On 10/16/2012 04:47 PM, Marcus Karlsson wrote: > On Sun, Oct 14, 2012 at 03:26:26PM -0400, Cole Robinson wrote: >> On 10/11/2012 05:40 PM, Marcus Karlsson wrote: >>> Editing the description of a running guest will show a dialog that >>> changes will take effect after the next guest shutdown. However, libvirt >>> can change the description of a guest while it is running. >>> >>> Teach virt-manager to edit the description of a running guest without >>> requiring a shutdown. >> >> Hi Marcus, thanks for the patch! >> >> However there's kind of a problem here, in that this will error for libvirt >> less than 0.9.10 when setMetadata was introduced. > > I see. That should of course be avoided. No need to break backwards > compatibility. > >> In current virt-manager though we already emulate description 'hotplug': we >> always read the description from the inactive XML for the running VM, so a >> 'define' basically works like a hotplug. >> >> The only missing piece was working around that error message, which I've done >> with a new commit: >> >> http://git.fedorahosted.org/cgit/virt-manager.git/commit/?id=a341ce4534f60f79113ce27e64416abebcf241dd >> >> Also, I added a check to the virtinst support module to check for setMetadata >> support: >> >> http://git.fedorahosted.org/cgit/python-virtinst.git/commit/?id=849c1e02a3939a4b9d57e62c4974e34526249f0e >> >> So if you want to update your patch, we could use setMetadata only when >> supported. Move my comment from the virt-manager commit into the new >> vmmDomain.description_hotplug function, and if setMetadata isn't supported, >> just exit from the function early. > > OK. I'll prepare a new patch. > >> That way the only description hotplug hack can be used as a fallback. > > This last sentence I don't understand. Do you mean that you want to keep > the lambda as a fallback? Is it not enough to do just something like > this in hotplug_description? > > def hotplug_description(self, desc): > if virtinst.support.check_domain_support(self._backend, > virtinst.support.SUPPORT_DOMAIN_SET_METADATA): > flags = (libvirt.VIR_DOMAIN_AFFECT_LIVE | > libvirt.VIR_DOMAIN_AFFECT_CONFIG) > self._backend.setMetadata( > libvirt.VIR_DOMAIN_METADATA_DESCRIPTION, > desc, None, None, flags) > > That way setMetadata is not called if it's not supported. But > hotplug_description is always called so the error message should not > appear. > Sorry for unclarity, that code is what I mean. Though stylistically I would return early if that support condition is not met, so the setMetadata call doesn't need to be indented. Thanks, Cole
