Comment 8 for bug 1861643

Ok it is different, when spawning my focal guest I used my usual LXD profile (which can run KVM) but the bionic guest to test this was from scratch and didn't have that. So I actually checked a non-kvm capable bionic system.

I have to retest the list in comment #6

When doing so we can almost right away go for qemu probing:
$ sudo qemu-system-x86_64 --enable-kvm --nographic --nodefaults -S -qmp-pretty stdio
{"execute":"qmp_capabilities"}
{"execute":"query-cpu-definitions"}

That will list all known CPUs and if they are not usable for e.g. missing a CPU feature