netvsc: report per-channel stats in ethtool statistics

Report packets and bytes transferred through a vmbus channel via ethtool.
This supersedes need for per-cpu statistics.

Example:
$ ethtool -S eth0
NIC statistics:
...
     tx_queue_0_packets: 3523179
     tx_queue_0_bytes: 505370920
     rx_queue_0_packets: 41430490
     rx_queue_0_bytes: 62714661254
     tx_queue_1_packets: 0
     tx_queue_1_bytes: 0
     rx_queue_1_packets: 0
     rx_queue_1_bytes: 0
...
Reviewed-by: Long Li <longli@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Simon Xiao <sixiao@microsoft.com>
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/hyperv/hyperv_net.h

@@ -699,8 +699,6 @@ struct net_device_context {
 	u32 msg_enable; /* debug level */
 
 	u32 tx_checksum_mask;
-	struct netvsc_stats __percpu *tx_stats;
-	struct netvsc_stats __percpu *rx_stats;
 
 	/* Ethtool settings */
 	u8 duplex;
@@ -725,6 +723,9 @@ struct netvsc_channel {
 	struct multi_send_data msd;
 	struct multi_recv_comp mrc;
 	atomic_t queue_sends;
+
+	struct netvsc_stats tx_stats;
+	struct netvsc_stats rx_stats;
 };
 
 /* Per netvsc device */

drivers/net/hyperv/netvsc.c

@@ -621,7 +621,7 @@ static void netvsc_send_tx_complete(struct netvsc_device *net_device,
 		q_idx = packet->q_idx;
 		channel = incoming_channel;
 
-		tx_stats = this_cpu_ptr(net_device_ctx->tx_stats);
+		tx_stats = &net_device->chan_table[q_idx].tx_stats;
 
 		u64_stats_update_begin(&tx_stats->syncp);
 		tx_stats->packets += packet->total_packets;

drivers/net/hyperv/netvsc_drv.c

@@ -641,9 +641,12 @@ int netvsc_recv_callback(struct net_device *net,
 			 const struct ndis_pkt_8021q_info *vlan)
 {
 	struct net_device_context *net_device_ctx = netdev_priv(net);
+	struct netvsc_device *net_device = net_device_ctx->nvdev;
 	struct net_device *vf_netdev;
 	struct sk_buff *skb;
 	struct netvsc_stats *rx_stats;
+	u16 q_idx = channel->offermsg.offer.sub_channel_index;
+
 
 	if (net->reg_state != NETREG_REGISTERED)
 		return NVSP_STAT_FAIL;
@@ -669,15 +672,14 @@ int netvsc_recv_callback(struct net_device *net,
 	}
 
 	if (net != vf_netdev)
-		skb_record_rx_queue(skb,
-				    channel->offermsg.offer.sub_channel_index);
+		skb_record_rx_queue(skb, q_idx);
 
 	/*
 	 * Even if injecting the packet, record the statistics
 	 * on the synthetic device because modifying the VF device
 	 * statistics will not work correctly.
 	 */
-	rx_stats = this_cpu_ptr(net_device_ctx->rx_stats);
+	rx_stats = &net_device->chan_table[q_idx].rx_stats;
 	u64_stats_update_begin(&rx_stats->syncp);
 	rx_stats->packets++;
 	rx_stats->bytes += len;
@@ -882,34 +884,39 @@ static void netvsc_get_stats64(struct net_device *net,
 			       struct rtnl_link_stats64 *t)
 {
 	struct net_device_context *ndev_ctx = netdev_priv(net);
-	int cpu;
-
-	for_each_possible_cpu(cpu) {
-		struct netvsc_stats *tx_stats = per_cpu_ptr(ndev_ctx->tx_stats,
-							    cpu);
-		struct netvsc_stats *rx_stats = per_cpu_ptr(ndev_ctx->rx_stats,
-							    cpu);
-		u64 tx_packets, tx_bytes, rx_packets, rx_bytes, rx_multicast;
+	struct netvsc_device *nvdev = ndev_ctx->nvdev;
+	int i;
+
+	if (!nvdev)
+		return;
+
+	for (i = 0; i < nvdev->num_chn; i++) {
+		const struct netvsc_channel *nvchan = &nvdev->chan_table[i];
+		const struct netvsc_stats *stats;
+		u64 packets, bytes, multicast;
 		unsigned int start;
 
+		stats = &nvchan->tx_stats;
 		do {
-			start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
-			tx_packets = tx_stats->packets;
-			tx_bytes = tx_stats->bytes;
-		} while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
+			start = u64_stats_fetch_begin_irq(&stats->syncp);
+			packets = stats->packets;
+			bytes = stats->bytes;
+		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
+
+		t->tx_bytes	+= bytes;
+		t->tx_packets	+= packets;
 
+		stats = &nvchan->rx_stats;
 		do {
-			start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
-			rx_packets = rx_stats->packets;
-			rx_bytes = rx_stats->bytes;
-			rx_multicast = rx_stats->multicast + rx_stats->broadcast;
-		} while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
-
-		t->tx_bytes	+= tx_bytes;
-		t->tx_packets	+= tx_packets;
-		t->rx_bytes	+= rx_bytes;
-		t->rx_packets	+= rx_packets;
-		t->multicast	+= rx_multicast;
+			start = u64_stats_fetch_begin_irq(&stats->syncp);
+			packets = stats->packets;
+			bytes = stats->bytes;
+			multicast = stats->multicast + stats->broadcast;
+		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
+
+		t->rx_bytes	+= bytes;
+		t->rx_packets	+= packets;
+		t->multicast	+= multicast;
 	}
 
 	t->tx_dropped	= net->stats.tx_dropped;
@@ -954,11 +961,19 @@ static const struct {
 	{ "tx_busy",	  offsetof(struct netvsc_ethtool_stats, tx_busy) },
 };
 
+#define NETVSC_GLOBAL_STATS_LEN	ARRAY_SIZE(netvsc_stats)
+
+/* 4 statistics per queue (rx/tx packets/bytes) */
+#define NETVSC_QUEUE_STATS_LEN(dev) ((dev)->num_chn * 4)
+
 static int netvsc_get_sset_count(struct net_device *dev, int string_set)
 {
+	struct net_device_context *ndc = netdev_priv(dev);
+	struct netvsc_device *nvdev = ndc->nvdev;
+
 	switch (string_set) {
 	case ETH_SS_STATS:
-		return ARRAY_SIZE(netvsc_stats);
+		return NETVSC_GLOBAL_STATS_LEN + NETVSC_QUEUE_STATS_LEN(nvdev);
 	default:
 		return -EINVAL;
 	}
@@ -968,22 +983,63 @@ static void netvsc_get_ethtool_stats(struct net_device *dev,
 				     struct ethtool_stats *stats, u64 *data)
 {
 	struct net_device_context *ndc = netdev_priv(dev);
+	struct netvsc_device *nvdev = ndc->nvdev;
 	const void *nds = &ndc->eth_stats;
-	int i;
+	const struct netvsc_stats *qstats;
+	unsigned int start;
+	u64 packets, bytes;
+	int i, j;
 
-	for (i = 0; i < ARRAY_SIZE(netvsc_stats); i++)
+	for (i = 0; i < NETVSC_GLOBAL_STATS_LEN; i++)
 		data[i] = *(unsigned long *)(nds + netvsc_stats[i].offset);
+
+	for (j = 0; j < nvdev->num_chn; j++) {
+		qstats = &nvdev->chan_table[j].tx_stats;
+
+		do {
+			start = u64_stats_fetch_begin_irq(&qstats->syncp);
+			packets = qstats->packets;
+			bytes = qstats->bytes;
+		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
+		data[i++] = packets;
+		data[i++] = bytes;
+
+		qstats = &nvdev->chan_table[j].rx_stats;
+		do {
+			start = u64_stats_fetch_begin_irq(&qstats->syncp);
+			packets = qstats->packets;
+			bytes = qstats->bytes;
+		} while (u64_stats_fetch_retry_irq(&qstats->syncp, start));
+		data[i++] = packets;
+		data[i++] = bytes;
+	}
 }
 
 static void netvsc_get_strings(struct net_device *dev, u32 stringset, u8 *data)
 {
+	struct net_device_context *ndc = netdev_priv(dev);
+	struct netvsc_device *nvdev = ndc->nvdev;
+	u8 *p = data;
 	int i;
 
 	switch (stringset) {
 	case ETH_SS_STATS:
 		for (i = 0; i < ARRAY_SIZE(netvsc_stats); i++)
-			memcpy(data + i * ETH_GSTRING_LEN,
+			memcpy(p + i * ETH_GSTRING_LEN,
 			       netvsc_stats[i].name, ETH_GSTRING_LEN);
+
+		p += i * ETH_GSTRING_LEN;
+		for (i = 0; i < nvdev->num_chn; i++) {
+			sprintf(p, "tx_queue_%u_packets", i);
+			p += ETH_GSTRING_LEN;
+			sprintf(p, "tx_queue_%u_bytes", i);
+			p += ETH_GSTRING_LEN;
+			sprintf(p, "rx_queue_%u_packets", i);
+			p += ETH_GSTRING_LEN;
+			sprintf(p, "rx_queue_%u_bytes", i);
+			p += ETH_GSTRING_LEN;
+		}
+
 		break;
 	}
 }
@@ -1237,15 +1293,6 @@ static void netvsc_link_change(struct work_struct *w)
 	rtnl_unlock();
 }
 
-static void netvsc_free_netdev(struct net_device *netdev)
-{
-	struct net_device_context *net_device_ctx = netdev_priv(netdev);
-
-	free_percpu(net_device_ctx->tx_stats);
-	free_percpu(net_device_ctx->rx_stats);
-	free_netdev(netdev);
-}
-
 static struct net_device *get_netvsc_bymac(const u8 *mac)
 {
 	struct net_device *dev;
@@ -1423,18 +1470,6 @@ static int netvsc_probe(struct hv_device *dev,
 		netdev_dbg(net, "netvsc msg_enable: %d\n",
 			   net_device_ctx->msg_enable);
 
-	net_device_ctx->tx_stats = netdev_alloc_pcpu_stats(struct netvsc_stats);
-	if (!net_device_ctx->tx_stats) {
-		free_netdev(net);
-		return -ENOMEM;
-	}
-	net_device_ctx->rx_stats = netdev_alloc_pcpu_stats(struct netvsc_stats);
-	if (!net_device_ctx->rx_stats) {
-		free_percpu(net_device_ctx->tx_stats);
-		free_netdev(net);
-		return -ENOMEM;
-	}
-
 	hv_set_drvdata(dev, net);
 
 	net_device_ctx->start_remove = false;
@@ -1460,7 +1495,7 @@ static int netvsc_probe(struct hv_device *dev,
 	ret = rndis_filter_device_add(dev, &device_info);
 	if (ret != 0) {
 		netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
-		netvsc_free_netdev(net);
+		free_netdev(net);
 		hv_set_drvdata(dev, NULL);
 		return ret;
 	}
@@ -1487,7 +1522,7 @@ static int netvsc_probe(struct hv_device *dev,
 	if (ret != 0) {
 		pr_err("Unable to register netdev.\n");
 		rndis_filter_device_remove(dev, nvdev);
-		netvsc_free_netdev(net);
+		free_netdev(net);
 	}
 
 	return ret;
@@ -1530,7 +1565,7 @@ static int netvsc_remove(struct hv_device *dev)
 
 	hv_set_drvdata(dev, NULL);
 
-	netvsc_free_netdev(net);
+	free_netdev(net);
 	return 0;
 }