Re: [PATCH 01/15] x86/virt/tdx: Read global metadata for TDX Module Extensions

[Dan Williams (nvidia)]

Xu Yilun wrote:
> Add reading of the global metadata for TDX Module Extensions.
> 
> TDX Module Extensions is an add-on feature enumerated by TDX_FEATURES0.
> But for the Module's integrity, Linux requires that all features that a
> Module advertises must have a complete, valid set of metadata, and the
> validation must succeed at core TDX initialization time.
> 
> Check TDX_FEATURES0 before reading these metadata. If a feature is
> advertised, a failure in reading associated metadata causes the entire
> TDX initialization to fail, otherwise skip.

Others already commented on the patch ordering, so I will just comment
on the changelog to recommend referring back to the "any available
extension, all the time" implementation policy rather than saying "Linux
requires" which is ambiguous.

The patch reordering will make it more clear that
memory_pool_required_pages scales based on the number of features that
Linux grows enabling for at configuration time.