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| author | Radim Krčmář <rkrcmar@redhat.com> | 2017-11-29 22:23:41 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-12-14 09:26:42 +0100 |
| commit | 2a140f3b6e23a309453b6f68709a50ece543f0f4 (patch) | |
| tree | 43238968c23a24ead1f0c0ff568f5e7d978c7511 /arch/x86/kvm/x86.h | |
| parent | 0d37d26f11bc1c0085d0c89ba603e3bb2c7f7076 (diff) | |
| download | linux-0-day-2a140f3b6e23a309453b6f68709a50ece543f0f4.tar.gz linux-0-day-2a140f3b6e23a309453b6f68709a50ece543f0f4.tar.xz | |
KVM: x86: prevent MWAIT in guest with buggy MONITOR
The bug prevents MWAIT from waking up after a write to the monitored
cache line.
KVM might emulate a CPU model that shouldn't have the bug, so the guest
would not employ a workaround and possibly miss wakeups.
Better to avoid the situation.
Reviewed-by: Alexander Graf <agraf@suse.de>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.h')
| -rw-r--r-- | arch/x86/kvm/x86.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index d0b95b7a90b4e..81f5f50794f66 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -281,6 +281,9 @@ static inline bool kvm_mwait_in_guest(void) return false; } + if (boot_cpu_has_bug(X86_BUG_MONITOR)) + return false; + /* * Intel CPUs without CPUID5_ECX_INTERRUPT_BREAK are problematic as * they would allow guest to stop the CPU completely by disabling |