From: Stefano Garzarella <sgarzare@redhat.com>

The size of data in the virtio_blk_request must be a multiple
of 512 bytes for IN and OUT requests, or a multiple of the size
of struct virtio_blk_discard_write_zeroes for DISCARD and
WRITE_ZEROES requests.

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20190221103314.58500-8-sgarzare@redhat.com
Message-Id: <20190221103314.58500-8-sgarzare@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 tests/virtio-blk-test.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/tests/virtio-blk-test.c b/tests/virtio-blk-test.c
index 04c608764b..0739498da7 100644
--- a/tests/virtio-blk-test.c
+++ b/tests/virtio-blk-test.c
@@ -144,7 +144,20 @@ static uint64_t virtio_blk_request(QGuestAllocator *alloc, QVirtioDevice *d,
     uint64_t addr;
     uint8_t status = 0xFF;
 
-    g_assert_cmpuint(data_size % 512, ==, 0);
+    switch (req->type) {
+    case VIRTIO_BLK_T_IN:
+    case VIRTIO_BLK_T_OUT:
+        g_assert_cmpuint(data_size % 512, ==, 0);
+        break;
+    case VIRTIO_BLK_T_DISCARD:
+    case VIRTIO_BLK_T_WRITE_ZEROES:
+        g_assert_cmpuint(data_size %
+                         sizeof(struct virtio_blk_discard_write_zeroes), ==, 0);
+        break;
+    default:
+        g_assert_cmpuint(data_size, ==, 0);
+    }
+
     addr = guest_alloc(alloc, sizeof(*req) + data_size);
 
     virtio_blk_fix_request(d, req);
-- 
2.20.1