Re: [PATCH v14 07/13] KVM: VMX: Emulate reads and writes to CET MSRs

From: Yang Weijiang
Date: Fri Jan 29 2021 - 02:56:28 EST


On Thu, Jan 28, 2021 at 06:45:08PM +0100, Paolo Bonzini wrote:
> On 06/11/20 02:16, Yang Weijiang wrote:
> >
> > +static bool cet_is_ssp_msr_accessible(struct kvm_vcpu *vcpu,
> > + struct msr_data *msr)
> > +{
> > + u64 mask;
> > +
> > + if (!kvm_cet_supported())
> > + return false;
> > +
> > + if (msr->host_initiated)
> > + return true;
> > +
> > + if (!guest_cpuid_has(vcpu, X86_FEATURE_SHSTK))
> > + return false;
> > +
> > + if (msr->index == MSR_IA32_INT_SSP_TAB)
> > + return false;
>
> Shouldn't this return true?
>
Hi, Paolo,
Thanks for the feedback!
Yes, it should be true, will fix it in next release.
> Paolo
>
> > + mask = (msr->index == MSR_IA32_PL3_SSP) ? XFEATURE_MASK_CET_USER :
> > + XFEATURE_MASK_CET_KERNEL;
> > + return !!(vcpu->arch.guest_supported_xss & mask);
> > +}