On Fri, Apr 24, 2020 at 07:55:29AM -0700, Sean Christopherson wrote: > On Fri, Apr 24, 2020 at 10:07:51PM +0800, Yang Weijiang wrote: > > On Thu, Apr 23, 2020 at 09:27:49AM -0700, Sean Christopherson wrote: > > > On Thu, Mar 26, 2020 at 04:18:39PM +0800, Yang Weijiang wrote: > > > > @@ -7102,6 +7138,10 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu) > > > > vmx_set_guest_msr(vmx, msr, enabled ? 0 : TSX_CTRL_RTM_DISABLE); > > > > } > > > > } > > > > + > > > > + if (guest_cpuid_has(vcpu, X86_FEATURE_SHSTK) || > > > > + guest_cpuid_has(vcpu, X86_FEATURE_IBT)) > > > > + vmx_update_intercept_for_cet_msr(vcpu); > > > > > > This is wrong, it will miss the case where userspace double configures CPUID > > > and goes from CET=1 to CET=0. This should instead be: > > > > > > if (supported_xss & (XFEATURE_MASK_CET_KERNEL | XFEATURE_MASK_CET_USER)) > > > vmx_update_intercept_for_cet_msr(vcpu); > > > > > > > } > > Here CET=1/0, did you mean the CET bit in XSS or CR4.CET? If it's the > > former, then it's OK for me. > > The former, i.e. update the CET MSRs if KVM supports CET virtualization and > the guest's CPUID configuration is changing. Yep, this case should be taken into account, thank you for pointing it out!
