Re: [Part1 PATCH v7 00/17] x86: Secure Encrypted Virtualization (AMD)

Steve Rutherford
2017-11-21T23:19:25Z

On Thu, Nov 16, 2017 at 6:41 AM, Tom Lendacky <thomas.lendacky@amd.com> wrote:
> On 11/16/2017 4:02 AM, Borislav Petkov wrote:
>>
>> On Wed, Nov 15, 2017 at 03:57:13PM -0800, Steve Rutherford wrote:
>>>
>>> One piece that seems missing here is the handling of the vmm
>>> communication exception. What's the plan for non-automatic exits? In
>>> particular, what's the plan for emulated devices that are currently
>>> accessed through MMIO (e.g. the IOAPIC)?
>>
>>
>> First of all, please do not top-post.
>>
>> Then, maybe this would answer some of your questions:
>>
>>
>> http://support.amd.com/TechDocs/Protecting%20VM%20Register%20State%20with%20SEV-ES.pdf
>>
>> But I'd look in Tom's direction for further comments.
>
>
> I'm not sure what the question really is...
>
> MMIO works just fine using the data contained in the VMCB on exit
> (exit_info_1, exit_info_2, insn_bytes, etc.).
>
> These patches are for SEV support. If the question is related to SEV-ES
> (based on the non-automatic exit comment), that support is not part of
> these patches and will require additional changes to be able to both
> launch a guest as an SEV-ES guest and run as an SEV-ES guest.

I conflated SEV with SEV-ES, which I suspect answers everything here.
The reason it doesn't have support for the #VC exception is because
it's not supposed to... yet.

I'm still interested in the plan for the #VC exception handler, but
this thread doesn't seem like the place.

>
>>
>>> Maybe I'm getting ahead of myself: What's the testing story? (since I
>>> don't think linux would boot with these patches, I'm curious what you
>>> are doing to ensure these pieces work)
>>
>>
>> Seems to boot fine here :)
>
>
> Using these patches we have successfully booted and tested a guest both
> with and without SEV enabled.
>
> Thanks,
> Tom
>
>>
>

Thanks,
Steve