Re: [libvirt] libvirt can't get capablities

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