Re: [PATCH v4 1/4] KVM: TDX: Synchronize user-return MSRs immediately after VP.ENTER

Edgecombe, Rick P
2025-10-21T20:49:09Z

On Tue, 2025-10-21 at 12:33 -0700, Sean Christopherson wrote:
> /facepalm
>
> diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
> index 63abfa251243..cde91a995076 100644
> --- a/arch/x86/kvm/vmx/tdx.c
> +++ b/arch/x86/kvm/vmx/tdx.c
> @@ -801,8 +801,8 @@ void tdx_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
>          * state.
>          */
>         for (i = 0; i < ARRAY_SIZE(tdx_uret_msrs); i++)
> -               kvm_set_user_return_msr(i, tdx_uret_msrs[i].slot,
> -                                       tdx_uret_msrs[i].defval);
> +               kvm_set_user_return_msr(tdx_uret_msrs[i].slot,
> +                                       tdx_uret_msrs[i].defval, -1ull);
>  }
>
>  static void tdx_prepare_switch_to_host(struct kvm_vcpu *vcpu)

Ah ok, I'll give it another spin after I finish debugging step 0, which is
figure out what has gone wrong with my TDX dev machine.