1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 5f3d6c06fcf7..0aaca902699a 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -43,6 +43,23 @@
 #define XENVIF_QUEUE_LENGTH 32
 #define XENVIF_NAPI_WEIGHT  64
 
+/* This function is used to set SKBTX_DEV_ZEROCOPY as well as
+ * increasing the inflight counter. We need to increase the inflight
+ * counter because core driver calls into xenvif_zerocopy_callback
+ * which calls xenvif_skb_zerocopy_complete.
+ */
+void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
+                                 struct sk_buff *skb)
+{
+        skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
+        atomic_inc(&queue->inflight_packets);
+}
+
+void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)
+{
+        atomic_dec(&queue->inflight_packets);
+}
+
 static inline void xenvif_stop_queue(struct xenvif_queue *queue)
 {
         struct net_device *dev = queue->vif->dev;
@@ -557,6 +574,7 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
 
         init_waitqueue_head(&queue->wq);
         init_waitqueue_head(&queue->dealloc_wq);
+        atomic_set(&queue->inflight_packets, 0);
 
         if (tx_evtchn == rx_evtchn) {
                 /* feature-split-event-channels == 0 */