Comment 42 for bug 1673467

OK - some updates

I've tested with 2.5.0 and 3.5.0 of libvirt using OpenStack Ocata.

2.5.0 libvirt/qemu does not support host-model - only host-passthrough so I agree that we should just being doing the right thing either in the charm (as we've done for other non-x86 arch) or the nova codebase - my preference is for the first as we avoid to much magic behaviour.

3.5.0 has the same limitation; I'm actually bumping into a different issue for which I'll raise another bug for arm64 instances using that libvirt stack.

tl;dr - lets just use host-passthrough and move on.