[libvirt-users] CPU Model detection with virsh capabilities

Jiri Denemark jdenemar at redhat.com
Fri Sep 9 06:52:23 UTC 2011


> I wanted to emulate another CPU than the classical qemu32 using virsh. 
> So I used the virsh capabilites command to detect how is detected my CPU 
> host which is an Intel Xeon E5410 and my problem is that this CPU is 
> detected only with the cpumodel "pentium3".

Libvirt detects host CPU feature-wise. It knows several models and features
they provide (look at /usr/share/libvirt/cpu_map.xml) and selects a model that
implements most of the features of host CPU and there are no features in the
model that host CPU doesn't support. The reason why your CPU is not detected
as more advanced model is most likely that your host CPU doesn't support some
features included in such models. Can you send us full copy of the <cpu>
element and its children from virsh capabilities?

You can also learn more about configuring guest CPUs with libvirt at


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