11-21 21:35:06 +00004492 depends on the host machine). The default if icount is enabled
4493 is ``align=off``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004494
Peter Maydellfa647902020-11-21 21:35:06 +00004495 When the ``rr`` option is specified deterministic record/replay is
4496 enabled. The ``rrfile=`` option must also be provided to
4497 specify the path to the replay log. In record mode data is written
4498 to this file, and in replay mode it is read back.
4499 If the ``rrsnapshot`` option is given then it specifies a VM snapshot
4500 name. In record mode, a new VM snapshot with the given name is created
4501 at the start of execution recording. In replay mode this option
4502 specifies the snapshot name used to load the initial VM state.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004503ERST
blueswir15824d652009-03-28 06:44:27 +00004504
Richard W.M. Jones9dd986c2009-04-25 13:56:19 +01004505DEF("watchdog-action", HAS_ARG, QEMU_OPTION_watchdog_action, \
Markus Armbruster7ad92702017-10-02 16:03:07 +02004506 "-watchdog-action reset|shutdown|poweroff|inject-nmi|pause|debug|none\n" \
Blue Swirlad960902010-03-29 19:23:52 +00004507 " action when watchdog fires [default=reset]\n",
4508 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004509SRST
4510``-watchdog-action action``
4511 The action controls what QEMU will do when the watchdog timer
4512 expires. The default is ``reset`` (forcefully reset the guest).
4513 Other possible actions are: ``shutdown`` (attempt to gracefully
4514 shutdown the guest), ``poweroff`` (forcefully poweroff the guest),
4515 ``inject-nmi`` (inject a NMI into the guest), ``pause`` (pause the
4516 guest), ``debug`` (print a debug message and continue), or ``none``
4517 (do nothing).
4518
4519 Note that the ``shutdown`` action requires that the guest responds
4520 to ACPI signals, which it may not be able to do in the sort of
4521 situations where the watchdog would have expired, and thus
4522 ``-watchdog-action shutdown`` is not recommended for production use.
4523
4524 Examples:
4525
Paolo Bonzini5433af72022-09-10 13:44:47 +02004526 ``-device i6300esb -watchdog-action pause``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004527
4528ERST
Richard W.M. Jones9dd986c2009-04-25 13:56:19 +01004529
blueswir15824d652009-03-28 06:44:27 +00004530DEF("echr", HAS_ARG, QEMU_OPTION_echr, \
Blue Swirlad960902010-03-29 19:23:52 +00004531 "-echr chr set terminal escape character instead of ctrl-a\n",
4532 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004533SRST
4534``-echr numeric_ascii_value``
4535 Change the escape character used for switching to the monitor when
4536 using monitor and serial sharing. The default is ``0x01`` when using
4537 the ``-nographic`` option. ``0x01`` is equal to pressing
4538 ``Control-a``. You can select a different character from the ascii
4539 control keys where 1 through 26 map to Control-a through Control-z.
4540 For instance you could use the either of the following to change the
4541 escape character to Control-t.
4542
4543 ``-echr 0x14``; \ ``-echr 20``
4544
4545ERST
blueswir15824d652009-03-28 06:44:27 +00004546
blueswir15824d652009-03-28 06:44:27 +00004547DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \
Daniel P. Berrangébf240952021-02-16 19:10:22 +00004548 "-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]\n" \
4549 "-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]\n" \
Michael Tokarev7c601802015-02-10 22:40:47 +03004550 "-incoming unix:socketpath\n" \
4551 " prepare for incoming migration, listen on\n" \
4552 " specified protocol and socket address\n" \
4553 "-incoming fd:fd\n" \
4554 "-incoming exec:cmdline\n" \
4555 " accept incoming migration on given file descriptor\n" \
Dr. David Alan Gilbert15970512015-05-29 19:52:52 +01004556 " or from given external command\n" \
4557 "-incoming defer\n" \
4558 " wait for the URI to be specified via migrate_incoming\n",
Blue Swirlad960902010-03-29 19:23:52 +00004559 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004560SRST
Daniel P. Berrangébf240952021-02-16 19:10:22 +00004561``-incoming tcp:[host]:port[,to=maxport][,ipv4=on|off][,ipv6=on|off]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00004562 \
Daniel P. Berrangébf240952021-02-16 19:10:22 +00004563``-incoming rdma:host:port[,ipv4=on|off][,ipv6=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004564 Prepare for incoming migration, listen on a given tcp port.
4565
4566``-incoming unix:socketpath``
4567 Prepare for incoming migration, listen on a given unix socket.
4568
4569``-incoming fd:fd``
4570 Accept incoming migration from a given filedescriptor.
4571
4572``-incoming exec:cmdline``
4573 Accept incoming migration as an output from specified external
4574 command.
4575
4576``-incoming defer``
4577 Wait for the URI to be specified via migrate\_incoming. The monitor
4578 can be used to change settings (such as migration parameters) prior
4579 to issuing the migrate\_incoming to allow the migration to begin.
4580ERST
blueswir15824d652009-03-28 06:44:27 +00004581
Ashijeet Acharyad15c05f2017-01-16 17:01:51 +05304582DEF("only-migratable", 0, QEMU_OPTION_only_migratable, \
4583 "-only-migratable allow only migratable devices\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004584SRST
4585``-only-migratable``
4586 Only allow migratable devices. Devices will not be allowed to enter
4587 an unmigratable state.
4588ERST
Ashijeet Acharyad15c05f2017-01-16 17:01:51 +05304589
Gerd Hoffmannd8c208d2009-12-08 13:11:46 +01004590DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
Blue Swirlad960902010-03-29 19:23:52 +00004591 "-nodefaults don't create default devices\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004592SRST
4593``-nodefaults``
4594 Don't create default devices. Normally, QEMU sets the default
4595 devices like serial port, parallel port, virtual console, monitor
4596 device, VGA adapter, floppy and CD-ROM drive and others. The
4597 ``-nodefaults`` option will disable all those default devices.
4598ERST
Gerd Hoffmannd8c208d2009-12-08 13:11:46 +01004599
blueswir15824d652009-03-28 06:44:27 +00004600#ifndef _WIN32
4601DEF("chroot", HAS_ARG, QEMU_OPTION_chroot, \
Blue Swirlad960902010-03-29 19:23:52 +00004602 "-chroot dir chroot to dir just before starting the VM\n",
4603 QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00004604#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004605SRST
4606``-chroot dir``
4607 Immediately before starting guest execution, chroot to the specified
4608 directory. Especially useful in combination with -runas.
4609ERST
blueswir15824d652009-03-28 06:44:27 +00004610
4611#ifndef _WIN32
4612DEF("runas", HAS_ARG, QEMU_OPTION_runas, \
Ian Jackson2c42f1e2017-09-15 18:10:44 +01004613 "-runas user change to user id user just before starting the VM\n" \
4614 " user can be numeric uid:gid instead\n",
Blue Swirlad960902010-03-29 19:23:52 +00004615 QEMU_ARCH_ALL)
blueswir15824d652009-03-28 06:44:27 +00004616#endif
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004617SRST
4618``-runas user``
4619 Immediately before starting guest execution, drop root privileges,
4620 switching to the specified user.
4621ERST
blueswir15824d652009-03-28 06:44:27 +00004622
blueswir15824d652009-03-28 06:44:27 +00004623DEF("prom-env", HAS_ARG, QEMU_OPTION_prom_env,
4624 "-prom-env variable=value\n"
Blue Swirlad960902010-03-29 19:23:52 +00004625 " set OpenBIOS nvram variables\n",
4626 QEMU_ARCH_PPC | QEMU_ARCH_SPARC)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004627SRST
4628``-prom-env variable=value``
4629 Set OpenBIOS nvram variable to given value (PPC, SPARC only).
4630
4631 ::
4632
4633 qemu-system-sparc -prom-env 'auto-boot?=false' \
4634 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
4635
4636 ::
4637
4638 qemu-system-ppc -prom-env 'auto-boot?=false' \
4639 -prom-env 'boot-device=hd:2,\yaboot' \
4640 -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
4641ERST
blueswir15824d652009-03-28 06:44:27 +00004642DEF("semihosting", 0, QEMU_OPTION_semihosting,
Michael Wallef7bbcfb2014-04-22 20:18:42 +02004643 "-semihosting semihosting mode\n",
Markus Armbruster9d49bcf2021-05-03 10:40:33 +02004644 QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA |
Keith Packarda10b9d92021-01-08 22:42:52 +00004645 QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004646SRST
4647``-semihosting``
Keith Packarda10b9d92021-01-08 22:42:52 +00004648 Enable semihosting mode (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V only).
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004649
4650 Note that this allows guest direct access to the host filesystem, so
4651 should only be used with a trusted guest OS.
4652
4653 See the -semihosting-config option documentation for further
4654 information about the facilities this enables.
4655ERST
Liviu Ionescua38bb072014-12-11 12:07:48 +00004656DEF("semihosting-config", HAS_ARG, QEMU_OPTION_semihosting_config,
Peter Maydell52028612022-08-22 15:12:24 +01004657 "-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]\n" \
Leon Alraea59d31a2015-06-19 14:17:45 +01004658 " semihosting configuration\n",
Markus Armbruster9d49bcf2021-05-03 10:40:33 +02004659QEMU_ARCH_ARM | QEMU_ARCH_M68K | QEMU_ARCH_XTENSA |
Keith Packarda10b9d92021-01-08 22:42:52 +00004660QEMU_ARCH_MIPS | QEMU_ARCH_NIOS2 | QEMU_ARCH_RISCV)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004661SRST
Peter Maydell52028612022-08-22 15:12:24 +01004662``-semihosting-config [enable=on|off][,target=native|gdb|auto][,chardev=id][,userspace=on|off][,arg=str[,...]]``
Keith Packarda10b9d92021-01-08 22:42:52 +00004663 Enable and configure semihosting (ARM, M68K, Xtensa, MIPS, Nios II, RISC-V
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004664 only).
4665
4666 Note that this allows guest direct access to the host filesystem, so
4667 should only be used with a trusted guest OS.
4668
4669 On Arm this implements the standard semihosting API, version 2.0.
4670
4671 On M68K this implements the "ColdFire GDB" interface used by
4672 libgloss.
4673
4674 Xtensa semihosting provides basic file IO calls, such as
4675 open/read/write/seek/select. Tensilica baremetal libc for ISS and
4676 linux platform "sim" use this interface.
4677
Keith Packarda10b9d92021-01-08 22:42:52 +00004678 On RISC-V this implements the standard semihosting API, version 0.2.
4679
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004680 ``target=native|gdb|auto``
4681 Defines where the semihosting calls will be addressed, to QEMU
4682 (``native``) or to GDB (``gdb``). The default is ``auto``, which
4683 means ``gdb`` during debug sessions and ``native`` otherwise.
4684
4685 ``chardev=str1``
4686 Send the output to a chardev backend output for native or auto
4687 output when not in gdb
4688
Peter Maydell52028612022-08-22 15:12:24 +01004689 ``userspace=on|off``
4690 Allows code running in guest userspace to access the semihosting
4691 interface. The default is that only privileged guest code can
4692 make semihosting calls. Note that setting ``userspace=on`` should
4693 only be used if all guest code is trusted (for example, in
4694 bare-metal test case code).
4695
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004696 ``arg=str1,arg=str2,...``
4697 Allows the user to pass input arguments, and can be used
4698 multiple times to build up a list. The old-style
4699 ``-kernel``/``-append`` method of passing a command line is
4700 still supported for backward compatibility. If both the
4701 ``--semihosting-config arg`` and the ``-kernel``/``-append`` are
4702 specified, the former is passed to semihosting as it always
4703 takes precedence.
4704ERST
blueswir15824d652009-03-28 06:44:27 +00004705DEF("old-param", 0, QEMU_OPTION_old_param,
Blue Swirlad960902010-03-29 19:23:52 +00004706 "-old-param old param mode\n", QEMU_ARCH_ARM)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004707SRST
4708``-old-param``
4709 Old param mode (ARM only).
4710ERST
Stefan Weil95d5f082010-01-20 22:25:27 +01004711
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03004712DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01004713 "-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
Eduardo Otubo24f8cdc2017-03-13 22:18:51 +01004714 " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
Eduardo Otubo2b716fa2017-03-01 23:17:29 +01004715 " Enable seccomp mode 2 system call filter (default 'off').\n" \
4716 " use 'obsolete' to allow obsolete system calls that are provided\n" \
4717 " by the kernel, but typically no longer used by modern\n" \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01004718 " C library implementations.\n" \
Philippe Mathieu-Daudéd42304b2021-03-03 19:46:43 +01004719 " use 'elevateprivileges' to allow or deny the QEMU process ability\n" \
4720 " to elevate privileges using set*uid|gid system calls.\n" \
Eduardo Otubo73a1e642017-03-13 22:13:27 +01004721 " The value 'children' will deny set*uid|gid system calls for\n" \
Eduardo Otubo995a2262017-03-13 22:16:01 +01004722 " main QEMU process but will allow forks and execves to run unprivileged\n" \
4723 " use 'spawn' to avoid QEMU to spawn new threads or processes by\n" \
Philippe Mathieu-Daudéd42304b2021-03-03 19:46:43 +01004724 " blocking *fork and execve\n" \
Eduardo Otubo24f8cdc2017-03-13 22:18:51 +01004725 " use 'resourcecontrol' to disable process affinity and schedular priority\n",
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03004726 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004727SRST
4728``-sandbox arg[,obsolete=string][,elevateprivileges=string][,spawn=string][,resourcecontrol=string]``
4729 Enable Seccomp mode 2 system call filter. 'on' will enable syscall
4730 filtering and 'off' will disable it. The default is 'off'.
4731
4732 ``obsolete=string``
4733 Enable Obsolete system calls
4734
4735 ``elevateprivileges=string``
4736 Disable set\*uid\|gid system calls
4737
4738 ``spawn=string``
4739 Disable \*fork and execve
4740
4741 ``resourcecontrol=string``
4742 Disable process affinity and schedular priority
4743ERST
Eduardo Otubo7d76ad42012-08-14 18:44:08 -03004744
Gerd Hoffmann715a6642009-10-14 10:39:28 +02004745DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
Paolo Bonzinie960a7e2022-04-14 10:57:21 -04004746 "-readconfig <file>\n"
4747 " read config file\n", QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004748SRST
4749``-readconfig file``
4750 Read device configuration from file. This approach is useful when
4751 you want to spawn QEMU process with many command line options but
4752 you don't want to exceed the command line character limit.
4753ERST
Thomas Huth2feac452018-08-21 12:59:56 +02004754
Eduardo Habkostf29a5612012-05-02 13:07:29 -03004755DEF("no-user-config", 0, QEMU_OPTION_nouserconfig,
4756 "-no-user-config\n"
Eduardo Habkost3478eae2017-10-04 00:00:25 -03004757 " do not load default user-provided config files at startup\n",
Eduardo Habkostf29a5612012-05-02 13:07:29 -03004758 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004759SRST
4760``-no-user-config``
4761 The ``-no-user-config`` option makes QEMU not load any of the
4762 user-provided config files on sysconfdir.
4763ERST
Thomas Huth2feac452018-08-21 12:59:56 +02004764
Prerna Saxenaab6540d2010-08-09 11:48:32 +01004765DEF("trace", HAS_ARG, QEMU_OPTION_trace,
Paolo Bonzini10578a22016-01-07 16:55:26 +03004766 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
LluĂ­s23d15e82011-08-31 20:31:31 +02004767 " specify tracing options\n",
Prerna Saxenaab6540d2010-08-09 11:48:32 +01004768 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004769SRST
4770``-trace [[enable=]pattern][,events=file][,file=file]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00004771 .. include:: ../qemu-option-trace.rst.inc
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004772
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004773ERST
LluĂ­s Vilanova42229a72017-07-24 17:28:22 +03004774DEF("plugin", HAS_ARG, QEMU_OPTION_plugin,
Mahmoud Mandour3a445ac2021-07-30 15:58:05 +02004775 "-plugin [file=]<file>[,<argname>=<argvalue>]\n"
LluĂ­s Vilanova42229a72017-07-24 17:28:22 +03004776 " load a plugin\n",
4777 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004778SRST
Mahmoud Mandour3a445ac2021-07-30 15:58:05 +02004779``-plugin file=file[,argname=argvalue]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004780 Load a plugin.
4781
4782 ``file=file``
4783 Load the given plugin from a shared library file.
4784
Mahmoud Mandour3a445ac2021-07-30 15:58:05 +02004785 ``argname=argvalue``
4786 Argument passed to the plugin. (Can be given multiple times.)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004787ERST
Stefan Weil3dbf2c72010-01-16 18:19:44 +01004788
Markus Armbruster31e70d62013-02-13 19:49:37 +01004789HXCOMM Internal use
4790DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
4791DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
Anthony Liguoric7f0f3b2012-03-28 15:42:02 +02004792
Claudio Imbrendac891c242022-08-12 15:34:53 +02004793#ifdef __linux__
4794DEF("async-teardown", 0, QEMU_OPTION_asyncteardown,
4795 "-async-teardown enable asynchronous teardown\n",
4796 QEMU_ARCH_ALL)
4797#endif
4798SRST
4799``-async-teardown``
4800 Enable asynchronous teardown. A new process called "cleanup/<QEMU_PID>"
4801 will be created at startup sharing the address space with the main qemu
4802 process, using clone. It will wait for the main qemu process to
4803 terminate completely, and then exit.
4804 This allows qemu to terminate very quickly even if the guest was
4805 huge, leaving the teardown of the address space to the cleanup
4806 process. Since the cleanup process shares the same cgroups as the
4807 main qemu process, accounting is performed correctly. This only
4808 works if the cleanup process is not forcefully killed with SIGKILL
4809 before the main qemu process has terminated completely.
4810ERST
4811
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04004812DEF("msg", HAS_ARG, QEMU_OPTION_msg,
Mario Smarduch2880ffb2020-06-26 13:19:00 -07004813 "-msg [timestamp[=on|off]][,guest-name=[on|off]]\n"
Markus Armbrusterdeda4972019-10-10 10:15:08 +02004814 " control error message format\n"
Mario Smarduch2880ffb2020-06-26 13:19:00 -07004815 " timestamp=on enables timestamps (default: off)\n"
4816 " guest-name=on enables guest name prefix but only if\n"
4817 " -name guest option is set (default: off)\n",
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04004818 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004819SRST
Mario Smarduch2880ffb2020-06-26 13:19:00 -07004820``-msg [timestamp[=on|off]][,guest-name[=on|off]]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004821 Control error message format.
4822
4823 ``timestamp=on|off``
4824 Prefix messages with a timestamp. Default is off.
Mario Smarduch2880ffb2020-06-26 13:19:00 -07004825
4826 ``guest-name=on|off``
4827 Prefix messages with guest name but only if -name guest option is set
4828 otherwise the option is ignored. Default is off.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004829ERST
Seiji Aguchi5e2ac512013-07-03 23:02:46 -04004830
Amit Shahabfd9ce2014-06-20 18:56:08 +05304831DEF("dump-vmstate", HAS_ARG, QEMU_OPTION_dump_vmstate,
4832 "-dump-vmstate <file>\n"
4833 " Output vmstate information in JSON format to file.\n"
4834 " Use the scripts/vmstate-static-checker.py file to\n"
4835 " check for possible regressions in migration code\n"
Laurent Vivier23820532015-09-04 21:30:04 +02004836 " by comparing two such vmstate dumps.\n",
Amit Shahabfd9ce2014-06-20 18:56:08 +05304837 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004838SRST
4839``-dump-vmstate file``
4840 Dump json-encoded vmstate information for current machine type to
4841 file in file
4842ERST
Amit Shahabfd9ce2014-06-20 18:56:08 +05304843
Emilio G. Cota12df1892018-08-15 11:42:49 -04004844DEF("enable-sync-profile", 0, QEMU_OPTION_enable_sync_profile,
4845 "-enable-sync-profile\n"
4846 " enable synchronization profiling\n",
4847 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004848SRST
4849``-enable-sync-profile``
4850 Enable synchronization profiling.
4851ERST
Emilio G. Cota12df1892018-08-15 11:42:49 -04004852
Paolo Bonzini43f187a2017-01-04 13:50:37 +01004853DEFHEADING()
Markus Armbrusterde6b4f92017-10-02 16:03:00 +02004854
4855DEFHEADING(Generic object creation:)
Daniel P. Berrangeb9174d42015-05-13 17:14:03 +01004856
4857DEF("object", HAS_ARG, QEMU_OPTION_object,
4858 "-object TYPENAME[,PROP1=VALUE1,...]\n"
4859 " create a new object of type TYPENAME setting properties\n"
4860 " in the order they are specified. Note that the 'id'\n"
4861 " property must be set. These objects are placed in the\n"
4862 " '/objects' path.\n",
4863 QEMU_ARCH_ALL)
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004864SRST
4865``-object typename[,prop1=value1,...]``
4866 Create a new object of type typename setting properties in the order
4867 they are specified. Note that the 'id' property must be set. These
4868 objects are placed in the '/objects' path.
4869
Stefan Hajnoczi86635aa2021-01-04 17:13:19 +00004870 ``-object memory-backend-file,id=id,size=size,mem-path=dir,share=on|off,discard-data=on|off,merge=on|off,dump=on|off,prealloc=on|off,host-nodes=host-nodes,policy=default|preferred|bind|interleave,align=align,readonly=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004871 Creates a memory file backend object, which can be used to back
4872 the guest RAM with huge pages.
4873
4874 The ``id`` parameter is a unique ID that will be used to
Robert Hoo56c9f002021-04-22 16:42:02 +08004875 reference this memory region in other parameters, e.g. ``-numa``,
4876 ``-device nvdimm``, etc.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004877
4878 The ``size`` option provides the size of the memory region, and
Robert Hoo56c9f002021-04-22 16:42:02 +08004879 accepts common suffixes, e.g. ``500M``.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004880
4881 The ``mem-path`` provides the path to either a shared memory or
4882 huge page filesystem mount.
4883
4884 The ``share`` boolean option determines whether the memory
4885 region is marked as private to QEMU, or shared. The latter
4886 allows a co-operating external process to access the QEMU memory
4887 region.
4888
4889 The ``share`` is also required for pvrdma devices due to
4890 limitations in the RDMA API provided by Linux.
4891
4892 Setting share=on might affect the ability to configure NUMA
4893 bindings for the memory backend under some circumstances, see
4894 Documentation/vm/numa\_memory\_policy.txt on the Linux kernel
4895 source tree for additional details.
4896
4897 Setting the ``discard-data`` boolean option to on indicates that
4898 file contents can be destroyed when QEMU exits, to avoid
4899 unnecessarily flushing data to the backing file. Note that
4900 ``discard-data`` is only an optimization, and QEMU might not
4901 discard file contents if it aborts unexpectedly or is terminated
4902 using SIGKILL.
4903
4904 The ``merge`` boolean option enables memory merge, also known as
4905 MADV\_MERGEABLE, so that Kernel Samepage Merging will consider
4906 the pages for memory deduplication.
4907
4908 Setting the ``dump`` boolean option to off excludes the memory
4909 from core dumps. This feature is also known as MADV\_DONTDUMP.
4910
4911 The ``prealloc`` boolean option enables memory preallocation.
4912
4913 The ``host-nodes`` option binds the memory range to a list of
4914 NUMA host nodes.
4915
4916 The ``policy`` option sets the NUMA policy to one of the
4917 following values:
4918
4919 ``default``
4920 default host policy
4921
4922 ``preferred``
4923 prefer the given host node list for allocation
4924
4925 ``bind``
4926 restrict memory allocation to the given host node list
4927
4928 ``interleave``
4929 interleave memory allocations across the given host node
4930 list
4931
4932 The ``align`` option specifies the base address alignment when
4933 QEMU mmap(2) ``mem-path``, and accepts common suffixes, eg
4934 ``2M``. Some backend store specified by ``mem-path`` requires an
4935 alignment different than the default one used by QEMU, eg the
4936 device DAX /dev/dax0.0 requires 2M alignment rather than 4K. In
4937 such cases, users can specify the required alignment via this
4938 option.
4939
4940 The ``pmem`` option specifies whether the backing file specified
4941 by ``mem-path`` is in host persistent memory that can be
4942 accessed using the SNIA NVM programming model (e.g. Intel
4943 NVDIMM). If ``pmem`` is set to 'on', QEMU will take necessary
4944 operations to guarantee the persistence of its own writes to
4945 ``mem-path`` (e.g. in vNVDIMM label emulation and live
4946 migration). Also, we will map the backend-file with MAP\_SYNC
4947 flag, which ensures the file metadata is in sync for
4948 ``mem-path`` in case of host crash or a power failure. MAP\_SYNC
4949 requires support from both the host kernel (since Linux kernel
4950 4.15) and the filesystem of ``mem-path`` mounted with DAX
4951 option.
4952
Stefan Hajnoczi86635aa2021-01-04 17:13:19 +00004953 The ``readonly`` option specifies whether the backing file is opened
4954 read-only or read-write (default).
4955
Peter Maydelle2fcbf42020-03-06 10:07:14 +00004956 ``-object memory-backend-ram,id=id,merge=on|off,dump=on|off,share=on|off,prealloc=on|off,size=size,host-nodes=host-nodes,policy=default|preferred|bind|interleave``
4957 Creates a memory backend object, which can be used to back the
4958 guest RAM. Memory backend objects offer more control than the
4959 ``-m`` option that is traditionally used to define guest RAM.
4960 Please refer to ``memory-backend-file`` for a description of the
4961 options.
4962
4963 ``-object memory-backend-memfd,id=id,merge=on|off,dump=on|off,share=on|off,prealloc=on|off,size=size,host-nodes=host-nodes,policy=default|preferred|bind|interleave,seal=on|off,hugetlb=on|off,hugetlbsize=size``
4964 Creates an anonymous memory file backend object, which allows
4965 QEMU to share the memory with an external process (e.g. when
4966 using vhost-user). The memory is allocated with memfd and
4967 optional sealing. (Linux only)
4968
4969 The ``seal`` option creates a sealed-file, that will block
4970 further resizing the memory ('on' by default).
4971
4972 The ``hugetlb`` option specify the file to be created resides in
4973 the hugetlbfs filesystem (since Linux 4.14). Used in conjunction
4974 with the ``hugetlb`` option, the ``hugetlbsize`` option specify
4975 the hugetlb page size on systems that support multiple hugetlb
4976 page sizes (it must be a power of 2 value supported by the
4977 system).
4978
4979 In some versions of Linux, the ``hugetlb`` option is
4980 incompatible with the ``seal`` option (requires at least Linux
4981 4.16).
4982
4983 Please refer to ``memory-backend-file`` for a description of the
4984 other options.
4985
4986 The ``share`` boolean option is on by default with memfd.
4987
4988 ``-object rng-builtin,id=id``
4989 Creates a random number generator backend which obtains entropy
4990 from QEMU builtin functions. The ``id`` parameter is a unique ID
4991 that will be used to reference this entropy backend from the
4992 ``virtio-rng`` device. By default, the ``virtio-rng`` device
4993 uses this RNG backend.
4994
4995 ``-object rng-random,id=id,filename=/dev/random``
4996 Creates a random number generator backend which obtains entropy
4997 from a device on the host. The ``id`` parameter is a unique ID
4998 that will be used to reference this entropy backend from the
4999 ``virtio-rng`` device. The ``filename`` parameter specifies
5000 which file to obtain entropy from and if omitted defaults to
5001 ``/dev/urandom``.
5002
5003 ``-object rng-egd,id=id,chardev=chardevid``
5004 Creates a random number generator backend which obtains entropy
5005 from an external daemon running on the host. The ``id``
5006 parameter is a unique ID that will be used to reference this
5007 entropy backend from the ``virtio-rng`` device. The ``chardev``
5008 parameter is the unique ID of a character device backend that
5009 provides the connection to the RNG daemon.
5010
5011 ``-object tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off``
5012 Creates a TLS anonymous credentials object, which can be used to
5013 provide TLS support on network backends. The ``id`` parameter is
5014 a unique ID which network backends will use to access the
5015 credentials. The ``endpoint`` is either ``server`` or ``client``
5016 depending on whether the QEMU network backend that uses the
5017 credentials will be acting as a client or as a server. If
5018 ``verify-peer`` is enabled (the default) then once the handshake
5019 is completed, the peer credentials will be verified, though this
5020 is a no-op for anonymous credentials.
5021
5022 The dir parameter tells QEMU where to find the credential files.
5023 For server endpoints, this directory may contain a file
5024 dh-params.pem providing diffie-hellman parameters to use for the
5025 TLS server. If the file is missing, QEMU will generate a set of
5026 DH parameters at startup. This is a computationally expensive
5027 operation that consumes random pool entropy, so it is
5028 recommended that a persistent set of parameters be generated
5029 upfront and saved.
5030
5031 ``-object tls-creds-psk,id=id,endpoint=endpoint,dir=/path/to/keys/dir[,username=username]``
5032 Creates a TLS Pre-Shared Keys (PSK) credentials object, which
5033 can be used to provide TLS support on network backends. The
5034 ``id`` parameter is a unique ID which network backends will use
5035 to access the credentials. The ``endpoint`` is either ``server``
5036 or ``client`` depending on whether the QEMU network backend that
5037 uses the credentials will be acting as a client or as a server.
5038 For clients only, ``username`` is the username which will be
5039 sent to the server. If omitted it defaults to "qemu".
5040
5041 The dir parameter tells QEMU where to find the keys file. It is
5042 called "dir/keys.psk" and contains "username:key" pairs. This
5043 file can most easily be created using the GnuTLS ``psktool``
5044 program.
5045
5046 For server endpoints, dir may also contain a file dh-params.pem
5047 providing diffie-hellman parameters to use for the TLS server.
5048 If the file is missing, QEMU will generate a set of DH
5049 parameters at startup. This is a computationally expensive
5050 operation that consumes random pool entropy, so it is
5051 recommended that a persistent set of parameters be generated up
5052 front and saved.
5053
5054 ``-object tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,priority=priority,verify-peer=on|off,passwordid=id``
5055 Creates a TLS anonymous credentials object, which can be used to
5056 provide TLS support on network backends. The ``id`` parameter is
5057 a unique ID which network backends will use to access the
5058 credentials. The ``endpoint`` is either ``server`` or ``client``
5059 depending on whether the QEMU network backend that uses the
5060 credentials will be acting as a client or as a server. If
5061 ``verify-peer`` is enabled (the default) then once the handshake
5062 is completed, the peer credentials will be verified. With x509
5063 certificates, this implies that the clients must be provided
5064 with valid client certificates too.
5065
5066 The dir parameter tells QEMU where to find the credential files.
5067 For server endpoints, this directory may contain a file
5068 dh-params.pem providing diffie-hellman parameters to use for the
5069 TLS server. If the file is missing, QEMU will generate a set of
5070 DH parameters at startup. This is a computationally expensive
5071 operation that consumes random pool entropy, so it is
5072 recommended that a persistent set of parameters be generated
5073 upfront and saved.
5074
5075 For x509 certificate credentials the directory will contain
5076 further files providing the x509 certificates. The certificates
5077 must be stored in PEM format, in filenames ca-cert.pem,
5078 ca-crl.pem (optional), server-cert.pem (only servers),
5079 server-key.pem (only servers), client-cert.pem (only clients),
5080 and client-key.pem (only clients).
5081
5082 For the server-key.pem and client-key.pem files which contain
5083 sensitive private keys, it is possible to use an encrypted
5084 version by providing the passwordid parameter. This provides the
5085 ID of a previously created ``secret`` object containing the
5086 password for decryption.
5087
5088 The priority parameter allows to override the global default
5089 priority used by gnutls. This can be useful if the system
5090 administrator needs to use a weaker set of crypto priorities for
5091 QEMU without potentially forcing the weakness onto all
5092 applications. Or conversely if one wants wants a stronger
5093 default for QEMU than for all other applications, they can do
5094 this through this parameter. Its format is a gnutls priority
5095 string as described at
5096 https://gnutls.org/manual/html_node/Priority-Strings.html.
5097
Philippe Mathieu-Daudé993aec22018-10-11 20:21:11 +02005098 ``-object tls-cipher-suites,id=id,priority=priority``
5099 Creates a TLS cipher suites object, which can be used to control
5100 the TLS cipher/protocol algorithms that applications are permitted
5101 to use.
5102
5103 The ``id`` parameter is a unique ID which frontends will use to
5104 access the ordered list of permitted TLS cipher suites from the
5105 host.
5106
5107 The ``priority`` parameter allows to override the global default
5108 priority used by gnutls. This can be useful if the system
5109 administrator needs to use a weaker set of crypto priorities for
5110 QEMU without potentially forcing the weakness onto all
5111 applications. Or conversely if one wants wants a stronger
5112 default for QEMU than for all other applications, they can do
5113 this through this parameter. Its format is a gnutls priority
5114 string as described at
5115 https://gnutls.org/manual/html_node/Priority-Strings.html.
5116
Philippe Mathieu-Daudé69699f32020-05-14 15:15:47 +02005117 An example of use of this object is to control UEFI HTTPS Boot.
5118 The tls-cipher-suites object exposes the ordered list of permitted
5119 TLS cipher suites from the host side to the guest firmware, via
5120 fw_cfg. The list is represented as an array of IANA_TLS_CIPHER
5121 objects. The firmware uses the IANA_TLS_CIPHER array for configuring
5122 guest-side TLS.
5123
5124 In the following example, the priority at which the host-side policy
5125 is retrieved is given by the ``priority`` property.
5126 Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to
5127 refer to /etc/crypto-policies/back-ends/gnutls.config.
5128
5129 .. parsed-literal::
5130
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005131 # |qemu_system| \\
5132 -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \\
Philippe Mathieu-Daudé69699f32020-05-14 15:15:47 +02005133 -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0
5134
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005135 ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]``
5136 Interval t can't be 0, this filter batches the packet delivery:
5137 all packets arriving in a given interval on netdev netdevid are
5138 delayed until the end of the interval. Interval is in
5139 microseconds. ``status`` is optional that indicate whether the
5140 netfilter is on (enabled) or off (disabled), the default status
5141 for netfilter will be 'on'.
5142
5143 queue all\|rx\|tx is an option that can be applied to any
5144 netfilter.
5145
5146 ``all``: the filter is attached both to the receive and the
5147 transmit queue of the netdev (default).
5148
5149 ``rx``: the filter is attached to the receive queue of the
5150 netdev, where it will receive packets sent to the netdev.
5151
5152 ``tx``: the filter is attached to the transmit queue of the
5153 netdev, where it will receive packets sent by the netdev.
5154
5155 position head\|tail\|id=<id> is an option to specify where the
5156 filter should be inserted in the filter list. It can be applied
5157 to any netfilter.
5158
5159 ``head``: the filter is inserted at the head of the filter list,
5160 before any existing filters.
5161
5162 ``tail``: the filter is inserted at the tail of the filter list,
5163 behind any existing filters (default).
5164
5165 ``id=<id>``: the filter is inserted before or behind the filter
5166 specified by <id>, see the insert option below.
5167
5168 insert behind\|before is an option to specify where to insert
5169 the new filter relative to the one specified with
5170 position=id=<id>. It can be applied to any netfilter.
5171
5172 ``before``: insert before the specified filter.
5173
5174 ``behind``: insert behind the specified filter (default).
5175
5176 ``-object filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]``
5177 filter-mirror on netdev netdevid,mirror net packet to
5178 chardevchardevid, if it has the vnet\_hdr\_support flag,
5179 filter-mirror will mirror packet with vnet\_hdr\_len.
5180
5181 ``-object filter-redirector,id=id,netdev=netdevid,indev=chardevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]``
5182 filter-redirector on netdev netdevid,redirect filter's net
5183 packet to chardev chardevid,and redirect indev's packet to
5184 filter.if it has the vnet\_hdr\_support flag, filter-redirector
5185 will redirect packet with vnet\_hdr\_len. Create a
5186 filter-redirector we need to differ outdev id from indev id, id
5187 can not be the same. we can just use indev or outdev, but at
5188 least one of indev or outdev need to be specified.
5189
5190 ``-object filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support][,position=head|tail|id=<id>][,insert=behind|before]``
5191 Filter-rewriter is a part of COLO project.It will rewrite tcp
5192 packet to secondary from primary to keep secondary tcp
5193 connection,and rewrite tcp packet to primary from secondary make
5194 tcp packet can be handled by client.if it has the
5195 vnet\_hdr\_support flag, we can parse packet with vnet header.
5196
5197 usage: colo secondary: -object
5198 filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object
5199 filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object
5200 filter-rewriter,id=rew0,netdev=hn0,queue=all
5201
5202 ``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len][,position=head|tail|id=<id>][,insert=behind|before]``
5203 Dump the network traffic on netdev dev to the file specified by
5204 filename. At most len bytes (64k by default) per packet are
5205 stored. The file format is libpcap, so it can be analyzed with
5206 tools such as tcpdump or Wireshark.
5207
Zhang Chena2e5cb72020-06-24 09:20:41 +08005208 ``-object colo-compare,id=id,primary_in=chardevid,secondary_in=chardevid,outdev=chardevid,iothread=id[,vnet_hdr_support][,notify_dev=id][,compare_timeout=@var{ms}][,expired_scan_cycle=@var{ms}][,max_queue_size=@var{size}]``
Zhang Chen2b28a7e2020-06-24 09:20:42 +08005209 Colo-compare gets packet from primary\_in chardevid and
5210 secondary\_in, then compare whether the payload of primary packet
5211 and secondary packet are the same. If same, it will output
5212 primary packet to out\_dev, else it will notify COLO-framework to do
5213 checkpoint and send primary packet to out\_dev. In order to
5214 improve efficiency, we need to put the task of comparison in
5215 another iothread. If it has the vnet\_hdr\_support flag,
5216 colo compare will send/recv packet with vnet\_hdr\_len.
5217 The compare\_timeout=@var{ms} determines the maximum time of the
5218 colo-compare hold the packet. The expired\_scan\_cycle=@var{ms}
5219 is to set the period of scanning expired primary node network packets.
5220 The max\_queue\_size=@var{size} is to set the max compare queue
5221 size depend on user environment.
5222 If user want to use Xen COLO, need to add the notify\_dev to
Zhang Chen9cc43c92020-03-18 16:23:19 +08005223 notify Xen colo-frame to do checkpoint.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005224
Zhang Chen2b28a7e2020-06-24 09:20:42 +08005225 COLO-compare must be used with the help of filter-mirror,
5226 filter-redirector and filter-rewriter.
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005227
5228 ::
5229
5230 KVM COLO
5231
5232 primary:
5233 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
5234 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005235 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off
5236 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off
5237 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005238 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005239 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005240 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
5241 -object iothread,id=iothread1
5242 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
5243 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
5244 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
5245 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1
5246
5247 secondary:
5248 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
5249 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
5250 -chardev socket,id=red0,host=3.3.3.3,port=9003
5251 -chardev socket,id=red1,host=3.3.3.3,port=9004
5252 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
5253 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
5254
5255
5256 Xen COLO
5257
5258 primary:
5259 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
5260 -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005261 -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server=on,wait=off
5262 -chardev socket,id=compare1,host=3.3.3.3,port=9004,server=on,wait=off
5263 -chardev socket,id=compare0,host=3.3.3.3,port=9001,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005264 -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005265 -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005266 -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
Daniel P. Berrangébfdc1262021-02-16 19:10:19 +00005267 -chardev socket,id=notify_way,host=3.3.3.3,port=9009,server=on,wait=off
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005268 -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
5269 -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
5270 -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
5271 -object iothread,id=iothread1
5272 -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1
5273
5274 secondary:
5275 -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
5276 -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
5277 -chardev socket,id=red0,host=3.3.3.3,port=9003
5278 -chardev socket,id=red1,host=3.3.3.3,port=9004
5279 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
5280 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
5281
5282 If you want to know the detail of above command line, you can
5283 read the colo-compare git log.
5284
5285 ``-object cryptodev-backend-builtin,id=id[,queues=queues]``
Stefan Weil1e458f12022-10-30 11:59:44 +01005286 Creates a cryptodev backend which executes crypto operations from
5287 the QEMU cipher APIs. The id parameter is a unique ID that will
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005288 be used to reference this cryptodev backend from the
5289 ``virtio-crypto`` device. The queues parameter is optional,
5290 which specify the queue number of cryptodev backend, the default
5291 of queues is 1.
5292
Peter Maydell09ce5f22020-02-28 15:36:13 +00005293 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005294
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005295 # |qemu_system| \\
5296 [...] \\
5297 -object cryptodev-backend-builtin,id=cryptodev0 \\
5298 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005299 [...]
5300
5301 ``-object cryptodev-vhost-user,id=id,chardev=chardevid[,queues=queues]``
5302 Creates a vhost-user cryptodev backend, backed by a chardev
5303 chardevid. The id parameter is a unique ID that will be used to
5304 reference this cryptodev backend from the ``virtio-crypto``
5305 device. The chardev should be a unix domain socket backed one.
5306 The vhost-user uses a specifically defined protocol to pass
5307 vhost ioctl replacement messages to an application on the other
5308 end of the socket. The queues parameter is optional, which
5309 specify the queue number of cryptodev backend for multiqueue
5310 vhost-user, the default of queues is 1.
5311
Peter Maydell09ce5f22020-02-28 15:36:13 +00005312 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005313
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005314 # |qemu_system| \\
5315 [...] \\
5316 -chardev socket,id=chardev0,path=/path/to/socket \\
5317 -object cryptodev-vhost-user,id=cryptodev0,chardev=chardev0 \\
5318 -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005319 [...]
5320
5321 ``-object secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]``
Peter Maydell09ce5f22020-02-28 15:36:13 +00005322 \
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005323 ``-object secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]``
5324 Defines a secret to store a password, encryption key, or some
5325 other sensitive data. The sensitive data can either be passed
5326 directly via the data parameter, or indirectly via the file
5327 parameter. Using the data parameter is insecure unless the
5328 sensitive data is encrypted.
5329
5330 The sensitive data can be provided in raw format (the default),
5331 or base64. When encoded as JSON, the raw format only supports
5332 valid UTF-8 characters, so base64 is recommended for sending
5333 binary data. QEMU will convert from which ever format is
5334 provided to the format it needs internally. eg, an RBD password
5335 can be provided in raw format, even though it will be base64
5336 encoded when passed onto the RBD sever.
5337
5338 For added protection, it is possible to encrypt the data
5339 associated with a secret using the AES-256-CBC cipher. Use of
5340 encryption is indicated by providing the keyid and iv
5341 parameters. The keyid parameter provides the ID of a previously
5342 defined secret that contains the AES-256 decryption key. This
5343 key should be 32-bytes long and be base64 encoded. The iv
5344 parameter provides the random initialization vector used for
5345 encryption of this particular secret and should be a base64
5346 encrypted string of the 16-byte IV.
5347
5348 The simplest (insecure) usage is to provide the secret inline
5349
Peter Maydell09ce5f22020-02-28 15:36:13 +00005350 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005351
5352 # |qemu_system| -object secret,id=sec0,data=letmein,format=raw
5353
5354 The simplest secure usage is to provide the secret via a file
5355
5356 # printf "letmein" > mypasswd.txt # QEMU\_SYSTEM\_MACRO -object
5357 secret,id=sec0,file=mypasswd.txt,format=raw
5358
5359 For greater security, AES-256-CBC should be used. To illustrate
5360 usage, consider the openssl command line tool which can encrypt
5361 the data. Note that when encrypting, the plaintext must be
5362 padded to the cipher block size (32 bytes) using the standard
5363 PKCS#5/6 compatible padding algorithm.
5364
5365 First a master key needs to be created in base64 encoding:
5366
5367 ::
5368
5369 # openssl rand -base64 32 > key.b64
5370 # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"')
5371
5372 Each secret to be encrypted needs to have a random
5373 initialization vector generated. These do not need to be kept
5374 secret
5375
5376 ::
5377
5378 # openssl rand -base64 16 > iv.b64
5379 # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"')
5380
5381 The secret to be defined can now be encrypted, in this case
5382 we're telling openssl to base64 encode the result, but it could
5383 be left as raw bytes if desired.
5384
5385 ::
5386
5387 # SECRET=$(printf "letmein" |
5388 openssl enc -aes-256-cbc -a -K $KEY -iv $IV)
5389
5390 When launching QEMU, create a master secret pointing to
5391 ``key.b64`` and specify that to be used to decrypt the user
5392 password. Pass the contents of ``iv.b64`` to the second secret
5393
Peter Maydell09ce5f22020-02-28 15:36:13 +00005394 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005395
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005396 # |qemu_system| \\
5397 -object secret,id=secmaster0,format=base64,file=key.b64 \\
5398 -object secret,id=sec0,keyid=secmaster0,format=base64,\\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005399 data=$SECRET,iv=$(<iv.b64)
5400
Dov Murik55cdf562021-11-11 10:00:43 +00005401 ``-object sev-guest,id=id,cbitpos=cbitpos,reduced-phys-bits=val,[sev-device=string,policy=policy,handle=handle,dh-cert-file=file,session-file=file,kernel-hashes=on|off]``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005402 Create a Secure Encrypted Virtualization (SEV) guest object,
5403 which can be used to provide the guest memory encryption support
5404 on AMD processors.
5405
5406 When memory encryption is enabled, one of the physical address
5407 bit (aka the C-bit) is utilized to mark if a memory page is
5408 protected. The ``cbitpos`` is used to provide the C-bit
5409 position. The C-bit position is Host family dependent hence user
5410 must provide this value. On EPYC, the value should be 47.
5411
5412 When memory encryption is enabled, we loose certain bits in
5413 physical address space. The ``reduced-phys-bits`` is used to
5414 provide the number of bits we loose in physical address space.
5415 Similar to C-bit, the value is Host family dependent. On EPYC,
5416 the value should be 5.
5417
5418 The ``sev-device`` provides the device file to use for
5419 communicating with the SEV firmware running inside AMD Secure
5420 Processor. The default device is '/dev/sev'. If hardware
5421 supports memory encryption then /dev/sev devices are created by
5422 CCP driver.
5423
5424 The ``policy`` provides the guest policy to be enforced by the
5425 SEV firmware and restrict what configuration and operational
5426 commands can be performed on this guest by the hypervisor. The
5427 policy should be provided by the guest owner and is bound to the
5428 guest and cannot be changed throughout the lifetime of the
5429 guest. The default is 0.
5430
5431 If guest ``policy`` allows sharing the key with another SEV
5432 guest then ``handle`` can be use to provide handle of the guest
5433 from which to share the key.
5434
5435 The ``dh-cert-file`` and ``session-file`` provides the guest
5436 owner's Public Diffie-Hillman key defined in SEV spec. The PDH
5437 and session parameters are used for establishing a cryptographic
5438 session with the guest owner to negotiate keys used for
5439 attestation. The file must be encoded in base64.
5440
Dov Murik55cdf562021-11-11 10:00:43 +00005441 The ``kernel-hashes`` adds the hashes of given kernel/initrd/
5442 cmdline to a designated guest firmware page for measured Linux
5443 boot with -kernel. The default is off. (Since 6.2)
5444
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005445 e.g to launch a SEV guest
5446
Peter Maydell09ce5f22020-02-28 15:36:13 +00005447 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005448
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005449 # |qemu_system_x86| \\
5450 ...... \\
5451 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \\
5452 -machine ...,memory-encryption=sev0 \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005453 .....
5454
5455 ``-object authz-simple,id=id,identity=string``
5456 Create an authorization object that will control access to
5457 network services.
5458
5459 The ``identity`` parameter is identifies the user and its format
5460 depends on the network service that authorization object is
5461 associated with. For authorizing based on TLS x509 certificates,
5462 the identity must be the x509 distinguished name. Note that care
5463 must be taken to escape any commas in the distinguished name.
5464
5465 An example authorization object to validate a x509 distinguished
5466 name would look like:
5467
Peter Maydell09ce5f22020-02-28 15:36:13 +00005468 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005469
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005470 # |qemu_system| \\
5471 ... \\
5472 -object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,O=Example Org,,L=London,,ST=London,,C=GB' \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005473 ...
5474
5475 Note the use of quotes due to the x509 distinguished name
5476 containing whitespace, and escaping of ','.
5477
Daniel P. Berrangé4d7beea2020-11-04 13:57:21 +00005478 ``-object authz-listfile,id=id,filename=path,refresh=on|off``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005479 Create an authorization object that will control access to
5480 network services.
5481
5482 The ``filename`` parameter is the fully qualified path to a file
5483 containing the access control list rules in JSON format.
5484
5485 An example set of rules that match against SASL usernames might
5486 look like:
5487
5488 ::
5489
5490 {
5491 "rules": [
5492 { "match": "fred", "policy": "allow", "format": "exact" },
5493 { "match": "bob", "policy": "allow", "format": "exact" },
5494 { "match": "danb", "policy": "deny", "format": "glob" },
5495 { "match": "dan*", "policy": "allow", "format": "exact" },
5496 ],
5497 "policy": "deny"
5498 }
5499
5500 When checking access the object will iterate over all the rules
5501 and the first rule to match will have its ``policy`` value
5502 returned as the result. If no rules match, then the default
5503 ``policy`` value is returned.
5504
5505 The rules can either be an exact string match, or they can use
5506 the simple UNIX glob pattern matching to allow wildcards to be
5507 used.
5508
5509 If ``refresh`` is set to true the file will be monitored and
5510 automatically reloaded whenever its content changes.
5511
5512 As with the ``authz-simple`` object, the format of the identity
5513 strings being matched depends on the network service, but is
5514 usually a TLS x509 distinguished name, or a SASL username.
5515
5516 An example authorization object to validate a SASL username
5517 would look like:
5518
Peter Maydell09ce5f22020-02-28 15:36:13 +00005519 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005520
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005521 # |qemu_system| \\
5522 ... \\
Daniel P. Berrangé4d7beea2020-11-04 13:57:21 +00005523 -object authz-simple,id=auth0,filename=/etc/qemu/vnc-sasl.acl,refresh=on \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005524 ...
5525
5526 ``-object authz-pam,id=id,service=string``
5527 Create an authorization object that will control access to
5528 network services.
5529
5530 The ``service`` parameter provides the name of a PAM service to
5531 use for authorization. It requires that a file
5532 ``/etc/pam.d/service`` exist to provide the configuration for
5533 the ``account`` subsystem.
5534
5535 An example authorization object to validate a TLS x509
5536 distinguished name would look like:
5537
Peter Maydell09ce5f22020-02-28 15:36:13 +00005538 .. parsed-literal::
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005539
Laszlo Ersek353a06b2020-09-08 19:21:11 +02005540 # |qemu_system| \\
5541 ... \\
5542 -object authz-pam,id=auth0,service=qemu-vnc \\
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005543 ...
5544
5545 There would then be a corresponding config file for PAM at
5546 ``/etc/pam.d/qemu-vnc`` that contains:
5547
5548 ::
5549
5550 account requisite pam_listfile.so item=user sense=allow \
5551 file=/etc/qemu/vnc.allow
5552
5553 Finally the ``/etc/qemu/vnc.allow`` file would contain the list
Stefan Weil1e458f12022-10-30 11:59:44 +01005554 of x509 distinguished names that are permitted access
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005555
5556 ::
5557
5558 CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB
5559
Stefano Garzarella1793ad02021-07-21 11:42:10 +02005560 ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink,aio-max-batch=aio-max-batch``
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005561 Creates a dedicated event loop thread that devices can be
5562 assigned to. This is known as an IOThread. By default device
5563 emulation happens in vCPU threads or the main event loop thread.
5564 This can become a scalability bottleneck. IOThreads allow device
5565 emulation and I/O to run on other host CPUs.
5566
5567 The ``id`` parameter is a unique ID that will be used to
5568 reference this IOThread from ``-device ...,iothread=id``.
5569 Multiple devices can be assigned to an IOThread. Note that not
5570 all devices support an ``iothread`` parameter.
5571
5572 The ``query-iothreads`` QMP command lists IOThreads and reports
5573 their thread IDs so that the user can configure host CPU
5574 pinning/affinity.
5575
5576 IOThreads use an adaptive polling algorithm to reduce event loop
5577 latency. Instead of entering a blocking system call to monitor
5578 file descriptors and then pay the cost of being woken up when an
5579 event occurs, the polling algorithm spins waiting for events for
5580 a short time. The algorithm's default parameters are suitable
5581 for many cases but can be adjusted based on knowledge of the
5582 workload and/or host device latency.
5583
5584 The ``poll-max-ns`` parameter is the maximum number of
5585 nanoseconds to busy wait for events. Polling can be disabled by
5586 setting this value to 0.
5587
5588 The ``poll-grow`` parameter is the multiplier used to increase
5589 the polling time when the algorithm detects it is missing events
5590 due to not polling long enough.
5591
5592 The ``poll-shrink`` parameter is the divisor used to decrease
5593 the polling time when the algorithm detects it is spending too
5594 long polling without encountering events.
5595
Stefano Garzarella1793ad02021-07-21 11:42:10 +02005596 The ``aio-max-batch`` parameter is the maximum number of requests
5597 in a batch for the AIO engine, 0 means that the engine will use
5598 its default.
5599
5600 The IOThread parameters can be modified at run-time using the
Peter Maydelle2fcbf42020-03-06 10:07:14 +00005601 ``qom-set`` command (where ``iothread1`` is the IOThread's
5602 ``id``):
5603
5604 ::
5605
5606 (qemu) qom-set /objects/iothread1 poll-max-ns 100000
5607ERST
Daniel P. Berrangeb9174d42015-05-13 17:14:03 +01005608
5609
Stefan Weil3dbf2c72010-01-16 18:19:44 +01005610HXCOMM This is the last statement. Insert new options before this line!
Paolo Bonzinifd5fc4b2021-05-17 07:34:21 -04005611
5612#undef DEF
5613#undef DEFHEADING
5614#undef ARCHHEADING