...
"Phenom" doesn't exist in the
/usr/share/libvirt/cpu_map.xml, therefore libvirt? chooses probably the closest to
specification,
and it is always Opteron_G3, even if cpu mode='host-passthrough'.
Is this the culprit, dunno, but both systems do have a tendency to "hose".
And this is nothing new, it is ongoing long since.
To correct myself, there is "phenom" in the 'cpu_map.xml', although this
is not the second generation.
However the question is whether it is at all important to libvirt/qemu given the limited
number of used properties.
Also, this can be surpassed by cpu mode='host-passthrough' although even that is
not fully applied, probably related to the limitation of the qemu BIOS i.e. due to the
lack of susceptibility to "subtle" differences in socket - core relation.
But even that did not help.
Finally, one small thing helped, and this is not the daisy.
3.18.1-2.fc22.x86_64
Someone once said, the Earth is round.