vdpa/mlx5: Add RX counters to debugfs

For each interface, either VLAN tagged or untagged, add two hardware
counters: one for unicast and another for multicast. The counters count
RX packets and bytes and can be read through debugfs:

$ cat /sys/kernel/debug/mlx5/mlx5_core.sf.1/vdpa-0/rx/untagged/mcast/packets
$ cat /sys/kernel/debug/mlx5/mlx5_core.sf.1/vdpa-0/rx/untagged/ucast/bytes

This feature is controlled via the config option
MLX5_VDPA_STEERING_DEBUG. It is off by default as it may have some
impact on performance.

includes a fixup By Yang Yingliang <yangyingliang@huawei.com>:

vdpa/mlx5: fix check wrong pointer in mlx5_vdpa_add_mac_vlan_rules()

The local variable 'rule' is not used anymore, fix return value
check after calling mlx5_add_flow_rules().
Signed-off-by: Eli Cohen <elic@nvidia.com>
Message-Id: <20221114131759.57883-9-elic@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Message-Id: <20230104074418.1737510-1-yangyingliang@huawei.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Eli Cohen <elic@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>

drivers/vdpa/Kconfig

@@ -71,6 +71,18 @@ config MLX5_VDPA_NET
 	  be executed by the hardware. It also supports a variety of stateless
 	  offloads depending on the actual device used and firmware version.
 
+config MLX5_VDPA_STEERING_DEBUG
+	bool "expose steering counters on debugfs"
+	select MLX5_VDPA
+	help
+	  Expose RX steering counters in debugfs to aid in debugging. For each VLAN
+	  or non VLAN interface, two hardware counters are added to the RX flow
+	  table: one for unicast and one for multicast.
+	  The counters counts the number of packets and bytes and exposes them in
+	  debugfs. Once can read the counters using, e.g.:
+	  cat /sys/kernel/debug/mlx5/mlx5_core.sf.1/vdpa-0/rx/untagged/ucast/packets
+	  cat /sys/kernel/debug/mlx5/mlx5_core.sf.1/vdpa-0/rx/untagged/mcast/bytes
+
 config VP_VDPA
 	tristate "Virtio PCI bridge vDPA driver"
 	select VIRTIO_PCI_LIB

drivers/vdpa/mlx5/net/debug.c

@@ -49,6 +49,92 @@ void mlx5_vdpa_add_rx_flow_table(struct mlx5_vdpa_net *ndev)
 						  ndev, &rx_flow_table_fops);
 }
 
+#if defined(CONFIG_MLX5_VDPA_STEERING_DEBUG)
+static int packets_show(struct seq_file *file, void *priv)
+{
+	struct mlx5_vdpa_counter *counter = file->private;
+	u64 packets;
+	u64 bytes;
+	int err;
+
+	err = mlx5_fc_query(counter->mdev, counter->counter, &packets, &bytes);
+	if (err)
+		return err;
+
+	seq_printf(file, "0x%llx\n", packets);
+	return 0;
+}
+
+static int bytes_show(struct seq_file *file, void *priv)
+{
+	struct mlx5_vdpa_counter *counter = file->private;
+	u64 packets;
+	u64 bytes;
+	int err;
+
+	err = mlx5_fc_query(counter->mdev, counter->counter, &packets, &bytes);
+	if (err)
+		return err;
+
+	seq_printf(file, "0x%llx\n", bytes);
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(packets);
+DEFINE_SHOW_ATTRIBUTE(bytes);
+
+static void add_counter_node(struct mlx5_vdpa_counter *counter,
+			     struct dentry *parent)
+{
+	debugfs_create_file("packets", 0444, parent, counter,
+			    &packets_fops);
+	debugfs_create_file("bytes", 0444, parent, counter,
+			    &bytes_fops);
+}
+
+void mlx5_vdpa_add_rx_counters(struct mlx5_vdpa_net *ndev,
+			       struct macvlan_node *node)
+{
+	static const char *ut = "untagged";
+	char vidstr[9];
+	u16 vid;
+
+	node->ucast_counter.mdev = ndev->mvdev.mdev;
+	node->mcast_counter.mdev = ndev->mvdev.mdev;
+	if (node->tagged) {
+		vid = key2vid(node->macvlan);
+		snprintf(vidstr, sizeof(vidstr), "0x%x", vid);
+	} else {
+		strcpy(vidstr, ut);
+	}
+
+	node->dent = debugfs_create_dir(vidstr, ndev->rx_dent);
+	if (IS_ERR(node->dent)) {
+		node->dent = NULL;
+		return;
+	}
+
+	node->ucast_counter.dent = debugfs_create_dir("ucast", node->dent);
+	if (IS_ERR(node->ucast_counter.dent))
+		return;
+
+	add_counter_node(&node->ucast_counter, node->ucast_counter.dent);
+
+	node->mcast_counter.dent = debugfs_create_dir("mcast", node->dent);
+	if (IS_ERR(node->mcast_counter.dent))
+		return;
+
+	add_counter_node(&node->mcast_counter, node->mcast_counter.dent);
+}
+
+void mlx5_vdpa_remove_rx_counters(struct mlx5_vdpa_net *ndev,
+				  struct macvlan_node *node)
+{
+	if (node->dent && ndev->debugfs)
+		debugfs_remove_recursive(node->dent);
+}
+#endif
+
 void mlx5_vdpa_add_debugfs(struct mlx5_vdpa_net *ndev)
 {
 	struct mlx5_core_dev *mdev;

drivers/vdpa/mlx5/net/mlx5_vnet.c

@@ -1404,25 +1404,69 @@ static void destroy_tir(struct mlx5_vdpa_net *ndev)
 #define MAX_STEERING_ENT 0x8000
 #define MAX_STEERING_GROUPS 2
 
+#if defined(CONFIG_MLX5_VDPA_STEERING_DEBUG)
+       #define NUM_DESTS 2
+#else
+       #define NUM_DESTS 1
+#endif
+
+static int add_steering_counters(struct mlx5_vdpa_net *ndev,
+				 struct macvlan_node *node,
+				 struct mlx5_flow_act *flow_act,
+				 struct mlx5_flow_destination *dests)
+{
+#if defined(CONFIG_MLX5_VDPA_STEERING_DEBUG)
+	int err;
+
+	node->ucast_counter.counter = mlx5_fc_create(ndev->mvdev.mdev, false);
+	if (IS_ERR(node->ucast_counter.counter))
+		return PTR_ERR(node->ucast_counter.counter);
+
+	node->mcast_counter.counter = mlx5_fc_create(ndev->mvdev.mdev, false);
+	if (IS_ERR(node->mcast_counter.counter)) {
+		err = PTR_ERR(node->mcast_counter.counter);
+		goto err_mcast_counter;
+	}
+
+	dests[1].type = MLX5_FLOW_DESTINATION_TYPE_COUNTER;
+	flow_act->action |= MLX5_FLOW_CONTEXT_ACTION_COUNT;
+	return 0;
+
+err_mcast_counter:
+	mlx5_fc_destroy(ndev->mvdev.mdev, node->ucast_counter.counter);
+	return err;
+#else
+	return 0;
+#endif
+}
+
+static void remove_steering_counters(struct mlx5_vdpa_net *ndev,
+				     struct macvlan_node *node)
+{
+#if defined(CONFIG_MLX5_VDPA_STEERING_DEBUG)
+	mlx5_fc_destroy(ndev->mvdev.mdev, node->mcast_counter.counter);
+	mlx5_fc_destroy(ndev->mvdev.mdev, node->ucast_counter.counter);
+#endif
+}
+
 static int mlx5_vdpa_add_mac_vlan_rules(struct mlx5_vdpa_net *ndev, u8 *mac,
-					u16 vid, bool tagged,
-					struct mlx5_flow_handle **ucast,
-					struct mlx5_flow_handle **mcast)
+					struct macvlan_node *node)
 {
-	struct mlx5_flow_destination dest = {};
+	struct mlx5_flow_destination dests[NUM_DESTS] = {};
 	struct mlx5_flow_act flow_act = {};
-	struct mlx5_flow_handle *rule;
 	struct mlx5_flow_spec *spec;
 	void *headers_c;
 	void *headers_v;
 	u8 *dmac_c;
 	u8 *dmac_v;
 	int err;
+	u16 vid;
 
 	spec = kvzalloc(sizeof(*spec), GFP_KERNEL);
 	if (!spec)
 		return -ENOMEM;
 
+	vid = key2vid(node->macvlan);
 	spec->match_criteria_enable = MLX5_MATCH_OUTER_HEADERS;
 	headers_c = MLX5_ADDR_OF(fte_match_param, spec->match_criteria, outer_headers);
 	headers_v = MLX5_ADDR_OF(fte_match_param, spec->match_value, outer_headers);
@@ -1434,44 +1478,58 @@ static int mlx5_vdpa_add_mac_vlan_rules(struct mlx5_vdpa_net *ndev, u8 *mac,
 		MLX5_SET(fte_match_set_lyr_2_4, headers_c, cvlan_tag, 1);
 		MLX5_SET_TO_ONES(fte_match_set_lyr_2_4, headers_c, first_vid);
 	}
-	if (tagged) {
+	if (node->tagged) {
 		MLX5_SET(fte_match_set_lyr_2_4, headers_v, cvlan_tag, 1);
 		MLX5_SET(fte_match_set_lyr_2_4, headers_v, first_vid, vid);
 	}
 	flow_act.action = MLX5_FLOW_CONTEXT_ACTION_FWD_DEST;
-	dest.type = MLX5_FLOW_DESTINATION_TYPE_TIR;
-	dest.tir_num = ndev->res.tirn;
-	rule = mlx5_add_flow_rules(ndev->rxft, spec, &flow_act, &dest, 1);
-	if (IS_ERR(rule))
-		return PTR_ERR(rule);
+	dests[0].type = MLX5_FLOW_DESTINATION_TYPE_TIR;
+	dests[0].tir_num = ndev->res.tirn;
+	err = add_steering_counters(ndev, node, &flow_act, dests);
+	if (err)
+		goto out_free;
 
-	*ucast = rule;
+#if defined(CONFIG_MLX5_VDPA_STEERING_DEBUG)
+	dests[1].counter_id = mlx5_fc_id(node->ucast_counter.counter);
+#endif
+	node->ucast_rule = mlx5_add_flow_rules(ndev->rxft, spec, &flow_act, dests, NUM_DESTS);
+	if (IS_ERR(node->ucast_rule)) {
+		err = PTR_ERR(node->ucast_rule);
+		goto err_ucast;
+	}
+
+#if defined(CONFIG_MLX5_VDPA_STEERING_DEBUG)
+	dests[1].counter_id = mlx5_fc_id(node->mcast_counter.counter);
+#endif
 
 	memset(dmac_c, 0, ETH_ALEN);
 	memset(dmac_v, 0, ETH_ALEN);
 	dmac_c[0] = 1;
 	dmac_v[0] = 1;
-	rule = mlx5_add_flow_rules(ndev->rxft, spec, &flow_act, &dest, 1);
-	kvfree(spec);
-	if (IS_ERR(rule)) {
-		err = PTR_ERR(rule);
+	node->mcast_rule = mlx5_add_flow_rules(ndev->rxft, spec, &flow_act, dests, NUM_DESTS);
+	if (IS_ERR(node->mcast_rule)) {
+		err = PTR_ERR(node->mcast_rule);
 		goto err_mcast;
 	}
-
-	*mcast = rule;
+	kvfree(spec);
+	mlx5_vdpa_add_rx_counters(ndev, node);
 	return 0;
 
 err_mcast:
-	mlx5_del_flow_rules(*ucast);
+	mlx5_del_flow_rules(node->ucast_rule);
+err_ucast:
+	remove_steering_counters(ndev, node);
+out_free:
+	kvfree(spec);
 	return err;
 }
 
 static void mlx5_vdpa_del_mac_vlan_rules(struct mlx5_vdpa_net *ndev,
-					 struct mlx5_flow_handle *ucast,
-					 struct mlx5_flow_handle *mcast)
+					 struct macvlan_node *node)
 {
-	mlx5_del_flow_rules(ucast);
-	mlx5_del_flow_rules(mcast);
+	mlx5_vdpa_remove_rx_counters(ndev, node);
+	mlx5_del_flow_rules(node->ucast_rule);
+	mlx5_del_flow_rules(node->mcast_rule);
 }
 
 static u64 search_val(u8 *mac, u16 vlan, bool tagged)
@@ -1505,14 +1563,14 @@ static struct macvlan_node *mac_vlan_lookup(struct mlx5_vdpa_net *ndev, u64 valu
 	return NULL;
 }
 
-static int mac_vlan_add(struct mlx5_vdpa_net *ndev, u8 *mac, u16 vlan, bool tagged) // vlan -> vid
+static int mac_vlan_add(struct mlx5_vdpa_net *ndev, u8 *mac, u16 vid, bool tagged)
 {
 	struct macvlan_node *ptr;
 	u64 val;
 	u32 idx;
 	int err;
 
-	val = search_val(mac, vlan, tagged);
+	val = search_val(mac, vid, tagged);
 	if (mac_vlan_lookup(ndev, val))
 		return -EEXIST;
 
@@ -1520,12 +1578,13 @@ static int mac_vlan_add(struct mlx5_vdpa_net *ndev, u8 *mac, u16 vlan, bool tagg
 	if (!ptr)
 		return -ENOMEM;
 
-	err = mlx5_vdpa_add_mac_vlan_rules(ndev, ndev->config.mac, vlan, tagged,
-					   &ptr->ucast_rule, &ptr->mcast_rule);
+	ptr->tagged = tagged;
+	ptr->macvlan = val;
+	ptr->ndev = ndev;
+	err = mlx5_vdpa_add_mac_vlan_rules(ndev, ndev->config.mac, ptr);
 	if (err)
 		goto err_add;
 
-	ptr->macvlan = val;
 	idx = hash_64(val, 8);
 	hlist_add_head(&ptr->hlist, &ndev->macvlan_hash[idx]);
 	return 0;
@@ -1544,7 +1603,8 @@ static void mac_vlan_del(struct mlx5_vdpa_net *ndev, u8 *mac, u16 vlan, bool tag
 		return;
 
 	hlist_del(&ptr->hlist);
-	mlx5_vdpa_del_mac_vlan_rules(ndev, ptr->ucast_rule, ptr->mcast_rule);
+	mlx5_vdpa_del_mac_vlan_rules(ndev, ptr);
+	remove_steering_counters(ndev, ptr);
 	kfree(ptr);
 }
 
@@ -1557,7 +1617,8 @@ static void clear_mac_vlan_table(struct mlx5_vdpa_net *ndev)
 	for (i = 0; i < MLX5V_MACVLAN_SIZE; i++) {
 		hlist_for_each_entry_safe(pos, n, &ndev->macvlan_hash[i], hlist) {
 			hlist_del(&pos->hlist);
-			mlx5_vdpa_del_mac_vlan_rules(ndev, pos->ucast_rule, pos->mcast_rule);
+			mlx5_vdpa_del_mac_vlan_rules(ndev, pos);
+			remove_steering_counters(ndev, pos);
 			kfree(pos);
 		}
 	}

drivers/vdpa/mlx5/net/mlx5_vnet.h

@@ -21,6 +21,11 @@ struct mlx5_vdpa_net_resources {
 
 #define MLX5V_MACVLAN_SIZE 256
 
+static inline u16 key2vid(u64 key)
+{
+	return (u16)(key >> 48) & 0xfff;
+}
+
 struct mlx5_vdpa_net {
 	struct mlx5_vdpa_dev mvdev;
 	struct mlx5_vdpa_net_resources res;
@@ -47,11 +52,24 @@ struct mlx5_vdpa_net {
 	struct dentry *debugfs;
 };
 
+struct mlx5_vdpa_counter {
+	struct mlx5_fc *counter;
+	struct dentry *dent;
+	struct mlx5_core_dev *mdev;
+};
+
 struct macvlan_node {
 	struct hlist_node hlist;
 	struct mlx5_flow_handle *ucast_rule;
 	struct mlx5_flow_handle *mcast_rule;
 	u64 macvlan;
+	struct mlx5_vdpa_net *ndev;
+	bool tagged;
+#if defined(CONFIG_MLX5_VDPA_STEERING_DEBUG)
+	struct dentry *dent;
+	struct mlx5_vdpa_counter ucast_counter;
+	struct mlx5_vdpa_counter mcast_counter;
+#endif
 };
 
 void mlx5_vdpa_add_debugfs(struct mlx5_vdpa_net *ndev);
@@ -60,5 +78,17 @@ void mlx5_vdpa_add_rx_flow_table(struct mlx5_vdpa_net *ndev);
 void mlx5_vdpa_remove_rx_flow_table(struct mlx5_vdpa_net *ndev);
 void mlx5_vdpa_add_tirn(struct mlx5_vdpa_net *ndev);
 void mlx5_vdpa_remove_tirn(struct mlx5_vdpa_net *ndev);
+#if defined(CONFIG_MLX5_VDPA_STEERING_DEBUG)
+void mlx5_vdpa_add_rx_counters(struct mlx5_vdpa_net *ndev,
+			       struct macvlan_node *node);
+void mlx5_vdpa_remove_rx_counters(struct mlx5_vdpa_net *ndev,
+				  struct macvlan_node *node);
+#else
+static inline void mlx5_vdpa_add_rx_counters(struct mlx5_vdpa_net *ndev,
+					     struct macvlan_node *node) {}
+static inline void mlx5_vdpa_remove_rx_counters(struct mlx5_vdpa_net *ndev,
+						struct macvlan_node *node) {}
+#endif
+
 
 #endif /* __MLX5_VNET_H__ */