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

[Peter Fang]

On Mon, Sep 28, 2026 at 02:25:48PM -0700, Edgecombe, Rick P wrote:
> On Mon, 2026-09-28 at 14:25 -0700, Rick Edgecombe wrote:
> > > 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?
> > 
> > Ah right.
> 
> But that means the memset length is a real functional change?

In a way yes. Previously when the driver was just using the 128KB
constant, there was not a need to explicitly expose this header math. So
the 128KB implicity considered "header + actual quote". Now that's it's
an ABI, pushing this header math into the TDX module would mean less
flexibility in the future to use something other than the GHCI for
quoting.