This test case covers the basic bdrv_aio_multiwrite() scenarios:
1. Single request
2. Sequential requests (AABB)
3. Superset overlapping requests (AABBAA)
4. Subset overlapping requests (BBAABB)
5. Head overlapping requests (AABB)
6. Tail overlapping requests (BBAA)
7. Disjoint requests (AA BB)
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>