Re: [PATCH v2 07/21] KVM:x86: Refresh CPUID on write to guest MSR_IA32_XSS

[Yang, Weijiang]

On 4/24/2023 9:38 AM, Binbin Wu wrote:
> On 4/21/2023 9:46 PM, Yang Weijiang wrote:
> >
[...]
> > @@ -276,9 +276,14 @@ static void __kvm_update_cpuid_runtime(struct 
> > kvm_vcpu *vcpu, struct kvm_cpuid_e
> >           best->ebx = xstate_required_size(vcpu->arch.xcr0, false);
> >         best = cpuid_entry2_find(entries, nent, 0xD, 1);
> > -    if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
> > -             cpuid_entry_has(best, X86_FEATURE_XSAVEC)))
> > -        best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
> > +    if (best) {
> > +        if (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
> > +            cpuid_entry_has(best, X86_FEATURE_XSAVEC))  {
>
> Is it necessary to change to use two ifs?

Good catch! I changed the patch a bit, but forgot to re-shape it.

> > +            u64 xstate = vcpu->arch.xcr0 | vcpu->arch.ia32_xss;
> > +
> > +            best->ebx = xstate_required_size(xstate, true);
[...]