Re: [PATCHv7 00/14] mm, x86/cc: Implement support for unaccepted memory

[Tom Lendacky]

On 7/19/22 17:02, Dave Hansen wrote:
> On 7/19/22 14:50, Borislav Petkov wrote:
> > On Tue, Jul 19, 2022 at 02:35:45PM -0700, Dave Hansen wrote:
> > > They're trying to design something that can (forever) handle guests that
> > > might not be able to accept memory.
> > Wait, what?
> >
> > If you can't modify those guests to teach them to accept memory, how do
> > you add TDX or SNP guest support to them?
>
> Mainline today, for instance, doesn't have unaccepted memory support for
> TDX or SEV-SNP guests.  But, they both still boot fine because folks
> either configure it on the host side not to *have* any unaccepted
> memory.  Or, they just live with the small (4GB??) amount of
> pre-accepted memory, which is fine for testing things.

Today, for SEV-SNP, OVMF accepts all of the memory in advance of booting 
the kernel.

Thanks,
Tom

>