On 07/12/2013 10:00 AM, Eric Blake wrote:
>
> That shouldn't happen I think. For any runing guest, we have recorded
> the original capabilities in the domain status XML file. So any caps
> we detect against QEMU binaries upon restart will only impact newly
> started guests.
I seem to recall difficulties in the past, such as when developing on a
RHEL machine, where the upstream and the downstream list of cap bits are
different, and where restarting upstream libvirtd had problems with
domains already started by downstream libvirtd. I'd feel better if this
were explicitly tested (easy enough to do - build libvirtd without this
patch, start a domain, rebuild libvirtd with the patch, restart
libvirtd, and see if virsh can still control the domain).
Or maybe the difficulty I'm recalling is the case of _unknown_ cap bits.
You may be right that a known, but differently-set bit, behaves nicer
than parsing the XML with a bit that is completely unknown.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library
http://libvirt.org