[libvirt] libvirt can't get capablities

[Daniel P. Berrange]

On Mon, Jul 02, 2012 at 05:47:08PM +0800, Li Zhang wrote:
> 
> Hi,
> 
> I have suffered several times on both x86 machine and power machine.
> 
> When we want to use libvirt to create on VMs, it reports "unknown OS
> type hvm".
> 
> We can't get <guest> capabilities.
> 
> The log is as the following(log_level=1):
> 
> 2003-01-02 01:21:39.895+0000: 12214: error :
> virDomainDefParseXML:8491 : unknown OS type hvm
> 2003-01-02 01:21:39.896+0000: 12214: error :
> virDomainDefParseXML:8491 : unknown OS type hvm
> 2003-01-02 01:22:00.135+0000: 12207: error :
> qemuCapsComputeCmdFlags:1218 : unsupported configuration: this qemu
> binary requires libvirt to be compiled with yajl
> 2003-01-02 01:22:13.342+0000: 12207: error :
> qemuCapsComputeCmdFlags:1218 : unsupported configuration: this qemu
> binary requires libvirt to be compiled with yajl

Hmm, this shows a flaw in the way we deal with QEMU. When detecting
QEMU for the purpose of the capabilities XML, IMHO, we should *not*
be raising this error.   Errors in detecting capabilities are more
or less invisible to users of libvirt, since they do not occur in
response to a specific API call.

Thus, we should have reported the capabilities XML as normal here,
and only reported the YAJL compatibility error at the time the user
tries to actually start a guest.
 

Daniel
-- 
|: http://berrange.com      -o-    http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org              -o-             http://virt-manager.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org       -o-       http://live.gnome.org/gtk-vnc :|