Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20201002' into staging

s390x update
- support extended sccb and diagnose 0x318
- implement additional instructions in tcg
- bug fixes

# gpg: Signature made Fri 02 Oct 2020 13:05:16 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-20201002:
  s390x/tcg: Implement CIPHER MESSAGE WITH AUTHENTICATION (KMA)
  s390x/tcg: We support Miscellaneous-Instruction-Extensions Facility 2
  s390x/tcg: Implement MULTIPLY SINGLE (MSC, MSGC, MSGRKC, MSRKC)
  s390x/tcg: Implement BRANCH INDIRECT ON CONDITION (BIC)
  s390x/tcg: Implement MULTIPLY HALFWORD (MGH)
  s390x/tcg: Implement MULTIPLY (MG, MGRK)
  s390x/tcg: Implement SUBTRACT HALFWORD (SGH)
  s390x/tcg: Implement ADD HALFWORD (AGH)
  s390x/cpumodel: S390_FEAT_MISC_INSTRUCTION_EXT -> S390_FEAT_MISC_INSTRUCTION_EXT2
  vfio-ccw: plug memory leak while getting region info
  s390x/tcg: Implement MONITOR CALL
  s390: guest support for diagnose 0x318
  s390/sclp: add extended-length sccb support for kvm guest
  s390/sclp: use cpu offset to locate cpu entries
  s390/sclp: check sccb len before filling in data
  s390/sclp: read sccb from mem based on provided length
  s390/sclp: rework sclp boundary checks
  s390/sclp: get machine once during read scp/cpu info
  hw/s390x/css: Remove double initialization

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