On Fri, Mar 13, 2015 at 11:18:15AM -0600, Chris Friesen wrote: > On 03/13/2015 07:50 AM, Daniel P. Berrange wrote: > >On Fri, Mar 13, 2015 at 08:42:25AM -0400, Steve Gordon wrote: > >>----- Original Message ----- > >>>From: "park" <jianlong...@gmail.com> > >>>To: "OpenStack Development Mailing List (not for usage questions)" > >>><openstack-dev@lists.openstack.org> > >>> > >>>hello Nova > >>> > >>>By default, nova libvirt driver configuration for guest cpu as "cpu_mode > >>>= none", > >>>you could add cpu features by changing flavor section as below, there > >>>will NOT > >>>be any issues for this cmd. > >>> > >>>$nova flavor-key m1.small set "capabilities:cpu_info:features"="<in> ***" > >>>but, nova will ignore the cpu features after the guest boot up > >>>successfully, which > >>>means the feature does NOT take effect(not be written into the xml for > >>>the guest). > >>> > >>>And there is no message telling the users that the features does NOT > >>>take effect... > >>>this may make the users confused... > >> > >>This issue is more general than the cpu_mode=none case, in that the > >>capabilities filter is filtering *hosts* based on their CPU features. > >>As you have discovered, whether they are actually exposing those > >>features to guests in their current configuration is not taken into > >>account (that is, cpu_mode/cpu_model settings aren't considered at > >>all). Ideally they would be, but I'm not sure this is trivial. > > > >If you set 'cpu_mode=host-model' or 'cpu_mode=host-passthrough' > >then it will take effect, as the guest will see the full CPU model > >of the host that is picked. IMHO the capabilities:cpu_info:features > >filter only makes sense when using those two cpu modes. If you > >left the default cpu_mode=None or set cpu_mode=custom, then this > >capabilities feature is meaningless from a conceptual POV. So the > >fact that it has no effect on the guest CPU is not a bug it is > >by design. > > If the cpu features aren't going to be passed through into the guest, does > it make sense for the scheduler to filter based on them?
If the admin has not enabled host-model/passthrough CPU mode, then they should simply not set the capabilities:cpu_info:features property on the flavours they have setup. Regards, Daniel -- |: 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 :| __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev