1 files changed, 43 insertions, 132 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 22d894101c01..db88dcaefb20 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -425,9 +425,6 @@ struct virtnet_info {
 	u16 rss_indir_table_size;
 	u32 rss_hash_types_supported;
 	u32 rss_hash_types_saved;
-	struct virtio_net_rss_config_hdr *rss_hdr;
-	struct virtio_net_rss_config_trailer rss_trailer;
-	u8 rss_hash_key_data[VIRTIO_NET_RSS_MAX_KEY_SIZE];
 
 	/* Has control virtqueue */
 	bool has_cvq;
@@ -441,9 +438,6 @@ struct virtnet_info {
 	/* Packet virtio header size */
 	u8 hdr_len;
 
-	/* Work struct for delayed refilling if we run low on memory. */
-	struct delayed_work refill;
-
 	/* UDP tunnel support */
 	bool tx_tnl;
 
@@ -451,12 +445,6 @@ struct virtnet_info {
 
 	bool rx_tnl_csum;
 
-	/* Is delayed refill enabled? */
-	bool refill_enabled;
-
-	/* The lock to synchronize the access to refill_enabled */
-	spinlock_t refill_lock;
-
 	/* Work struct for config space updates */
 	struct work_struct config_work;
 
@@ -493,7 +481,16 @@ struct virtnet_info {
 	struct failover *failover;
 
 	u64 device_stats_cap;
+
+	struct virtio_net_rss_config_hdr *rss_hdr;
+
+	/* Must be last as it ends in a flexible-array member. */
+	TRAILING_OVERLAP(struct virtio_net_rss_config_trailer, rss_trailer, hash_key_data,
+		u8 rss_hash_key_data[VIRTIO_NET_RSS_MAX_KEY_SIZE];
+	);
 };
+static_assert(offsetof(struct virtnet_info, rss_trailer.hash_key_data) ==
+	      offsetof(struct virtnet_info, rss_hash_key_data));
 
 struct padded_vnet_hdr {
 	struct virtio_net_hdr_v1_hash hdr;
@@ -720,20 +717,6 @@ static void virtnet_rq_free_buf(struct virtnet_info *vi,
 		put_page(virt_to_head_page(buf));
 }
 
-static void enable_delayed_refill(struct virtnet_info *vi)
-{
-	spin_lock_bh(&vi->refill_lock);
-	vi->refill_enabled = true;
-	spin_unlock_bh(&vi->refill_lock);
-}
-
-static void disable_delayed_refill(struct virtnet_info *vi)
-{
-	spin_lock_bh(&vi->refill_lock);
-	vi->refill_enabled = false;
-	spin_unlock_bh(&vi->refill_lock);
-}
-
 static void enable_rx_mode_work(struct virtnet_info *vi)
 {
 	rtnl_lock();
@@ -2948,42 +2931,6 @@ static void virtnet_napi_disable(struct receive_queue *rq)
 	napi_disable(napi);
 }
 
-static void refill_work(struct work_struct *work)
-{
-	struct virtnet_info *vi =
-		container_of(work, struct virtnet_info, refill.work);
-	bool still_empty;
-	int i;
-
-	for (i = 0; i < vi->curr_queue_pairs; i++) {
-		struct receive_queue *rq = &vi->rq[i];
-
-		/*
-		 * When queue API support is added in the future and the call
-		 * below becomes napi_disable_locked, this driver will need to
-		 * be refactored.
-		 *
-		 * One possible solution would be to:
-		 *   - cancel refill_work with cancel_delayed_work (note:
-		 *     non-sync)
-		 *   - cancel refill_work with cancel_delayed_work_sync in
-		 *     virtnet_remove after the netdev is unregistered
-		 *   - wrap all of the work in a lock (perhaps the netdev
-		 *     instance lock)
-		 *   - check netif_running() and return early to avoid a race
-		 */
-		napi_disable(&rq->napi);
-		still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
-		virtnet_napi_do_enable(rq->vq, &rq->napi);
-
-		/* In theory, this can happen: if we don't get any buffers in
-		 * we will *never* try to fill again.
-		 */
-		if (still_empty)
-			schedule_delayed_work(&vi->refill, HZ/2);
-	}
-}
-
 static int virtnet_receive_xsk_bufs(struct virtnet_info *vi,
 				    struct receive_queue *rq,
 				    int budget,
@@ -3046,16 +2993,16 @@ static int virtnet_receive(struct receive_queue *rq, int budget,
 	else
 		packets = virtnet_receive_packets(vi, rq, budget, xdp_xmit, &stats);
 
+	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)) {
-			spin_lock(&vi->refill_lock);
-			if (vi->refill_enabled)
-				schedule_delayed_work(&vi->refill, 0);
-			spin_unlock(&vi->refill_lock);
-		}
+		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_set(&stats.packets, packets);
 	u64_stats_update_begin(&rq->stats.syncp);
 	for (i = 0; i < ARRAY_SIZE(virtnet_rq_stats_desc); i++) {
 		size_t offset = virtnet_rq_stats_desc[i].offset;
@@ -3226,13 +3173,12 @@ static int virtnet_open(struct net_device *dev)
 	struct virtnet_info *vi = netdev_priv(dev);
 	int i, err;
 
-	enable_delayed_refill(vi);
-
 	for (i = 0; i < vi->max_queue_pairs; i++) {
 		if (i < vi->curr_queue_pairs)
-			/* Make sure we have some buffers: if oom use wq. */
-			if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
-				schedule_delayed_work(&vi->refill, 0);
+			/* Pre-fill rq agressively, to make sure we are ready to
+			 * get packets immediately.
+			 */
+			try_fill_recv(vi, &vi->rq[i], GFP_KERNEL);
 
 		err = virtnet_enable_queue_pair(vi, i);
 		if (err < 0)
@@ -3251,9 +3197,6 @@ static int virtnet_open(struct net_device *dev)
 	return 0;
 
 err_enable_qp:
-	disable_delayed_refill(vi);
-	cancel_delayed_work_sync(&vi->refill);
-
 	for (i--; i >= 0; i--) {
 		virtnet_disable_queue_pair(vi, i);
 		virtnet_cancel_dim(vi, &vi->rq[i].dim);
@@ -3432,8 +3375,8 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 	return NETDEV_TX_OK;
 }
 
-static void __virtnet_rx_pause(struct virtnet_info *vi,
-			       struct receive_queue *rq)
+static void virtnet_rx_pause(struct virtnet_info *vi,
+			     struct receive_queue *rq)
 {
 	bool running = netif_running(vi->dev);
 
@@ -3447,62 +3390,37 @@ static void virtnet_rx_pause_all(struct virtnet_info *vi)
 {
 	int i;
 
-	/*
-	 * Make sure refill_work does not run concurrently to
-	 * avoid napi_disable race which leads to deadlock.
-	 */
-	disable_delayed_refill(vi);
-	cancel_delayed_work_sync(&vi->refill);
 	for (i = 0; i < vi->max_queue_pairs; i++)
-		__virtnet_rx_pause(vi, &vi->rq[i]);
+		virtnet_rx_pause(vi, &vi->rq[i]);
 }
 
-static void virtnet_rx_pause(struct virtnet_info *vi, struct receive_queue *rq)
+static void virtnet_rx_resume(struct virtnet_info *vi,
+			      struct receive_queue *rq,
+			      bool refill)
 {
-	/*
-	 * Make sure refill_work does not run concurrently to
-	 * avoid napi_disable race which leads to deadlock.
-	 */
-	disable_delayed_refill(vi);
-	cancel_delayed_work_sync(&vi->refill);
-	__virtnet_rx_pause(vi, rq);
-}
-
-static void __virtnet_rx_resume(struct virtnet_info *vi,
-				struct receive_queue *rq,
-				bool refill)
-{
-	bool running = netif_running(vi->dev);
-	bool schedule_refill = false;
+	if (netif_running(vi->dev)) {
+		/* Pre-fill rq agressively, to make sure we are ready to get
+		 * packets immediately.
+		 */
+		if (refill)
+			try_fill_recv(vi, rq, GFP_KERNEL);
 
-	if (refill && !try_fill_recv(vi, rq, GFP_KERNEL))
-		schedule_refill = true;
-	if (running)
 		virtnet_napi_enable(rq);
-
-	if (schedule_refill)
-		schedule_delayed_work(&vi->refill, 0);
+	}
 }
 
 static void virtnet_rx_resume_all(struct virtnet_info *vi)
 {
 	int i;
 
-	enable_delayed_refill(vi);
 	for (i = 0; i < vi->max_queue_pairs; i++) {
 		if (i < vi->curr_queue_pairs)
-			__virtnet_rx_resume(vi, &vi->rq[i], true);
+			virtnet_rx_resume(vi, &vi->rq[i], true);
 		else
-			__virtnet_rx_resume(vi, &vi->rq[i], false);
+			virtnet_rx_resume(vi, &vi->rq[i], false);
 	}
 }
 
-static void virtnet_rx_resume(struct virtnet_info *vi, struct receive_queue *rq)
-{
-	enable_delayed_refill(vi);
-	__virtnet_rx_resume(vi, rq, true);
-}
-
 static int virtnet_rx_resize(struct virtnet_info *vi,
 			     struct receive_queue *rq, u32 ring_num)
 {
@@ -3516,7 +3434,7 @@ static int virtnet_rx_resize(struct virtnet_info *vi,
 	if (err)
 		netdev_err(vi->dev, "resize rx fail: rx queue index: %d err: %d\n", qindex, err);
 
-	virtnet_rx_resume(vi, rq);
+	virtnet_rx_resume(vi, rq, true);
 	return err;
 }
 
@@ -3829,11 +3747,12 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
 	}
 succ:
 	vi->curr_queue_pairs = queue_pairs;
-	/* virtnet_open() will refill when device is going to up. */
-	spin_lock_bh(&vi->refill_lock);
-	if (dev->flags & IFF_UP && vi->refill_enabled)
-		schedule_delayed_work(&vi->refill, 0);
-	spin_unlock_bh(&vi->refill_lock);
+	if (dev->flags & IFF_UP) {
+		local_bh_disable();
+		for (int i = 0; i < vi->curr_queue_pairs; ++i)
+			virtqueue_napi_schedule(&vi->rq[i].napi, vi->rq[i].vq);
+		local_bh_enable();
+	}
 
 	return 0;
 }
@@ -3843,10 +3762,6 @@ static int virtnet_close(struct net_device *dev)
 	struct virtnet_info *vi = netdev_priv(dev);
 	int i;
 
-	/* Make sure NAPI doesn't schedule refill work */
-	disable_delayed_refill(vi);
-	/* Make sure refill_work doesn't re-enable napi! */
-	cancel_delayed_work_sync(&vi->refill);
 	/* Prevent the config change callback from changing carrier
 	 * after close
 	 */
@@ -5802,7 +5717,6 @@ static int virtnet_restore_up(struct virtio_device *vdev)
 
 	virtio_device_ready(vdev);
 
-	enable_delayed_refill(vi);
 	enable_rx_mode_work(vi);
 
 	if (netif_running(vi->dev)) {
@@ -5892,7 +5806,7 @@ static int virtnet_rq_bind_xsk_pool(struct virtnet_info *vi, struct receive_queu
 
 	rq->xsk_pool = pool;
 
-	virtnet_rx_resume(vi, rq);
+	virtnet_rx_resume(vi, rq, true);
 
 	if (pool)
 		return 0;
@@ -6559,7 +6473,6 @@ static int virtnet_alloc_queues(struct virtnet_info *vi)
 	if (!vi->rq)
 		goto err_rq;
 
-	INIT_DELAYED_WORK(&vi->refill, refill_work);
 	for (i = 0; i < vi->max_queue_pairs; i++) {
 		vi->rq[i].pages = NULL;
 		netif_napi_add_config(vi->dev, &vi->rq[i].napi, virtnet_poll,
@@ -6901,7 +6814,6 @@ 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);
-	spin_lock_init(&vi->refill_lock);
 
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) {
 		vi->mergeable_rx_bufs = true;
@@ -7165,7 +7077,6 @@ free_failover:
 	net_failover_destroy(vi->failover);
 free_vqs:
 	virtio_reset_device(vdev);
-	cancel_delayed_work_sync(&vi->refill);
 	free_receive_page_frags(vi);
 	virtnet_del_vqs(vi);
 free: