If no drive=... option is passed (for an empty drive), we don't only
lack the BlockBackend normally created by parse_drive(), but we also
need to manually call blk_attach_dev().
IDE does not support hot unplug, but if it did, qdev would take care to
call the matching blk_detach_dev() on unplug.
This fixes at least the bug that such devices didn't show up in
query-block, and probably some more problems.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
947231ad3b