Merge tag 'kvm-s390-next-4.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git...

Merge tag 'kvm-s390-next-4.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: vSIE (nested virtualization) feature for 4.8 (kvm/next)

With an updated QEMU this allows to create nested KVM guests
(KVM under KVM) on s390.

s390 memory management changes from Martin Schwidefsky or
acked by Martin. One common code memory management change (pageref)
acked by Andrew Morton.

The feature has to be enabled with the nested medule parameter.