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

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Message-ID: <0aefda219df1fd6eb0cd4f96fbe96f1e2a43c1f3.camel@intel.com>
Date: Tue, 21 Oct 2025 20:49:02 +0000
From: "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
To: "seanjc@...gle.com" <seanjc@...gle.com>
CC: "x86@...nel.org" <x86@...nel.org>, "hou, wenlong"
	<houwenlong.hwl@...group.com>, "kas@...nel.org" <kas@...nel.org>, "Li,
 Xiaoyao" <xiaoyao.li@...el.com>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, "Hunter, Adrian" <adrian.hunter@...el.com>,
	"Zhao, Yan Y" <yan.y.zhao@...el.com>, "kvm@...r.kernel.org"
	<kvm@...r.kernel.org>, "pbonzini@...hat.com" <pbonzini@...hat.com>,
	"linux-coco@...ts.linux.dev" <linux-coco@...ts.linux.dev>
Subject: Re: [PATCH v4 1/4] KVM: TDX: Synchronize user-return MSRs immediately
 after VP.ENTER

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.