On Fri, Oct 07, 2022, Jim Mattson wrote: > CPUID.80000021H:EAX[bit 9] indicates that the SMM_CTL MSR (0xc0010116) > is not supported. This defeature can be advertised by > KVM_GET_SUPPORTED_CPUID regardless of whether or not the host > enumerates it. Might be worth noting that KVM will only enumerate the bit if the host happens to have a max extend leaf > 80000021. > > Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx> > --- > arch/x86/kvm/cpuid.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 2796dde06302..b748fac2ae37 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -1199,8 +1199,12 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) > * Other defined bits are for MSRs that KVM does not expose: > * EAX 3 SPCL, SMM page configuration lock > * EAX 13 PCMSR, Prefetch control MSR > + * > + * KVM doesn't support SMM_CTL. > + * EAX 9 SMM_CTL MSR is not supported > */ > entry->eax &= BIT(0) | BIT(2) | BIT(6); I don't suppose I can bribe you to add a kvm_only_cpuid_leafs entry for these? :-) > + entry->eax |= BIT(9); > if (static_cpu_has(X86_FEATURE_LFENCE_RDTSC)) > entry->eax |= BIT(2); > if (!static_cpu_has_bug(X86_BUG_NULL_SEG)) > -- > 2.38.0.rc1.362.ged0d419d3c-goog >
