I'm currently looking at getting libvirt working with AMD's SEV-SNP
encrypted virtualization technology. I have access to a test machine
with an AMD EPYC 7713 processor which I can use to launch SNP guests
with qemu, but only when I specify one of the following versioned -cpu
values:
- EPYC-v4
- EPYC-Milan-v2
- EPYC-Rome-v3
From what I understand, the unversioned CPU models in qemu are supposed
to resolve to a specific versioned CPU model depending on the machine
type. But I'm not exactly sure how machine type influences it.
I've got some libvirt patches to launch an SEV-SNP guest working now
except for the CPU model specification. As far as I can tell, I can
currently only specify the un-versioned model in libvirt. Is there any
way to request a particular versioned CPU from qemu? I feel like I'm
missing something here.
I should perhaps also mention that I'm running a development version of
qemu from Cole's copr repo[1], which could still have some related bugs
[1] https://copr.fedorainfracloud.org/coprs/g/virtmaint-sig/sev-snp-coconut/
Thanks,
Jonathon
