On 12/08/2017 15:35, Yu Zhang wrote: > + ctxt->ops->get_cpuid(ctxt, &eax, NULL, NULL, NULL); > + maxphyaddr = eax * 0xff; This is "&", not "*". You can also use rsvd_bits here. > + rsvd = (~((1UL << maxphyaddr) - 1)) & > + ~CR3_PCID_INVD; > + } > > if (new_val & rsvd) > return emulate_gp(ctxt, 0); > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index e40a779..d9100c4 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -813,10 +813,10 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) > return 0; > } > > - if (is_long_mode(vcpu)) { > - if (cr3 & CR3_L_MODE_RESERVED_BITS) > - return 1; > - } else if (is_pae(vcpu) && is_paging(vcpu) && > + if (is_long_mode(vcpu) && > + (cr3 & rsvd_bits(cpuid_maxphyaddr(vcpu), 63))) > + return 1; 62 is a little better, since 63 is the PCID invalidate bit. Paolo > + else if (is_pae(vcpu) && is_paging(vcpu) && > !load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3)) > return 1; >