Re: [PATCH v5 5/6] x86/tdx: Add a helper to query maximum Quote size

[Peter Fang]

On Mon, Sep 28, 2026 at 11:50:32AM -0700, Edgecombe, Rick P wrote:
> On Mon, 2026-09-28 at 03:08 -0700, Peter Fang wrote:
> > [1] Intel TDX Module ABI Definitions, August 2026, TD-scope metadata
> >     field "TD_QUOTE_MAX_SIZE"
> 
> The latest seems to be June 2026:
> https://www.intel.com/content/www/us/en/developer/tools/trust-domain-extensions/documentation.html

I think that's "Intel TDX Module ABI Specification". "Intel TDX Module
ABI Definitions" was updated in August. Yeah these names can be
confusing sometimes.

> 
> So where is this? Does it say anything about being page aligned already?

In the pdf the wording is "Maximum size of the buffer that must be
allocated to contain the TDX Quote received from TDX Module". It doesn't
say anything about page alignment. I can confirm with the TDX module
folks.

But even if the reported size is always page aligned, the driver would
still need to slap the GHCI header in front of it, and that would make
the total buffer size again not page aligned. So would it be useful in
the end?