[Qemu-devel] [PATCH 10/14] virtio: don't mark unaccessed memory as dirty

["Michael S. Tsirkin" <mst@redhat.com>]

offset of accessed buffer is calculated using iov_length, so it
can exceed accessed len. If that happens
math in len - offset wraps around, and size becomes wrong.
As real value is 0, so this is harmless but unnecessary.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/virtio.c b/hw/virtio.c
index 209c763..b5764bb 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -241,7 +241,7 @@ void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
                                   elem->in_sg[i].iov_len,
                                   1, size);
 
-        offset += elem->in_sg[i].iov_len;
+        offset += size;
     }
 
     for (i = 0; i < elem->out_num; i++)
-- 
MST