Il 20/03/26 13:40, Daniel P. Berrangé ha scritto:
> On Fri, Mar 20, 2026 at 08:44:40AM +0100, Markus Armbruster wrote:
>> Daniel P. Berrangé <[email protected]> writes:
>>
>>> On Tue, Mar 17, 2026 at 12:38:36PM +0100, Tommaso Califano wrote:
>>>> With this change it is possible to run a VM with the SEV CPUID active
>>>> adding:
>>>>
>>>> -accel tcg \
>>>> -object sev-emulated,id=sev0,cbitpos=47,reduced-phys-bits=1 \
>>>> -machine memory-encryption=sev0
>>>
>>> snip
>>>
>>>> diff --git a/qapi/qom.json b/qapi/qom.json
>>>> index c653248f85..35cda819ec 100644
>>>> --- a/qapi/qom.json
>>>> +++ b/qapi/qom.json
>>>> @@ -1057,6 +1057,19 @@
>>>> '*handle': 'uint32',
>>>> '*legacy-vm-type': 'OnOffAuto' } }
>>>>
>>>> +##
>>>> +# @SevEmulatedProperties:
>>>> +#
>>>> +# Properties for sev-emulated objects.
>>>> +# This object functionally emulates AMD SEV hardware via TCG, so
>>>> +# it does not require real hardware to run.
>>>> +#
>>>> +# Since: 10.1.0
>>>> +##
>>>> +{ 'struct': 'SevEmulatedProperties',
>>>> + 'base': 'SevGuestProperties',
>>>> + 'data': {}}
>>>
>>> This is deriving 'sev-emulated' from 'sev-guest' which means it
>>> supports all the properties that 'sev-guest' does, which for
>>> the record is:
>>
>> Uh, I somehow misread the base as SevCommonProperties! Had I read
>> correctly, I would've had similar questions.
>
> Even SevCommonProperties has stuff that's irrelevant for
> emulation that I mentioned.
>
Maybe I'm missing something, but the only sev-common property not being
used is `sev-device`, since "/dev/sev" doesn't exist in the emulated context.
That said, all other properties are functional:
- cbitpos=<int>
- reduced-phys-bits=<int>
- kernel-hashes=<bool>
Additionally, deriving from sev-common ensures the TYPE_SEV_COMMON type
for the sev_enabled() cast.
So I think deriving from sev-common is beneficial.
Best regards,
Tommaso Califano
