Hey Jens,
Please git pull the following branch:
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/for-jens-4.5
which has one bug-fix. I had it in my tree at some point and after an rebase
(done months ago) lost it!
It solves an migration problem where the number of queues may differ from
one host to another.