s390/kvm: support collaborative memory management

This patch enables Collaborative Memory Management (CMM) for kvm
on s390. CMM allows the guest to inform the host about page usage
(see arch/s390/mm/cmm.c). The host uses this information to avoid
swapping in unused pages in the page fault handler. Further, a CPU
provided list of unused invalid pages is processed to reclaim swap
space of not yet accessed unused pages.

[ Martin Schwidefsky: patch reordering and cleanup ]

Signed-off-by: Konstantin Weitz <konstantin.weitz@gmail.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --cc arch/s390/include/asm/kvm_host.h
Simple merge

diff --cc arch/s390/include/asm/pgtable.h
Simple merge

diff --cc arch/s390/kvm/kvm-s390.c
Simple merge

diff --cc arch/s390/kvm/kvm-s390.h
Simple merge

diff --cc arch/s390/kvm/priv.c
Simple merge

diff --cc arch/s390/mm/pgtable.c
Simple merge