Since 2.9 it is possible for a user to care only about nodes and qdev devices,
but not about BlockBackends, by defining with -blockdev and using their node
name in -device. Devices create an anonymous BlockBackend internally then.

One of the major problems in this setup is that such devices are not listed in
query-block or HMP 'info block' because the BBs are not monitor-owned. A recent
discussion concluded that we really want to replace query-block and friends
with something that matches QEMU's internals better, but there's no way to do
that in 2.10 (and I wouldn't bet on it to be completed for 2.11). So for now,
just make the devices appear in query-block and add the qdev ID there in order
to make the devices identifiable (they have 'device': '' because the BB is
anonymous).

With the additional qdev field, it turned out that with empty drives, ide-cd
and scsi-cd weren't even properly attached to the BlockBackend. If you do it
right, this even results in crashes. (Floppy already gets it right, in case you
wondered.)

After this series, -device drive=<node-name> should be reasonably usable
without a major loss of functionality like before.

Kevin Wolf (9):
  block: Make blk_get_attached_dev_id() public
  block/qapi: Add qdev device name to query-block
  block: Make blk_all_next() public
  block/qapi: Use blk_all_next() for query-block
  block: List anonymous device BBs in query-block
  ide: bdrv_attach_dev() for empty CD-ROM
  scsi-disk: bdrv_attach_dev() for empty CD-ROM
  qemu-iotests: Test 'info block'
  qemu-iotests: Test unplug of -device without drive

 block/block-backend.c          |   5 +-
 block/qapi.c                   |  20 +-
 hmp.c                          |  11 +-
 hw/ide/qdev.c                  |   3 +
 hw/scsi/scsi-disk.c            |   5 +
 include/sysemu/block-backend.h |   2 +
 qapi/block-core.json           |   5 +-
 tests/qemu-iotests/067         |  13 ++
 tests/qemu-iotests/067.out     |  40 ++++
 tests/qemu-iotests/186         | 147 +++++++++++++
 tests/qemu-iotests/186.out     | 489 +++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/group       |   1 +
 12 files changed, 731 insertions(+), 10 deletions(-)
 create mode 100755 tests/qemu-iotests/186
 create mode 100644 tests/qemu-iotests/186.out

-- 
1.8.3.1