dbe5c58f2a
if the iscsi driver receives a write zeroes request with the BDRV_REQ_MAY_UNMAP flag set it fails with -ENOTSUP if the iscsi target does not support WRITE SAME with UNMAP. However, the BDRV_REQ_MAY_UNMAP is only a hint and writing zeroes with WRITE SAME will still be better than falling back to writing zeroes with WRITE16. Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>