The HMP command 'qemu-io' is a bit tricky because it wants to work on
the original BlockBackend, but additional permissions could be required.
The details are explained in a comment in the code, but in summary, just
request whatever permissions the current qemu-io command needs.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Acked-by: NFam Zheng <famz@redhat.com>