Граф коммитов

194 Коммитов

Автор SHA1 Сообщение Дата
Avi Kivity 399ec807dd KVM: Userspace controlled irq routing
Currently KVM has a static routing from GSI numbers to interrupts (namely,
0-15 are mapped 1:1 to both PIC and IOAPIC, and 16:23 are mapped 1:1 to
the IOAPIC).  This is insufficient for several reasons:

- HPET requires non 1:1 mapping for the timer interrupt
- MSIs need a new method to assign interrupt numbers and dispatch them
- ACPI APIC mode needs to be able to reassign the PCI LINK interrupts to the
  ioapics

This patch implements an interrupt routing table (as a linked list, but this
can be easily changed) and a userspace interface to replace the table.  The
routing table is initialized according to the current hardwired mapping.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:03:06 +02:00
Amit Shah 1935547504 KVM: x86: Fix typos and whitespace errors
Some typos, comments, whitespace errors corrected in the cpuid code

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:03:05 +02:00
Avi Kivity 5a41accd3f KVM: MMU: Only enable cr4_pge role in shadow mode
Two dimensional paging is only confused by it.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:03:04 +02:00
Avi Kivity 269e05e485 KVM: Properly lock PIT creation
Otherwise, two threads can create a PIT in parallel and cause a memory leak.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:03:01 +02:00
Marcelo Tosatti 52d939a0bf KVM: PIT: provide an option to disable interrupt reinjection
Certain clocks (such as TSC) in older 2.6 guests overaccount for lost
ticks, causing severe time drift. Interrupt reinjection magnifies the
problem.

Provide an option to disable it.

[avi: allow room for expansion in case we want to disable reinjection
      of other timers]

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:55 +02:00
Avi Kivity 61a6bd672b KVM: Fallback support for MSR_VM_HSAVE_PA
Since we advertise MSR_VM_HSAVE_PA, userspace will attempt to read it
even on Intel.  Implement fake support for this MSR to avoid the
warnings.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:54 +02:00
Izik Eidus 0f34607440 KVM: remove the vmap usage
vmap() on guest pages hides those pages from the Linux mm for an extended
(userspace determined) amount of time.  Get rid of it.

Signed-off-by: Izik Eidus <ieidus@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:54 +02:00
Izik Eidus 77c2002e7c KVM: introduce kvm_read_guest_virt, kvm_write_guest_virt
This commit change the name of emulator_read_std into kvm_read_guest_virt,
and add new function name kvm_write_guest_virt that allow writing into a
guest virtual address.

Signed-off-by: Izik Eidus <ieidus@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:54 +02:00
Marcelo Tosatti 53f658b3c3 KVM: VMX: initialize TSC offset relative to vm creation time
VMX initializes the TSC offset for each vcpu at different times, and
also reinitializes it for vcpus other than 0 on APIC SIPI message.

This bug causes the TSC's to appear unsynchronized in the guest, even if
the host is good.

Older Linux kernels don't handle the situation very well, so
gettimeofday is likely to go backwards in time:

http://www.mail-archive.com/kvm@vger.kernel.org/msg02955.html
http://sourceforge.net/tracker/index.php?func=detail&aid=2025534&group_id=180599&atid=893831

Fix it by initializating the offset of each vcpu relative to vm creation
time, and moving it from vmx_vcpu_reset to vmx_vcpu_setup, out of the
APIC MP init path.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:53 +02:00
Avi Kivity 2f0b3d60b2 KVM: MMU: Segregate mmu pages created with different cr4.pge settings
Don't allow a vcpu with cr4.pge cleared to use a shadow page created with
cr4.pge set; this might cause a cr3 switch not to sync ptes that have the
global bit set (the global bit has no effect if !cr4.pge).

This can only occur on smp with different cr4.pge settings for different
vcpus (since a cr4 change will resync the shadow ptes), but there's no
cost to being correct here.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:51 +02:00
Jan Kiszka ae675ef01c KVM: x86: Wire-up hardware breakpoints for guest debugging
Add the remaining bits to make use of debug registers also for guest
debugging, thus enabling the use of hardware breakpoints and
watchpoints.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:50 +02:00
Jan Kiszka 42dbaa5a05 KVM: x86: Virtualize debug registers
So far KVM only had basic x86 debug register support, once introduced to
realize guest debugging that way. The guest itself was not able to use
those registers.

This patch now adds (almost) full support for guest self-debugging via
hardware registers. It refactors the code, moving generic parts out of
SVM (VMX was already cleaned up by the KVM_SET_GUEST_DEBUG patches), and
it ensures that the registers are properly switched between host and
guest.

This patch also prepares debug register usage by the host. The latter
will (once wired-up by the following patch) allow for hardware
breakpoints/watchpoints in guest code. If this is enabled, the guest
will only see faked debug registers without functionality, but with
content reflecting the guest's modifications.

Tested on Intel only, but SVM /should/ work as well, but who knows...

Known limitations: Trapping on tss switch won't work - most probably on
Intel.

Credits also go to Joerg Roedel - I used his once posted debugging
series as platform for this patch.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:49 +02:00
Jan Kiszka d0bfb940ec KVM: New guest debug interface
This rips out the support for KVM_DEBUG_GUEST and introduces a new IOCTL
instead: KVM_SET_GUEST_DEBUG. The IOCTL payload consists of a generic
part, controlling the "main switch" and the single-step feature. The
arch specific part adds an x86 interface for intercepting both types of
debug exceptions separately and re-injecting them when the host was not
interested. Moveover, the foundation for guest debugging via debug
registers is layed.

To signal breakpoint events properly back to userland, an arch-specific
data block is now returned along KVM_EXIT_DEBUG. For x86, the arch block
contains the PC, the debug exception, and relevant debug registers to
tell debug events properly apart.

The availability of this new interface is signaled by
KVM_CAP_SET_GUEST_DEBUG. Empty stubs for not yet supported archs are
provided.

Note that both SVM and VTX are supported, but only the latter was tested
yet. Based on the experience with all those VTX corner case, I would be
fairly surprised if SVM will work out of the box.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:49 +02:00
Alexander Graf d80174745b KVM: SVM: Only allow setting of EFER_SVME when CPUID SVM is set
Userspace has to tell the kernel module somehow that nested SVM should be used.
The easiest way that doesn't break anything I could think of is to implement

if (cpuid & svm)
    allow write to efer
else
    deny write to efer

Old userspaces mask the SVM capability bit, so they don't break.
In order to find out that the SVM capability is set, I had to split the
kvm_emulate_cpuid into a finding and an emulating part.

(introduced in v6)

Acked-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:48 +02:00
Alexander Graf b286d5d8b0 KVM: SVM: Implement hsave
Implement the hsave MSR, that gives the VCPU a GPA to save the
old guest state in.

v2 allows userspace to save/restore hsave
v4 dummys out the hsave MSR, so we use a host page
v6 remembers the guest's hsave and exports the MSR

Acked-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:46 +02:00
Marcelo Tosatti abe6655dd6 KVM: x86: disable kvmclock on non constant TSC hosts
This is better.

Currently, this code path is posing us big troubles,
and we won't have a decent patch in time. So, temporarily
disable it.

Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-02-15 02:47:36 +02:00
Sheng Yang ba4cef31d5 KVM: Fix racy in kvm_free_assigned_irq
In the past, kvm_get_kvm() and kvm_put_kvm() was called in assigned device irq
handler and interrupt_work, in order to prevent cancel_work_sync() in
kvm_free_assigned_irq got a illegal state when waiting for interrupt_work done.
But it's tricky and still got two problems:

1. A bug ignored two conditions that cancel_work_sync() would return true result
in a additional kvm_put_kvm().

2. If interrupt type is MSI, we would got a window between cancel_work_sync()
and free_irq(), which interrupt would be injected again...

This patch discard the reference count used for irq handler and interrupt_work,
and ensure the legal state by moving the free function at the very beginning of
kvm_destroy_vm(). And the patch fix the second bug by disable irq before
cancel_work_sync(), which may result in nested disable of irq but OK for we are
going to free it.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-02-15 02:47:36 +02:00
Sheng Yang ad8ba2cd44 KVM: Add kvm_arch_sync_events to sync with asynchronize events
kvm_arch_sync_events is introduced to quiet down all other events may happen
contemporary with VM destroy process, like IRQ handler and work struct for
assigned device.

For kvm_arch_sync_events is called at the very beginning of kvm_destroy_vm(), so
the state of KVM here is legal and can provide a environment to quiet down other
events.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-02-15 02:47:36 +02:00
Joerg Roedel 19de40a847 KVM: change KVM to use IOMMU API
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-01-03 14:11:07 +01:00
Jan Kiszka 4531220b71 KVM: x86: Rework user space NMI injection as KVM_CAP_USER_NMI
There is no point in doing the ready_for_nmi_injection/
request_nmi_window dance with user space. First, we don't do this for
in-kernel irqchip anyway, while the code path is the same as for user
space irqchip mode. And second, there is nothing to loose if a pending
NMI is overwritten by another one (in contrast to IRQs where we have to
save the number). Actually, there is even the risk of raising spurious
NMIs this way because the reason for the held-back NMI might already be
handled while processing the first one.

Therefore this patch creates a simplified user space NMI injection
interface, exporting it under KVM_CAP_USER_NMI and dropping the old
KVM_CAP_NMI capability. And this time we also take care to provide the
interface only on archs supporting NMIs via KVM (right now only x86).

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:47 +02:00
Avi Kivity ca9edaee1a KVM: Consolidate userspace memory capability reporting into common code
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:46 +02:00
Marcelo Tosatti ad218f85e3 KVM: MMU: prepopulate the shadow on invlpg
If the guest executes invlpg, peek into the pagetable and attempt to
prepopulate the shadow entry.

Also stop dirty fault updates from interfering with the fork detector.

2% improvement on RHEL3/AIM7.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:44 +02:00
Marcelo Tosatti 6cffe8ca4a KVM: MMU: skip global pgtables on sync due to cr3 switch
Skip syncing global pages on cr3 switch (but not on cr4/cr0). This is
important for Linux 32-bit guests with PAE, where the kmap page is
marked as global.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:44 +02:00
Nitin A Kamble 0fdf8e59fa KVM: Fix cpuid iteration on multiple leaves per eac
The code to traverse the cpuid data array list for counting type of leaves is
currently broken.

This patches fixes the 2 things in it.

 1. Set the 1st counting entry's flag KVM_CPUID_FLAG_STATE_READ_NEXT. Without
    it the code will never find a valid entry.

 2. Also the stop condition in the for loop while looking for the next unflaged
    entry is broken. It needs to stop when it find one matching entry;
    and in the case of count of 1, it will be the same entry found in this
    iteration.

Signed-Off-By: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:52:24 +02:00
Nitin A Kamble 0853d2c1d8 KVM: Fix cpuid leaf 0xb loop termination
For cpuid leaf 0xb the bits 8-15 in ECX register define the end of counting
leaf.      The previous code was using bits 0-7 for this purpose, which is
a bug.

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:52:24 +02:00
Sheng Yang 6eb55818c0 KVM: Enable Function Level Reset for assigned device
Ideally, every assigned device should in a clear condition before and after
assignment, so that the former state of device won't affect later work.
Some devices provide a mechanism named Function Level Reset, which is
defined in PCI/PCI-e document. We should execute it before and after device
assignment.

(But sadly, the feature is new, and most device on the market now don't
support it. We are considering using D0/D3hot transmit to emulate it later,
but not that elegant and reliable as FLR itself.)

[Update: Reminded by Xiantao, execute FLR after we ensure that the device can
be assigned to the guest.]

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:49 +02:00
Guillaume Thouvenin e93f36bcfa KVM: allow emulator to adjust rip for emulated pio instructions
If we call the emulator we shouldn't call skip_emulated_instruction()
in the first place, since the emulator already computes the next rip
for us. Thus we move ->skip_emulated_instruction() out of
kvm_emulate_pio() and into handle_io() (and the svm equivalent). We
also replaced "return 0" by "break" in the "do_io:" case because now
the shadow register state needs to be committed. Otherwise eip will never
be updated.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:48 +02:00
Amit Shah b8222ad2e5 KVM: x86: Fix typo in function name
get_segment_descritptor_dtable() contains an obvious type.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:47 +02:00
Sheng Yang 64d4d52175 KVM: Enable MTRR for EPT
The effective memory type of EPT is the mixture of MSR_IA32_CR_PAT and memory
type field of EPT entry.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:45 +02:00
Sheng Yang 468d472f3f KVM: VMX: Add PAT support for EPT
GUEST_PAT support is a new feature introduced by Intel Core i7 architecture.
With this, cpu would save/load guest and host PAT automatically, for EPT memory
type in guest depends on MSR_IA32_CR_PAT.

Also add save/restore for MSR_IA32_CR_PAT.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:44 +02:00
Sheng Yang 0bed3b568b KVM: Improve MTRR structure
As well as reset mmu context when set MTRR.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:44 +02:00
Gleb Natapov 5f179287fa KVM: call kvm_arch_vcpu_reset() instead of the kvm_x86_ops callback
Call kvm_arch_vcpu_reset() instead of directly using arch callback.
The function does additional things.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:43 +02:00
Jan Kiszka c4abb7c9cd KVM: x86: Support for user space injected NMIs
Introduces the KVM_NMI IOCTL to the generic x86 part of KVM for
injecting NMIs from user space and also extends the statistic report
accordingly.

Based on the original patch by Sheng Yang.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:42 +02:00
Jan Kiszka 0496fbb973 KVM: x86: VCPU with pending NMI is runnabled
Ensure that a VCPU with pending NMIs is considered runnable.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:42 +02:00
Jan Kiszka 448fa4a9c5 KVM: x86: Reset pending/inject NMI state on CPU reset
CPU reset invalidates pending or already injected NMIs, therefore reset
the related state variables.

Based on original patch by Gleb Natapov.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:40 +02:00
Sheng Yang 5550af4df1 KVM: Fix guest shared interrupt with in-kernel irqchip
Every call of kvm_set_irq() should offer an irq_source_id, which is
allocated by kvm_request_irq_source_id(). Based on irq_source_id, we
identify the irq source and implement logical OR for shared level
interrupts.

The allocated irq_source_id can be freed by kvm_free_irq_source_id().

Currently, we support at most sizeof(unsigned long) different irq sources.

[Amit: - rebase to kvm.git HEAD
       - move definition of KVM_USERSPACE_IRQ_SOURCE_ID to common file
       - move kvm_request_irq_source_id to the update_irq ioctl]

[Xiantao: - Add kvm/ia64 stuff and make it work for kvm/ia64 guests]

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-28 14:21:34 +02:00
Linus Torvalds 08d19f51f0 Merge branch 'kvm-updates/2.6.28' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm
* 'kvm-updates/2.6.28' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: (134 commits)
  KVM: ia64: Add intel iommu support for guests.
  KVM: ia64: add directed mmio range support for kvm guests
  KVM: ia64: Make pmt table be able to hold physical mmio entries.
  KVM: Move irqchip_in_kernel() from ioapic.h to irq.h
  KVM: Separate irq ack notification out of arch/x86/kvm/irq.c
  KVM: Change is_mmio_pfn to kvm_is_mmio_pfn, and make it common for all archs
  KVM: Move device assignment logic to common code
  KVM: Device Assignment: Move vtd.c from arch/x86/kvm/ to virt/kvm/
  KVM: VMX: enable invlpg exiting if EPT is disabled
  KVM: x86: Silence various LAPIC-related host kernel messages
  KVM: Device Assignment: Map mmio pages into VT-d page table
  KVM: PIC: enhance IPI avoidance
  KVM: MMU: add "oos_shadow" parameter to disable oos
  KVM: MMU: speed up mmu_unsync_walk
  KVM: MMU: out of sync shadow core
  KVM: MMU: mmu_convert_notrap helper
  KVM: MMU: awareness of new kvm_mmu_zap_page behaviour
  KVM: MMU: mmu_parent_walk
  KVM: x86: trap invlpg
  KVM: MMU: sync roots on mmu reload
  ...
2008-10-16 15:36:00 -07:00
Harvey Harrison 80a914dc05 misc: replace __FUNCTION__ with __func__
__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 11:21:30 -07:00
Xiantao Zhang 8a98f6648a KVM: Move device assignment logic to common code
To share with other archs, this patch moves device assignment
logic to common parts.

Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 14:25:33 +02:00
Jan Kiszka 1b10bf31a5 KVM: x86: Silence various LAPIC-related host kernel messages
KVM-x86 dumps a lot of debug messages that have no meaning for normal
operation:
 - INIT de-assertion is ignored
 - SIPIs are sent and received
 - APIC writes are unaligned or < 4 byte long
   (Windows Server 2003 triggers this on SMP)

Degrade them to true debug messages, keeping the host kernel log clean
for real problems.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-15 14:25:30 +02:00
Marcelo Tosatti e48258009d KVM: PIC: enhance IPI avoidance
The PIC code makes little effort to avoid kvm_vcpu_kick(), resulting in
unnecessary guest exits in some conditions.

For example, if the timer interrupt is routed through the IOAPIC, IRR
for IRQ 0 will get set but not cleared, since the APIC is handling the
acks.

This means that everytime an interrupt < 16 is triggered, the priority
logic will find IRQ0 pending and send an IPI to vcpu0 (in case IRQ0 is
not masked, which is Linux's case).

Introduce a new variable isr_ack to represent the IRQ's for which the
guest has been signalled / cleared the ISR. Use it to avoid more than
one IPI per trigger-ack cycle, in addition to the avoidance when ISR is
set in get_priority().

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-15 14:25:28 +02:00
Marcelo Tosatti 4731d4c7a0 KVM: MMU: out of sync shadow core
Allow guest pagetables to go out of sync.  Instead of emulating write
accesses to guest pagetables, or unshadowing them, we un-write-protect
the page table and allow the guest to modify it at will.  We rely on
invlpg executions to synchronize individual ptes, and will synchronize
the entire pagetable on tlb flushes.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-15 14:25:25 +02:00
Marcelo Tosatti a7052897b3 KVM: x86: trap invlpg
With pages out of sync invlpg needs to be trapped. For now simply nuke
the entry.

Untested on AMD.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-15 14:25:21 +02:00
Marcelo Tosatti 0ba73cdadb KVM: MMU: sync roots on mmu reload
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-15 14:25:20 +02:00
Gleb Natapov af2152f545 KVM: don't enter guest after SIPI was received by a CPU
The vcpu should process pending SIPI message before entering guest mode again.
kvm_arch_vcpu_runnable() returns true if the vcpu is in SIPI state, so
we can't call it here.

Signed-off-by: Gleb Natapov <gleb@qumranet.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-15 14:25:09 +02:00
Harvey Harrison 2259e3a7a6 KVM: x86.c make kvm_load_realmode_segment static
Noticed by sparse:
arch/x86/kvm/x86.c:3591:5: warning: symbol 'kvm_load_realmode_segment' was not declared. Should it be static?

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-15 14:25:07 +02:00
Marcelo Tosatti 4c2155ce81 KVM: switch to get_user_pages_fast
Convert gfn_to_pfn to use get_user_pages_fast, which can do lockless
pagetable lookups on x86. Kernel compilation on 4-way guest is 3.7%
faster on VMX.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-15 14:25:06 +02:00
Amit Shah bfadaded0d KVM: Device Assignment: Free device structures if IRQ allocation fails
When an IRQ allocation fails, we free up the device structures and
disable the device so that we can unregister the device in the
userspace and not expose it to the guest at all.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-15 14:25:04 +02:00
Ben-Ami Yassour 62c476c7c7 KVM: Device Assignment with VT-d
Based on a patch by: Kay, Allen M <allen.m.kay@intel.com>

This patch enables PCI device assignment based on VT-d support.
When a device is assigned to the guest, the guest memory is pinned and
the mapping is updated in the VT-d IOMMU.

[Amit: Expose KVM_CAP_IOMMU so we can check if an IOMMU is present
and also control enable/disable from userspace]

Signed-off-by: Kay, Allen M <allen.m.kay@intel.com>
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Ben-Ami Yassour <benami@il.ibm.com>
Signed-off-by: Amit Shah <amit.shah@qumranet.com>

Acked-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 14:25:04 +02:00
Marcelo Tosatti 9c3e4aab5a KVM: x86: unhalt vcpu0 on reset
Since "KVM: x86: do not execute halted vcpus", HLT by vcpu0 before system
reset by the IO thread will hang the guest.

Mark vcpu as runnable in such case.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:26 +02:00
Marcelo Tosatti d76901750a KVM: x86: do not execute halted vcpus
Offline or uninitialized vcpu's can be executed if requested to perform
userspace work.

Follow Avi's suggestion to handle halted vcpu's in the main loop,
simplifying kvm_emulate_halt(). Introduce a new vcpu->requests bit to
indicate events that promote state from halted to running.

Also standardize vcpu wake sites.

Signed-off-by: Marcelo Tosatti <mtosatti <at> redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:26 +02:00
Avi Kivity fa89a81766 KVM: Add statistics for guest irq injections
These can help show whether a guest is making progress or not.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:25 +02:00
Joerg Roedel a89c1ad270 KVM: add MC5_MISC msr read support
Currently KVM implements MC0-MC4_MISC read support. When booting Linux this
results in KVM warnings in the kernel log when the guest tries to read
MC5_MISC. Fix this warnings with this patch.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:24 +02:00
Avi Kivity acee3c04e8 KVM: Allocate guest memory as MAP_PRIVATE, not MAP_SHARED
There is no reason to share internal memory slots with fork()ed instances.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:23 +02:00
Avi Kivity f4bbd9aaaa KVM: Load real mode segments correctly
Real mode segments to not reference the GDT or LDT; they simply compute
base = selector * 16.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:21 +02:00
Harvey Harrison ee032c993e KVM: make irq ack notifier functions static
sparse says:

arch/x86/kvm/x86.c:107:32: warning: symbol 'kvm_find_assigned_dev' was not declared. Should it be static?
arch/x86/kvm/i8254.c:225:6: warning: symbol 'kvm_pit_ack_irq' was not declared. Should it be static?

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:21 +02:00
Amit Shah 29c8fa32c5 KVM: Use kvm_set_irq to inject interrupts
... instead of using the pic and ioapic variants

Signed-off-by: Amit Shah <amit.shah@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:21 +02:00
Amit Shah 6762b7299a KVM: Device assignment: Check for privileges before assigning irq
Even though we don't share irqs at the moment, we should ensure
regular user processes don't try to allocate system resources.

We check for capability to access IO devices (CAP_SYS_RAWIO) before
we request_irq on behalf of the guest.

Noticed by Avi.

Signed-off-by: Amit Shah <amit.shah@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:20 +02:00
Marcelo Tosatti 29415c37f0 KVM: set debug registers after "schedulable" section
The vcpu thread can be preempted after the guest_debug_pre() callback,
resulting in invalid debug registers on the new vcpu.

Move it inside the non-preemptable section.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:19 +02:00
Dave Hansen b772ff362e KVM: Reduce stack usage in kvm_arch_vcpu_ioctl()
[sheng: fix KVM_GET_LAPIC using wrong size]

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:18 +02:00
Dave Hansen f0d662759a KVM: Reduce kvm stack usage in kvm_arch_vm_ioctl()
On my machine with gcc 3.4, kvm uses ~2k of stack in a few
select functions.  This is mostly because gcc fails to
notice that the different case: statements could have their
stack usage combined.  It overflows very nicely if interrupts
happen during one of these large uses.

This patch uses two methods for reducing stack usage.
1. dynamically allocate large objects instead of putting
   on the stack.
2. Use a union{} member for all of the case variables. This
   tricks gcc into combining them all into a single stack
   allocation. (There's also a comment on this)

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:18 +02:00
Ben-Ami Yassour 4d5c5d0fe8 KVM: pci device assignment
Based on a patch from: Amit Shah <amit.shah@qumranet.com>

This patch adds support for handling PCI devices that are assigned to
the guest.

The device to be assigned to the guest is registered in the host kernel
and interrupt delivery is handled.  If a device is already assigned, or
the device driver for it is still loaded on the host, the device
assignment is failed by conveying a -EBUSY reply to the userspace.

Devices that share their interrupt line are not supported at the moment.

By itself, this patch will not make devices work within the guest.
The VT-d extension is required to enable the device to perform DMA.
Another alternative is PVDMA.

Signed-off-by: Amit Shah <amit.shah@qumranet.com>
Signed-off-by: Ben-Ami Yassour <benami@il.ibm.com>
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:18 +02:00
Alexander Graf b5e2fec0eb KVM: Ignore DEBUGCTL MSRs with no effect
Netware writes to DEBUGCTL and reads from the DEBUGCTL and LAST*IP MSRs
without further checks and is really confused to receive a #GP during that.
To make it happy we should just make them stubs, which is exactly what SVM
already does.

Writes to DEBUGCTL that are vendor-specific are resembled to behave as if the
virtual CPU does not know them.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:15 +02:00
Avi Kivity 26eef70c3e KVM: Clear exception queue before emulating an instruction
If we're emulating an instruction, either it will succeed, in which case
any previously queued exception will be spurious, or we will requeue the
same exception.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:13 +02:00
Marcelo Tosatti 5fdbf9765b KVM: x86: accessors for guest registers
As suggested by Avi, introduce accessors to read/write guest registers.
This simplifies the ->cache_regs/->decache_regs interface, and improves
register caching which is important for VMX, where the cost of
vmcs_read/vmcs_write is significant.

[avi: fix warnings]

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:13:57 +02:00
Avi Kivity ed84862433 KVM: Advertise synchronized mmu support to userspace
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-29 12:34:02 +03:00
Andrea Arcangeli 604b38ac03 KVM: Allow browsing memslots with mmu_lock
This allows reading memslots with only the mmu_lock hold for mmu
notifiers that runs in atomic context and with mmu_lock held.

Signed-off-by: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-29 12:33:50 +03:00
Andrea Arcangeli a1708ce8a3 KVM: Allow reading aliases with mmu_lock
This allows the mmu notifier code to run unalias_gfn with only the
mmu_lock held.  Only alias writes need the mmu_lock held. Readers will
either take the slots_lock in read mode or the mmu_lock.

Signed-off-by: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-29 12:33:40 +03:00
Marcelo Tosatti c93cd3a588 KVM: task switch: translate guest segment limit to virt-extension byte granular field
If 'g' is one then limit is 4kb granular.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-27 11:34:10 +03:00
Marcelo Tosatti 34198bf842 KVM: task switch: use seg regs provided by subarch instead of reading from GDT
There is no guarantee that the old TSS descriptor in the GDT contains
the proper base address. This is the case for Windows installation's
reboot-via-triplefault.

Use guest registers instead. Also translate the address properly.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-27 11:34:09 +03:00
Marcelo Tosatti 98899aa0e0 KVM: task switch: segment base is linear address
The segment base is always a linear address, so translate before
accessing guest memory.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-27 11:34:09 +03:00
Marcelo Tosatti 34d4cb8fca KVM: MMU: nuke shadowed pgtable pages and ptes on memslot destruction
Flush the shadow mmu before removing regions to avoid stale entries.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:40 +03:00
Avi Kivity d6e88aec07 KVM: Prefix some x86 low level function with kvm_, to avoid namespace issues
Fixes compilation with CONFIG_VMI enabled.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:39 +03:00
Avi Kivity ac9f6dc0db KVM: Apply the kernel sigmask to vcpus blocked due to being uninitialized
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:38 +03:00
Marcelo Tosatti f8b78fa3d4 KVM: move slots_lock acquision down to vapic_exit
There is no need to grab slots_lock if the vapic_page will not
be touched.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:36 +03:00
Avi Kivity 7a5b56dfd3 KVM: x86 emulator: lazily evaluate segment registers
Instead of prefetching all segment bases before emulation, read them at the
last moment.  Since most of them are unneeded, we save some cycles on
Intel machines where this is a bit expensive.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:35 +03:00
Avi Kivity f76c710d75 KVM: Use printk_rlimit() instead of reporting emulation failures just once
Emulation failure reports are useful, so allow more than one per the lifetime
of the module.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:32 +03:00
Glauber Costa 25be46080f KVM: Do not calculate linear rip in emulation failure report
If we're not gonna do anything (case in which failure is already
reported), we do not need to even bother with calculating the linear rip.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:32 +03:00
Laurent Vivier 542472b53e KVM: Add coalesced MMIO support (x86 part)
This patch enables coalesced MMIO for x86 architecture.
It defines KVM_MMIO_PAGE_OFFSET and KVM_CAP_COALESCED_MMIO.
It enables the compilation of coalesced_mmio.c.

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:31 +03:00
Laurent Vivier 92760499d0 KVM: kvm_io_device: extend in_range() to manage len and write attribute
Modify member in_range() of structure kvm_io_device to pass length and the type
of the I/O (write or read).

This modification allows to use kvm_io_device with coalesced MMIO.

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:30 +03:00
Guillaume Thouvenin 3e6e0aab1b KVM: Prefixes segment functions that will be exported with "kvm_"
Prefixes functions that will be exported with kvm_.
We also prefixed set_segment() even if it still static
to be coherent.

signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:27 +03:00
Avi Kivity 9ba075a664 KVM: MTRR support
Add emulation for the memory type range registers, needed by VMware esx 3.5,
and by pci device assignment.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:26 +03:00
Sheng Yang f08864b42a KVM: VMX: Enable NMI with in-kernel irqchip
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:26 +03:00
Sheng Yang 3419ffc8e4 KVM: IOAPIC/LAPIC: Enable NMI support
[avi: fix ia64 build breakage]

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:25 +03:00
Avi Kivity 50d40d7fb9 KVM: Remove unnecessary ->decache_regs() call
Since we aren't modifying any register, there's no need to decache
the register state.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:25 +03:00
Avi Kivity 7cc8883074 KVM: Remove decache_vcpus_on_cpu() and related callbacks
Obsoleted by the vmx-specific per-cpu list.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:25 +03:00
Avi Kivity 543e424366 KVM: VMX: Add list of potentially locally cached vcpus
VMX hardware can cache the contents of a vcpu's vmcs.  This cache needs
to be flushed when migrating a vcpu to another cpu, or (which is the case
that interests us here) when disabling hardware virtualization on a cpu.

The current implementation of decaching iterates over the list of all vcpus,
picks the ones that are potentially cached on the cpu that is being offlined,
and flushes the cache.  The problem is that it uses mutex_trylock() to gain
exclusive access to the vcpu, which fires off a (benign) warning about using
the mutex in an interrupt context.

To avoid this, and to make things generally nicer, add a new per-cpu list
of potentially cached vcus.  This makes the decaching code much simpler.  The
list is vmx-specific since other hardware doesn't have this issue.

[andrea: fix crash on suspend/resume]

Signed-off-by: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:24 +03:00
Joerg Roedel 54e445ca84 KVM: add missing kvmtrace bits
This patch adds some kvmtrace bits to the generic x86 code
where it is instrumented from SVM.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:48 +03:00
Harvey Harrison 8b2cf73cc1 KVM: add statics were possible, function definition in lapic.h
Noticed by sparse:
arch/x86/kvm/vmx.c:1583:6: warning: symbol 'vmx_disable_intercept_for_msr' was not declared. Should it be static?
arch/x86/kvm/x86.c:3406:5: warning: symbol 'kvm_task_switch_16' was not declared. Should it be static?
arch/x86/kvm/x86.c:3429:5: warning: symbol 'kvm_task_switch_32' was not declared. Should it be static?
arch/x86/kvm/mmu.c:1968:6: warning: symbol 'kvm_mmu_remove_one_alloc_mmu_page' was not declared. Should it be static?
arch/x86/kvm/mmu.c:2014:6: warning: symbol 'mmu_destroy_caches' was not declared. Should it be static?
arch/x86/kvm/lapic.c:862:5: warning: symbol 'kvm_lapic_get_base' was not declared. Should it be static?
arch/x86/kvm/i8254.c:94:5: warning: symbol 'pit_get_gate' was not declared. Should it be static?
arch/x86/kvm/i8254.c:196:5: warning: symbol '__pit_timer_fn' was not declared. Should it be static?
arch/x86/kvm/i8254.c:561:6: warning: symbol '__inject_pit_timer_intr' was not declared. Should it be static?

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:40:46 +03:00
Jens Axboe 8691e5a8f6 smp_call_function: get rid of the unused nonatomic/retry argument
It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.

Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-26 11:24:35 +02:00
Gerd Hoffmann 50d0a0f987 KVM: Make kvm host use the paravirt clocksource structs
This patch updates the kvm host code to use the pvclock structs.
It also makes the paravirt clock compatible with Xen.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 21:02:32 +03:00
Marcelo Tosatti 06e0564566 KVM: close timer injection race window in __vcpu_run
If a timer fires after kvm_inject_pending_timer_irqs() but before
local_irq_disable() the code will enter guest mode and only inject such
timer interrupt the next time an unrelated event causes an exit.

It would be simpler if the timer->pending irq conversion could be done
with IRQ's disabled, so that the above problem cannot happen.

For now introduce a new vcpu requests bit to cancel guest entry.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 12:16:59 +03:00
Marcelo Tosatti d4acf7e7ab KVM: Fix race between timer migration and vcpu migration
A guest vcpu instance can be scheduled to a different physical CPU
between the test for KVM_REQ_MIGRATE_TIMER and local_irq_disable().

If that happens, the timer will only be migrated to the current pCPU on
the next exit, meaning that guest LAPIC timer event can be delayed until
a host interrupt is triggered.

Fix it by cancelling guest entry if any vcpu request is pending.  This
has the side effect of nicely consolidating vcpu->requests checks.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 12:16:52 +03:00
Marcelo Tosatti 2f5997140f KVM: migrate PIT timer
Migrate the PIT timer to the physical CPU which vcpu0 is scheduled on,
similarly to what is done for the LAPIC timers, otherwise PIT interrupts
will be delayed until an unrelated event causes an exit.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:25:51 +03:00
Andrea Arcangeli bc1a34f1bf KVM: avoid fx_init() schedule in atomic
This make sure not to schedule in atomic during fx_init. I also
changed the name of fpu_init to fx_finit to avoid duplicating the name
with fpu_init that is already used in the kernel, this makes grep
simpler if nothing else.

Signed-off-by: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-04 14:44:48 +03:00
Jan Kiszka b4f14abd95 KVM: Avoid spurious execeptions after setting registers
Clear pending exceptions when setting new register values. This avoids
spurious exceptions after restoring a vcpu state or after
reset-on-triple-fault.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-04 14:44:47 +03:00
Izik Eidus 3fe913e7c5 KVM: x86: task switch: fix wrong bit setting for the busy flag
The busy bit is bit 1 of the type field, not bit 8.

Signed-off-by: Izik Eidus <izike@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-04 14:44:43 +03:00
Sheng Yang b7ebfb0509 KVM: VMX: Prepare an identity page table for EPT in real mode
[aliguory: plug leak]

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-04 14:44:41 +03:00
Sheng Yang 7b52345e2c KVM: MMU: Add EPT support
Enable kvm_set_spte() to generate EPT entries.

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-04 14:44:38 +03:00
Marcelo Tosatti e9571ed54b KVM: fix kvm_vcpu_kick vs __vcpu_run race
There is a window open between testing of pending IRQ's
and assignment of guest_mode in __vcpu_run.

Injection of IRQ's can race with __vcpu_run as follows:

CPU0                                CPU1
kvm_x86_ops->run()
vcpu->guest_mode = 0                SET_IRQ_LINE ioctl
..
kvm_x86_ops->inject_pending_irq
kvm_cpu_has_interrupt()

                                    apic_test_and_set_irr()
                                    kvm_vcpu_kick
                                    if (vcpu->guest_mode)
                                        send_ipi()

vcpu->guest_mode = 1

So move guest_mode=1 assignment before ->inject_pending_irq, and make
sure that it won't reorder after it.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27 18:21:32 +03:00