libvirtError: unsupported configuration: CPU specification not supported by hypervisor

If you’re in staging or testing phase of openstack development, it’s possible for you using an Virtual Machine as Compute Node / Hypervisor. That’s mean you will create and running an VM over an VM.

Typically we only define virt_type = qemu inside of [libvirt] section of nova.conf file. Because we use a VM as a Hypervisor, it is possible to raise an error like this :

libvirtError: unsupported configuration: CPU specification not supported by hypervisor

By default nova will define libvirt cpu-mode using “host-model”. So if you are running your compute node/hypervisor using an Virtual Machine, you should specify libvirt cpu-mode using an “none” option. Add this line inside of [libvirt] section of nova.conf file.

So your [libvirt] section of nova.conf will be look like this :

[libvirt]
virt_type = qemu
cpu_mode = "none"