Re: [svsm-devel] Potential project on implementing AMD SEV emulation in QEMU

On Tue, Apr 22, 2025 at 08:56:51AM +0100, Daniel P. Berrangé wrote:
>On Fri, Apr 18, 2025 at 10:31:57AM +0200, Stefano Garzarella wrote:
>> Hi Tom,
>>
>> On Thu, 17 Apr 2025 at 22:14, Tom Lendacky <[email protected]> wrote:
>> >
>> > On 4/17/25 10:26, Stefano Garzarella wrote:
>> > > Hi Tom,
>> >
>> > Hi Stefano,
>> >
>> > > yesterday in the Coconut-SVSM community call we talked about a
>> > > potential project with the University of Pisa to emulate AMD
>> > > SEV/SEV-ES/SEV-SNP support in QEMU.
>> > >
>> > > Joerg rightly suggested having a step-by-step approach, supporting SEV
>> > > initially, as supporting SEV-SNP directly might be too much for a
>> > > master's thesis (about 6 months of work).
>> > >
>> > > We wondered if you knew of any attempts already made in this regard,
>> >
>> > Nothing that I'm aware of.
>> >
>> > > but especially if you think it's a feasible thing.
>> >
>> > Anything is possible I guess, but I'm not sure what it would take to
>> > accomplish that. Attestation would tell you if you're on real hardware
>> > vs emulated hardware.
>>
>> As I wrote to Dionna, I did not explain the ultimate goal well:
>> Test/develop SVSM and guest OS interaction without having the hardware in place.
>>
>> So that's why IMO it's perfectly fine for attestation to be
>> unsuccessful, plus I don't think it's even necessary to implement any
>> encryption.
>
>IMHO attestation is required to make this fully usable even for SVSM
>dev. eg consider the work underway for persistent vTPM, which relies
>on attestation during SVSM. It would also be required for any of the
>guest OS / application layer to test/devel SEV(SNP) support fully.
>
>I would consider attestation in scope for any QEMU impl, but I agree
>that encryption of memory is not likely a priority.

Yeah, I agree with that, by “unsuccessful attestation” I meant that it 
is perfectly fine for the attestation process to tell you that you are 
not on a real hw, but emulated.

Anyway, I agree that we should emulate the generation of the attestation 
report, obviously signed with a self-generated certificate (or even 
unsigned, but I don't know if this is expected).

Thanks,
Stefano