KVM: VMX: Handle NMI VM-Exits in noinstr region

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Move VMX's handling of NMI VM-Exits into vmx_vcpu_enter_exit() so that
the NMI is handled prior to leaving the safety of noinstr.  Handling the
NMI after leaving noinstr exposes the kernel to potential ordering
problems as an instrumentation-induced fault, e.g. #DB, #BP, #PF, etc.
will unblock NMIs when IRETing back to the faulting instruction.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221213060912.654668-8-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

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This commit is contained in:

Sean Christopherson 2022-12-13 06:09:12 +00:00

parent 4f76e86f7e

commit 11df586d77

4 changed files with 30 additions and 22 deletions

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4

arch/x86/kvm/vmx/vmcs.h

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8

arch/x86/kvm/vmx/vmenter.S

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34

arch/x86/kvm/vmx/vmx.c

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4

arch/x86/kvm/x86.h

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