Merge tag 'kvm-s390-next-20150728' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-next

KVM: s390: Fixes and features for kvm/next (4.3)

1. Rework logging infrastructure (s390dbf) to integrate feedback learned
   when debugging performance and test issues
2. Some cleanups and simplifications for CMMA handling
3. Fix gdb debugging and single stepping on some instructions
4. Error handling for storage key setup