Re: [PATCH 1/2] KVM: MMU: fix ept=0/pte.u=0/pte.w=0/CR0.WP=0/CR4.SMEP=1/EFER.NX=0 combo

From: Paolo Bonzini
Date: Thu Mar 10 2016 - 05:47:47 EST




On 10/03/2016 09:27, Xiao Guangrong wrote:
> So it only hurts the box which has cpu_has_load_ia32_efer support otherwise
> NX is inherited from kernel (kernel always sets NX if CPU supports it),
> right?

Yes, but I think !cpu_has_load_ia32_efer && SMEP does not exist. On the
other hand it's really only when disabling ept, so it's a weird corner
case that only happens during testing.

Paolo