Re: [Qemu-devel] [PATCH v2 0/9] block: -device drive=<node-name> fixes

[John Snow]

On 07/13/2017 07:41 AM, Kevin Wolf wrote:
> 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.
> 
> v2:
> - Updated example QMP outputs in schema comments [Eric]
> - Added missing "since" tag in schema [Eric]
> - Improved some commit messages [Eric]
> 
> 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

oops...

>   scsi-disk: bdrv_attach_dev() for empty CD-ROM

Well, at least I'm in good company.

>   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           |   9 +-
>  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, 735 insertions(+), 10 deletions(-)
>  create mode 100755 tests/qemu-iotests/186
>  create mode 100644 tests/qemu-iotests/186.out
> 

Series:

Reviewed-by: John Snow <address@hidden>