Block backends defined with "-drive if=T" with T other than "none" are
meant to be picked up by machine initialization code: a suitable
frontend gets created and wired up automatically.
If machine initialization code doesn't comply, the block backend
remains unused. This triggers a warning since commit a66c9dc, v2.2.0.
Drives created by default are exempted; use -nodefaults to get rid of
them.
Turn this warning into an error.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1487153147-11530-8-git-send-email-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
720b8dc052