net: introduce and use generic XDP stats

Documentation/networking/statistics.rst

@@ -41,6 +41,29 @@ If `-s` is specified once the detailed errors won't be shown.
 
 `ip` supports JSON formatting via the `-j` option.
 
+For some interfaces, standard XDP statistics are available.
+It can be accessed the same ways, e.g. `ip`::
+
+  $ ip link xdpstats dev enp178s0
+  16: enp178s0:
+  xdp-channel0-rx_xdp_packets: 0
+  xdp-channel0-rx_xdp_bytes: 1
+  xdp-channel0-rx_xdp_errors: 2
+  xdp-channel0-rx_xdp_aborted: 3
+  xdp-channel0-rx_xdp_drop: 4
+  xdp-channel0-rx_xdp_invalid: 5
+  xdp-channel0-rx_xdp_pass: 6
+  xdp-channel0-rx_xdp_redirect: 7
+  xdp-channel0-rx_xdp_redirect_errors: 8
+  xdp-channel0-rx_xdp_tx: 9
+  xdp-channel0-rx_xdp_tx_errors: 10
+  xdp-channel0-tx_xdp_xmit_packets: 11
+  xdp-channel0-tx_xdp_xmit_bytes: 12
+  xdp-channel0-tx_xdp_xmit_errors: 13
+  xdp-channel0-tx_xdp_xmit_full: 14
+
+Those are usually per-channel. JSON is also supported via the `-j` opt.
+
 Protocol-specific statistics
 ----------------------------
 
@@ -147,6 +170,8 @@ Statistics are reported both in the responses to link information
 requests (`RTM_GETLINK`) and statistic requests (`RTM_GETSTATS`,
 when `IFLA_STATS_LINK_64` bit is set in the `.filter_mask` of the request).
 
+`IFLA_STATS_LINK_XDP_XSTATS` bit is used to retrieve standard XDP statstics.
+
 ethtool
 -------
 
@@ -206,6 +231,14 @@ Retrieving ethtool statistics is a multi-syscall process, drivers are advised
 to keep the number of statistics constant to avoid race conditions with
 user space trying to read them.
 
+It is up to the developers whether to implement XDP statistics or not due to
+possible performance hits. If so, it is encouraged to export it using generic
+XDP statistics infrastructure, not driver-defined Ethtool stats.
+It can be achieve by implementing `.ndo_get_xdp_stats` and, optionally but
+preferred, `.ndo_get_xdp_stats_nch`. There are several common helper structures
+and functions in `include/net/xdp.h` to make this simpler and keep the code
+compact.
+
 Statistics must persist across routine operations like bringing the interface
 down and up.
 

drivers/net/ethernet/amazon/ena/ena_netdev.c

@@ -3313,12 +3313,65 @@ static void ena_get_stats64(struct net_device *netdev,
 	stats->tx_errors = 0;
 }
 
+static int ena_get_xdp_stats_nch(const struct net_device *netdev, u32 attr_id)
+{
+	const struct ena_adapter *adapter = netdev_priv(netdev);
+
+	switch (attr_id) {
+	case IFLA_XDP_XSTATS_TYPE_XDP:
+		return adapter->num_io_queues;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ena_get_xdp_stats(const struct net_device *netdev, u32 attr_id,
+			     void *attr_data)
+{
+	const struct ena_adapter *adapter = netdev_priv(netdev);
+	struct ifla_xdp_stats *xdp_stats = attr_data;
+	u32 i;
+
+	switch (attr_id) {
+	case IFLA_XDP_XSTATS_TYPE_XDP:
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	for (i = 0; i < adapter->num_io_queues; i++) {
+		const struct u64_stats_sync *syncp;
+		const struct ena_stats_rx *stats;
+		u32 start;
+
+		stats = &adapter->rx_ring[i].rx_stats;
+		syncp = &adapter->rx_ring[i].syncp;
+
+		do {
+			start = u64_stats_fetch_begin_irq(syncp);
+
+			xdp_stats->drop = stats->xdp_drop;
+			xdp_stats->pass = stats->xdp_pass;
+			xdp_stats->tx = stats->xdp_tx;
+			xdp_stats->redirect = stats->xdp_redirect;
+			xdp_stats->aborted = stats->xdp_aborted;
+			xdp_stats->invalid = stats->xdp_invalid;
+		} while (u64_stats_fetch_retry_irq(syncp, start));
+
+		xdp_stats++;
+	}
+
+	return 0;
+}
+
 static const struct net_device_ops ena_netdev_ops = {
 	.ndo_open		= ena_open,
 	.ndo_stop		= ena_close,
 	.ndo_start_xmit		= ena_start_xmit,
 	.ndo_select_queue	= ena_select_queue,
 	.ndo_get_stats64	= ena_get_stats64,
+	.ndo_get_xdp_stats_nch	= ena_get_xdp_stats_nch,
+	.ndo_get_xdp_stats	= ena_get_xdp_stats,
 	.ndo_tx_timeout		= ena_tx_timeout,
 	.ndo_change_mtu		= ena_change_mtu,
 	.ndo_set_mac_address	= NULL,

drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c

@@ -1973,6 +1973,49 @@ static void dpaa2_eth_get_stats(struct net_device *net_dev,
 	}
 }
 
+static int dpaa2_eth_get_xdp_stats_nch(const struct net_device *net_dev,
+				       u32 attr_id)
+{
+	const struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
+
+	switch (attr_id) {
+	case IFLA_XDP_XSTATS_TYPE_XDP:
+		return priv->num_channels;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int dpaa2_eth_get_xdp_stats(const struct net_device *net_dev,
+				   u32 attr_id, void *attr_data)
+{
+	const struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
+	struct ifla_xdp_stats *xdp_stats = attr_data;
+	u32 i;
+
+	switch (attr_id) {
+	case IFLA_XDP_XSTATS_TYPE_XDP:
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	for (i = 0; i < priv->num_channels; i++) {
+		const struct dpaa2_eth_ch_stats *ch_stats;
+
+		ch_stats = &priv->channel[i]->stats;
+
+		xdp_stats->drop = ch_stats->xdp_drop;
+		xdp_stats->redirect = ch_stats->xdp_redirect;
+		xdp_stats->tx = ch_stats->xdp_tx;
+		xdp_stats->tx_errors = ch_stats->xdp_tx_err;
+
+		xdp_stats++;
+	}
+
+	return 0;
+}
+
 /* Copy mac unicast addresses from @net_dev to @priv.
  * Its sole purpose is to make dpaa2_eth_set_rx_mode() more readable.
  */
@@ -2601,6 +2644,8 @@ static const struct net_device_ops dpaa2_eth_ops = {
 	.ndo_stop = dpaa2_eth_stop,
 	.ndo_set_mac_address = dpaa2_eth_set_addr,
 	.ndo_get_stats64 = dpaa2_eth_get_stats,
+	.ndo_get_xdp_stats_nch = dpaa2_eth_get_xdp_stats_nch,
+	.ndo_get_xdp_stats = dpaa2_eth_get_xdp_stats,
 	.ndo_set_rx_mode = dpaa2_eth_set_rx_mode,
 	.ndo_set_features = dpaa2_eth_set_features,
 	.ndo_eth_ioctl = dpaa2_eth_ioctl,

drivers/net/ethernet/freescale/enetc/enetc.c

@@ -2575,6 +2575,54 @@ struct net_device_stats *enetc_get_stats(struct net_device *ndev)
 	return stats;
 }
 
+int enetc_get_xdp_stats_nch(const struct net_device *ndev, u32 attr_id)
+{
+	const struct enetc_ndev_priv *priv = netdev_priv(ndev);
+
+	switch (attr_id) {
+	case IFLA_XDP_XSTATS_TYPE_XDP:
+		return max(priv->num_rx_rings, priv->num_tx_rings);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+int enetc_get_xdp_stats(const struct net_device *ndev, u32 attr_id,
+			void *attr_data)
+{
+	struct ifla_xdp_stats *xdp_iter, *xdp_stats = attr_data;
+	const struct enetc_ndev_priv *priv = netdev_priv(ndev);
+	const struct enetc_ring_stats *stats;
+	u32 i;
+
+	switch (attr_id) {
+	case IFLA_XDP_XSTATS_TYPE_XDP:
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	for (i = 0; i < priv->num_tx_rings; i++) {
+		stats = &priv->tx_ring[i]->stats;
+		xdp_iter = xdp_stats + i;
+
+		xdp_iter->tx = stats->xdp_tx;
+		xdp_iter->tx_errors = stats->xdp_tx_drops;
+	}
+
+	for (i = 0; i < priv->num_rx_rings; i++) {
+		stats = &priv->rx_ring[i]->stats;
+		xdp_iter = xdp_stats + i;
+
+		xdp_iter->drop = stats->xdp_drops;
+		xdp_iter->redirect = stats->xdp_redirect;
+		xdp_iter->redirect_errors = stats->xdp_redirect_failures;
+		xdp_iter->redirect_errors += stats->xdp_redirect_sg;
+	}
+
+	return 0;
+}
+
 static int enetc_set_rss(struct net_device *ndev, int en)
 {
 	struct enetc_ndev_priv *priv = netdev_priv(ndev);

drivers/net/ethernet/freescale/enetc/enetc.h

@@ -389,6 +389,9 @@ void enetc_start(struct net_device *ndev);
 void enetc_stop(struct net_device *ndev);
 netdev_tx_t enetc_xmit(struct sk_buff *skb, struct net_device *ndev);
 struct net_device_stats *enetc_get_stats(struct net_device *ndev);
+int enetc_get_xdp_stats_nch(const struct net_device *ndev, u32 attr_id);
+int enetc_get_xdp_stats(const struct net_device *ndev, u32 attr_id,
+			void *attr_data);
 int enetc_set_features(struct net_device *ndev,
 		       netdev_features_t features);
 int enetc_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd);

drivers/net/ethernet/freescale/enetc/enetc_pf.c

@@ -729,6 +729,8 @@ static const struct net_device_ops enetc_ndev_ops = {
 	.ndo_stop		= enetc_close,
 	.ndo_start_xmit		= enetc_xmit,
 	.ndo_get_stats		= enetc_get_stats,
+	.ndo_get_xdp_stats_nch	= enetc_get_xdp_stats_nch,
+	.ndo_get_xdp_stats	= enetc_get_xdp_stats,
 	.ndo_set_mac_address	= enetc_pf_set_mac_addr,
 	.ndo_set_rx_mode	= enetc_pf_set_rx_mode,
 	.ndo_vlan_rx_add_vid	= enetc_vlan_rx_add_vid,

drivers/net/ethernet/intel/i40e/i40e.h

@@ -942,6 +942,7 @@ struct i40e_vsi {
 	irqreturn_t (*irq_handler)(int irq, void *data);
 
 	unsigned long *af_xdp_zc_qps; /* tracks AF_XDP ZC enabled qps */
+	struct xdp_drv_stats *xdp_stats; /* XDP/XSK stats array */
 } ____cacheline_internodealigned_in_smp;
 
 struct i40e_netdev_priv {

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -11087,7 +11087,7 @@ static int i40e_set_num_rings_in_vsi(struct i40e_vsi *vsi)
 static int i40e_vsi_alloc_arrays(struct i40e_vsi *vsi, bool alloc_qvectors)
 {
 	struct i40e_ring **next_rings;
-	int size;
+	int size, i;
 	int ret = 0;
 
 	/* allocate memory for both Tx, XDP Tx and Rx ring pointers */
@@ -11103,6 +11103,15 @@ static int i40e_vsi_alloc_arrays(struct i40e_vsi *vsi, bool alloc_qvectors)
 	}
 	vsi->rx_rings = next_rings;
 
+	vsi->xdp_stats = kcalloc(vsi->alloc_queue_pairs,
+				 sizeof(*vsi->xdp_stats),
+				 GFP_KERNEL);
+	if (!vsi->xdp_stats)
+		goto err_xdp_stats;
+
+	for (i = 0; i < vsi->alloc_queue_pairs; i++)
+		xdp_init_drv_stats(vsi->xdp_stats + i);
+
 	if (alloc_qvectors) {
 		/* allocate memory for q_vector pointers */
 		size = sizeof(struct i40e_q_vector *) * vsi->num_q_vectors;
@@ -11115,6 +11124,10 @@ static int i40e_vsi_alloc_arrays(struct i40e_vsi *vsi, bool alloc_qvectors)
 	return ret;
 
 err_vectors:
+	kfree(vsi->xdp_stats);
+	vsi->xdp_stats = NULL;
+
+err_xdp_stats:
 	kfree(vsi->tx_rings);
 	return ret;
 }
@@ -11225,6 +11238,10 @@ static void i40e_vsi_free_arrays(struct i40e_vsi *vsi, bool free_qvectors)
 		kfree(vsi->q_vectors);
 		vsi->q_vectors = NULL;
 	}
+
+	kfree(vsi->xdp_stats);
+	vsi->xdp_stats = NULL;
+
 	kfree(vsi->tx_rings);
 	vsi->tx_rings = NULL;
 	vsi->rx_rings = NULL;
@@ -11347,6 +11364,7 @@ static int i40e_alloc_rings(struct i40e_vsi *vsi)
 		if (vsi->back->hw_features & I40E_HW_WB_ON_ITR_CAPABLE)
 			ring->flags = I40E_TXR_FLAGS_WB_ON_ITR;
 		ring->itr_setting = pf->tx_itr_default;
+		ring->xdp_stats = vsi->xdp_stats + i;
 		WRITE_ONCE(vsi->tx_rings[i], ring++);
 
 		if (!i40e_enabled_xdp_vsi(vsi))
@@ -11365,6 +11383,7 @@ static int i40e_alloc_rings(struct i40e_vsi *vsi)
 			ring->flags = I40E_TXR_FLAGS_WB_ON_ITR;
 		set_ring_xdp(ring);
 		ring->itr_setting = pf->tx_itr_default;
+		ring->xdp_stats = vsi->xdp_stats + i;
 		WRITE_ONCE(vsi->xdp_rings[i], ring++);
 
 setup_rx:
@@ -11378,6 +11397,7 @@ static int i40e_alloc_rings(struct i40e_vsi *vsi)
 		ring->size = 0;
 		ring->dcb_tc = 0;
 		ring->itr_setting = pf->rx_itr_default;
+		ring->xdp_stats = vsi->xdp_stats + i;
 		WRITE_ONCE(vsi->rx_rings[i], ring);
 	}
 
@@ -13308,6 +13328,19 @@ static int i40e_xdp(struct net_device *dev,
 	}
 }
 
+static int i40e_get_xdp_stats_nch(const struct net_device *dev, u32 attr_id)
+{
+	const struct i40e_netdev_priv *np = netdev_priv(dev);
+
+	switch (attr_id) {
+	case IFLA_XDP_XSTATS_TYPE_XDP:
+	case IFLA_XDP_XSTATS_TYPE_XSK:
+		return np->vsi->alloc_queue_pairs;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static const struct net_device_ops i40e_netdev_ops = {
 	.ndo_open		= i40e_open,
 	.ndo_stop		= i40e_close,
@@ -13343,6 +13376,8 @@ static const struct net_device_ops i40e_netdev_ops = {
 	.ndo_bpf		= i40e_xdp,
 	.ndo_xdp_xmit		= i40e_xdp_xmit,
 	.ndo_xsk_wakeup	        = i40e_xsk_wakeup,
+	.ndo_get_xdp_stats_nch	= i40e_get_xdp_stats_nch,
+	.ndo_get_xdp_stats	= xdp_get_drv_stats_generic,
 	.ndo_dfwd_add_station	= i40e_fwd_add,
 	.ndo_dfwd_del_station	= i40e_fwd_del,
 };
@@ -13487,6 +13522,7 @@ static int i40e_config_netdev(struct i40e_vsi *vsi)
 	netdev->netdev_ops = &i40e_netdev_ops;
 	netdev->watchdog_timeo = 5 * HZ;
 	i40e_set_ethtool_ops(netdev);
+	netdev->xstats = vsi->xdp_stats;
 
 	/* MTU range: 68 - 9706 */
 	netdev->min_mtu = ETH_MIN_MTU;