[libvirt] Segfault in virDomainObjListSearchName when listing domains (qemu backend)

[Guido Winkelmann]

Am Freitag, 25. Juni 2010 schrieb Daniel P. Berrange:
> On Fri, Jun 25, 2010 at 06:08:07PM +0200, Guido Winkelmann wrote:
> > This is the guest's XML config:
> > =====================
> > <domain type='kvm'>
> >   <name>testserver-a</name>
> >   <uuid>ce57ebe0-ea37-0353-bbe0-e23dbbd17708</uuid>
> >   <description>libvirt C-API Test</description>
> >   <memory>262144</memory>
> >   <currentMemory>262144</currentMemory>
> >   <vcpu>1</vcpu>
> >   <os>
> >     <type arch='x86_64' machine='pc-0.13'>hvm</type>
> >     <boot dev='hd'/>
> 
> [snip]
> 
> > =====================
> >
> > (as found in /usr/local/etc/libvirt/qemu/)
> >
> > and here are the last few lines from the logfile
> > (/usr/local/var/log/libvirt/qemu/testserver-a.log):
> 
> Have you set any LIBVIRT_LOG environment variables or set any of
> the logging settings in /etc/libvirt/libvirtd.conf ? If so, which
> ones ?  Your log file contains alot of stuff I wouldn't normally
> expect to be there & I wonder if there is a verbose logging level
> enabled that is causing a buffer overflow somewhre ?

I have log_level = 1 in /usr/local/etc/libvirt/libvirtd.conf.
 
[...]
> > affinity 17:21:14.803: debug : qemuSecurityDACSetProcessLabel:546 :
> > Dropping privileges of VM to 0:0
> > Supported machines are:
> > pc         Standard PC (alias of pc-0.12)
> > pc-0.12    Standard PC (default)
> > pc-0.11    Standard PC, qemu 0.11
> > pc-0.10    Standard PC, qemu 0.10
> > isapc      ISA-only PC
> 
> This is the ultimate problem - your guest XML lists 'pc-0.13', so I assume
> you must have deployed this guest with a newer QEMU and now trying to start
> it with an older one.

Could be... I've been switching from qemu-kvm release 0.12.4 to git and back a 
couple of times, mostly because libvirt used to silently require support of 
the "-nodefconfig" option in qemu until a couple of commits ago...

> Changing the XML to list one of these valid machine
> types should let you start the guest

Undefining and redefining the guest domains (without an explicit machine type) 
made it possible to start them again.
 
IMHO, though, the segfault is a separate issue, and still should not have 
happened.

	Guido