Comment 7 for bug 1546674

At least in my instance, and based on at least one other reporter's
description, the issue manifests on upgrade of the host to Xenial with
existing guests. If you create new guests in Xenial or newer they may very
well be configured correctly (I really don't know). My interpretation was
that virt-aa-helper added some functionality in Xenial+ which requires this
access, but configs from older versions have not granted it. Or at least
maybe that would make repro easier?