vhost/net: virtio 1.0 byte swap

I had to add an explicit tag to suppress compiler warning:
gcc isn't smart enough to notice that
len is always initialized since function is called with size > 0.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index dce5c58174b7..c218188c8880 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -416,7 +416,7 @@ static void handle_tx(struct vhost_net *net)
                         struct ubuf_info *ubuf;
                         ubuf = nvq->ubuf_info + nvq->upend_idx;
 
-                        vq->heads[nvq->upend_idx].id = head;
+                        vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head);
                         vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
                         ubuf->callback = vhost_zerocopy_callback;
                         ubuf->ctx = nvq->ubufs;
@@ -500,6 +500,10 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
         int headcount = 0;
         unsigned d;
         int r, nlogs = 0;
+        /* len is always initialized before use since we are always called with
+         * datalen > 0.
+         */
+        u32 uninitialized_var(len);
 
         while (datalen > 0 && headcount < quota) {
                 if (unlikely(seg >= UIO_MAXIOV)) {
@@ -527,13 +531,14 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
                         nlogs += *log_num;
                         log += *log_num;
                 }
-                heads[headcount].id = d;
-                heads[headcount].len = iov_length(vq->iov + seg, in);
-                datalen -= heads[headcount].len;
+                heads[headcount].id = cpu_to_vhost32(vq, d);
+                len = iov_length(vq->iov + seg, in);
+                heads[headcount].len = cpu_to_vhost32(vq, len);
+                datalen -= len;
                 ++headcount;
                 seg += in;
         }
-        heads[headcount - 1].len += datalen;
+        heads[headcount - 1].len = cpu_to_vhost32(vq, len - datalen);
         *iovcount = seg;
         if (unlikely(log))
                 *log_num = nlogs;