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2013-04-26kvm: destroy emulated devices on VM exitScott Wood
The hassle of getting refcounting right was greater than the hassle of keeping a list of devices to destroy on VM exit. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-26kvm/ppc/mpic: in-kernel MPIC emulationScott Wood
Hook the MPIC code up to the KVM interfaces, add locking, etc. Signed-off-by: Scott Wood <scottwood@freescale.com> [agraf: add stub function for kvmppc_mpic_set_epr, non-booke, 64bit] Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-26kvm: add device control APIScott Wood
Currently, devices that are emulated inside KVM are configured in a hardcoded manner based on an assumption that any given architecture only has one way to do it. If there's any need to access device state, it is done through inflexible one-purpose-only IOCTLs (e.g. KVM_GET/SET_LAPIC). Defining new IOCTLs for every little thing is cumbersome and depletes a limited numberspace. This API provides a mechanism to instantiate a device of a certain type, returning an ID that can be used to set/get attributes of the device. Attributes may include configuration parameters (e.g. register base address), device state, operational commands, etc. It is similar to the ONE_REG API, except that it acts on devices rather than vcpus. Both device types and individual attributes can be tested without having to create the device or get/set the attribute, without the need for separately managing enumerated capabilities. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-26KVM: Move irqfd resample cap handling to generic codeAlexander Graf
Now that we have most irqfd code completely platform agnostic, let's move irqfd's resample capability return to generic code as well. Signed-off-by: Alexander Graf <agraf@suse.de> Acked-by: Michael S. Tsirkin <mst@redhat.com>
2013-04-26KVM: Move irq routing setup to irqchip.cAlexander Graf
Setting up IRQ routes is nothing IOAPIC specific. Extract everything that really is generic code into irqchip.c and only leave the ioapic specific bits to irq_comm.c. Signed-off-by: Alexander Graf <agraf@suse.de> Acked-by: Michael S. Tsirkin <mst@redhat.com>
2013-04-26KVM: Extract generic irqchip logic into irqchip.cAlexander Graf
The current irq_comm.c file contains pieces of code that are generic across different irqchip implementations, as well as code that is fully IOAPIC specific. Split the generic bits out into irqchip.c. Signed-off-by: Alexander Graf <agraf@suse.de> Acked-by: Michael S. Tsirkin <mst@redhat.com>
2013-04-26KVM: Move irq routing to generic codeAlexander Graf
The IRQ routing set ioctl lives in the hacky device assignment code inside of KVM today. This is definitely the wrong place for it. Move it to the much more natural kvm_main.c. Signed-off-by: Alexander Graf <agraf@suse.de> Acked-by: Michael S. Tsirkin <mst@redhat.com>
2013-04-26KVM: Introduce CONFIG_HAVE_KVM_IRQ_ROUTINGAlexander Graf
Quite a bit of code in KVM has been conditionalized on availability of IOAPIC emulation. However, most of it is generically applicable to platforms that don't have an IOPIC, but a different type of irq chip. Make code that only relies on IRQ routing, not an APIC itself, on CONFIG_HAVE_KVM_IRQ_ROUTING, so that we can reuse it later. Signed-off-by: Alexander Graf <agraf@suse.de> Acked-by: Michael S. Tsirkin <mst@redhat.com>
2013-04-26KVM: Add KVM_IRQCHIP_NUM_PINS in addition to KVM_IOAPIC_NUM_PINSAlexander Graf
The concept of routing interrupt lines to an irqchip is nothing that is IOAPIC specific. Every irqchip has a maximum number of pins that can be linked to irq lines. So let's add a new define that allows us to reuse generic code for non-IOAPIC platforms. Signed-off-by: Alexander Graf <agraf@suse.de> Acked-by: Michael S. Tsirkin <mst@redhat.com>
2013-04-16KVM: VMX: Add the deliver posted interrupt algorithmYang Zhang
Only deliver the posted interrupt when target vcpu is running and there is no previous interrupt pending in pir. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-16KVM: Set TMR when programming ioapic entryYang Zhang
We already know the trigger mode of a given interrupt when programming the ioapice entry. So it's not necessary to set it in each interrupt delivery. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-16KVM: Call common update function when ioapic entry changed.Yang Zhang
Both TMR and EOI exit bitmap need to be updated when ioapic changed or vcpu's id/ldr/dfr changed. So use common function instead eoi exit bitmap specific function. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15KVM: Use eoi to track RTC interrupt delivery statusYang Zhang
Current interrupt coalescing logci which only used by RTC has conflict with Posted Interrupt. This patch introduces a new mechinism to use eoi to track interrupt: When delivering an interrupt to vcpu, the pending_eoi set to number of vcpu that received the interrupt. And decrease it when each vcpu writing eoi. No subsequent RTC interrupt can deliver to vcpu until all vcpus write eoi. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15KVM: Let ioapic know the irq line statusYang Zhang
Userspace may deliver RTC interrupt without query the status. So we want to track RTC EOI for this case. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15KVM: Force vmexit with virtual interrupt deliveryYang Zhang
Need the EOI to track interrupt deliver status, so force vmexit on EOI for rtc interrupt when enabling virtual interrupt delivery. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15KVM: Add reset/restore rtc_status supportYang Zhang
restore rtc_status from migration or save/restore Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15KVM: Return destination vcpu on interrupt injectionYang Zhang
Add a new parameter to know vcpus who received the interrupt. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15KVM: Introduce struct rtc_statusYang Zhang
rtc_status is used to track RTC interrupt delivery status. The pending_eoi will be increased by vcpu who received RTC interrupt and will be decreased when EOI to this interrupt. Also, we use dest_map to record the destination vcpu to avoid the case that vcpu who didn't get the RTC interupt, but issued EOI with same vector of RTC and descreased pending_eoi by mistake. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15KVM: Add vcpu info to ioapic_update_eoi()Yang Zhang
Add vcpu info to ioapic_update_eoi, so we can know which vcpu issued this EOI. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-08KVM: Move kvm_spurious_fault to x86.cGeoff Levand
The routine kvm_spurious_fault() is an x86 specific routine, so move it from virt/kvm/kvm_main.c to arch/x86/kvm/x86.c. Fixes this sparse warning when building on arm64: virt/kvm/kvm_main.c:warning: symbol 'kvm_spurious_fault' was not declared. Should it be static? Signed-off-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-08KVM: Make local routines staticGeoff Levand
The routines get_user_page_nowait(), kvm_io_bus_sort_cmp(), kvm_io_bus_insert_dev() and kvm_io_bus_get_first_dev() are only referenced within kvm_main.c, so give them static linkage. Fixes sparse warnings like these: virt/kvm/kvm_main.c: warning: symbol 'get_user_page_nowait' was not declared. Should it be static? Signed-off-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-07kvm: fix MMIO/PIO collision misdetectionMichael S. Tsirkin
PIO and MMIO are separate address spaces, but ioeventfd registration code mistakenly detected two eventfds as duplicate if they use the same address, even if one is PIO and another one MMIO. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-07KVM: Call kvm_apic_match_dest() to check destination vcpuYang Zhang
For a given vcpu, kvm_apic_match_dest() will tell you whether the vcpu in the destination list quickly. Drop kvm_calculate_eoi_exitmap() and use kvm_apic_match_dest() instead. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-04-07KVM: Allow cross page reads and writes from cached translations.Andrew Honig
This patch adds support for kvm_gfn_to_hva_cache_init functions for reads and writes that will cross a page. If the range falls within the same memslot, then this will be a fast operation. If the range is split between two memslots, then the slower kvm_read_guest and kvm_write_guest are used. Tested: Test against kvm_clock unit tests. Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-21Merge remote-tracking branch 'upstream/master' into queueMarcelo Tosatti
Merge reason: From: Alexander Graf <agraf@suse.de> "Just recently this really important patch got pulled into Linus' tree for 3.9: commit 1674400aaee5b466c595a8fc310488263ce888c7 Author: Anton Blanchard <anton <at> samba.org> Date: Tue Mar 12 01:51:51 2013 +0000 Without that commit, I can not boot my G5, thus I can't run automated tests on it against my queue. Could you please merge kvm/next against linus/master, so that I can base my trees against that?" * upstream/master: (653 commits) PCI: Use ROM images from firmware only if no other ROM source available sparc: remove unused "config BITS" sparc: delete "if !ULTRA_HAS_POPULATION_COUNT" KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798) KVM: x86: Convert MSR_KVM_SYSTEM_TIME to use gfn_to_hva_cache functions (CVE-2013-1797) KVM: x86: fix for buffer overflow in handling of MSR_KVM_SYSTEM_TIME (CVE-2013-1796) arm64: Kconfig.debug: Remove unused CONFIG_DEBUG_ERRORS arm64: Do not select GENERIC_HARDIRQS_NO_DEPRECATED inet: limit length of fragment queue hash table bucket lists qeth: Fix scatter-gather regression qeth: Fix invalid router settings handling qeth: delay feature trace sgy-cts1000: Remove __dev* attributes KVM: x86: fix deadlock in clock-in-progress request handling KVM: allow host header to be included even for !CONFIG_KVM hwmon: (lm75) Fix tcn75 prefix hwmon: (lm75.h) Update header inclusion MAINTAINERS: Remove Mark M. Hoffman xfs: ensure we capture IO errors correctly xfs: fix xfs_iomap_eof_prealloc_initial_size type ... Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-19KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798)Andy Honig
If the guest specifies a IOAPIC_REG_SELECT with an invalid value and follows that with a read of the IOAPIC_REG_WINDOW KVM does not properly validate that request. ioapic_read_indirect contains an ASSERT(redir_index < IOAPIC_NUM_PINS), but the ASSERT has no effect in non-debug builds. In recent kernels this allows a guest to cause a kernel oops by reading invalid memory. In older kernels (pre-3.3) this allows a guest to read from large ranges of host memory. Tested: tested against apic unit tests. Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-11kvm: Iterate over only vcpus that are preemptedRaghavendra K T
This helps in filtering out the eligible candidates further and thus potentially helps in quickly allowing preempted lockholders to run. Note that if a vcpu was spinning during preemption we filter them by checking whether they are preempted due to pause loop exit. Reviewed-by: Chegu Vinod <chegu_vinod@hp.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-11kvm: Record the preemption status of vcpus using preempt notifiersRaghavendra K T
Note that we mark as preempted only when vcpu's task state was Running during preemption. Thanks Jiannan, Avi for preemption notifier ideas. Thanks Gleb, PeterZ for their precious suggestions. Thanks Srikar for an idea on avoiding rcu lock while checking task state that improved overcommit numbers. Reviewed-by: Chegu Vinod <chegu_vinod@hp.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-03-05KVM: ioeventfd for virtio-ccw devices.Cornelia Huck
Enhance KVM_IOEVENTFD with a new flag that allows to attach to virtio-ccw devices on s390 via the KVM_VIRTIO_CCW_NOTIFY_BUS. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-05KVM: Initialize irqfd from kvm_init().Cornelia Huck
Currently, eventfd introduces module_init/module_exit functions to initialize/cleanup the irqfd workqueue. This only works, however, if no other module_init/module_exit functions are built into the same module. Let's just move the initialization and cleanup to kvm_init and kvm_exit. This way, it is also clearer where kvm startup may fail. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-04KVM: set_memory_region: Refactor commit_memory_region()Takuya Yoshikawa
This patch makes the parameter old a const pointer to the old memory slot and adds a new parameter named change to know the change being requested: the former is for removing extra copying and the latter is for cleaning up the code. Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-04KVM: set_memory_region: Refactor prepare_memory_region()Takuya Yoshikawa
This patch drops the parameter old, a copy of the old memory slot, and adds a new parameter named change to know the change being requested. This not only cleans up the code but also removes extra copying of the memory slot structure. Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-04KVM: set_memory_region: Make kvm_mr_change available to arch codeTakuya Yoshikawa
This will be used for cleaning up prepare/commit_memory_region() later. Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-04KVM: set_memory_region: Drop user_alloc from set_memory_region()Takuya Yoshikawa
Except ia64's stale code, KVM_SET_MEMORY_REGION support, this is only used for sanity checks in __kvm_set_memory_region() which can easily be changed to use slot id instead. Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-03-04KVM: set_memory_region: Drop user_alloc from prepare/commit_memory_region()Takuya Yoshikawa
X86 does not use this any more. The remaining user, s390's !user_alloc check, can be simply removed since KVM_SET_MEMORY_REGION ioctl is no longer supported. Note: fixed powerpc's indentations with spaces to suppress checkpatch errors. Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-02-27hlist: drop the node parameter from iteratorsSasha Levin
I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-11KVM: Remove user_alloc from struct kvm_memory_slotTakuya Yoshikawa
This field was needed to differentiate memory slots created by the new API, KVM_SET_USER_MEMORY_REGION, from those by the old equivalent, KVM_SET_MEMORY_REGION, whose support was dropped long before: commit b74a07beed0e64bfba413dcb70dd6749c57f43dc KVM: Remove kernel-allocated memory regions Although we also have private memory slots to which KVM allocates memory with vm_mmap(), !user_alloc slots in other words, the slot id should be enough for differentiating them. Note: corresponding function parameters will be removed later. Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-02-04KVM: set_memory_region: Disallow changing read-only attribute laterTakuya Yoshikawa
As Xiao pointed out, there are a few problems with it: - kvm_arch_commit_memory_region() write protects the memory slot only for GET_DIRTY_LOG when modifying the flags. - FNAME(sync_page) uses the old spte value to set a new one without checking KVM_MEM_READONLY flag. Since we flush all shadow pages when creating a new slot, the simplest fix is to disallow such problematic flag changes: this is safe because no one is doing such things. Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-02-04KVM: set_memory_region: Identify the requested change explicitlyTakuya Yoshikawa
KVM_SET_USER_MEMORY_REGION forces __kvm_set_memory_region() to identify what kind of change is being requested by checking the arguments. The current code does this checking at various points in code and each condition being used there is not easy to understand at first glance. This patch consolidates these checks and introduces an enum to name the possible changes to clean up the code. Although this does not introduce any functional changes, there is one change which optimizes the code a bit: if we have nothing to change, the new code returns 0 immediately. Note that the return value for this case cannot be changed since QEMU relies on it: we noticed this when we changed it to -EINVAL and got a section mismatch error at the final stage of live migration. Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-01-29kvm: Handle yield_to failure return code for potential undercommit caseRaghavendra K T
yield_to returns -ESRCH, When source and target of yield_to run queue length is one. When we see three successive failures of yield_to we assume we are in potential undercommit case and abort from PLE handler. The assumption is backed by low probability of wrong decision for even worst case scenarios such as average runqueue length between 1 and 2. More detail on rationale behind using three tries: if p is the probability of finding rq length one on a particular cpu, and if we do n tries, then probability of exiting ple handler is: p^(n+1) [ because we would have come across one source with rq length 1 and n target cpu rqs with length 1 ] so num tries: probability of aborting ple handler (1.5x overcommit) 1 1/4 2 1/8 3 1/16 We can increase this probability with more tries, but the problem is the overhead. Also, If we have tried three times that means we would have iterated over 3 good eligible vcpus along with many non-eligible candidates. In worst case if we iterate all the vcpus, we reduce 1x performance and overcommit performance get hit. note that we do not update last boosted vcpu in failure cases. Thank Avi for raising question on aborting after first fail from yield_to. Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Tested-by: Chegu Vinod <chegu_vinod@hp.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-29x86, apicv: add virtual interrupt delivery supportYang Zhang
Virtual interrupt delivery avoids KVM to inject vAPIC interrupts manually, which is fully taken care of by the hardware. This needs some special awareness into existing interrupr injection path: - for pending interrupt, instead of direct injection, we may need update architecture specific indicators before resuming to guest. - A pending interrupt, which is masked by ISR, should be also considered in above update action, since hardware will decide when to inject it at right time. Current has_interrupt and get_interrupt only returns a valid vector from injection p.o.v. Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-27kvm: Obey read-only mappings in iommuAlex Williamson
We've been ignoring read-only mappings and programming everything into the iommu as read-write. Fix this to only include the write access flag when read-only is not set. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-27kvm: Force IOMMU remapping on memory slot read-only flag changesAlex Williamson
Memory slot flags can be altered without changing other parameters of the slot. The read-only attribute is the only one the IOMMU cares about, so generate an un-map, re-map when this occurs. This also avoid unnecessarily re-mapping the slot when no IOMMU visible changes are made. Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-17KVM: set_memory_region: Remove unnecessary variable memslotTakuya Yoshikawa
One such variable, slot, is enough for holding a pointer temporarily. We also remove another local variable named slot, which is limited in a block, since it is confusing to have the same name in this function. Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-17KVM: set_memory_region: Don't check for overlaps unless we create or move a slotTakuya Yoshikawa
Don't need the check for deleting an existing slot or just modifiying the flags. Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-17KVM: set_memory_region: Don't jump to out_free unnecessarilyTakuya Yoshikawa
This makes the separation between the sanity checks and the rest of the code a bit clearer. Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-01-14KVM: Write protect the updated slot only when dirty logging is enabledTakuya Yoshikawa
Calling kvm_mmu_slot_remove_write_access() for a deleted slot does nothing but search for non-existent mmu pages which have mappings to that deleted memory; this is safe but a waste of time. Since we want to make the function rmap based in a later patch, in a manner which makes it unsafe to be called for a deleted slot, we makes the caller see if the slot is non-zero and being dirty logged. Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-12-24KVM: move the code that installs new slots array to a separate function.Gleb Natapov
Move repetitive code sequence to a separate function. Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-12-23kvm: Fix memory slot generation updatesAlex Williamson
Previous patch "kvm: Minor memory slot optimization" (b7f69c555ca43) overlooked the generation field of the memory slots. Re-using the original memory slots left us with with two slightly different memory slots with the same generation. To fix this, make update_memslots() take a new parameter to specify the last generation. This also makes generation management more explicit to avoid such problems in the future. Reported-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-12-23KVM: remove a wrong hack of delivery PIT intr to vcpu0Yang Zhang
This hack is wrong. The pin number of PIT is connected to 2 not 0. This means this hack never takes effect. So it is ok to remove it. Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>