[libvirt] Modern CPU models cannot be used with libvirt

Daniel P. Berrange berrange at redhat.com
Thu Dec 15 15:42:44 UTC 2011

On Thu, Dec 15, 2011 at 03:54:15PM +0100, Jiri Denemark wrote:
> Hi,
> Recently I realized that all modern CPU models defined in
> /etc/qemu/target-x86_64.conf are useless when qemu is used through libvirt.
> That's because we start qemu with -nodefconfig which results in qemu ignoring
> that file with CPU model definitions. We have a very good reason for using
> -nodefconfig because we need to control the ABI presented to a guest OS and we
> don't want any configuration file that can contain lots of things including
> device definitions to be read by qemu. However, we would really like the new
> CPU models to be understood by qemu even if used through libvirt. What would
> be the best way to solve this?

Ideally libvirt would just write out a config file with the CPU
that was configured in libvirt and pass -readconfig /var/lib/libvirt/qemu/guestcpu.conf
That way libvirt can configure CPU models without regard for
what the particular QEMU version might have in its config.

|: http://berrange.com      -o-    http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org              -o-             http://virt-manager.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org       -o-       http://live.gnome.org/gtk-vnc :|

More information about the libvir-list mailing list