On Mon, May 10, 2021, Maxim Levitsky wrote: > On Tue, 2021-05-04 at 10:17 -0700, Sean Christopherson wrote: > > @@ -6929,18 +6942,10 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu) > > goto free_vpid; > > } > > > > - BUILD_BUG_ON(ARRAY_SIZE(vmx_uret_msrs_list) != MAX_NR_USER_RETURN_MSRS); > > + for (i = 0; i < vmx_nr_uret_msrs; ++i) { > > + vmx->guest_uret_msrs[i].data = 0; > > > > - for (i = 0; i < ARRAY_SIZE(vmx_uret_msrs_list); ++i) { > > - u32 index = vmx_uret_msrs_list[i]; > > - int j = vmx->nr_uret_msrs; > > - > > - if (kvm_probe_user_return_msr(index)) > > - continue; > > - > > - vmx->guest_uret_msrs[j].slot = i; > I don't see anything initalizing the .slot after this patch. > Now this code is removed later which masks this bug, > but for the bisect sake, I think that this patch > should still be fixed. Egad, indeed it's broken. I'll retest the whole series to verify the other patches will bisect cleanly. Nice catch!