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

Tom Lendacky
2022-07-19T22:08:42Z

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

>