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

[Sohil Mehta]

>>
>> 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
good to clarify in the cover letter.

> 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).

> 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.
>