On Mon, Jan 30, 2012 at 17:25:19 +0100, Martin Kletzander wrote:
In qemu there are 2 cpu models (cpu64-rhel5 and cpu64-rhel6) not supported by libvirt. This patch adds the support with the flags specifications from /usr/share/qemu-kvm/cpu-model/cpu-x86_64.conf
Hmm, I didn't actually look at the model definitions until now... I haven't checked them with qemu sources, but the definitions look weird.
diff --git a/src/cpu/cpu_map.xml b/src/cpu/cpu_map.xml index 693caf1..8c9da42 100644 --- a/src/cpu/cpu_map.xml +++ b/src/cpu/cpu_map.xml @@ -327,6 +327,72 @@ <feature name='svm'/> </model>
+ <model name='cpu64-rhel5'> + <vendor name='AMD'/> + <feature name='3dnow'/> + <feature name='3dnowext'/> ... + <feature name='svm'/> ... + </model>
Why are these virtual models marked as made by AMD and why do they contain those AMD-only features? The vendor is probably not a big deal, libvirt will just avoid using these models for describing a host CPU which is not made by AMD. However, the AMD-only features make these models incompatible with any Intel CPU. Thus the following guest CPU element <cpu match='exact'> <model>cpu64-rhel?</model> <feature name='3dnow' policy='disable'/> <feature name='3dnowext' policy='disable'/> <feature name='svm' policy='disable'/> </cpu> will be needed to use this model on Intel host. Are these features in fact emulated by qemu even if host CPU doesn't support them? Jirka