Re: [PATCH v2 03/17] x86/virt/tdx: Detect if the extensions initialization is required

[Edgecombe, Rick P]

On Mon, 2026-07-27 at 20:38 +0800, Xu Yilun wrote:
> > This is not true. There are some normal (non-extension) SEAMCALLs also are
> > preemptible and resumable. For example,
> > 
> > - TDH.PHYMEM.CACHE.WB
> > - TDH.SYS.DISABLE
> > - TDH.MEM.SEPT.ADD with version 1
> 
> No they are not preemptible and resumable. They just intentionally
> yield and don't have a generic way to save/resume their context. You
> can't rely on that to implement complex tasks in TDX module considering
> the complexity. That's the main reason why TDX module extensions are
> needed.

We have RESUMABLE seamcalls today. They are guaranteed to save state and make
forward progress. Xiaoyao is right, this is not a new concept from the VMM side.
But also why highlight this for the patch here. Are you trying to explain why
extension initialization needs some special step?