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

Pull request

# gpg: Signature made Fri 22 Feb 2019 14:07:01 GMT
# gpg:                using RSA key 9CA4ABB381AB73C8
# 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: (27 commits)
  tests/virtio-blk: add test for DISCARD command
  tests/virtio-blk: add test for WRITE_ZEROES command
  tests/virtio-blk: add virtio_blk_fix_dwz_hdr() function
  tests/virtio-blk: change assert on data_size in virtio_blk_request()
  virtio-blk: add DISCARD and WRITE_ZEROES features
  virtio-blk: set config size depending on the features enabled
  virtio-net: make VirtIOFeature usable for other virtio devices
  virtio-blk: add "discard" and "write-zeroes" properties
  virtio-blk: add host_features field in VirtIOBlock
  virtio-blk: add acct_failed param to virtio_blk_handle_rw_error()
  hw/ide: drop iov field from IDEDMA
  hw/ide: drop iov field from IDEBufferedRequest
  hw/ide: drop iov field from IDEState
  tests/test-bdrv-drain: use QEMU_IOVEC_INIT_BUF
  migration/block: use qemu_iovec_init_buf
  qemu-img: use qemu_iovec_init_buf
  block/vmdk: use qemu_iovec_init_buf
  block/qed: use qemu_iovec_init_buf
  block/qcow2: use qemu_iovec_init_buf
  block/qcow: use qemu_iovec_init_buf
  ...

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