Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20190425' into staging

- properly detect page size of initial memory
- support for IPL (boot) from ECKD DASD passed through via vfio-ccw

# gpg: Signature made Thu 25 Apr 2019 14:11:18 BST
# gpg:                using RSA key C3D0D66DC3624FF6A8C018CEDECF6B93C6F02FAF
# gpg:                issuer "cohuck@redhat.com"
# gpg: Good signature from "Cornelia Huck <conny@cornelia-huck.de>" [unknown]
# gpg:                 aka "Cornelia Huck <huckc@linux.vnet.ibm.com>" [full]
# gpg:                 aka "Cornelia Huck <cornelia.huck@de.ibm.com>" [full]
# gpg:                 aka "Cornelia Huck <cohuck@kernel.org>" [unknown]
# gpg:                 aka "Cornelia Huck <cohuck@redhat.com>" [unknown]
# Primary key fingerprint: C3D0 D66D C362 4FF6 A8C0  18CE DECF 6B93 C6F0 2FAF

* remotes/cohuck/tags/s390x-20190425:
  exec: Introduce qemu_maxrampagesize() and rename qemu_getrampagesize()
  s390x/kvm: Configure page size after memory has actually been initialized
  pc-bios/s390: Update firmware images
  s390-bios: Use control unit type to find bootable devices
  s390-bios: Support booting from real dasd device
  s390-bios: Add channel command codes/structs needed for dasd-ipl
  s390-bios: Use control unit type to determine boot method
  s390-bios: Refactor virtio to run channel programs via cio
  s390-bios: Factor finding boot device out of virtio code path
  s390-bios: Extend find_dev() for non-virtio devices
  s390-bios: cio error handling
  s390-bios: Support for running format-0/1 channel programs
  s390-bios: ptr2u32 and u32toptr
  s390-bios: Map low core memory
  s390-bios: Decouple channel i/o logic from virtio
  s390-bios: Clean up cio.h
  s390-bios: decouple common boot logic from virtio
  s390-bios: decouple cio setup from virtio
  s390 vfio-ccw: Add bootindex property and IPLB data

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>