Re: [PATCH v3 0/4] KVM: TDX: Validate directly configurable CPUID bits
From: Binbin Wu
Date: Wed Sep 02 2026 - 12:38:31 EST
On 9/2/2026 9:13 PM, Edgecombe, Rick P wrote:
> On Wed, 2026-09-02 at 18:29 +0800, Xiaoyao Li wrote:
>> So the proposal is making TDX behave as if the relevant VMCS save/load
>> controls (if any) are set around TDH.VP.ENTER.
>>
>> In fact, what matters for host vmm is just the VM_EXIT_LOAD_XXX control.
>> So the proposal becomes "If there is VM_EXIT_LOAD_XXX control for a
>> state, TDX needs to restore the host state after TDH.VP.ENTER. If no
>> such contorl, TDX sets the state to INIT state after TDH.VP.ENTER".
>>
>> It's a fancy idea. And it provides a clear rule of how TDX handles
>> states of a feature so that host VMM developers don't need to read the
>> TDX module API to figure out what's the value of a state after TDH.VP.ENTER.
>>
>> It's helpful for host VMM developers, though I'm not sure on TDX module
>> developers.
>
> I don't think they have agreed to it yet (Binbin?),
Not yet. We just brought the topic to the community for discussion first.
> but I think it mostly works
> this way already. Why do you think it is a burden on TDX module developers?
>
> Also, I think this can be the guideline. We could have exceptions.