Merge remote-tracking branch 'remotes/stefanha-gitlab/tags/block-pull-request' into staging

Pull request

# gpg: Signature made Wed 12 Jan 2022 17:13:54 GMT
# gpg:                using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha-gitlab/tags/block-pull-request:
  virtio: unify dataplane and non-dataplane ->handle_output()
  virtio: use ->handle_output() instead of ->handle_aio_output()
  virtio-scsi: prepare virtio_scsi_handle_cmd for dataplane
  virtio-blk: drop unused virtio_blk_handle_vq() return value
  virtio: get rid of VirtIOHandleAIOOutput
  aio-posix: split poll check from ready handler

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