[PATCH net v3 2/4] gve: Fix backward stats when interface goes down or configuration is adjusted

@@ -871,6 +871,10 @@ struct gve_ctrl_ops {
 	int (*report_link_speed)(struct gve_priv *priv);
 };
 
+struct gve_ring_err_stats {
+	u64 rx_alloc_fails;
+};
+
 struct gve_priv {
 	struct net_device *dev;
 	struct gve_tx_ring *tx; /* array of tx_cfg.num_queues */

@@ -962,6 +966,8 @@ struct gve_priv {
 	unsigned long service_task_flags;
 	unsigned long state_flags;
 
+	struct gve_ring_err_stats base_ring_err_stats;
+	struct rtnl_link_stats64 base_net_stats;
 	struct gve_stats_report *stats_report;
 	u64 stats_report_len;
 	dma_addr_t stats_report_bus; /* dma address for the stats report */

@@ -61,15 +61,25 @@ static netdev_tx_t gve_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		return gve_tx_dqo(skb, dev);
 }
 
-static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s)
+static void gve_add_base_stats(struct gve_priv *priv,
+			       struct rtnl_link_stats64 *s)
+{
+	struct rtnl_link_stats64 *base_stats = &priv->base_net_stats;
+
+	s->rx_packets += base_stats->rx_packets;
+	s->rx_bytes += base_stats->rx_bytes;
+	s->tx_packets += base_stats->tx_packets;
+	s->tx_bytes += base_stats->tx_bytes;
+}
+
+static void gve_get_ring_stats(struct gve_priv *priv,
+			       struct rtnl_link_stats64 *s)
 {
-	struct gve_priv *priv = netdev_priv(dev);
 	unsigned int start;
 	u64 packets, bytes;
 	int num_tx_queues;
 	int ring;
 
-	spin_lock_bh(&priv->stats_lock);
 	num_tx_queues = gve_num_tx_queues(priv);
 	if (priv->rx) {
 		for (ring = 0; ring < priv->rx_cfg.num_queues; ring++) {

@@ -97,6 +107,38 @@ static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s)
 			s->tx_bytes += bytes;
 		}
 	}
+}
+
+static void gve_get_ring_err_stats(struct gve_priv *priv,
+				   struct gve_ring_err_stats *err_stats)
+{
+	int ring;
+
+	if (!priv->rx)
+		return;
+
+	for (ring = 0; ring < priv->rx_cfg.num_queues; ring++) {
+		struct gve_rx_ring *rx = &priv->rx[ring];
+		unsigned int start;
+		u64 rx_alloc_fails;
+
+		do {
+			start = u64_stats_fetch_begin(&rx->statss);
+			rx_alloc_fails = rx->rx_skb_alloc_fail +
+					 rx->rx_buf_alloc_fail;
+		} while (u64_stats_fetch_retry(&rx->statss, start));
+
+		err_stats->rx_alloc_fails += rx_alloc_fails;
+	}
+}
+
+static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s)
+{
+	struct gve_priv *priv = netdev_priv(dev);
+
+	spin_lock_bh(&priv->stats_lock);
+	gve_get_ring_stats(priv, s);
+	gve_add_base_stats(priv, s);
 	spin_unlock_bh(&priv->stats_lock);
 }
 

@@ -646,6 +688,9 @@ static void gve_queues_mem_remove(struct gve_priv *priv)
 	gve_get_curr_alloc_cfgs(priv, &tx_alloc_cfg, &rx_alloc_cfg);
 
 	spin_lock_bh(&priv->stats_lock);
+	gve_get_ring_stats(priv, &priv->base_net_stats);
+	gve_get_ring_err_stats(priv, &priv->base_ring_err_stats);
+
 	priv->tx = NULL;
 	priv->rx = NULL;
 	spin_unlock_bh(&priv->stats_lock);

@@ -2689,8 +2734,20 @@ static int gve_rx_queue_stop(struct net_device *dev, void *per_q_mem, int idx)
 	gve_turnup_and_check_status(priv);
 
 	gve_per_q_mem = (struct gve_rx_ring *)per_q_mem;
+	spin_lock_bh(&priv->stats_lock);
+	priv->base_net_stats.rx_packets += priv->rx[idx].rpackets;
+	priv->base_net_stats.rx_bytes += priv->rx[idx].rbytes;
+	priv->base_ring_err_stats.rx_alloc_fails +=
+		priv->rx[idx].rx_skb_alloc_fail +
+		priv->rx[idx].rx_buf_alloc_fail;
 	*gve_per_q_mem = priv->rx[idx];
 	memset(&priv->rx[idx], 0, sizeof(priv->rx[idx]));
+	spin_unlock_bh(&priv->stats_lock);
+
+	gve_per_q_mem->rpackets = 0;
+	gve_per_q_mem->rbytes = 0;
+	gve_per_q_mem->rx_skb_alloc_fail = 0;
+	gve_per_q_mem->rx_buf_alloc_fail = 0;
 	return 0;
 }
 

@@ -2844,12 +2901,22 @@ static void gve_get_base_stats(struct net_device *dev,
 			       struct netdev_queue_stats_rx *rx,
 			       struct netdev_queue_stats_tx *tx)
 {
-	rx->packets = 0;
-	rx->bytes = 0;
-	rx->alloc_fail = 0;
+	const struct gve_ring_err_stats *base_err_stats;
+	const struct rtnl_link_stats64 *base_stats;
+	struct gve_priv *priv;
+
+	priv = netdev_priv(dev);
+	base_stats = &priv->base_net_stats;
+	base_err_stats = &priv->base_ring_err_stats;
+
+	spin_lock_bh(&priv->stats_lock);
+	rx->packets = base_stats->rx_packets;
+	rx->bytes = base_stats->rx_bytes;
+	rx->alloc_fail = base_err_stats->rx_alloc_fails;
 
-	tx->packets = 0;
-	tx->bytes = 0;
+	tx->packets = base_stats->tx_packets;
+	tx->bytes = base_stats->tx_bytes;
+	spin_unlock_bh(&priv->stats_lock);
 }
 
 static const struct netdev_stat_ops gve_stat_ops = {