Re: [PATCH v7 1/9] KVM: x86: Define KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT

[Jim Mattson]

On Mon, Apr 6, 2026 at 4:27 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
>
> On Fri, Mar 27, 2026, Jim Mattson wrote:
> > diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
> > index ff1e4b4dc998..74014110b550 100644
> > --- a/arch/x86/kvm/svm/svm.h
> > +++ b/arch/x86/kvm/svm/svm.h
> > @@ -616,6 +616,17 @@ static inline bool nested_npt_enabled(struct vcpu_svm *svm)
> >       return svm->nested.ctl.misc_ctl & SVM_MISC_ENABLE_NP;
> >  }
> >
> > +static inline bool l2_has_separate_pat(struct vcpu_svm *svm)
>
> Take @vcpu instead of @svm.  All of the callers have a "vcpu", but not all have
> a local "svm".  That will shorten the quirk check far enough to let it poke out.

What is the actual line length limit?

> > +{
> > +     /*
> > +      * If KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT is disabled while a vCPU
> > +      * is running, the L2 IA32_PAT semantics for that vCPU are undefined.
> > +      */
> > +     return nested_npt_enabled(svm) &&
> > +             !kvm_check_has_quirk(svm->vcpu.kvm,
> > +                                  KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT);
>
> Align indentation.  With the @svm => @vcpu change, this becomes:
>
>         return nested_npt_enabled(to_svm(vcpu)) &&
>                !kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_NESTED_SVM_SHARED_PAT);

You wouldn't happen to know the Emacs configuration for the alignment
you like, would you? I asked Gemini, but it lied to me.

> > +}
> > +
> >  static inline bool nested_vnmi_enabled(struct vcpu_svm *svm)
> >  {
> >       return guest_cpu_cap_has(&svm->vcpu, X86_FEATURE_VNMI) &&
> > --
> > 2.53.0.1018.g2bb0e51243-goog
> >