Re: [edk2-devel] [RFC PATCH 02/14] OvmfPkg/PlatformPei: Mark SEC GHCB page in the page encrpytion bitmap.

["Ashish Kalra" <ashish.kalra@amd.com>]

On Wed, Mar 03, 2021 at 09:56:00AM -0500, Tobin Feldman-Fitzthum wrote:
> 
> > Hello Tobin,
> > 
> > Just a high level question, why is this patch included in this
> > patch series, i don't think you are supporting SEV-ES platform
> > migration in this patch-set ?
> 
> You are correct that we don't support migration for SEV-ES machines,
> although our approach can potentially be adapted for SEV-ES. I was on the
> fence about including this patch, because we don't strictly need it for
> migration. I'm not sure if the SEC GHCB would be significant even if we did
> support SEV-ES migration. Ultimately it seemed like a good idea because the
> SEV firmware build does otherwise support SEV-ES. Since I was introducing
> the hypercall in an environment where SEV-ES can be enabled, it seemed
> reasonable to include. Syncing page encryption status hypothetically has
> uses beyond migration.
> 
> Note that I am not adding full support for the hypercall in OVMF, which
> might be a good idea at some point.
> 

Yes, i don't see the assembler code stub for the hypercall in the OVMF 
patches, so i was wondering the same.

Thanks,
Ashish