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

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

Block layer patches:

- block: AioContext management, part 1
- qmp: forbid qmp_cont in RUN_STATE_FINISH_MIGRATE
- nvme: fix copy direction in DMA reads going to CMB
- file-posix: Fix block status for unaligned raw images with O_DIRECT
- file-posix: Fix xfs_write_zeroes() after EOF
- Documentation and iotests improvements

# gpg: Signature made Mon 20 May 2019 16:12:38 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <[email protected]>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (24 commits)
  iotests: Make 245 faster and more reliable
  iotests.py: Fix VM.run_job
  iotests.py: Let assert_qmp() accept an array
  block: Improve "Block node is read-only" message
  qemu-img.texi: Describe human-readable info output
  qemu-img.texi: Be specific about JSON object types
  iotests: Test unaligned raw images with O_DIRECT
  block/file-posix: Unaligned O_DIRECT block-status
  test-block-iothread: Test AioContext propagation for block jobs
  blockjob: Remove AioContext notifiers
  blockjob: Propagate AioContext change to all job nodes
  block: Add blk_set_allow_aio_context_change()
  block: Implement .(can_)set_aio_ctx for BlockBackend
  test-block-iothread: Test AioContext propagation through the tree
  block: Propagate AioContext change to parents
  block: Move recursion to bdrv_set_aio_context()
  block: Make bdrv_attach/detach_aio_context() static
  block: Add bdrv_try_set_aio_context()
  nvme: fix copy direction in DMA reads going to CMB
  iotest: fix 169: do not run qmp_cont in RUN_STATE_FINISH_MIGRATE
  ...

Signed-off-by: Peter Maydell <[email protected]>