[PATCH v3 0/7] Switch iotests to using Async QMP

[John Snow]

Based-on: <20211012214152.802483-1-jsnow@redhat.com>
          [PULL 00/10] Python patches
GitLab: https://gitlab.com/jsnow/qemu/-/commits/python-aqmp-iotest-wrapper
CI: https://gitlab.com/jsnow/qemu/-/pipelines/387210591

Hiya,

This series continues where the last two AQMP series left off and adds a
synchronous 'legacy' wrapper around the new AQMP interface, then drops
it straight into iotests to prove that AQMP is functional and totally
cool and fine. The disruption and churn to iotests is pretty minimal.

In the event that a regression happens and I am not physically proximate
to inflict damage upon, one may set the QEMU_PYTHON_LEGACY_QMP variable
to any non-empty string as it pleases you to engage the QMP machinery
you are used to.

I'd like to try and get this committed early in the 6.2 development
cycle to give ample time to smooth over any possible regressions. I've
tested it locally and via gitlab CI, across Python versions 3.6 through
3.10, and "worksforme". If something bad happens, we can revert the
actual switch-flip very trivially.

V3:

001/7:[----] [--] 'python/machine: remove has_quit argument'
002/7:[0002] [FC] 'python/machine: Handle QMP errors on close more meticulously'
003/7:[----] [--] 'python/aqmp: Remove scary message'
004/7:[0006] [FC] 'iotests: Accommodate async QMP Exception classes'
005/7:[0003] [FC] 'iotests: Conditionally silence certain AQMP errors'
006/7:[0009] [FC] 'python/aqmp: Create sync QMP wrapper for iotests'
007/7:[----] [--] 'python, iotests: replace qmp with aqmp'

002: Account for force-kill cases, too.
003: Shuffled earlier into the series to prevent a mid-series regression.
004: Rewrite the imports to be less "heterogeneous" ;)
005: Add in a TODO for me to trip over in the future.
006: Fix a bug surfaced by a new iotest where waiting with pull_event for a
     timeout of 0.0 will cause a timeout exception to be raised even if there
     was an event ready to be read.

V2:

001/17:[----] [--] 'python/aqmp: add greeting property to QMPClient'
002/17:[----] [--] 'python/aqmp: add .empty() method to EventListener'
003/17:[----] [--] 'python/aqmp: Return cleared events from 
EventListener.clear()'
004/17:[0007] [FC] 'python/aqmp: add send_fd_scm'
005/17:[down] 'python/aqmp: Add dict conversion method to Greeting object'
006/17:[down] 'python/aqmp: Reduce severity of EOFError-caused loop 
terminations'
007/17:[down] 'python/aqmp: Disable logging messages by default'

008/17:[0002] [FC] 'python/qmp: clear events on get_events() call'
009/17:[----] [--] 'python/qmp: add send_fd_scm directly to QEMUMonitorProtocol'
010/17:[----] [--] 'python, iotests: remove socket_scm_helper'
011/17:[0013] [FC] 'python/machine: remove has_quit argument'
012/17:[down] 'python/machine: Handle QMP errors on close more meticulously'

013/17:[0009] [FC] 'iotests: Accommodate async QMP Exception classes'
014/17:[down] 'iotests: Conditionally silence certain AQMP errors'

015/17:[0016] [FC] 'python/aqmp: Create sync QMP wrapper for iotests'
016/17:[0002] [FC] 'python/aqmp: Remove scary message'
017/17:[----] [--] 'python, iotests: replace qmp with aqmp'

- Rebased on jsnow/python, which was recently rebased on origin/master.
- Make aqmp's send_fd_scm method bark if the socket isn't AF_UNIX (Hanna)
- Uh... modify send_fd_scm so it doesn't break when Python 3.11 comes out ...
  See the commit message for more detail.
- Drop the "python/aqmp: Create MessageModel and StandaloneModel class"
  patch and replace with a far simpler method that just adds an
  _asdict() method.
- Add patches 06 and 07 to change how the AQMP library handles logging.
- Adjust docstring in patch 08 (Hanna)
- Rename "_has_quit" attribute to "_quid_issued" (Hanna)
- Renamed patch 12, simplified the logic in _soft_shutdown a tiny bit.
- Fixed bad exception handling logic in 13 (Hanna)
- Introduce a helper in patch 14 to silence log output when it's unwanted.
- Small addition of _get_greeting() helper in patch 15, coinciding with the
  new patch 05 here.
- Contextual changes in 16.

John Snow (7):
  python/machine: remove has_quit argument
  python/machine: Handle QMP errors on close more meticulously
  python/aqmp: Remove scary message
  iotests: Accommodate async QMP Exception classes
  iotests: Conditionally silence certain AQMP errors
  python/aqmp: Create sync QMP wrapper for iotests
  python, iotests: replace qmp with aqmp

 python/qemu/aqmp/__init__.py              |  12 --
 python/qemu/aqmp/legacy.py                | 138 ++++++++++++++++++++++
 python/qemu/machine/machine.py            |  85 +++++++++----
 scripts/simplebench/bench_block_job.py    |   3 +-
 tests/qemu-iotests/040                    |   7 +-
 tests/qemu-iotests/218                    |   2 +-
 tests/qemu-iotests/255                    |   2 +-
 tests/qemu-iotests/iotests.py             |  20 +++-
 tests/qemu-iotests/tests/mirror-top-perms |  17 ++-
 9 files changed, 238 insertions(+), 48 deletions(-)
 create mode 100644 python/qemu/aqmp/legacy.py

-- 
2.31.1