diff options
| author | Sean Christopherson <seanjc@google.com> | 2022-06-09 00:45:12 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-06-20 17:50:42 +0200 |
| commit | bfbcc81bb82cbbad8bf4e40cea274f42b50674e2 (patch) | |
| tree | 644d8901c84e9720c22a819b706773951201e31c /arch/x86/include/asm | |
| parent | KVM: x86: Ignore benign host writes to "unsupported" F15H_PERF_CTL MSRs (diff) | |
| download | linux-bfbcc81bb82cbbad8bf4e40cea274f42b50674e2.tar.xz linux-bfbcc81bb82cbbad8bf4e40cea274f42b50674e2.zip | |
KVM: x86: Add a quirk for KVM's "MONITOR/MWAIT are NOPs!" behavior
Add a quirk for KVM's behavior of emulating intercepted MONITOR/MWAIT
instructions a NOPs regardless of whether or not they are supported in
guest CPUID. KVM's current behavior was likely motiviated by a certain
fruity operating system that expects MONITOR/MWAIT to be supported
unconditionally and blindly executes MONITOR/MWAIT without first checking
CPUID. And because KVM does NOT advertise MONITOR/MWAIT to userspace,
that's effectively the default setup for any VMM that regurgitates
KVM_GET_SUPPORTED_CPUID to KVM_SET_CPUID2.
Note, this quirk interacts with KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT. The
behavior is actually desirable, as userspace VMMs that want to
unconditionally hide MONITOR/MWAIT from the guest can leave the
MISC_ENABLE quirk enabled.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220608224516.3788274-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 1038ccb7056a..e37727a74d0a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -2076,6 +2076,7 @@ int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages); KVM_X86_QUIRK_LAPIC_MMIO_HOLE | \ KVM_X86_QUIRK_OUT_7E_INC_RIP | \ KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT | \ - KVM_X86_QUIRK_FIX_HYPERCALL_INSN) + KVM_X86_QUIRK_FIX_HYPERCALL_INSN | \ + KVM_X86_QUIRK_MWAIT_NEVER_FAULTS) #endif /* _ASM_X86_KVM_HOST_H */ |