Libvirt fails to start VM with virtio related "unsupported configuration"

[Nicolas Melot]

Libvirt fails to start any VM on a fresh OpenStack Zed install on Rocky 9, also freshly installed. The logs show the line below:

[root@cs2 ~]# openstack server delete test; openstack server create --flavor "1CPU-512RAM-0Root-0Pad-0Swap-1RXTX" --image "cirros 0.4.0" --nic net-id=internal --security-group bf35c9bc-84c8-4f43-b1d2-a3fb04231245 --key-name nicolasm-gate test

[root@cs2 ~]# tail -f /var/log/nova/nova.log
....
libvirt.libvirtError: unsupported configuration: domain configuration does not support video model 'virtio'
....

I attached the full log that also include the machine configuration nova generated to start the VM.

I tried installing packages "qemu-kvm-device-display-virtio-vga-7.0.0-13.el9.x86_64", "qemu-kvm-device-display-virtio-gpu-7.0.0-13.el9.x86_64", "qemu-kvm-device-display-virtio-gpu-gl-7.0.0-13.el9.x86_64" and "qemu-kvm-device-display-virtio-vga-gl-7.0.0-13.el9.x86_64", nova/libvirt still fail with the same error, even after restarting nova-compute and libvirtd services, or even the whole computer.

Trying to start a VM with virtio video directly on the host via vist-manager yields the same error:
Unable to complete install: 'unsupported configuration: USB redirection is not supported by this version of QEMU'

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 89, in cb_wrapper
    callback(asyncjob, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/create.py", line 2552, in _do_async_install
    guest.start_install(meter=meter)
  File "/usr/share/virt-manager/virtinst/guest.py", line 495, in start_install
    doboot, transient)
  File "/usr/share/virt-manager/virtinst/guest.py", line 431, in _create_guest
    domain = self.conn.createXML(install_xml or final_xml, 0)
  File "/usr/lib64/python2.7/site-packages/libvirt.py", line 3725, in createXML
    if ret is None:raise libvirtError('virDomainCreateXML() failed', conn=self)
libvirtError: unsupported configuration: USB redirection is not supported by this version of QEMU

Hinting that the problem is probably not on nova's side.

Finally, qemu seems to be able to spawn a VM with virtio vga device:

[root@cs2 ~]# /usr/libexec/qemu-kvm -vga virtio
qemu-kvm: Machine type 'pc-i440fx-rhel7.6.0' is deprecated: machine types for previous major releases are deprecated
qemu-kvm: warning: CPU model qemu64-x86_64-cpu is deprecated -- use at least 'Nehalem' / 'Opteron_G4', or 'host' / 'max'
VNC server running on ::1:5900
^Cqemu-kvm: terminating on signal 2
[root@cs2 ~]#

So the issue seems to be on Libvirt side.

I encountered the same issue on another install on rocky 9, but I do not remember how I solved it. Since the problem happened twice independently, I suppose you might have encountered it too. Are you aware of a solution?

[Nicolas Melot (nicmel)]

The problem seems to have disappeared after I had installed the list of packages below

qemu-kvm-ui-opengl
qemu-kvm-device-display-virtio-gpu
qemu-kvm-device-display-virtio-gpu-gl
qemu-kvm-device-display-virtio-gpu-pci
qemu-kvm-device-display-virtio-gpu-pci-gl
qemu-kvm-device-display-virtio-vga
qemu-kvm-device-display-virtio-vga-gl
qemu-kvm-device-usb-host
qemu-kvm-device-usb-redirect

Problem is, I tried to uninstall them all to check which fixed the issue, but I could not pinpoint to the definitive culprit. I could not remove "qemu-kvm-device-display-virtio-vga" because it would uninstall openstack-nova-compute too. I had another error after I removed "qemu-kvm-device-display-virtio-gpu" that prevented any VM to be powered up.
When these to packages are installed, and every other is uninstalled, I can create VMs, but the logs show the error below:

Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.752 4266 ERROR oslo_policy._parser [None req-bd5cf02f-c95f-4c3e-9c36-3bbc3a66c3a5 1018 dacc3bfe218f4476bb12cc493b98c941 - - default default] Failed to understand rule true: ValueError: not enough values to unpack (expected 2, got 1)
Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.752 4266 ERROR oslo_policy._parser Traceback (most recent call last):
Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.752 4266 ERROR oslo_policy._parser File "/usr/lib/python3.9/site-packages/oslo_policy/_parser.py", line 209, in _parse_check
Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.752 4266 ERROR oslo_policy._parser kind, match = rule.split(':', 1)
Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.752 4266 ERROR oslo_policy._parser ValueError: not enough values to unpack (expected 2, got 1)
Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.752 4266 ERROR oslo_policy._parser
Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.752 4266 ERROR oslo_policy._parser [None req-bd5cf02f-c95f-4c3e-9c36-3bbc3a66c3a5 1018 dacc3bfe218f4476bb12cc493b98c941 - - default default] Failed to understand rule true: ValueError: not enough values to unpack (expected 2, got 1)
Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.752 4266 ERROR oslo_policy._parser Traceback (most recent call last):
Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.752 4266 ERROR oslo_policy._parser File "/usr/lib/python3.9/site-packages/oslo_policy/_parser.py", line 209, in _parse_check
Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.752 4266 ERROR oslo_policy._parser kind, match = rule.split(':', 1)
Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.752 4266 ERROR oslo_policy._parser ValueError: not enough values to unpack (expected 2, got 1)
Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.752 4266 ERROR oslo_policy._parser
Dec 16 16:37:32 cs2 nova-compute[4266]: 2022-12-16 16:37:32.758 4266 INFO nova.virt.libvirt.driver [None req-bd5cf02f-c95f-4c3e-9c36-3bbc3a66c3a5 1018 dacc3bfe218f4476bb12cc493b98c941 - - default default] [instance: 64271687-6925-4024-8311-f7a4db5453ef] Creating image(s)

I will post again if I encounter the same issue again next time I setup a comp...

[Nicolas Melot (nicmel)]

The "not enough values to unpack" error disappeared from the logs after I fixed a rule in nova's policy.yaml file, from "true" to "value:true"

[Artom Lifshitz (notartom)]

Sounds like you fixed your host to support virtio, and then your policy file syntax error. Is it OK if I move this to Invalid since this is not a Nova bug?

[Nicolas Melot (nicmel)]

Yes, please proceed

[jacky (ishijx)]

May be the cpu-module of set VM problem, "host-model" is OK, but host-passthrough that's "libvirt.libvirtError: unsupported configuration: domain configuration does not support video model 'virtio'"