Re: [PATCH v7 7/8] KVM: VMX: Expose PKS to guest

[Wang, Lei]

On 5/25/2022 7:34 AM, Sean Christopherson wrote:
> On Sun, Apr 24, 2022, Lei Wang wrote:
> > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> > index 9d0588e85410..cbcb0d7b47a4 100644
> > --- a/arch/x86/kvm/vmx/vmx.c
> > +++ b/arch/x86/kvm/vmx/vmx.c
> > @@ -3250,7 +3250,7 @@ void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
> >   		}
> >   
> >   		/*
> > -		 * SMEP/SMAP/PKU is disabled if CPU is in non-paging mode in
> > +		 * SMEP/SMAP/PKU/PKS is disabled if CPU is in non-paging mode in
> >   		 * hardware.  To emulate this behavior, SMEP/SMAP/PKU needs
> Heh, missed one ;-)  Let's reduce future pain and reword this whole comment:
>
> 		/*
> 		 * SMEP/SMAP/PKU/PKS are effectively disabled if the CPU is in
> 		 * non-paging mode in hardware.  To emulate this behavior,
> 		 * clear them in the hardware CR4 when the guest switches to
> 		 * non-paging mode and unrestricted guest is disabled, as KVM
> 		 * must run the guest with hardware CR0.PG=1.
> 		 */
Nice catch, will fix it ;-)