Re: [PATCH 00/15] Enable TDX Module Extensions and DICE-based TDX Quoting

[Xu Yilun]

On Mon, Jun 01, 2026 at 01:17:59PM -0700, Sohil Mehta wrote:
> 
> >>
> >> Let's say a future platform has a lot more features and needs
> >> significantly more memory. Wouldn't loading a legacy kernel with this
> >> default policy lead to excessive wastage?
> > 
> > A legacy kernel won't consume Extensions memory. The Extensions memory
> > is only required by TDX module when add-ons features are explicitly
> > configured via TDH.SYS.CONFIG [1]. 
> 
> So, the TDX module will only report memory_pool_required_pages for
> add-on features that have been configured by the kernel? This would be

Correct.

> good to clarify in the cover letter.

Will do.

> 
> > For legacy kernel, no add-on features configured so no memory
> > consumption.
> > 
> 
> I was referring to the first kernel that has support for one TDX
> extension. I am mainly trying to ensure that a kernel with support for
> one TDX extension only consumes memory for that feature (even when it is
> loaded on a hardware platform that supports multiple TDX extensions).

Yes. The first kernel that supports for one add-on feature will only
consume memory for that feature. The other HW/FW supported features
will not be configured so will not consume extra memory.

I think I should refactor the cover-letter and changelogs based on all
these comments. Thanks for all the inputs that help me see what missed.

> 
> > But yes, if the features grow rapidly out of expectation, may need new
> > options to switch something off. I think if we discuss later when the
> > need actually arises.
> > 
>