Re: [RFC PATCH v2 1/4] KVM: x86: TDX: Track supported configurable CPUID bits

[Sean Christopherson]

On Mon, Jun 29, 2026, Binbin Wu wrote:
> On 6/26/2026 1:04 AM, Sean Christopherson wrote:
> > On Thu, Jun 04, 2026, Binbin Wu wrote:
> > CPUID.0x1E is a bit different because it's kinda sorta a feature?  That one is
> > probably worth restricting, but again that's easy to do in a case-statement.
> 
> Only CPUID.0x1E.EAX has TDX directly configurable bits currently, no special
> handling needed for the rest of CPUID.0x1E.

But isn't the whole point to guard against TDX Modules gaining support for features
KVM doesn't know about?  What happens if hardware extends into CPUID.0x1E.ECX,
and the TDX Module follows suit?

I guess that applies to all the feature leaves?