Commit Graph

87 Commits

Author SHA1 Message Date
Linus Torvalds
039aeb9deb ARM:
- Move the arch-specific code into arch/arm64/kvm
 - Start the post-32bit cleanup
 - Cherry-pick a few non-invasive pre-NV patches
 
 x86:
 - Rework of TLB flushing
 - Rework of event injection, especially with respect to nested virtualization
 - Nested AMD event injection facelift, building on the rework of generic code
 and fixing a lot of corner cases
 - Nested AMD live migration support
 - Optimization for TSC deadline MSR writes and IPIs
 - Various cleanups
 - Asynchronous page fault cleanups (from tglx, common topic branch with tip tree)
 - Interrupt-based delivery of asynchronous "page ready" events (host side)
 - Hyper-V MSRs and hypercalls for guest debugging
 - VMX preemption timer fixes
 
 s390:
 - Cleanups
 
 Generic:
 - switch vCPU thread wakeup from swait to rcuwait
 
 The other architectures, and the guest side of the asynchronous page fault
 work, will come next week.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:
   - Move the arch-specific code into arch/arm64/kvm

   - Start the post-32bit cleanup

   - Cherry-pick a few non-invasive pre-NV patches

  x86:
   - Rework of TLB flushing

   - Rework of event injection, especially with respect to nested
     virtualization

   - Nested AMD event injection facelift, building on the rework of
     generic code and fixing a lot of corner cases

   - Nested AMD live migration support

   - Optimization for TSC deadline MSR writes and IPIs

   - Various cleanups

   - Asynchronous page fault cleanups (from tglx, common topic branch
     with tip tree)

   - Interrupt-based delivery of asynchronous "page ready" events (host
     side)

   - Hyper-V MSRs and hypercalls for guest debugging

   - VMX preemption timer fixes

  s390:
   - Cleanups

  Generic:
   - switch vCPU thread wakeup from swait to rcuwait

  The other architectures, and the guest side of the asynchronous page
  fault work, will come next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (256 commits)
  KVM: selftests: fix rdtsc() for vmx_tsc_adjust_test
  KVM: check userspace_addr for all memslots
  KVM: selftests: update hyperv_cpuid with SynDBG tests
  x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls
  x86/kvm/hyper-v: enable hypercalls regardless of hypercall page
  x86/kvm/hyper-v: Add support for synthetic debugger interface
  x86/hyper-v: Add synthetic debugger definitions
  KVM: selftests: VMX preemption timer migration test
  KVM: nVMX: Fix VMX preemption timer migration
  x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit
  KVM: x86/pmu: Support full width counting
  KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in
  KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT
  KVM: x86: acknowledgment mechanism for async pf page ready notifications
  KVM: x86: interrupt based APF 'page ready' event delivery
  KVM: introduce kvm_read_guest_offset_cached()
  KVM: rename kvm_arch_can_inject_async_page_present() to kvm_arch_can_dequeue_async_page_present()
  KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info
  Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously"
  KVM: VMX: Replace zero-length array with flexible-array
  ...
2020-06-03 15:13:47 -07:00
Christoph Hellwig
88dca4ca5a mm: remove the pgprot argument to __vmalloc
The pgprot argument to __vmalloc is always PAGE_KERNEL now, so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com> [hyperv]
Acked-by: Gao Xiang <xiang@kernel.org> [erofs]
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Wei Liu <wei.liu@kernel.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200414131348.444715-22-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:11 -07:00
Wei Wang
cbd717585b KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in
Change kvm_pmu_get_msr() to get the msr_data struct, as the host_initiated
field from the struct could be used by get_msr. This also makes this API
consistent with kvm_pmu_set_msr. No functional changes.

Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Message-Id: <20200529074347.124619-2-like.xu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:08 -04:00
Vitaly Kuznetsov
68fd66f100 KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info
Currently, APF mechanism relies on the #PF abuse where the token is being
passed through CR2. If we switch to using interrupts to deliver page-ready
notifications we need a different way to pass the data. Extent the existing
'struct kvm_vcpu_pv_apf_data' with token information for page-ready
notifications.

While on it, rename 'reason' to 'flags'. This doesn't change the semantics
as we only have reasons '1' and '2' and these can be treated as bit flags
but KVM_PV_REASON_PAGE_READY is going away with interrupt based delivery
making 'reason' name misleading.

The newly introduced apf_put_user_ready() temporary puts both flags and
token information, this will be changed to put token only when we switch
to interrupt based notifications.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200525144125.143875-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:06 -04:00
Paolo Bonzini
cc440cdad5 KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE
Similar to VMX, the state that is captured through the currently available
IOCTLs is a mix of L1 and L2 state, dependent on whether the L2 guest was
running at the moment when the process was interrupted to save its state.

In particular, the SVM-specific state for nested virtualization includes
the L1 saved state (including the interrupt flag), the cached L2 controls,
and the GIF.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:05 -04:00
Paolo Bonzini
929d1cfaa6 KVM: MMU: pass arbitrary CR0/CR4/EFER to kvm_init_shadow_mmu
This allows fetching the registers from the hsave area when setting
up the NPT shadow MMU, and is needed for KVM_SET_NESTED_STATE (which
runs long after the CR0, CR4 and EFER values in vcpu have been switched
to hold L2 guest state).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:03 -04:00
Paolo Bonzini
c513f484c5 KVM: nSVM: leave guest mode when clearing EFER.SVME
According to the AMD manual, the effect of turning off EFER.SVME while a
guest is running is undefined.  We make it leave guest mode immediately,
similar to the effect of clearing the VMX bit in MSR_IA32_FEAT_CTL.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:03 -04:00
Paolo Bonzini
ca46d739e3 KVM: nSVM: split nested_vmcb_check_controls
The authoritative state does not come from the VMCB once in guest mode,
but KVM_SET_NESTED_STATE can still perform checks on L1's provided SVM
controls because we get them from userspace.

Therefore, split out a function to do them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:03 -04:00
Paolo Bonzini
08245e6d2e KVM: nSVM: remove HF_HIF_MASK
The L1 flags can be found in the save area of svm->nested.hsave, fish
it from there so that there is one fewer thing to migrate.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:02 -04:00
Paolo Bonzini
e9fd761a46 KVM: nSVM: remove HF_VINTR_MASK
Now that the int_ctl field is stored in svm->nested.ctl.int_ctl, we can
use it instead of vcpu->arch.hflags to check whether L2 is running
in V_INTR_MASKING mode.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:02 -04:00
Paolo Bonzini
36e2e98363 KVM: nSVM: synthesize correct EXITINTINFO on vmexit
This bit was added to nested VMX right when nested_run_pending was
introduced, but it is not yet there in nSVM.  Since we can have pending
events that L0 injected directly into L2 on vmentry, we have to transfer
them into L1's queue.

For this to work, one important change is required: svm_complete_interrupts
(which clears the "injected" fields from the previous VMRUN, and updates them
from svm->vmcb's EXITINTINFO) must be placed before we inject the vmexit.
This is not too scary though; VMX even does it in vmx_vcpu_run.

While at it, the nested_vmexit_inject tracepoint is moved towards the
end of nested_svm_vmexit.  This ensures that the synthesized EXITINTINFO
is visible in the trace.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:02 -04:00
Paolo Bonzini
91b7130cb6 KVM: SVM: preserve VGIF across VMCB switch
There is only one GIF flag for the whole processor, so make sure it is not clobbered
when switching to L2 (in which case we also have to include the V_GIF_ENABLE_MASK,
lest we confuse enable_gif/disable_gif/gif_set).  When going back, L1 could in
theory have entered L2 without issuing a CLGI so make sure the svm_set_gif is
done last, after svm->vmcb->control.int_ctl has been copied back from hsave.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:01 -04:00
Paolo Bonzini
ffdf7f9e80 KVM: nSVM: extract svm_set_gif
Extract the code that is needed to implement CLGI and STGI,
so that we can run it from VMRUN and vmexit (and in the future,
KVM_SET_NESTED_STATE).  Skip the request for KVM_REQ_EVENT unless needed,
subsuming the evaluate_pending_interrupts optimization that is found
in enter_svm_guest_mode.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:01 -04:00
Paolo Bonzini
31031098fe KVM: nSVM: remove unnecessary if
kvm_vcpu_apicv_active must be false when nested virtualization is enabled,
so there is no need to check it in clgi_interception.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:01 -04:00
Paolo Bonzini
2d8a42be0e KVM: nSVM: synchronize VMCB controls updated by the processor on every vmexit
The control state changes on every L2->L0 vmexit, and we will have to
serialize it in the nested state.  So keep it up to date in svm->nested.ctl
and just copy them back to the nested VMCB in nested_svm_vmexit.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:00 -04:00
Paolo Bonzini
d8e4e58f4b KVM: nSVM: restore clobbered INT_CTL fields after clearing VINTR
Restore the INT_CTL value from the guest's VMCB once we've stopped using
it, so that virtual interrupts can be injected as requested by L1.
V_TPR is up-to-date however, and it can change if the guest writes to CR8,
so keep it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:00 -04:00
Paolo Bonzini
e670bf68f4 KVM: nSVM: save all control fields in svm->nested
In preparation for nested SVM save/restore, store all data that matters
from the VMCB control area into svm->nested.  It will then become part
of the nested SVM state that is saved by KVM_SET_NESTED_STATE and
restored by KVM_GET_NESTED_STATE, just like the cached vmcs12 for nVMX.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:26:00 -04:00
Paolo Bonzini
2f675917ef KVM: nSVM: pass vmcb_control_area to copy_vmcb_control_area
This will come in handy when we put a struct vmcb_control_area in
svm->nested.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:25:59 -04:00
Paolo Bonzini
18fc6c55d1 KVM: nSVM: clean up tsc_offset update
Use l1_tsc_offset to compute svm->vcpu.arch.tsc_offset and
svm->vmcb->control.tsc_offset, instead of relying on hsave.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:25:59 -04:00
Paolo Bonzini
69cb877487 KVM: nSVM: move MMU setup to nested_prepare_vmcb_control
Everything that is needed during nested state restore is now part of
nested_prepare_vmcb_control.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:25:58 -04:00
Paolo Bonzini
f241d711b2 KVM: nSVM: extract preparation of VMCB for nested run
Split out filling svm->vmcb.save and svm->vmcb.control before VMRUN.
Only the latter will be useful when restoring nested SVM state.

This patch introduces no semantic change, so the MMU setup is still
done in nested_prepare_vmcb_save.  The next patch will clean up things.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:25:58 -04:00
Paolo Bonzini
3e06f0163f KVM: nSVM: extract load_nested_vmcb_control
When restoring SVM nested state, the control state cache in svm->nested
will have to be filled, but the save state will not have to be moved
into svm->vmcb.  Therefore, pull the code that handles the control area
into a separate function.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:25:58 -04:00
Paolo Bonzini
69c9dfa24b KVM: nSVM: move map argument out of enter_svm_guest_mode
Unmapping the nested VMCB in enter_svm_guest_mode is a bit of a wart,
since the map argument is not used elsewhere in the function.  There are
just two callers, and those are also the place where kvm_vcpu_map is
called, so it is cleaner to unmap there.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01 04:24:32 -04:00
Paolo Bonzini
978ce5837c KVM: SVM: always update CR3 in VMCB
svm_load_mmu_pgd is delaying the write of GUEST_CR3 to prepare_vmcs02 as
an optimization, but this is only correct before the nested vmentry.
If userspace is modifying CR3 with KVM_SET_SREGS after the VM has
already been put in guest mode, the value of CR3 will not be updated.
Remove the optimization, which almost never triggers anyway.
This was was added in commit 689f3bf216 ("KVM: x86: unify callbacks
to load paging root", 2020-03-16) just to keep the two vendor-specific
modules closer, but we'll fix VMX too.

Fixes: 689f3bf216 ("KVM: x86: unify callbacks to load paging root")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-28 11:46:18 -04:00
Paolo Bonzini
5b67240866 KVM: nSVM: correctly inject INIT vmexits
The usual drill at this point, except there is no code to remove because this
case was not handled at all.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-28 11:46:18 -04:00
Paolo Bonzini
bd279629f7 KVM: nSVM: remove exit_required
All events now inject vmexits before vmentry rather than after vmexit.  Therefore,
exit_required is not set anymore and we can remove it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-28 11:46:17 -04:00
Paolo Bonzini
7c86663b68 KVM: nSVM: inject exceptions via svm_check_nested_events
This allows exceptions injected by the emulator to be properly delivered
as vmexits.  The code also becomes simpler, because we can just let all
L0-intercepted exceptions go through the usual path.  In particular, our
emulation of the VMX #DB exit qualification is very much simplified,
because the vmexit injection path can use kvm_deliver_exception_payload
to update DR6.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-28 11:46:17 -04:00
Paolo Bonzini
c9d40913ac KVM: x86: enable event window in inject_pending_event
In case an interrupt arrives after nested.check_events but before the
call to kvm_cpu_has_injectable_intr, we could end up enabling the interrupt
window even if the interrupt is actually going to be a vmexit.  This is
useless rather than harmful, but it really complicates reasoning about
SVM's handling of the VINTR intercept.  We'd like to never bother with
the VINTR intercept if V_INTR_MASKING=1 && INTERCEPT_INTR=1, because in
that case there is no interrupt window and we can just exit the nested
guest whenever we want.

This patch moves the opening of the interrupt window inside
inject_pending_event.  This consolidates the check for pending
interrupt/NMI/SMI in one place, and makes KVM's usage of immediate
exits more consistent, extending it beyond just nested virtualization.

There are two functional changes here.  They only affect corner cases,
but overall they simplify the inject_pending_event.

- re-injection of still-pending events will also use req_immediate_exit
instead of using interrupt-window intercepts.  This should have no impact
on performance on Intel since it simply replaces an interrupt-window
or NMI-window exit for a preemption-timer exit.  On AMD, which has no
equivalent of the preemption time, it may incur some overhead but an
actual effect on performance should only be visible in pathological cases.

- kvm_arch_interrupt_allowed and kvm_vcpu_has_events will return true
if an interrupt, NMI or SMI is blocked by nested_run_pending.  This
makes sense because entering the VM will allow it to make progress
and deliver the event.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-28 11:41:46 -04:00
Vitaly Kuznetsov
b6162e82ae KVM: nSVM: Preserve registers modifications done before nested_svm_vmexit()
L2 guest hang is observed after 'exit_required' was dropped and nSVM
switched to check_nested_events() completely. The hang is a busy loop when
e.g. KVM is emulating an instruction (e.g. L2 is accessing MMIO space and
we drop to userspace). After nested_svm_vmexit() and when L1 is doing VMRUN
nested guest's RIP is not advanced so KVM goes into emulating the same
instruction which caused nested_svm_vmexit() and the loop continues.

nested_svm_vmexit() is not new, however, with check_nested_events() we're
now calling it later than before. In case by that time KVM has modified
register state we may pick stale values from VMCB when trying to save
nested guest state to nested VMCB.

nVMX code handles this case correctly: sync_vmcs02_to_vmcs12() called from
nested_vmx_vmexit() does e.g 'vmcs12->guest_rip = kvm_rip_read(vcpu)' and
this ensures KVM-made modifications are preserved. Do the same for nSVM.

Generally, nested_vmx_vmexit()/nested_svm_vmexit() need to pick up all
nested guest state modifications done by KVM after vmexit. It would be
great to find a way to express this in a way which would not require to
manually track these changes, e.g. nested_{vmcb,vmcs}_get_field().

Co-debugged-with: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200527090102.220647-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-27 13:11:12 -04:00
Paolo Bonzini
6c0238c4a6 KVM: nSVM: leave ASID aside in copy_vmcb_control_area
Restoring the ASID from the hsave area on VMEXIT is wrong, because its
value depends on the handling of TLB flushes.  Just skipping the field in
copy_vmcb_control_area will do.

Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-27 13:11:11 -04:00
Paolo Bonzini
a3535be731 KVM: nSVM: fix condition for filtering async PF
Async page faults have to be trapped in the host (L1 in this case),
since the APF reason was passed from L0 to L1 and stored in the L1 APF
data page.  This was completely reversed: the page faults were passed
to the guest, a L2 hypervisor.

Cc: stable@vger.kernel.org
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-27 13:11:10 -04:00
Sean Christopherson
cb97c2d680 KVM: x86: Take an unsigned 32-bit int for has_emulated_msr()'s index
Take a u32 for the index in has_emulated_msr() to match hardware, which
treats MSR indices as unsigned 32-bit values.  Functionally, taking a
signed int doesn't cause problems with the current code base, but could
theoretically cause problems with 32-bit KVM, e.g. if the index were
checked via a less-than statement, which would evaluate incorrectly for
MSR indices with bit 31 set.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200218234012.7110-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-27 13:11:08 -04:00
Paolo Bonzini
7529e767c2 Merge branch 'kvm-master' into HEAD
Merge AMD fixes before doing more development work.
2020-05-27 13:10:29 -04:00
Paolo Bonzini
e7581caca4 KVM: x86: simplify is_mmio_spte
We can simply look at bits 52-53 to identify MMIO entries in KVM's page
tables.  Therefore, there is no need to pass a mask to kvm_mmu_set_mmio_spte_mask.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-27 13:08:29 -04:00
Paolo Bonzini
9d5272f5e3 Merge tag 'noinstr-x86-kvm-2020-05-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into HEAD 2020-05-20 03:40:09 -04:00
Linus Torvalds
5d438e071f A new testcase for guest debugging (gdbstub) that exposed a bunch of
bugs, mostly for AMD processors.  And a few other x86 fixes.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "A new testcase for guest debugging (gdbstub) that exposed a bunch of
  bugs, mostly for AMD processors. And a few other x86 fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Fix off-by-one error in kvm_vcpu_ioctl_x86_setup_mce
  KVM: x86: Fix pkru save/restore when guest CR4.PKE=0, move it to x86.c
  KVM: SVM: Disable AVIC before setting V_IRQ
  KVM: Introduce kvm_make_all_cpus_request_except()
  KVM: VMX: pass correct DR6 for GD userspace exit
  KVM: x86, SVM: isolate vcpu->arch.dr6 from vmcb->save.dr6
  KVM: SVM: keep DR6 synchronized with vcpu->arch.dr6
  KVM: nSVM: trap #DB and #BP to userspace if guest debugging is on
  KVM: selftests: Add KVM_SET_GUEST_DEBUG test
  KVM: X86: Fix single-step with KVM_SET_GUEST_DEBUG
  KVM: X86: Set RTM for DB_VECTOR too for KVM_EXIT_DEBUG
  KVM: x86: fix DR6 delivery for various cases of #DB injection
  KVM: X86: Declare KVM_CAP_SET_GUEST_DEBUG properly
2020-05-16 13:39:22 -07:00
Suravee Suthikulpanit
de18248162 KVM: SVM: Remove unnecessary V_IRQ unsetting
This has already been handled in the prior call to svm_clear_vintr().

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <1588771076-73790-5-git-send-email-suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-15 12:26:23 -04:00
Suravee Suthikulpanit
e14b7786cb KVM: SVM: Merge svm_enable_vintr into svm_set_vintr
Code clean up and remove unnecessary intercept check for
INTERCEPT_VINTR.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <1588771076-73790-4-git-send-email-suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-15 12:26:23 -04:00
Wanpeng Li
404d5d7bff KVM: X86: Introduce more exit_fastpath_completion enum values
Adds a fastpath_t typedef since enum lines are a bit long, and replace
EXIT_FASTPATH_SKIP_EMUL_INS with two new exit_fastpath_completion enum values.

- EXIT_FASTPATH_EXIT_HANDLED  kvm will still go through it's full run loop,
                              but it would skip invoking the exit handler.

- EXIT_FASTPATH_REENTER_GUEST complete fastpath, guest can be re-entered
                              without invoking the exit handler or going
                              back to vcpu_run

Tested-by: Haiwei Li <lihaiwei@tencent.com>
Cc: Haiwei Li <lihaiwei@tencent.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1588055009-12677-4-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-15 12:26:19 -04:00
Sean Christopherson
3bae0459bc KVM: x86/mmu: Drop KVM's hugepage enums in favor of the kernel's enums
Replace KVM's PT_PAGE_TABLE_LEVEL, PT_DIRECTORY_LEVEL and PT_PDPE_LEVEL
with the kernel's PG_LEVEL_4K, PG_LEVEL_2M and PG_LEVEL_1G.  KVM's
enums are borderline impossible to remember and result in code that is
visually difficult to audit, e.g.

        if (!enable_ept)
                ept_lpage_level = 0;
        else if (cpu_has_vmx_ept_1g_page())
                ept_lpage_level = PT_PDPE_LEVEL;
        else if (cpu_has_vmx_ept_2m_page())
                ept_lpage_level = PT_DIRECTORY_LEVEL;
        else
                ept_lpage_level = PT_PAGE_TABLE_LEVEL;

versus

        if (!enable_ept)
                ept_lpage_level = 0;
        else if (cpu_has_vmx_ept_1g_page())
                ept_lpage_level = PG_LEVEL_1G;
        else if (cpu_has_vmx_ept_2m_page())
                ept_lpage_level = PG_LEVEL_2M;
        else
                ept_lpage_level = PG_LEVEL_4K;

No functional change intended.

Suggested-by: Barret Rhoden <brho@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200428005422.4235-4-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-15 12:26:11 -04:00
Sean Christopherson
e93fd3b3e8 KVM: x86/mmu: Capture TDP level when updating CPUID
Snapshot the TDP level now that it's invariant (SVM) or dependent only
on host capabilities and guest CPUID (VMX).  This avoids having to call
kvm_x86_ops.get_tdp_level() when initializing a TDP MMU and/or
calculating the page role, and thus avoids the associated retpoline.

Drop the WARN in vmx_get_tdp_level() as updating CPUID while L2 is
active is legal, if dodgy.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200502043234.12481-11-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13 12:15:14 -04:00
Sean Christopherson
bd31fe495d KVM: VMX: Add proper cache tracking for CR0
Move CR0 caching into the standard register caching mechanism in order
to take advantage of the availability checks provided by regs_avail.
This avoids multiple VMREADs in the (uncommon) case where kvm_read_cr0()
is called multiple times in a single VM-Exit, and more importantly
eliminates a kvm_x86_ops hook, saves a retpoline on SVM when reading
CR0, and squashes the confusing naming discrepancy of "cache_reg" vs.
"decache_cr0_guest_bits".

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200502043234.12481-8-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13 12:15:12 -04:00
Sean Christopherson
f98c1e7712 KVM: VMX: Add proper cache tracking for CR4
Move CR4 caching into the standard register caching mechanism in order
to take advantage of the availability checks provided by regs_avail.
This avoids multiple VMREADs and retpolines (when configured) during
nested VMX transitions as kvm_read_cr4_bits() is invoked multiple times
on each transition, e.g. when stuffing CR0 and CR3.

As an added bonus, this eliminates a kvm_x86_ops hook, saves a retpoline
on SVM when reading CR4, and squashes the confusing naming discrepancy
of "cache_reg" vs. "decache_cr4_guest_bits".

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200502043234.12481-7-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13 12:15:10 -04:00
Sean Christopherson
56ba77a459 KVM: x86: Save L1 TSC offset in 'struct kvm_vcpu_arch'
Save L1's TSC offset in 'struct kvm_vcpu_arch' and drop the kvm_x86_ops
hook read_l1_tsc_offset().  This avoids a retpoline (when configured)
when reading L1's effective TSC, which is done at least once on every
VM-Exit.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200502043234.12481-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13 12:15:04 -04:00
Paolo Bonzini
fede8076aa KVM: x86: handle wrap around 32-bit address space
KVM is not handling the case where EIP wraps around the 32-bit address
space (that is, outside long mode).  This is needed both in vmx.c
and in emulate.c.  SVM with NRIPS is okay, but it can still print
an error to dmesg due to integer overflow.

Reported-by: Nick Peterson <everdox@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13 12:14:59 -04:00
Paolo Bonzini
c300ab9f08 KVM: x86: Replace late check_nested_events() hack with more precise fix
Add an argument to interrupt_allowed and nmi_allowed, to checking if
interrupt injection is blocked.  Use the hook to handle the case where
an interrupt arrives between check_nested_events() and the injection
logic.  Drop the retry of check_nested_events() that hack-a-fixed the
same condition.

Blocking injection is also a bit of a hack, e.g. KVM should do exiting
and non-exiting interrupt processing in a single pass, but it's a more
precise hack.  The old comment is also misleading, e.g. KVM_REQ_EVENT is
purely an optimization, setting it on every run loop (which KVM doesn't
do) should not affect functionality, only performance.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-13-sean.j.christopherson@intel.com>
[Extend to SVM, add SMI and NMI.  Even though NMI and SMI cannot come
 asynchronously right now, making the fix generic is easy and removes a
 special case. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13 12:14:49 -04:00
Paolo Bonzini
221e761090 KVM: nSVM: Preserve IRQ/NMI/SMI priority irrespective of exiting behavior
Short circuit vmx_check_nested_events() if an unblocked IRQ/NMI/SMI is
pending and needs to be injected into L2, priority between coincident
events is not dependent on exiting behavior.

Fixes: b518ba9fa6 ("KVM: nSVM: implement check_nested_events for interrupts")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13 12:14:45 -04:00
Paolo Bonzini
fc6f7c03ad KVM: nSVM: Report interrupts as allowed when in L2 and exit-on-interrupt is set
Report interrupts as allowed when the vCPU is in L2 and L2 is being run with
exit-on-interrupts enabled and EFLAGS.IF=1 (either on the host or on the guest
according to VINTR).  Interrupts are always unblocked from L1's perspective
in this case.

While moving nested_exit_on_intr to svm.h, use INTERCEPT_INTR properly instead
of assuming it's zero (which it is of course).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13 12:14:44 -04:00
Paolo Bonzini
cae96af184 KVM: SVM: Split out architectural interrupt/NMI/SMI blocking checks
Move the architectural (non-KVM specific) interrupt/NMI/SMI blocking checks
to a separate helper so that they can be used in a future patch by
svm_check_nested_events().

No functional change intended.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13 12:14:40 -04:00
Paolo Bonzini
55714cddbf KVM: nSVM: Move SMI vmexit handling to svm_check_nested_events()
Unlike VMX, SVM allows a hypervisor to take a SMI vmexit without having
any special SMM-monitor enablement sequence.  Therefore, it has to be
handled like interrupts and NMIs.  Check for an unblocked SMI in
svm_check_nested_events() so that pending SMIs are correctly prioritized
over IRQs and NMIs when the latter events will trigger VM-Exit.

Note that there is no need to test explicitly for SMI vmexits, because
guests always runs outside SMM and therefore can never get an SMI while
they are blocked.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13 12:14:38 -04:00