[virt-tools-list] [PATCH] Edit description immediately without a shutdown

[Marcus Karlsson]

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.

Marcus

> Thanks,
> Cole
> 
> > ---
> >  src/virtManager/details.py |    1 +
> >  src/virtManager/domain.py  |    7 +++++++
> >  2 files changed, 8 insertions(+)
> > 
> > diff --git a/src/virtManager/details.py b/src/virtManager/details.py
> > index c53c67f..e57903a 100644
> > --- a/src/virtManager/details.py
> > +++ b/src/virtManager/details.py
> > @@ -2033,6 +2033,7 @@ class vmmDetails(vmmGObjectUI):
> >              desc_widget = self.widget("overview-description")
> >              desc = desc_widget.get_buffer().get_property("text") or ""
> >              add_define(self.vm.define_description, desc)
> > +            add_hotplug(self.vm.hotplug_description, desc)
> >  
> >          return self._change_config_helper(df, da, hf, ha)
> >  
> > diff --git a/src/virtManager/domain.py b/src/virtManager/domain.py
> > index 82680b8..227e8c1 100644
> > --- a/src/virtManager/domain.py
> > +++ b/src/virtManager/domain.py
> > @@ -813,6 +813,13 @@ class vmmDomain(vmmLibvirtObject):
> >          devobj.passwd = newval or None
> >          self.update_device(devobj)
> >  
> > +    def hotplug_description(self, desc):
> > +        flags = (libvirt.VIR_DOMAIN_AFFECT_LIVE |
> > +                libvirt.VIR_DOMAIN_AFFECT_CONFIG)
> > +        self._backend.setMetadata(
> > +                libvirt.VIR_DOMAIN_METADATA_DESCRIPTION,
> > +                desc, None, None, flags)
> > +
> >  
> >      ########################
> >      # Libvirt API wrappers #
> >