Re: [PATCH 04/15] x86/virt/tdx: Enable the Extensions right after basic TDX Module init

[Xu Yilun]

On Mon, May 25, 2026 at 09:00:32AM +0300, Tony Lindgren wrote:
> On Fri, May 22, 2026 at 11:41:17AM +0800, Xu Yilun wrote:
> > The detailed initialization flow for TDX Module Extensions has been
> > fully implemented. Enable the flow after basic TDX Module
> > initialization.
> > 
> > Theoretically, the Extensions doesn't need to be enabled right after
> > basic TDX initialization. It could be enabled right before the first
> > Extension SEAMCALL is issued. That would save or postpone memory usage.
> > But it isn't worth the complexity, the needs for the Extensions are vast
> > but the savings are little for a typical TDX capable system (about
> > 0.001% of memory). So the Linux decision is to just enable it along with
> > the basic TDX.
> > 
> > Note that the Extensions initialization flow will still not start if no
> > add-on features require Extensions. The enabling of add-on features will
> > be in later patches. Until then, the system hasn't consumed extra memory.
> 
> Looking at patch 15/15, we need to reload the TDX module metadata at least
> for the attestation. We need to do that early, so to me it seems that
> everything can be just tagged __init from the start.

I'm good to it. The Extension initialization will not start without
add-on features anyway. Let me move the patch as the first one to avoid
tag churn.