Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- Add qemu-storage-daemon (still experimental)
- rbd: Add support for ceph namespaces
- Fix bdrv_reopen() with backing file in different AioContext
- qcow2: Fix read-write reopen with persistent dirty bitmaps
- qcow2: Fix alloc_cluster_abort() for pre-existing clusters

# gpg: Signature made Fri 06 Mar 2020 17:12:31 GMT
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (29 commits)
  block: bdrv_reopen() with backing file in different AioContext
  iotests: Refactor blockdev-reopen test for iothreads
  block/rbd: Add support for ceph namespaces
  qemu-storage-daemon: Add --monitor option
  monitor: Add allow_hmp parameter to monitor_init()
  hmp: Fail gracefully if chardev is already in use
  qmp: Fail gracefully if chardev is already in use
  monitor: Create QAPIfied monitor_init()
  qapi: Create 'pragma' module
  stubs: Update monitor stubs for qemu-storage-daemon
  qemu-storage-daemon: Add --chardev option
  qemu-storage-daemon: Add main loop
  qemu-storage-daemon: Add --export option
  blockdev-nbd: Boxed argument type for nbd-server-add
  qemu-storage-daemon: Add --nbd-server option
  qemu-storage-daemon: Add --object option
  qapi: Flatten object-add
  qemu-storage-daemon: Add --blockdev option
  block: Move sysemu QMP commands to QAPI block module
  block: Move common QMP commands to block-core QAPI module
  ...

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