[libvirt] [PATCH] qemu conf: Use host-model for cpu mode by default
Daniel P. Berrange
berrange at redhat.com
Wed Nov 14 09:44:44 UTC 2012
On Wed, Nov 14, 2012 at 03:10:48AM +0000, Ichikawa, Ken wrote:
> Now, qemu guest's default cpu model is qemu32/64 and it can be
> configured per domain. In some case, host-model mode is suitable for
> getting enough performance in the guest because of features from cpu
> This patch adds a config option to qemu.conf to use 'host-model' mode
> as default and allow users to use host-model mode in domains on a host.
> This is useful because
> - Guest owners don't need to touch their domain's config.
> - An administrator can reduce an item in their checklist for VM
> performance and guarantee all guests should run in the best performance.
While I understand the benefits, I'm afraid I have to NACK this
at this time because using host-model doesn't really work when
trying to use nested-KVM. Until we have a solution for that, we
neeed to stick with a CPU model that works everywhere, since
users like OpenStack do actually use nested-KVM for testing work
and already complained about this when I made OpenStack set the
host-model by default.
|: 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