From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42319) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YVZqD-0000Mn-3t for qemu-devel@nongnu.org; Wed, 11 Mar 2015 02:10:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YVZq4-0001pg-FO for qemu-devel@nongnu.org; Wed, 11 Mar 2015 02:10:01 -0400 Received: from ozlabs.org ([103.22.144.67]:56102) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YVZq4-0001oz-3F for qemu-devel@nongnu.org; Wed, 11 Mar 2015 02:09:52 -0400 From: Rusty Russell Date: Wed, 11 Mar 2015 16:29:32 +1030 Message-Id: <1426053572-21326-3-git-send-email-rusty@rustcorp.com.au> In-Reply-To: <1426053572-21326-1-git-send-email-rusty@rustcorp.com.au> References: <1426053572-21326-1-git-send-email-rusty@rustcorp.com.au> Subject: [Qemu-devel] [PATCH 2/2] virtio-blk: fix length calculations for write operations. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: QEMU Developers , "Michael S. Tsirkin" Cc: Rusty Russell We only fill in the 'req->qiov.size' bytes on a (successful) read, not on a write. Signed-off-by: Rusty Russell --- hw/block/virtio-blk.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 258bb4c..98d87a9 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -50,11 +50,19 @@ static void virtio_blk_complete_request(VirtIOBlockReq *req, { VirtIOBlock *s = req->dev; VirtIODevice *vdev = VIRTIO_DEVICE(s); + int type = virtio_ldl_p(VIRTIO_DEVICE(req->dev), &req->out.type); trace_virtio_blk_req_complete(req, status); stb_p(&req->in->status, status); - virtqueue_push(s->vq, &req->elem, req->qiov.size + sizeof(*req->in)); + + /* If we didn't succeed, we *may* have written more, but don't + * count on it. */ + if (type == VIRTIO_BLK_T_IN && status == VIRTIO_BLK_S_OK) { + virtqueue_push(s->vq, &req->elem, req->qiov.size + sizeof(*req->in)); + } else { + virtqueue_push(s->vq, &req->elem, sizeof(*req->in)); + } virtio_notify(vdev, s->vq); } -- 2.1.0