Commit Graph

98 Commits

Author SHA1 Message Date
Avi Kivity
516a1a7e9d KVM: VMX: Flush volatile msrs before emulating rdmsr
Some msrs (notable MSR_KERNEL_GS_BASE) are held in the processor registers
and need to be flushed to the vcpu struture before they can be read.

This fixes cygwin longjmp() failure on Windows x64.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-02-15 02:47:39 +02:00
Marcelo Tosatti
b682b814e3 KVM: x86: fix LAPIC pending count calculation
Simplify LAPIC TMCCT calculation by using hrtimer provided
function to query remaining time until expiration.

Fixes host hang with nested ESX.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-02-15 02:47:38 +02:00
Sheng Yang
2aaf69dcee KVM: MMU: Map device MMIO as UC in EPT
Software are not allow to access device MMIO using cacheable memory type, the
patch limit MMIO region with UC and WC(guest can select WC using PAT and
PCD/PWT).

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-02-15 02:47:37 +02:00
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
Jan Kiszka
264ff01d55 KVM: VMX: Fix pending NMI-vs.-IRQ race for user space irqchip
As with the kernel irqchip, don't allow an NMI to stomp over an already
injected IRQ; instead wait for the IRQ injection to be completed.

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
Hannes Eder
efff9e538f KVM: VMX: fix sparse warning
Impact: make global function static

  arch/x86/kvm/vmx.c:134:3: warning: symbol 'vmx_capability' was not declared. Should it be static?

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:06 +02:00
Avi Kivity
df203ec9a7 KVM: VMX: Conditionally request interrupt window after injecting irq
If we're injecting an interrupt, and another one is pending, request
an interrupt window notification so we don't have excess latency on the
second interrupt.

This shouldn't happen in practice since an EOI will be issued, giving a second
chance to request an interrupt window, but...

Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:00 +02:00
Eduardo Habkost
710ff4a855 KVM: VMX: extract kvm_cpu_vmxoff() from hardware_disable()
Along with some comments on why it is different from the core cpu_vmxoff()
function.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:52:29 +02:00
Eduardo Habkost
6210e37b12 KVM: VMX: move cpu_has_kvm_support() to an inline on asm/virtext.h
It will be used by core code on kdump and reboot, to disable
vmx if needed.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:52:28 +02:00
Eduardo Habkost
13673a90f1 KVM: VMX: move vmx.h to include/asm
vmx.h will be used by core code that is independent of KVM, so I am
moving it outside the arch/x86/kvm directory.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:52:27 +02:00
Guillaume Thouvenin
1d5a4d9b92 KVM: VMX: Handle mmio emulation when guest state is invalid
If emulate_invalid_guest_state is enabled, the emulator is called
when guest state is invalid.  Until now, we reported an mmio failure
when emulate_instruction() returned EMULATE_DO_MMIO.  This patch adds
the case where emulate_instruction() failed and an MMIO emulation
is needed.

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
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
Sheng Yang
6fe639792c KVM: VMX: Move private memory slot position
PCI device assignment would map guest MMIO spaces as separate slot, so it is
possible that the device has more than 2 MMIO spaces and overwrite current
private memslot.

The patch move private memory slot to the top of userspace visible memory slots.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:46 +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
Jan Kiszka
3b86cd9967 KVM: VMX: work around lacking VNMI support
Older VMX supporting CPUs do not provide the "Virtual NMI" feature for
tracking the NMI-blocked state after injecting such events. For now
KVM is unable to inject NMIs on those CPUs.

Derived from Sheng Yang's suggestion to use the IRQ window notification
for detecting the end of NMI handlers, this patch implements virtual
NMI support without impact on the host's ability to receive real NMIs.
The downside is that the given approach requires some heuristics that
can cause NMI nesting in vary rare corner cases.

The approach works as follows:
 - inject NMI and set a software-based NMI-blocked flag
 - arm the IRQ window start notification whenever an NMI window is
   requested
 - if the guest exits due to an opening IRQ window, clear the emulated
   NMI-blocked flag
 - if the guest net execution time with NMI-blocked but without an IRQ
   window exceeds 1 second, force NMI-blocked reset and inject anyway

This approach covers most practical scenarios:
 - succeeding NMIs are seperated by at least one open IRQ window
 - the guest may spin with IRQs disabled (e.g. due to a bug), but
   leaving the NMI handler takes much less time than one second
 - the guest does not rely on strict ordering or timing of NMIs
   (would be problematic in virtualized environments anyway)

Successfully tested with the 'nmi n' monitor command, the kgdbts
testsuite on smp guests (additional patches required to add debug
register support to kvm) + the kernel's nmi_watchdog=1, and a Siemens-
specific board emulation (+ guest) that comes with its own NMI
watchdog mechanism.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:43 +02:00
Jan Kiszka
487b391d6e KVM: VMX: Provide support for user space injected NMIs
This patch adds the required bits to the VMX side for user space
injected NMIs. As with the preexisting in-kernel irqchip support, the
CPU must provide the "virtual NMI" feature for proper tracking of the
NMI blocking state.

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 16:51:43 +02:00
Jan Kiszka
66a5a347c2 KVM: VMX: fix real-mode NMI support
Fix NMI injection in real-mode with the same pattern we perform IRQ
injection.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:41 +02:00
Jan Kiszka
f460ee43e2 KVM: VMX: refactor IRQ and NMI window enabling
do_interrupt_requests and vmx_intr_assist go different way for
achieving the same: enabling the nmi/irq window start notification.
Unify their code over enable_{irq|nmi}_window, get rid of a redundant
call to enable_intr_window instead of direct enable_nmi_window
invocation and unroll enable_intr_window for both in-kernel and user
space irq injection accordingly.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:41 +02:00
Jan Kiszka
33f089ca5a KVM: VMX: refactor/fix IRQ and NMI injectability determination
There are currently two ways in VMX to check if an IRQ or NMI can be
injected:
 - vmx_{nmi|irq}_enabled and
 - vcpu.arch.{nmi|interrupt}_window_open.
Even worse, one test (at the end of vmx_vcpu_run) uses an inconsistent,
likely incorrect logic.

This patch consolidates and unifies the tests over
{nmi|interrupt}_window_open as cache + vmx_update_window_states
for updating the cache content.

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
Jan Kiszka
60637aacfd KVM: VMX: Support for NMI task gates
Properly set GUEST_INTR_STATE_NMI and reset nmi_injected when a
task-switch vmexit happened due to a task gate being used for handling
NMIs. Also avoid the false warning about valid vectoring info in
kvm_handle_exit.

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
Jan Kiszka
e4a41889ec KVM: VMX: Use INTR_TYPE_NMI_INTR instead of magic value
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
Jan Kiszka
a26bf12afb KVM: VMX: include all IRQ window exits in statistics
irq_window_exits only tracks IRQ window exits due to user space
requests, nmi_window_exits include all exits. The latter makes more
sense, so let's adjust irq_window_exits accounting.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:39 +02:00
Avi Kivity
bd2b3ca768 KVM: VMX: Fix interrupt loss during race with NMI
If an interrupt cannot be injected for some reason (say, page fault
when fetching the IDT descriptor), the interrupt is marked for
reinjection.  However, if an NMI is queued at this time, the NMI
will be injected instead and the NMI will be lost.

Fix by deferring the NMI injection until the interrupt has been
injected successfully.

Analyzed by Jan Kiszka.

Signed-off-by: Avi Kivity <avi@redhat.com>
2008-11-23 14:52:29 +02:00
Sheng Yang
928d4bf747 KVM: VMX: Set IGMT bit in EPT entry
There is a potential issue that, when guest using pagetable without vmexit when
EPT enabled, guest would use PAT/PCD/PWT bits to index PAT msr for it's memory,
which would be inconsistent with host side and would cause host MCE due to
inconsistent cache attribute.

The patch set IGMT bit in EPT entry to ignore guest PAT and use WB as default
memory type to protect host (notice that all memory mapped by KVM should be WB).

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-11-11 21:00:37 +02:00
Marcelo Tosatti
83dbc83a0d KVM: VMX: enable invlpg exiting if EPT is disabled
Manually disabling EPT via module option fails to re-enable INVLPG
exiting.

Reported-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 14:25:31 +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
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
Sheng Yang
9ea542facb KVM: VMX: Rename IA32_FEATURE_CONTROL bits
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:16:14 +02:00
Jan Kiszka
4b92fe0c9d KVM: VMX: Cleanup stalled INTR_INFO read
Commit 1c0f4f5011829dac96347b5f84ba37c2252e1e08 left a useless access
of VM_ENTRY_INTR_INFO_FIELD in vmx_intr_assist behind. Clean this up.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.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
Avi Kivity
a16b20da87 KVM: VMX: Change segment dpl at reset to 3
This is more emulation friendly, if not 100% correct.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:21 +02:00
Avi Kivity
5706be0daf KVM: VMX: Change cs reset state to be a data segment
Real mode cs is a data segment, not a code segment.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:21 +02:00
Mohammed Gamal
a89a8fb93b KVM: VMX: Modify mode switching and vmentry functions
This patch modifies mode switching and vmentry function in order to
drive invalid guest state emulation.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:20 +02:00
Mohammed Gamal
ea953ef0ca KVM: VMX: Add invalid guest state handler
This adds the invalid guest state handler function which invokes the x86
emulator until getting the guest to a VMX-friendly state.

[avi: leave atomic context if scheduling]
[guillaume: return to atomic context correctly]

Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:20 +02:00
Mohammed Gamal
04fa4d3211 KVM: VMX: Add module parameter and emulation flag.
The patch adds the module parameter required to enable emulating invalid
guest state, as well as the emulation_required flag used to drive
emulation whenever needed.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:20 +02:00
Mohammed Gamal
648dfaa7df KVM: VMX: Add Guest State Validity Checks
This patch adds functions to check whether guest state is VMX compliant.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:20 +02:00
Avi Kivity
ecfc79c700 KVM: VMX: Use interrupt queue for !irqchip_in_kernel
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:19 +02:00
Sheng Yang
464d17c8b7 KVM: VMX: Clean up magic number 0x66 in init_rmode_tss
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:19 +02:00
Avi Kivity
313dbd49dc KVM: VMX: Avoid vmwrite(HOST_RSP) when possible
Usually HOST_RSP retains its value across guest entries.  Take advantage
of this and avoid a vmwrite() when this is so.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:15 +02:00
Avi Kivity
c801949ddf KVM: VMX: Unify register save/restore across 32 and 64 bit hosts
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:14 +02:00
Jan Kiszka
77ab6db0a1 KVM: VMX: Reinject real mode exception
As we execute real mode guests in VM86 mode, exception have to be
reinjected appropriately when the guest triggered them. For this purpose
the patch adopts the real-mode injection pattern used in vmx_inject_irq
to vmx_queue_exception, additionally taking care that the IP is set
correctly for #BP exceptions. Furthermore it extends
handle_rmode_exception to reinject all those exceptions that can be
raised in real mode.

This fixes the execution of himem.exe from FreeDOS and also makes its
debug.com work properly.

Note that guest debugging in real mode is broken now. This has to be
fixed by the scheduled debugging infrastructure rework (will be done
once base patches for QEMU have been accepted).

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:14 +02:00
Jan Kiszka
19bd8afdc4 KVM: Consolidate XX_VECTOR defines
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:14 +02:00
Mohammed Gamal
60bd83a125 KVM: VMX: Remove redundant check in handle_rmode_exception
Since checking for vcpu->arch.rmode.active is already done whenever we
call handle_rmode_exception(), checking it inside the function is redundant.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:13 +02:00
Avi Kivity
f7d9238f5d KVM: VMX: Move interrupt post-processing to vmx_complete_interrupts()
Instead of looking at failed injections in the vm entry path, move
processing to the exit path in vmx_complete_interrupts().  This simplifes
the logic and removes any state that is hidden in vmx registers.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:13 +02:00
Avi Kivity
35920a3569 KVM: VMX: Fix pending exception processing
The vmx code assumes that IDT-Vectoring can only be set when an exception
is injected due to the exception in question.  That's not true, however:
if the exception is injected correctly, and later another exception occurs
but its delivery is blocked due to a fault, then we will incorrectly assume
the first exception was not delivered.

Fix by unconditionally dequeuing the pending exception, and requeuing it
(or the second exception) if we see it in the IDT-Vectoring field.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:13 +02:00
Avi Kivity
668f612fa0 KVM: VMX: Move nmi injection failure processing to vm exit path
Instead of processing nmi injection failure in the vm entry path, move
it to the vm exit path (vm_complete_interrupts()).  This separates nmi
injection from nmi post-processing, and moves the nmi state from the VT
state into vcpu state (new variable nmi_injected specifying an injection
in progress).

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:13 +02:00
Avi Kivity
cf393f7566 KVM: Move NMI IRET fault processing to new vmx_complete_interrupts()
Currently most interrupt exit processing is handled on the entry path,
which is confusing.  Move the NMI IRET fault processing to a new function,
vmx_complete_interrupts(), which is called on the vmexit path.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:12 +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
Sheng Yang
ca60dfbb69 KVM: VMX: Rename misnamed msr bits
MSR_IA32_FEATURE_LOCKED is just a bit in fact, which shouldn't be prefixed with
MSR_.  So is MSR_IA32_FEATURE_VMXON_ENABLED.

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:13:57 +02:00