[libvirt] Allow custom metadata in domain configuration XML

[Jiri Denemark]

On Mon, Jan 23, 2012 at 10:33:18 +0000, Daniel P. Berrange wrote:
> On Fri, Jan 20, 2012 at 02:55:27PM -0700, Eric Blake wrote:
> > 2. we probably need an API to allow the user to change this XML on the
> > fly for a running domain.  Which means you ought to investigate whether
> > you can merge your arbitrary XML alongside Peter's patch series [1] to
> > add <title> and alter <description>.  I think that adding a new flag
> > VIR_DOMAIN_DESCRIPTION_METADATA for use in virDomainSetDescription would
> > do the trick, rather than adding yet another API.
> > [1]https://www.redhat.com/archives/libvir-list/2012-January/msg00709.html
> 
> I'm not really convinced we need an API for setting the title/description
> either. Are we going to create APIs for setting every little attribute
> of the XML ? IMHO that's the job for libvirt-gconfig.

I think we still need a way to set title/description/... without the need to
call virDomainDefine. Going through complete XML and virDomainDefine changes
the configuration that will be used when a domain is started next time. For
things that can be changed in runtime, we also provide APIs to do that, e.g.,
device addition/removal/update, ... Metadata may also be changed in runtime
and I believe we should have some API(s) that would allow apps to do so.

Jirka