Re: [PATCH v2 2/3] KVM: vmx: Emulate MSR IA32_UMWAIT_CONTROL

[Tao Xu]

On 29/05/2019 09:29, Paolo Bonzini wrote:
> On 24/05/19 09:56, Tao Xu wrote:
> > +
> > +	if (rdmsrl_safe(MSR_IA32_UMWAIT_CONTROL, &host_umwait_control))
> > +		return;
> > +
>
> Does the host value ever change?  If not, this can perhaps be read once
> when kvm_intel is loaded.  And if it changes often, it should be
> shadowed into a percpu variable.
>
> Paolo

Yes, the host value may change, we contact the host patch author Fenghua 
to add the shadow in host when the host msr value change. And we will 
improve this in the next version of patch.