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:

- mirror: Fix deadlock

# gpg: Signature made Mon 03 Dec 2018 16:57:33 GMT
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  iotests: simple mirror test with kvm on 1G image
  mirror: fix dead-lock

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