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2013-05-08lguest: clear cached last cpu when guest_set_pgd() called.Rusty Russell
commit v3.9-rc1-53-g6d0cda9 "lguest: cache last cpu we ran on." missed one case, which causes a triple fault. The guest calls guest_set_pgd() on the top page, and we carefully remap the Switcher text page. But we didn't reset last_host_cpu, so map_switcher_in_guest() thinks the guest's regs and IDT/GDT etc are already mapped. Reported-by: Paul Bolle <pebolle@tiscali.nl> Tested-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-05-02Merge tag 'virtio-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull virtio & lguest updates from Rusty Russell: "Lots of virtio work which wasn't quite ready for last merge window. Plus I dived into lguest again, reworking the pagetable code so we can move the switcher page: our fixmaps sometimes take more than 2MB now..." Ugh. Annoying conflicts with the tcm_vhost -> vhost_scsi rename. Hopefully correctly resolved. * tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (57 commits) caif_virtio: Remove bouncing email addresses lguest: improve code readability in lg_cpu_start. virtio-net: fill only rx queues which are being used lguest: map Switcher below fixmap. lguest: cache last cpu we ran on. lguest: map Switcher text whenever we allocate a new pagetable. lguest: don't share Switcher PTE pages between guests. lguest: expost switcher_pages array (as lg_switcher_pages). lguest: extract shadow PTE walking / allocating. lguest: make check_gpte et. al return bool. lguest: assume Switcher text is a single page. lguest: rename switcher_page to switcher_pages. lguest: remove RESERVE_MEM constant. lguest: check vaddr not pgd for Switcher protection. lguest: prepare to make SWITCHER_ADDR a variable. virtio: console: replace EMFILE with EBUSY for already-open port virtio-scsi: reset virtqueue affinity when doing cpu hotplug virtio-scsi: introduce multiqueue support virtio-scsi: push vq lock/unlock into virtscsi_vq_done virtio-scsi: pass struct virtio_scsi to virtqueue completion function ...
2013-04-29lguest: rename random32() to prandom_u32()Akinobu Mita
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30lguest: improve code readability in lg_cpu_start.Cosmin Paraschiv
Make the container_of call friendlier and fix some comment slip-ups. Signed-off-by: Cosmin Paraschiv <csmnprschv@gmail.com> Cc: Daniel Baluta <dbaluta@ixiacom.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-22lguest: map Switcher below fixmap.Rusty Russell
Now we've adjusted all the code, we can simply set switcher_addr to wherever it needs to go below the fixmaps, rather than asserting that it should be so. With large NR_CPUS and PAE, people were hitting the "mapping switcher would thwack fixmap" message. Reported-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-22lguest: cache last cpu we ran on.Rusty Russell
This optimizes the frobbing of our Switcher map. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-22lguest: map Switcher text whenever we allocate a new pagetable.Rusty Russell
It's always to same, so no need to put in the PTE every time we're about to run. Keep a flag to track whether the pagetable has the Switcher entries allocated, and when allocating always initialize the Switcher text PTE. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-22lguest: don't share Switcher PTE pages between guests.Rusty Russell
We currently use the whole top PGD entry for the switcher, so we simply share a fixed page of PTEs between all guests (actually, it's one per Host CPU, to ensure isolation between guests). Changes to a scheme where every guest has its own mappings. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-22lguest: expost switcher_pages array (as lg_switcher_pages).Rusty Russell
We will need this in page_table.c soon. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-22lguest: extract shadow PTE walking / allocating.Rusty Russell
We want a separate find_pte() function so we can call it for populating the switcher PTE entries. We can also use it in page_writable(). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-22lguest: make check_gpte et. al return bool.Rusty Russell
This is a bit neater: we can immediately return if a PTE/PGD/PMD entry is invalid (which also kills the guest). It means we don't risk using invalid entries as we reshuffle the code. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-22lguest: assume Switcher text is a single page.Rusty Russell
ie. SHARED_SWITCHER_PAGES == 1. It is well under a page, and it's a minor simplification: it's nice to have *one* simplification in a patch series! Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-22lguest: rename switcher_page to switcher_pages.Rusty Russell
There is a single page with the Switcher in it, but it's followed by 2 pages per Host CPU. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-22lguest: remove RESERVE_MEM constant.Rusty Russell
We can use switcher_addr directly. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-22lguest: check vaddr not pgd for Switcher protection.Rusty Russell
We currently assume that the Switcher the top pgd; we want to remove this assumption, so check that vaddr is OK, rather then checking pgd index. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-22lguest: prepare to make SWITCHER_ADDR a variable.Rusty Russell
We currently use the whole top PGD entry for the switcher, but that's hitting the fixmap in some configurations (mainly, large NR_CPUS). Introduce a variable, currently set to the constant. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-03-07lguest: fix paths in commentsWanlong Gao
After commit 07fe997, lguest tool has already moved from Documentation/virtual/lguest/ to tools/lguest/. Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-02-26Merge tag 'virtio-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull virtio updates from Rusty Russell: "All trivial, thanks to the stuff which didn't quite make it time" * tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: virtio_console: Initialize guest_connected=true for rproc_serial virtio: use module_virtio_driver. virtio: Add module driver macro for virtio drivers. virtio_console: Use virtio device index to generate port name virtio: make pci_device_id const virtio: make config_ops const virtio-mmio: fix wrong comment about register offset virtio_console: Let unconnected rproc device receive data.
2013-02-21Merge tag 'tty-3.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial patches from Greg Kroah-Hartman: "Here's the big tty/serial driver patches for 3.9-rc1. More tty port rework and fixes from Jiri here, as well as lots of individual serial driver updates and fixes. All of these have been in the linux-next tree for a while." * tag 'tty-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (140 commits) tty: mxser: improve error handling in mxser_probe() and mxser_module_init() serial: imx: fix uninitialized variable warning serial: tegra: assume CONFIG_OF TTY: do not update atime/mtime on read/write lguest: select CONFIG_TTY to build properly. ARM defconfigs: add missing inclusions of linux/platform_device.h fb/exynos: include platform_device.h ARM: sa1100/assabet: include platform_device.h directly serial: imx: Fix recursive locking bug pps: Fix build breakage from decoupling pps from tty tty: Remove ancient hardpps() pps: Additional cleanups in uart_handle_dcd_change pps: Move timestamp read into PPS code proper pps: Don't crash the machine when exiting will do pps: Fix a use-after free bug when unregistering a source. pps: Use pps_lookup_dev to reduce ldisc coupling pps: Add pps_lookup_dev() function tty: serial: uartlite: Support uartlite on big and little endian systems tty: serial: uartlite: Fix sparse and checkpatch warnings serial/arc-uart: Miscll DT related updates (Grant's review comments) ... Fix up trivial conflicts, mostly just due to the TTY config option clashing with the EXPERIMENTAL removal.
2013-02-11virtio: make config_ops constStephen Hemminger
It is just a table of function pointers, make it const for cleanliness and security reasons. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-01-18tty: Added a CONFIG_TTY option to allow removal of TTYJoe Millenbach
The option allows you to remove TTY and compile without errors. This saves space on systems that won't support TTY interfaces anyway. bloat-o-meter output is below. The bulk of this patch consists of Kconfig changes adding "depends on TTY" to various serial devices and similar drivers that require the TTY layer. Ideally, these dependencies would occur on a common intermediate symbol such as SERIO, but most drivers "select SERIO" rather than "depends on SERIO", and "select" does not respect dependencies. bloat-o-meter output comparing our previous minimal to new minimal by removing TTY. The list is filtered to not show removed entries with awk '$3 != "-"' as the list was very long. add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350) function old new delta chr_dev_init 166 170 +4 allow_signal 80 82 +2 static.__warned 143 142 -1 disallow_signal 63 62 -1 __set_special_pids 95 94 -1 unregister_console 126 121 -5 start_kernel 546 541 -5 register_console 593 588 -5 copy_from_user 45 40 -5 sys_setsid 128 120 -8 sys_vhangup 32 19 -13 do_exit 1543 1526 -17 bitmap_zero 60 40 -20 arch_local_irq_save 137 117 -20 release_task 674 652 -22 static.spin_unlock_irqrestore 308 260 -48 Signed-off-by: Joe Millenbach <jmillenbach@gmail.com> Reviewed-by: Jamey Sharp <jamey@minilop.net> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-11drivers/lguest: remove depends on CONFIG_EXPERIMENTALKees Cook
The CONFIG_EXPERIMENTAL config item has not carried much meaning for a while now and is almost always enabled by default. As agreed during the Linux kernel summit, remove it from any "depends on" lines in Kconfigs. CC: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au>
2012-12-18lguest: fix typoAlex Russell
Signed-off-by: Alex Russell <giles.alex@hotmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-07Merge branch 'virtio-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull virtio changes from Rusty Russell: "New workflow: same git trees pulled by linux-next get sent straight to Linus. Git is awkward at shuffling patches compared with quilt or mq, but that doesn't happen often once things get into my -next branch." * 'virtio-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (24 commits) lguest: fix occasional crash in example launcher. virtio-blk: Disable callback in virtblk_done() virtio_mmio: Don't attempt to create empty virtqueues virtio_mmio: fix off by one error allocating queue drivers/virtio/virtio_pci.c: fix error return code virtio: don't crash when device is buggy virtio: remove CONFIG_VIRTIO_RING virtio: add help to CONFIG_VIRTIO option. virtio: support reserved vqs virtio: introduce an API to set affinity for a virtqueue virtio-ring: move queue_index to vring_virtqueue virtio_balloon: not EXPERIMENTAL any more. virtio-balloon: dependency fix virtio-blk: fix NULL checking in virtblk_alloc_req() virtio-blk: Add REQ_FLUSH and REQ_FUA support to bio path virtio-blk: Add bio-based IO path for virtio-blk virtio: console: fix error handling in init() function tools: Fix pthread flag for Makefile of trace-agent used by virtio-trace tools: Add guest trace agent as a user tool virtio/console: Allocate scatterlist according to the current pipe size ...
2012-09-28virtio: support reserved vqsMichael S. Tsirkin
virtio network device multiqueue support reserves vq 3 for future use (useful both for future extensions and to make it pretty - this way receive vqs have even and transmit - odd numbers). Make it possible to skip initialization for specific vq numbers by specifying NULL for name. Document this usage as well as (existing) NULL callback. Drivers using this not coded up yet, so I simply tested with virtio-pci and verified that this patch does not break existing drivers. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-28virtio-ring: move queue_index to vring_virtqueueJason Wang
Instead of storing the queue index in transport-specific virtio structs, this patch moves them to vring_virtqueue and introduces an helper to get the value. This lets drivers simplify their management and tracing of virtqueues. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-18lguest, x86: handle guest TS bit for lazy/non-lazy fpu host modelsSuresh Siddha
Instead of using unlazy_fpu() check if user_has_fpu() and set/clear the host TS bits so that the lguest works fine with both the lazy/non-lazy FPU host models with minimal changes. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1345842782-24175-6-git-send-email-suresh.b.siddha@intel.com Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-01-12lguest: Make sure interrupt is allocated ok by lguest_setup_irqStratos Psomadakis
Make sure the interrupt is allocated correctly by lguest_setup_irq (check the return value of irq_alloc_desc_at for -ENOMEM) Signed-off-by: Stratos Psomadakis <psomas@cslab.ece.ntua.gr> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cleanups and commentry)
2012-01-12lguest: move the lguest tool to the tools directoryDavidlohr Bueso
This is a better location instead of having it in Documentation. Signed-off-by: Davidlohr Bueso <dave@gnu.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (fixed compile)
2012-01-12lguest: switch segment-voodoo-numbers to readable symbolsJacek Galowicz
When studying lguest's x86 segment descriptor code, it is not longer necessary to have the Intel x86 architecture manual open on the page with the segment descriptor illustration to understand the crazy numbers assigned to both descriptor structure halves a/b. Now the struct desc_struct's fields, like suggested by Glauber de Oliveira Costa in 2008, are used. Signed-off-by: Jacek Galowicz <jacek@galowicz.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-12virtio: harsher barriers for rpmsg.Rusty Russell
We were cheating with our barriers; using the smp ones rather than the real device ones. That was fine, until rpmsg came along, which is used to talk to a real device (a non-SMP CPU). Unfortunately, just putting back the real barriers (reverting d57ed95d) causes a performance regression on virtio-pci. In particular, Amos reports netbench's TCP_RR over virtio_net CPU utilization increased up to 35% while throughput went down by up to 14%. By comparison, this branch is in the noise. Reference: https://lkml.org/lkml/2011/12/11/22 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1958 commits) net: pack skb_shared_info more efficiently net_sched: red: split red_parms into parms and vars net_sched: sfq: extend limits cnic: Improve error recovery on bnx2x devices cnic: Re-init dev->stats_addr after chip reset net_sched: Bug in netem reordering bna: fix sparse warnings/errors bna: make ethtool_ops and strings const xgmac: cleanups net: make ethtool_ops const vmxnet3" make ethtool ops const xen-netback: make ops structs const virtio_net: Pass gfp flags when allocating rx buffers. ixgbe: FCoE: Add support for ndo_get_fcoe_hbainfo() call netdev: FCoE: Add new ndo_get_fcoe_hbainfo() call igb: reset PHY after recovering from PHY power down igb: add basic runtime PM support igb: Add support for byte queue limits. e1000: cleanup CE4100 MDIO registers access e1000: unmap ce4100_gbe_mdio_base_virt in e1000_remove ...
2011-12-06x86: Fix rflags in FAKE_STACK_FRAMESeiichi Ikarashi
The x86_64 kernel pushes the fake kernel stack in arch/x86/kernel/entry_64.S:FAKE_STACK_FRAME, and rflags register in it does not conform to the specification. Although Intel's manual[1] says bit 1 of it shall be set to 1, this bit is cleared to 0 on pushing the fake stack. [1] Intel(R) 64 and IA-32 Architectures Software Developer's Manual Vol.1 3-21 Figure 3-8. EFLAGS Register If it is not on purpose, it is better to be fixed, because it can lead some tools misunderstanding the stack frame. For example, "crash" utility[2] actually detects it and warns you like below: RIP: ffffffff8005dfa2 RSP: ffff8104ce0c7f58 RFLAGS: 00000200 [...] bt: WARNING: possibly bogus exception frame Signed-off-by: Seiichi Ikarashi <s.ikarashi@jp.fujitsu.com> Tested-by: Masayoshi MIZUMA <m.mizuma@jp.fujitsu.com> Cc: Jan Beulich <JBeulich@suse.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-16enable virtio_net to return bus_info in ethtool -i consistent with emulated NICsRick Jones
Add a new .bus_name to virtio_config_ops then modify virtio_net to call through to it in an ethtool .get_drvinfo routine to report bus_info in ethtool -i output which is consistent with other emulated NICs and the output of lspci. Signed-off-by: Rick Jones <rick.jones2@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-31lguest: add export.h to lguest files for THIS_MODULE/EXPORT_SYMBOLPaul Gortmaker
We need this in advance of the module.h cleanup, or we'll get compile errors like this: CC drivers/lguest/lguest_device.o drivers/lguest/lguest_device.c: In function ‘lguest_devices_init’: drivers/lguest/lguest_device.c:490: error: ‘THIS_MODULE’ undeclared (first use in this function) Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-27lguest: move process freezing before pending signals checkMichal Hocko
run_guest tries to freeze the current process after it has handled pending interrupts and before it calls lguest_arch_run_guest. This doesn't work nicely if the task has been killed while being frozen and when we want to handle that signal as soon as possible. Let's move try_to_freeze before we check for pending signal so that we can get out of the loop as soon as possible. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-10-27lguest: Allow running under paravirt-enabled KVM.Rusty Russell
We actually can run under KVM, as it doesn't paravirtualize anything we need to use; reduce the check to checking we are the normal ringlevel. Reported-by: Stefanos Geraggelos <sgerag@cslab.ece.ntua.gr> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au># HG changeset patch
2011-07-22lguest: Fix in/out emulationRusty Russell
We were blatting too much of the register. Linux didn't care, but in theory it might. Reported-by: Jonas Maebe <jonas.maebe@elis.ugent.be> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-07-22lguest: update commentsRusty Russell
Also removes a long-unused #define and an extraneous semicolon. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-07-22lguest: Simplify device initialization.Rusty Russell
We used to notify the Host every time we updated a device's status. However, it only really needs to know when we're resetting the device, or failed to initialize it, or when we've finished our feature negotiation. In particular, we used to wait for VIRTIO_CONFIG_S_DRIVER_OK in the status byte before starting the device service threads. But this corresponds to the successful finish of device initialization, which might (like virtio_blk's partition scanning) use the device. So we had a hack, if they used the device before we expected we started the threads anyway. Now we hook into the finalize_features hook in the Guest: at that point we tell the Launcher that it can rely on the features we have acked. On the Launcher side, we look at the status at that point, and start servicing the device. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-07-22lguest: don't rewrite vmcall instructionsRusty Russell
Now we no longer use vmcall, we don't need to rewrite it in the Guest. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-07-22lguest: use a special 1:1 linear pagetable mode until first switch.Rusty Russell
The Host used to create some page tables for the Guest to use at the top of Guest memory; it would then tell the Guest where this was. In particular, it created linear mappings for 0 and 0xC0000000 addresses because lguest used to switch to its real page tables quite late in boot. However, since d50d8fe19 Linux initialized boot page tables in head_32.S even before the "are we lguest?" boot jump. So, now we can simplify things: the Host pagetable code assumes 1:1 linear mapping until it first calls the LHCALL_NEW_PGTABLE hypercall, which we now do before we reach C code. This also means that the Host doesn't need to know anything about the Guest's PAGE_OFFSET. (Non-Linux guests might not even have such a thing). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-05-06Correct occurrences ofRob Landley
- Documentation/kvm/ to Documentation/virtual/kvm - Documentation/uml/ to Documentation/virtual/uml - Documentation/lguest/ to Documentation/virtual/lguest throughout the kernel source tree. Signed-off-by: Rob Landley <rob@landley.net> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-01-20lguest: compile fixesRusty Russell
arch/x86/lguest/boot.c: In function ‘lguest_init_IRQ’: arch/x86/lguest/boot.c:824: error: macro "__this_cpu_write" requires 2 arguments, but only 1 given arch/x86/lguest/boot.c:824: error: ‘__this_cpu_write’ undeclared (first use in this function) arch/x86/lguest/boot.c:824: error: (Each undeclared identifier is reported only once arch/x86/lguest/boot.c:824: error: for each function it appears in.) drivers/lguest/x86/core.c: In function ‘copy_in_guest_info’: drivers/lguest/x86/core.c:94: error: lvalue required as left operand of assignment Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-01-20lguest: Use this_cpu_opsChristoph Lameter
Use this_cpu_ops in a couple of places in lguest. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-04-14lguest: stop using KVM hypercall mechanismRusty Russell
This is a partial revert of 4cd8b5e2a159 "lguest: use KVM hypercalls"; we revert to using (just as questionable but more reliable) int $15 for hypercalls. I didn't revert the register mapping, so we still use the same calling convention as kvm. KVM in more recent incarnations stopped injecting a fault when a guest tried to use the VMCALL instruction from ring 1, so lguest under kvm fails to make hypercalls. It was nice to share code with our KVM cousins, but this was overreach. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Matias Zabaljauregui <zabaljauregui@gmail.com> Cc: Avi Kivity <avi@redhat.com>
2010-04-14lguest: workaround cmpxchg8b_emu by ignoring cli in the guest.Rusty Russell
It's only used by cmpxchg8b_emu (see db677ffa5f5a for the gory details), and fixing that to be paravirt aware would be more work than simply ignoring it (and AFAICT only help lguest). This makes lguest work on machines which have cmpxchg8b, for kernels compiled for older processors. (We can't emulate it properly: the popf which expects to restore interrupts does not trap). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: virtualization@lists.osdl.org
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>