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

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

Pull request

# gpg: Signature made Wed 11 Mar 2020 12:40:36 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/tags/block-pull-request:
  aio-posix: remove idle poll handlers to improve scalability
  aio-posix: support userspace polling of fd monitoring
  aio-posix: add io_uring fd monitoring implementation
  aio-posix: simplify FDMonOps->update() prototype
  aio-posix: extract ppoll(2) and epoll(7) fd monitoring
  aio-posix: move RCU_READ_LOCK() into run_poll_handlers()
  aio-posix: completely stop polling when disabled
  aio-posix: remove confusing QLIST_SAFE_REMOVE()
  qemu/queue.h: clear linked list pointers on remove

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