Comment # 2 on bug 1001446 from James Fehlig

(In reply to Marcus Meissner from comment #1)
> i enabled virtlogd.socket and started it, then it worked.
> 
> not sure if that should be a dependency of virt-manager.service or similar

More like the libvirtd unit. This was fixed upstream by

http://libvirt.org/git/?p=libvirt.git;a=commit;h=839a060890d8b2408c0ea20e3c5997c7b2a4a079

But that commit wasn't quite right and further refined by

http://libvirt.org/git/?p=libvirt.git;a=commit;h=f496ce1df35df7498bd3d9d7e113bb2eb3e51ba9

In theory this bug affects SLE12 SP2 as well, since 42.2 packages are copied
from there.