1 files changed, 29 insertions, 5 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index f94ab786088f..2759d386ade7 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -47,8 +47,16 @@ module_param(gso, bool, 0444);
  */
 DECLARE_EWMA(pkt_len, 1, 64)
 
+/* With mergeable buffers we align buffer address and use the low bits to
+ * encode its true size. Buffer size is up to 1 page so we need to align to
+ * square root of page size to ensure we reserve enough bits to encode the true
+ * size.
+ */
+#define MERGEABLE_BUFFER_MIN_ALIGN_SHIFT ((PAGE_SHIFT + 1) / 2)
+
 /* Minimum alignment for mergeable packet buffers. */
-#define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)
+#define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, \
+				   1 << MERGEABLE_BUFFER_MIN_ALIGN_SHIFT)
 
 #define VIRTNET_DRIVER_VERSION "1.0.0"
 
@@ -548,7 +556,12 @@ static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 	hdr = skb_vnet_hdr(skb);
 	sg_init_table(rq->sg, 2);
 	sg_set_buf(rq->sg, hdr, vi->hdr_len);
-	skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
+
+	err = skb_to_sgvec(skb, rq->sg + 1, 0, skb->len);
+	if (unlikely(err < 0)) {
+		dev_kfree_skb(skb);
+		return err;
+	}
 
 	err = virtqueue_add_inbuf(rq->vq, rq->sg, 2, skb, gfp);
 	if (err < 0)
@@ -850,7 +863,7 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 	struct virtio_net_hdr_mrg_rxbuf *hdr;
 	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
 	struct virtnet_info *vi = sq->vq->vdev->priv;
-	unsigned num_sg;
+	int num_sg;
 	unsigned hdr_len = vi->hdr_len;
 	bool can_push;
 
@@ -903,11 +916,16 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
 	if (can_push) {
 		__skb_push(skb, hdr_len);
 		num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
+		if (unlikely(num_sg < 0))
+			return num_sg;
 		/* Pull header back to avoid skew in tx bytes calculations. */
 		__skb_pull(skb, hdr_len);
 	} else {
 		sg_set_buf(sq->sg, hdr, hdr_len);
-		num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
+		num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len);
+		if (unlikely(num_sg < 0))
+			return num_sg;
+		num_sg++;
 	}
 	return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
 }
@@ -1415,6 +1433,7 @@ static const struct net_device_ops virtnet_netdev = {
 #ifdef CONFIG_NET_RX_BUSY_POLL
 	.ndo_busy_poll		= virtnet_busy_poll,
 #endif
+	.ndo_features_check	= passthru_features_check,
 };
 
 static void virtnet_config_changed_work(struct work_struct *work)
@@ -1465,6 +1484,11 @@ static void virtnet_free_queues(struct virtnet_info *vi)
 		netif_napi_del(&vi->rq[i].napi);
 	}
 
+	/* We called napi_hash_del() before netif_napi_del(),
+	 * we need to respect an RCU grace period before freeing vi->rq
+	 */
+	synchronize_net();
+
 	kfree(vi->rq);
 	kfree(vi->sq);
 }
@@ -1888,8 +1912,8 @@ static int virtnet_probe(struct virtio_device *vdev)
 
 	/* Assume link up if device can't report link status,
 	   otherwise get link status from config. */
+	netif_carrier_off(dev);
 	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
-		netif_carrier_off(dev);
 		schedule_work(&vi->config_work);
 	} else {
 		vi->status = VIRTIO_NET_S_LINK_UP;