[libvirt-users] virDBusCallMethod:1173 : Launch helper exited with unknown return code

Good morning, I'm using libvirtd on Gentoo. This is libvirt version: 1.1.3.1 I have trouble starting a VM using virsh start $vm. I do this as root, because as non-root user it did not work at all (especially it failed attaching to the networks). So, when I run the command (with sudo), I get the following error in libvirtd.log: 2014-01-15 07:51:00.423+0000: 16158: warning : qemuDomainObjTaint:1573 : Domain id=5 name='vader' uuid=f5b8c05b-9c7a-3211-49b9-2bd635f7e2aa is tainted: high-privileges 2014-01-15 07:51:00.428+0000: 16158: error : virDBusCallMethod:1173 : Launch helper exited with unknown return code 1 At the same time I get an error in /var/log/messages which seems related: Jan 15 07:51:00  dbus[15845]: [system] Activating service name='org.freedesktop.machine1' (using servicehelper) Jan 15 07:51:00  dbus[15845]: [system] Activated service 'org.freedesktop.machine1' failed: Launch helper exited with unknown return code 1 Anyone ever seen this issue? I have no idea where to look for errors because the message don't really tell me much. I have tried to execute the qemu-kvm command on the command line directly and that worked immediately. So the problem must be in libvirt. Thanks for any pointers.