1 files changed, 45 insertions, 26 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index daab43ac92ce..dd2c41ef6fbe 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -125,6 +125,7 @@ struct virtnet_rq_stats {
 	u64_stats_t packets;
 	u64_stats_t bytes;
 	u64_stats_t drops;
+	u64_stats_t alloc_fail;
 	u64_stats_t xdp_packets;
 	u64_stats_t xdp_tx;
 	u64_stats_t xdp_redirects;
@@ -173,8 +174,9 @@ static const struct virtnet_stat_desc virtnet_sq_stats_desc_qstat[] = {
 };
 
 static const struct virtnet_stat_desc virtnet_rq_stats_desc_qstat[] = {
-	VIRTNET_RQ_STAT_QSTAT("packets", packets),
-	VIRTNET_RQ_STAT_QSTAT("bytes",   bytes),
+	VIRTNET_RQ_STAT_QSTAT("packets",    packets),
+	VIRTNET_RQ_STAT_QSTAT("bytes",      bytes),
+	VIRTNET_RQ_STAT_QSTAT("alloc_fail", alloc_fail),
 };
 
 #define VIRTNET_STATS_DESC_CQ(name) \
@@ -441,9 +443,6 @@ struct virtnet_info {
 	/* Work struct for setting rx mode */
 	struct work_struct rx_mode_work;
 
-	/* OK to queue work setting RX mode? */
-	bool rx_mode_work_enabled;
-
 	/* Does the affinity hint is set for virtqueues? */
 	bool affinity_hint_set;
 
@@ -710,16 +709,13 @@ static void virtnet_rq_free_buf(struct virtnet_info *vi,
 
 static void enable_rx_mode_work(struct virtnet_info *vi)
 {
-	rtnl_lock();
-	vi->rx_mode_work_enabled = true;
-	rtnl_unlock();
+	if (enable_work(&vi->rx_mode_work) && netif_running(vi->dev))
+		schedule_work(&vi->rx_mode_work);
 }
 
 static void disable_rx_mode_work(struct virtnet_info *vi)
 {
-	rtnl_lock();
-	vi->rx_mode_work_enabled = false;
-	rtnl_unlock();
+	disable_work_sync(&vi->rx_mode_work);
 }
 
 static void virtqueue_napi_schedule(struct napi_struct *napi,
@@ -906,6 +902,15 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 	}
 
 	BUG_ON(offset >= PAGE_SIZE);
+
+	/* The first frag starts at offset, each next frag is a full page. */
+	if (unlikely(DIV_ROUND_UP(offset + len, PAGE_SIZE) > MAX_SKB_FRAGS)) {
+		pr_debug("%s: rx error: len %u needs more than %d frags\n",
+			 vi->dev->name, len, MAX_SKB_FRAGS);
+		kfree_skb(skb);
+		return NULL;
+	}
+
 	while (len) {
 		unsigned int frag_size = min((unsigned)PAGE_SIZE - offset, len);
 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset,
@@ -1917,8 +1922,10 @@ static struct sk_buff *receive_small_xdp(struct net_device *dev,
 	}
 
 	skb = virtnet_build_skb(buf, buflen, xdp.data - buf, len);
-	if (unlikely(!skb))
+	if (unlikely(!skb)) {
+		u64_stats_inc(&stats->alloc_fail);
 		goto err;
+	}
 
 	if (metasize)
 		skb_metadata_set(skb, metasize);
@@ -1985,6 +1992,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
 		return skb;
 	}
 
+	u64_stats_inc(&stats->alloc_fail);
 err:
 	u64_stats_inc(&stats->drops);
 	page_pool_put_page(rq->page_pool, page, -1, true);
@@ -2016,8 +2024,10 @@ static struct sk_buff *receive_big(struct net_device *dev,
 
 	skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, 0);
 	u64_stats_add(&stats->bytes, len - vi->hdr_len);
-	if (unlikely(!skb))
+	if (unlikely(!skb)) {
+		u64_stats_inc(&stats->alloc_fail);
 		goto err;
+	}
 
 	return skb;
 
@@ -2298,8 +2308,10 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev,
 	switch (act) {
 	case XDP_PASS:
 		head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz);
-		if (unlikely(!head_skb))
+		if (unlikely(!head_skb)) {
+			u64_stats_inc(&stats->alloc_fail);
 			break;
+		}
 
 		skb_mark_for_recycle(head_skb);
 		return head_skb;
@@ -2414,8 +2426,10 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 	head_skb = page_to_skb(vi, rq, page, offset, len, truesize, headroom);
 	curr_skb = head_skb;
 
-	if (unlikely(!curr_skb))
+	if (unlikely(!curr_skb)) {
+		u64_stats_inc(&stats->alloc_fail);
 		goto err_skb;
+	}
 
 	skb_mark_for_recycle(head_skb);
 	while (--num_buf) {
@@ -2444,8 +2458,10 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 		truesize = mergeable_ctx_to_truesize(ctx);
 		curr_skb  = virtnet_skb_append_frag(rq, head_skb, curr_skb, page,
 						    buf, len, truesize);
-		if (!curr_skb)
+		if (!curr_skb) {
+			u64_stats_inc(&stats->alloc_fail);
 			goto err_skb;
+		}
 	}
 
 	ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
@@ -2930,12 +2946,14 @@ static int virtnet_receive(struct receive_queue *rq, int budget,
 
 	u64_stats_set(&stats.packets, packets);
 	if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) {
-		if (!try_fill_recv(vi, rq, GFP_ATOMIC))
+		if (!try_fill_recv(vi, rq, GFP_ATOMIC)) {
 			/* We need to retry refilling in the next NAPI poll so
 			 * we must return budget to make sure the NAPI is
 			 * repolled.
 			 */
 			packets = budget;
+			u64_stats_inc(&stats.alloc_fail);
+		}
 	}
 
 	u64_stats_update_begin(&rq->stats.syncp);
@@ -2950,6 +2968,7 @@ static int virtnet_receive(struct receive_queue *rq, int budget,
 
 	u64_stats_add(&rq->stats.packets, u64_stats_read(&stats.packets));
 	u64_stats_add(&rq->stats.bytes, u64_stats_read(&stats.bytes));
+	u64_stats_add(&rq->stats.alloc_fail, u64_stats_read(&stats.alloc_fail));
 
 	u64_stats_update_end(&rq->stats.syncp);
 
@@ -3925,8 +3944,7 @@ static void virtnet_set_rx_mode(struct net_device *dev)
 {
 	struct virtnet_info *vi = netdev_priv(dev);
 
-	if (vi->rx_mode_work_enabled)
-		schedule_work(&vi->rx_mode_work);
+	schedule_work(&vi->rx_mode_work);
 }
 
 static int virtnet_vlan_rx_add_vid(struct net_device *dev,
@@ -5677,6 +5695,7 @@ static void virtnet_get_base_stats(struct net_device *dev,
 	 */
 	rx->bytes = 0;
 	rx->packets = 0;
+	rx->alloc_fail = 0;
 
 	if (vi->device_stats_cap & VIRTIO_NET_STATS_TYPE_RX_BASIC) {
 		rx->hw_drops = 0;
@@ -5742,7 +5761,6 @@ static void virtnet_freeze_down(struct virtio_device *vdev)
 	/* Make sure no work handler is accessing the device */
 	flush_work(&vi->config_work);
 	disable_rx_mode_work(vi);
-	flush_work(&vi->rx_mode_work);
 
 	if (netif_running(vi->dev)) {
 		rtnl_lock();
@@ -5772,8 +5790,6 @@ static int virtnet_restore_up(struct virtio_device *vdev)
 
 	virtio_device_ready(vdev);
 
-	enable_rx_mode_work(vi);
-
 	if (netif_running(vi->dev)) {
 		rtnl_lock();
 		err = virtnet_open(vi->dev);
@@ -5785,6 +5801,8 @@ static int virtnet_restore_up(struct virtio_device *vdev)
 	netif_tx_lock_bh(vi->dev);
 	netif_device_attach(vi->dev);
 	netif_tx_unlock_bh(vi->dev);
+
+	enable_rx_mode_work(vi);
 	return 0;
 
 err_destroy_pools:
@@ -6717,7 +6735,8 @@ static void virtnet_set_big_packets(struct virtnet_info *vi, const int mtu)
 	 */
 	if (mtu > ETH_DATA_LEN || guest_gso) {
 		vi->big_packets = true;
-		vi->big_packets_num_skbfrags = guest_gso ? MAX_SKB_FRAGS : DIV_ROUND_UP(mtu, PAGE_SIZE);
+		vi->big_packets_num_skbfrags = guest_gso ? MAX_SKB_FRAGS - 1 :
+							   DIV_ROUND_UP(mtu, PAGE_SIZE);
 	}
 }
 
@@ -6880,6 +6899,7 @@ static int virtnet_probe(struct virtio_device *vdev)
 
 	INIT_WORK(&vi->config_work, virtnet_config_changed_work);
 	INIT_WORK(&vi->rx_mode_work, virtnet_rx_mode_work);
+	disable_work(&vi->rx_mode_work);
 
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) {
 		vi->mergeable_rx_bufs = true;
@@ -7038,8 +7058,6 @@ static int virtnet_probe(struct virtio_device *vdev)
 	if (vi->has_rss || vi->has_rss_hash_report)
 		virtnet_init_default_rss(vi);
 
-	enable_rx_mode_work(vi);
-
 	for (i = 0; i < ARRAY_SIZE(guest_offloads); i++) {
 		unsigned int fbit;
 
@@ -7143,6 +7161,8 @@ static int virtnet_probe(struct virtio_device *vdev)
 		goto free_unregister_netdev;
 	}
 
+	enable_rx_mode_work(vi);
+
 	pr_debug("virtnet: registered device %s with %d RX and TX vq's\n",
 		 dev->name, max_queue_pairs);
 
@@ -7195,7 +7215,6 @@ static void virtnet_remove(struct virtio_device *vdev)
 	/* Make sure no work handler is accessing the device. */
 	flush_work(&vi->config_work);
 	disable_rx_mode_work(vi);
-	flush_work(&vi->rx_mode_work);
 
 	virtnet_free_irq_moder(vi);