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:

- Introduce real BdrvChildRole
- blk/bdrv_make_empty() functions instead of calling callbacks directly
- mirror: Make sure that source and target size match
- block-copy: Fix uninitialized variable
- block/replication: Avoid cancelling the job twice
- ahci: Log lost IRQs
- iotests: Run pylint and mypy in a testcase
- iotests: log messages from notrun()

# gpg: Signature made Mon 18 May 2020 18:05:32 BST
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# 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: (52 commits)
  hw: Use QEMU_IS_ALIGNED() on parallel flash block size
  iotests/030: Reduce run time by unthrottling job earlier
  hw/ide/ahci: Log lost IRQs
  iotests: log messages from notrun()
  block/block-copy: Simplify block_copy_do_copy()
  block/block-copy: Fix uninitialized variable in block_copy_task_entry
  block: Drop @child_class from bdrv_child_perm()
  block: Pass BdrvChildRole in remaining cases
  block: Drop child_file
  block: Drop bdrv_format_default_perms()
  block: Make bdrv_filter_default_perms() static
  block: Use bdrv_default_perms()
  tests: Use child_of_bds instead of child_file
  block: Use child_of_bds in remaining places
  block: Make filter drivers use child_of_bds
  block: Make format drivers use child_of_bds
  block: Drop child_backing
  block: Make backing files child_of_bds children
  block: Drop child_format
  block: Switch child_format users to child_of_bds
  ...

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