ldoktor/autotest — comment on commit b96124e23251f77e10c72ca5a5599b7bc02050e2
File: client/tests/kvm/tests/cgroup.py line 55
By lmr:

Better to check for successful addition verifying if the pci device is on the output of info qtree.

qtree = self.monitor.info("qtree")

And then see if the backing file is there...