[libvirt] 1.4.0 memballoon bug?

[Serge Hallyn]

Quoting Serge Hallyn (serge.hallyn at ubuntu.com):
> Quoting Michal Privoznik (mprivozn at redhat.com):
> > On 05.04.2013 21:22, Serge Hallyn wrote:
> > > Hi,
> > > 
> > > When I run
> > > 
> > > virsh -c qemu:///system domxml-to-native qemu-argv /tmp/qatest.xml
> > > 
> > > from 1.4.0 with the qatest.xml below (which has no memballoon
> > > device specified), I get an 'unspecified error'.  Some printf
> > > debugging shows that virDomainDefParseXML is automatically
> > > adding a virtio memballoon device, but that its
> > > memballoon->info.type is 0, not the 1 or 8 which is required at
> > > qemuBuildMemballoonDevStr().
> > > 
> > > This didn't happen at 1.2.0, but I'm not sure where the
> > > error was introduced, as I don't see any suspicious changes around
> > 
> > You can run git-bisect to find which commit introduced this 'feature' in
> > case it is not obvious from git-log.
> 
> Yeah I just needed to first git upstream to reliably compile (with
> patch/unpatch around git bisect operations)
> 
> git bisect points to:
> [608512b24a89d9865e402905b2dbbfd1c8a0e83e] S390: QEMU driver support for CCW addresses

That commit appears to make an assumption that
qemuDomainAssignAddresses() will have been called if we get to
qemuBuildMemballoonDevStr(), but that doesn't appear to be the case
when we do domxml-to-native qemu-argv.  (a fopen+fprintf at that
location isn't being triggered)

-serge