Code review comment for ~rafaeldtinoco/ubuntu/+source/qemu:lp1805256-bionic

Okay, as we spoke in the hangout, wrapping up:

- Paolo patches backported to bionic likely fixed the original issue
- ... and the issue in all other versions Eoan, Focal, Groovy

- This "new" issue that appeared in Bionic in unrelated with the original one
- That explains why having patch:
  "- aio-posix: Don't count ctx->notifier as progress when polling"
  fixes "the issue" but it was a "loop forever inside RCU foreach macro"
- Original issue was not reproduced any longer

Bionic is good to go with all the patches:

* d/p/ubuntu/lp-1805256*: Fixes for QEMU on aarch64 ARM hosts
  - aio: rename aio_context_in_iothread() to in_aio_context_home_thread()
  - aio: Do aio_notify_accept only during blocking aio_poll
  - aio-posix: Assert that aio_poll() is always called in home thread
  - async: use explicit memory barriers (LP: #1805256)
  - aio-wait: delegate polling of main AioContext if BQL not held
  - aio-posix: Don't count ctx->notifier as progress when polling

All patches but the latest one are fixing the original (to LP: #1805256) issue and the last patch is fixing an issue observed by your tests with those backports (perhaps something that exited before or not, but we are sure it fixes the issue).

With this summary we're good to go for the SRU @cpaelzer.