Re: [PATCH 1/5] i386/sev: Add sev-emulated QOM object with TCG support

["Daniel P. Berrangé" <berrange@redhat.com>]

On Fri, Mar 20, 2026 at 08:44:40AM +0100, Markus Armbruster wrote:
> Daniel P. Berrangé <berrange@redhat.com> 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.

With regards,
Daniel
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