Re: TDG quote analysis

[Sean Christopherson <seanjc@google.com>]

On Wed, Sep 16, 2026, Peter Fang wrote:
> On Wed, Sep 16, 2026 at 03:31:50PM -0700, Edgecombe, Rick P wrote:
> > On Wed, 2026-09-16 at 12:27 -0700, Sean Christopherson wrote:
> > > > If you are thinking the implementation could punt on how to handle the guest
> > > > interrupts for now, that seems reasonable. I'd think exiting to handle the
> > > > host interrupts could not be skipped though.
> > > 
> > > I'm just trying to understand the scope of the problem we're trying to solve.
> > > E.g. I don't think any design will save us if generating a quote requires a
> > > CPU to be spinning for multiple milliseconds.
> > 
> > Elena, any updated estimates on CPU based quote generation and HW based?
> 
> The current estimate is 10s of milliseconds for HW based, and
> milliseconds or less for CPU based.

I am beyond confused.  What is "HW based" versus "CPU based"?

At this point, I don't care about the gory details, I just want to understand
the basics:

 - Does generating a quote require the CPU to actively execute instructions?
 - If not, how does software know when a quote is ready? 

I tried peeking at TDX Module source code, but I can't find anything relevant
even in the latest TDX 2.0 drop.