Re: [PATCH v3 32/49] i386/sev: Don't return launch measurements for SEV-SNP guests

[Daniel P . Berrangé]

On Wed, Mar 20, 2024 at 12:15:00PM +0000, Daniel P. Berrangé wrote:
> On Wed, Mar 20, 2024 at 03:39:28AM -0500, Michael Roth wrote:
> > For SEV-SNP guests, launch measurement is queried from within the guest
> > during attestation, so don't attempt to return it as part of
> > query-sev-launch-measure.
> > 
> > Signed-off-by: Michael Roth <michael.roth@amd.com>
> > ---
> >  target/i386/sev.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/target/i386/sev.c b/target/i386/sev.c
> > index b03d70a3d1..0c8e4bdb4c 100644
> > --- a/target/i386/sev.c
> > +++ b/target/i386/sev.c
> > @@ -803,7 +803,9 @@ sev_launch_get_measure(Notifier *notifier, void *unused)
> >  
> >  static char *sev_get_launch_measurement(void)
> >  {
> > -    SevGuestState *sev_guest = SEV_GUEST(MACHINE(qdev_get_machine())->cgs);
> > +    ConfidentialGuestSupport *cgs = MACHINE(qdev_get_machine())->cgs;
> > +    SevGuestState *sev_guest =
> > +        (SevGuestState *)object_dynamic_cast(OBJECT(cgs), TYPE_SEV_GUEST);
> >  
> >      if (sev_guest &&
> >          SEV_COMMON(sev_guest)->state >= SEV_STATE_LAUNCH_SECRET) {
> 
> The QAPI docs for query-sev-launch-measurement should be updated
> to reflect that this command is only valid to call for SEV/SEV-ES,
> not SNP.

Also, the same question about whether query-sev-attestation-report
and sev-inject-launch-secret need updating to declare them SEV/SEV-ES
only, or if they are expected work with SNP too ?


With regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|