On Fri, Dec 02, 2022, Paolo Bonzini wrote: > On 10/8/22 00:16, 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. > > > > 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); > > + 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)) > > Queued, thanks. Negative features suck, though. LOL, you and Jim should start a club, Jim's had a few good rants on negative features :-)
