Cannot find suitable CPU model for given data during VM starting

[Gannet]

Eachtime I'm trying to start VM through Virtual Machine Manager an error window appears:

Error during domain starting: internal error: Cannot find suitable CPU model for given data

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 96, in cb_wrapper
    callback(asyncjob, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 117, in tmpcb
    callback(*args, **kwargs)
  File "/usr/share/virt-manager/virtManager/domain.py", line 1162, in startup
    self._backend.create()
  File "/usr/lib/python2.7/dist-packages/libvirt.py", line 866, in create
    if ret == -1: raise libvirtError ('virDomainCreate() failed', dom=self)
libvirtError: internal error: Cannot find suitable CPU model for given data

The workaround found is to run:

sudo dpkg-reconfigure libvirt-bin
libvirt-bin stop/waiting
libvirt-bin start/running, process 16631
Setting up libvirt-bin dnsmasq configuration.

After this VM starts running. But till next system reboot. After restarting computer I must run dpkg-reconfigure again to make VM starting.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: libvirt-bin 1.2.2-0ubuntu13.1.1
ProcVersionSignature: Error: [Errno 2] No such file or directory: '/proc/version_signature'
Uname: Linux 3.15.6-031506-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
CurrentDesktop: KDE
Date: Mon Jul 21 20:47:56 2014
InstallationDate: Installed on 2014-06-08 (43 days ago)
InstallationMedia: Kubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.1)
SourcePackage: libvirt
UpgradeStatus: No upgrade log present (probably fresh install)
modified.conffile..etc.libvirt.qemu.conf: [inaccessible: [Errno 13] Access denied: '/etc/libvirt/qemu.conf']

[Serge Hallyn (serge-hallyn)]

Thanks for reporting this bug.

Please attach /etc/libvirt/qemu.conf.

Also please attach the result of 'virsh dumpxml vmname' both immediately after boot, and after the libvirt reconfigure.

[Serge Hallyn (serge-hallyn)]

Thanks. I would assume this is due to you having qemu run as user and group eugene. Do you have /dev/kvm owned by group eugene? If not, then I'm more surprised that your reconfiguration of libvirt allows the VM to start.

Could you please show the result of 'ls -l /dev/kvm; getfacl /dev/kvm' after a reboot and after a reconfiguration?

Also please attach /var/log/libvirt/qemu/win8.log

[Gannet (ken20001)]

Before:

ls -l /dev/kvm
crw-rw----+ 1 root kvm 10, 232 лип 31 13:46 /dev/kvm

getfacl /dev/kvm
getfacl: Видалення початкового '/' з абсолютних шляхів
# file: dev/kvm
# owner: root
# group: kvm
user::rw-
user:eugene:rw-
group::rw-
mask::rw-
other::---

After:

ls -l /dev/kvm
crw-rw----+ 1 root kvm 10, 232 лип 31 13:46 /dev/kvm

getfacl /dev/kvm
getfacl: Видалення початкового '/' з абсолютних шляхів
# file: dev/kvm
# owner: root
# group: kvm
user::rw-
user:eugene:rw-
group::rw-
mask::rw-
other::---

[Gannet (ken20001)]

Noting: I was need to change win8.log owner to add it as attachment.

[Serge Hallyn (serge-hallyn)]

Does changing the qemu.conf to comment out the user=eugene and group=eugene work around the issue?

[Gannet (ken20001)]

No it doesn't.

[Serge Hallyn (serge-hallyn)]

I don't believe this is a libvirt bug, because I can run VMS fine under libvirt. However, I can reproduce this (in utopic) with virt-manager.

When I manually insert cpu type 'qemu64', it complains about cpu flag svm not being applicable - this is on an intel laptop.

Somehow virt-manager is not getting the right cpu capabilities - this still could boil down to a libvirt bug (i.e. virsh capabilities giving wrong results).

[Gannet (ken20001)]

And this started to happen after last package updation. Before it this issue didn't existed.

[Gannet (ken20001)]

Now, seems, it works for me. I don't know what changed but now my VM starts without any error messages.

Linux: 3.15.9 x86_64
virt-manager: 0.9.5-1ubuntu3
libvirt-bin: 1.2.2-0ubuntu13.1.2

[Dustin Kirkland  (kirkland)]

I'm seeing this on Utopic as well.

[adrian (adrianlzt)]

This was fixed by stopping libvirt, removing all files on /var/cache/libvirt/qemu/capabilities/ and starting it again.

https://bugzilla.redhat.com/show_bug.cgi?id=1160318

Works for me in Ubuntu 14.10