Re: [PATCH] KVM: x86: Ignore cpuid faulting in SMM

[Jim Mattson]

On Mon, Mar 2, 2026 at 2:46 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:


> > --- a/arch/x86/kvm/emulate.c
> > +++ b/arch/x86/kvm/emulate.c
> > @@ -3583,10 +3583,10 @@ static int em_cpuid(struct x86_emulate_ctxt *ctxt)
> >       u64 msr = 0;
> >
> >       ctxt->ops->get_msr(ctxt, MSR_MISC_FEATURES_ENABLES, &msr);
> > -     if (msr & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT &&
> > -         ctxt->ops->cpl(ctxt)) {
> > +     if (!ctxt->ops->is_smm(ctxt) &&
> > +         (msr & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT &&
> > +          ctxt->ops->cpl(ctxt)))
>
> I assume you intended the parentheses to wrap the bitwise-AND.  I'll fixup to
> this when applying.
>
>         if (!ctxt->ops->is_smm(ctxt) &&
>             (msr & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT) &&
>             ctxt->ops->cpl(ctxt))

Yes, thanks. /facepalm