task #29077503
commit 8d4edcfe78c0008d95effc0c90455cee59e18d10 upstream
Let's be able to distinguish if the device or if memory is busy.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200507140139.17083-15-david@redhat.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>
(cherry picked from ccommit 8d4edcfe78c0008d95effc0c90455cee59e18d10)
Signed-off-by: NAlex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>