Re: [PATCH 21/25] KVM: x86: Introduce KVM_TDX_GET_CPUID

Edgecombe, Rick P
2024-08-27T20:41:02Z

On Tue, 2024-08-27 at 15:19 +0300, Nikolay Borisov wrote:

> >
> > But beyond checking for supported features, there are also bug fixes that
> > can
> > affect usability. In the NO_RBP_MOD case we need a specific recent TDX
> > module in
> > order to remove the RBP workaround patches.
>
> My point was that if having the NO_RPB_MOD implied that the CPUID
> 0x8000000 configuration capability is also there (not that there is a
> direct connection between the too but it seems the TDX module isn't
> being updated that often, I might be wrong of course!), there is no
> point in having the workaround as NO_RPB_MOD is the minimum required
> version.

Having NO_RBP_MOD won't imply 0x80000008 configuration capability. We will have
to check for a new feature bit for that. We should wait until it's finalized to
add the code.