team: lb: introduce infrastructure for userspace driven tx loadbalancing

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/team/team_mode_loadbalance.c

@@ -17,18 +17,163 @@
 #include <linux/filter.h>
 #include <linux/if_team.h>
 
+struct lb_priv;
+
+typedef struct team_port *lb_select_tx_port_func_t(struct team *,
+						   struct lb_priv *,
+						   struct sk_buff *,
+						   unsigned char);
+
+#define LB_TX_HASHTABLE_SIZE 256 /* hash is a char */
+
+struct lb_stats {
+	u64 tx_bytes;
+};
+
+struct lb_pcpu_stats {
+	struct lb_stats hash_stats[LB_TX_HASHTABLE_SIZE];
+	struct u64_stats_sync syncp;
+};
+
+struct lb_stats_info {
+	struct lb_stats stats;
+	struct lb_stats last_stats;
+	struct team_option_inst_info *opt_inst_info;
+};
+
+struct lb_port_mapping {
+	struct team_port __rcu *port;
+	struct team_option_inst_info *opt_inst_info;
+};
+
+struct lb_priv_ex {
+	struct team *team;
+	struct lb_port_mapping tx_hash_to_port_mapping[LB_TX_HASHTABLE_SIZE];
+	struct sock_fprog *orig_fprog;
+	struct {
+		unsigned int refresh_interval; /* in tenths of second */
+		struct delayed_work refresh_dw;
+		struct lb_stats_info info[LB_TX_HASHTABLE_SIZE];
+	} stats;
+};
+
 struct lb_priv {
 	struct sk_filter __rcu *fp;
-	struct sock_fprog *orig_fprog;
+	lb_select_tx_port_func_t __rcu *select_tx_port_func;
+	struct lb_pcpu_stats __percpu *pcpu_stats;
+	struct lb_priv_ex *ex; /* priv extension */
 };
 
-static struct lb_priv *lb_priv(struct team *team)
+static struct lb_priv *get_lb_priv(struct team *team)
 {
 	return (struct lb_priv *) &team->mode_priv;
 }
 
-static unsigned char lb_get_skb_hash(struct lb_priv *lb_priv,
-				     struct sk_buff *skb)
+struct lb_port_priv {
+	struct lb_stats __percpu *pcpu_stats;
+	struct lb_stats_info stats_info;
+};
+
+static struct lb_port_priv *get_lb_port_priv(struct team_port *port)
+{
+	return (struct lb_port_priv *) &port->mode_priv;
+}
+
+#define LB_HTPM_PORT_BY_HASH(lp_priv, hash) \
+	(lb_priv)->ex->tx_hash_to_port_mapping[hash].port
+
+#define LB_HTPM_OPT_INST_INFO_BY_HASH(lp_priv, hash) \
+	(lb_priv)->ex->tx_hash_to_port_mapping[hash].opt_inst_info
+
+static void lb_tx_hash_to_port_mapping_null_port(struct team *team,
+						 struct team_port *port)
+{
+	struct lb_priv *lb_priv = get_lb_priv(team);
+	bool changed = false;
+	int i;
+
+	for (i = 0; i < LB_TX_HASHTABLE_SIZE; i++) {
+		struct lb_port_mapping *pm;
+
+		pm = &lb_priv->ex->tx_hash_to_port_mapping[i];
+		if (pm->port == port) {
+			rcu_assign_pointer(pm->port, NULL);
+			team_option_inst_set_change(pm->opt_inst_info);
+			changed = true;
+		}
+	}
+	if (changed)
+		team_options_change_check(team);
+}
+
+/* Basic tx selection based solely by hash */
+static struct team_port *lb_hash_select_tx_port(struct team *team,
+						struct lb_priv *lb_priv,
+						struct sk_buff *skb,
+						unsigned char hash)
+{
+	int port_index;
+
+	port_index = hash % team->en_port_count;
+	return team_get_port_by_index_rcu(team, port_index);
+}
+
+/* Hash to port mapping select tx port */
+static struct team_port *lb_htpm_select_tx_port(struct team *team,
+						struct lb_priv *lb_priv,
+						struct sk_buff *skb,
+						unsigned char hash)
+{
+	return rcu_dereference(LB_HTPM_PORT_BY_HASH(lb_priv, hash));
+}
+
+struct lb_select_tx_port {
+	char *name;
+	lb_select_tx_port_func_t *func;
+};
+
+static const struct lb_select_tx_port lb_select_tx_port_list[] = {
+	{
+		.name = "hash",
+		.func = lb_hash_select_tx_port,
+	},
+	{
+		.name = "hash_to_port_mapping",
+		.func = lb_htpm_select_tx_port,
+	},
+};
+#define LB_SELECT_TX_PORT_LIST_COUNT ARRAY_SIZE(lb_select_tx_port_list)
+
+static char *lb_select_tx_port_get_name(lb_select_tx_port_func_t *func)
+{
+	int i;
+
+	for (i = 0; i < LB_SELECT_TX_PORT_LIST_COUNT; i++) {
+		const struct lb_select_tx_port *item;
+
+		item = &lb_select_tx_port_list[i];
+		if (item->func == func)
+			return item->name;
+	}
+	return NULL;
+}
+
+static lb_select_tx_port_func_t *lb_select_tx_port_get_func(const char *name)
+{
+	int i;
+
+	for (i = 0; i < LB_SELECT_TX_PORT_LIST_COUNT; i++) {
+		const struct lb_select_tx_port *item;
+
+		item = &lb_select_tx_port_list[i];
+		if (!strcmp(item->name, name))
+			return item->func;
+	}
+	return NULL;
+}
+
+static unsigned int lb_get_skb_hash(struct lb_priv *lb_priv,
+				    struct sk_buff *skb)
 {
 	struct sk_filter *fp;
 	uint32_t lhash;
@@ -42,18 +187,40 @@ static unsigned char lb_get_skb_hash(struct lb_priv *lb_priv,
 	return c[0] ^ c[1] ^ c[2] ^ c[3];
 }
 
+static void lb_update_tx_stats(unsigned int tx_bytes, struct lb_priv *lb_priv,
+			       struct lb_port_priv *lb_port_priv,
+			       unsigned char hash)
+{
+	struct lb_pcpu_stats *pcpu_stats;
+	struct lb_stats *port_stats;
+	struct lb_stats *hash_stats;
+
+	pcpu_stats = this_cpu_ptr(lb_priv->pcpu_stats);
+	port_stats = this_cpu_ptr(lb_port_priv->pcpu_stats);
+	hash_stats = &pcpu_stats->hash_stats[hash];
+	u64_stats_update_begin(&pcpu_stats->syncp);
+	port_stats->tx_bytes += tx_bytes;
+	hash_stats->tx_bytes += tx_bytes;
+	u64_stats_update_end(&pcpu_stats->syncp);
+}
+
 static bool lb_transmit(struct team *team, struct sk_buff *skb)
 {
+	struct lb_priv *lb_priv = get_lb_priv(team);
+	lb_select_tx_port_func_t *select_tx_port_func;
 	struct team_port *port;
-	int port_index;
+	unsigned char hash;
+	unsigned int tx_bytes = skb->len;
 
-	port_index = lb_get_skb_hash(lb_priv(team), skb) % team->en_port_count;
-	port = team_get_port_by_index_rcu(team, port_index);
+	hash = lb_get_skb_hash(lb_priv, skb);
+	select_tx_port_func = rcu_dereference(lb_priv->select_tx_port_func);
+	port = select_tx_port_func(team, lb_priv, skb, hash);
 	if (unlikely(!port))
 		goto drop;
 	skb->dev = port->dev;
 	if (dev_queue_xmit(skb))
 		return false;
+	lb_update_tx_stats(tx_bytes, lb_priv, get_lb_port_priv(port), hash);
 	return true;
 
 drop:
@@ -63,14 +230,16 @@ static bool lb_transmit(struct team *team, struct sk_buff *skb)
 
 static int lb_bpf_func_get(struct team *team, struct team_gsetter_ctx *ctx)
 {
-	if (!lb_priv(team)->orig_fprog) {
+	struct lb_priv *lb_priv = get_lb_priv(team);
+
+	if (!lb_priv->ex->orig_fprog) {
 		ctx->data.bin_val.len = 0;
 		ctx->data.bin_val.ptr = NULL;
 		return 0;
 	}
-	ctx->data.bin_val.len = lb_priv(team)->orig_fprog->len *
+	ctx->data.bin_val.len = lb_priv->ex->orig_fprog->len *
 				sizeof(struct sock_filter);
-	ctx->data.bin_val.ptr = lb_priv(team)->orig_fprog->filter;
+	ctx->data.bin_val.ptr = lb_priv->ex->orig_fprog->filter;
 	return 0;
 }
 
@@ -103,6 +272,7 @@ static void __fprog_destroy(struct sock_fprog *fprog)
 
 static int lb_bpf_func_set(struct team *team, struct team_gsetter_ctx *ctx)
 {
+	struct lb_priv *lb_priv = get_lb_priv(team);
 	struct sk_filter *fp = NULL;
 	struct sock_fprog *fprog = NULL;
 	int err;
@@ -119,14 +289,232 @@ static int lb_bpf_func_set(struct team *team, struct team_gsetter_ctx *ctx)
 		}
 	}
 
-	if (lb_priv(team)->orig_fprog) {
+	if (lb_priv->ex->orig_fprog) {
 		/* Clear old filter data */
-		__fprog_destroy(lb_priv(team)->orig_fprog);
-		sk_unattached_filter_destroy(lb_priv(team)->fp);
+		__fprog_destroy(lb_priv->ex->orig_fprog);
+		sk_unattached_filter_destroy(lb_priv->fp);
 	}
 
-	rcu_assign_pointer(lb_priv(team)->fp, fp);
-	lb_priv(team)->orig_fprog = fprog;
+	rcu_assign_pointer(lb_priv->fp, fp);
+	lb_priv->ex->orig_fprog = fprog;
+	return 0;
+}
+
+static int lb_tx_method_get(struct team *team, struct team_gsetter_ctx *ctx)
+{
+	struct lb_priv *lb_priv = get_lb_priv(team);
+	char *name;
+
+	name = lb_select_tx_port_get_name(lb_priv->select_tx_port_func);
+	BUG_ON(!name);
+	ctx->data.str_val = name;
+	return 0;
+}
+
+static int lb_tx_method_set(struct team *team, struct team_gsetter_ctx *ctx)
+{
+	struct lb_priv *lb_priv = get_lb_priv(team);
+	lb_select_tx_port_func_t *func;
+
+	func = lb_select_tx_port_get_func(ctx->data.str_val);
+	if (!func)
+		return -EINVAL;
+	rcu_assign_pointer(lb_priv->select_tx_port_func, func);
+	return 0;
+}
+
+static int lb_tx_hash_to_port_mapping_init(struct team *team,
+					   struct team_option_inst_info *info)
+{
+	struct lb_priv *lb_priv = get_lb_priv(team);
+	unsigned char hash = info->array_index;
+
+	LB_HTPM_OPT_INST_INFO_BY_HASH(lb_priv, hash) = info;
+	return 0;
+}
+
+static int lb_tx_hash_to_port_mapping_get(struct team *team,
+					  struct team_gsetter_ctx *ctx)
+{
+	struct lb_priv *lb_priv = get_lb_priv(team);
+	struct team_port *port;
+	unsigned char hash = ctx->info->array_index;
+
+	port = LB_HTPM_PORT_BY_HASH(lb_priv, hash);
+	ctx->data.u32_val = port ? port->dev->ifindex : 0;
+	return 0;
+}
+
+static int lb_tx_hash_to_port_mapping_set(struct team *team,
+					  struct team_gsetter_ctx *ctx)
+{
+	struct lb_priv *lb_priv = get_lb_priv(team);
+	struct team_port *port;
+	unsigned char hash = ctx->info->array_index;
+
+	list_for_each_entry(port, &team->port_list, list) {
+		if (ctx->data.u32_val == port->dev->ifindex) {
+			rcu_assign_pointer(LB_HTPM_PORT_BY_HASH(lb_priv, hash),
+					   port);
+			return 0;
+		}
+	}
+	return -ENODEV;
+}
+
+static int lb_hash_stats_init(struct team *team,
+			      struct team_option_inst_info *info)
+{
+	struct lb_priv *lb_priv = get_lb_priv(team);
+	unsigned char hash = info->array_index;
+
+	lb_priv->ex->stats.info[hash].opt_inst_info = info;
+	return 0;
+}
+
+static int lb_hash_stats_get(struct team *team, struct team_gsetter_ctx *ctx)
+{
+	struct lb_priv *lb_priv = get_lb_priv(team);
+	unsigned char hash = ctx->info->array_index;
+
+	ctx->data.bin_val.ptr = &lb_priv->ex->stats.info[hash].stats;
+	ctx->data.bin_val.len = sizeof(struct lb_stats);
+	return 0;
+}
+
+static int lb_port_stats_init(struct team *team,
+			      struct team_option_inst_info *info)
+{
+	struct team_port *port = info->port;
+	struct lb_port_priv *lb_port_priv = get_lb_port_priv(port);
+
+	lb_port_priv->stats_info.opt_inst_info = info;
+	return 0;
+}
+
+static int lb_port_stats_get(struct team *team, struct team_gsetter_ctx *ctx)
+{
+	struct team_port *port = ctx->info->port;
+	struct lb_port_priv *lb_port_priv = get_lb_port_priv(port);
+
+	ctx->data.bin_val.ptr = &lb_port_priv->stats_info.stats;
+	ctx->data.bin_val.len = sizeof(struct lb_stats);
+	return 0;
+}
+
+static void __lb_stats_info_refresh_prepare(struct lb_stats_info *s_info)
+{
+	memcpy(&s_info->last_stats, &s_info->stats, sizeof(struct lb_stats));
+	memset(&s_info->stats, 0, sizeof(struct lb_stats));
+}
+
+static bool __lb_stats_info_refresh_check(struct lb_stats_info *s_info,
+					  struct team *team)
+{
+	if (memcmp(&s_info->last_stats, &s_info->stats,
+	    sizeof(struct lb_stats))) {
+		team_option_inst_set_change(s_info->opt_inst_info);
+		return true;
+	}
+	return false;
+}
+
+static void __lb_one_cpu_stats_add(struct lb_stats *acc_stats,
+				   struct lb_stats *cpu_stats,
+				   struct u64_stats_sync *syncp)
+{
+	unsigned int start;
+	struct lb_stats tmp;
+
+	do {
+		start = u64_stats_fetch_begin_bh(syncp);
+		tmp.tx_bytes = cpu_stats->tx_bytes;
+	} while (u64_stats_fetch_retry_bh(syncp, start));
+	acc_stats->tx_bytes += tmp.tx_bytes;
+}
+
+static void lb_stats_refresh(struct work_struct *work)
+{
+	struct team *team;
+	struct lb_priv *lb_priv;
+	struct lb_priv_ex *lb_priv_ex;
+	struct lb_pcpu_stats *pcpu_stats;
+	struct lb_stats *stats;
+	struct lb_stats_info *s_info;
+	struct team_port *port;
+	bool changed = false;
+	int i;
+	int j;
+
+	lb_priv_ex = container_of(work, struct lb_priv_ex,
+				  stats.refresh_dw.work);
+
+	team = lb_priv_ex->team;
+	lb_priv = get_lb_priv(team);
+
+	if (!mutex_trylock(&team->lock)) {
+		schedule_delayed_work(&lb_priv_ex->stats.refresh_dw, 0);
+		return;
+	}
+
+	for (j = 0; j < LB_TX_HASHTABLE_SIZE; j++) {
+		s_info = &lb_priv->ex->stats.info[j];
+		__lb_stats_info_refresh_prepare(s_info);
+		for_each_possible_cpu(i) {
+			pcpu_stats = per_cpu_ptr(lb_priv->pcpu_stats, i);
+			stats = &pcpu_stats->hash_stats[j];
+			__lb_one_cpu_stats_add(&s_info->stats, stats,
+					       &pcpu_stats->syncp);
+		}
+		changed |= __lb_stats_info_refresh_check(s_info, team);
+	}
+
+	list_for_each_entry(port, &team->port_list, list) {
+		struct lb_port_priv *lb_port_priv = get_lb_port_priv(port);
+
+		s_info = &lb_port_priv->stats_info;
+		__lb_stats_info_refresh_prepare(s_info);
+		for_each_possible_cpu(i) {
+			pcpu_stats = per_cpu_ptr(lb_priv->pcpu_stats, i);
+			stats = per_cpu_ptr(lb_port_priv->pcpu_stats, i);
+			__lb_one_cpu_stats_add(&s_info->stats, stats,
+					       &pcpu_stats->syncp);
+		}
+		changed |= __lb_stats_info_refresh_check(s_info, team);
+	}
+
+	if (changed)
+		team_options_change_check(team);
+
+	schedule_delayed_work(&lb_priv_ex->stats.refresh_dw,
+			      (lb_priv_ex->stats.refresh_interval * HZ) / 10);
+
+	mutex_unlock(&team->lock);
+}
+
+static int lb_stats_refresh_interval_get(struct team *team,
+					 struct team_gsetter_ctx *ctx)
+{
+	struct lb_priv *lb_priv = get_lb_priv(team);
+
+	ctx->data.u32_val = lb_priv->ex->stats.refresh_interval;
+	return 0;
+}
+
+static int lb_stats_refresh_interval_set(struct team *team,
+					 struct team_gsetter_ctx *ctx)
+{
+	struct lb_priv *lb_priv = get_lb_priv(team);
+	unsigned int interval;
+
+	interval = ctx->data.u32_val;
+	if (lb_priv->ex->stats.refresh_interval == interval)
+		return 0;
+	lb_priv->ex->stats.refresh_interval = interval;
+	if (interval)
+		schedule_delayed_work(&lb_priv->ex->stats.refresh_dw, 0);
+	else
+		cancel_delayed_work(&lb_priv->ex->stats.refresh_dw);
 	return 0;
 }
 
@@ -137,23 +525,117 @@ static const struct team_option lb_options[] = {
 		.getter = lb_bpf_func_get,
 		.setter = lb_bpf_func_set,
 	},
+	{
+		.name = "lb_tx_method",
+		.type = TEAM_OPTION_TYPE_STRING,
+		.getter = lb_tx_method_get,
+		.setter = lb_tx_method_set,
+	},
+	{
+		.name = "lb_tx_hash_to_port_mapping",
+		.array_size = LB_TX_HASHTABLE_SIZE,
+		.type = TEAM_OPTION_TYPE_U32,
+		.init = lb_tx_hash_to_port_mapping_init,
+		.getter = lb_tx_hash_to_port_mapping_get,
+		.setter = lb_tx_hash_to_port_mapping_set,
+	},
+	{
+		.name = "lb_hash_stats",
+		.array_size = LB_TX_HASHTABLE_SIZE,
+		.type = TEAM_OPTION_TYPE_BINARY,
+		.init = lb_hash_stats_init,
+		.getter = lb_hash_stats_get,
+	},
+	{
+		.name = "lb_port_stats",
+		.per_port = true,
+		.type = TEAM_OPTION_TYPE_BINARY,
+		.init = lb_port_stats_init,
+		.getter = lb_port_stats_get,
+	},
+	{
+		.name = "lb_stats_refresh_interval",
+		.type = TEAM_OPTION_TYPE_U32,
+		.getter = lb_stats_refresh_interval_get,
+		.setter = lb_stats_refresh_interval_set,
+	},
 };
 
 static int lb_init(struct team *team)
 {
-	return team_options_register(team, lb_options,
-				     ARRAY_SIZE(lb_options));
+	struct lb_priv *lb_priv = get_lb_priv(team);
+	lb_select_tx_port_func_t *func;
+	int err;
+
+	/* set default tx port selector */
+	func = lb_select_tx_port_get_func("hash");
+	BUG_ON(!func);
+	rcu_assign_pointer(lb_priv->select_tx_port_func, func);
+
+	lb_priv->ex = kzalloc(sizeof(*lb_priv->ex), GFP_KERNEL);
+	if (!lb_priv->ex)
+		return -ENOMEM;
+	lb_priv->ex->team = team;
+
+	lb_priv->pcpu_stats = alloc_percpu(struct lb_pcpu_stats);
+	if (!lb_priv->pcpu_stats) {
+		err = -ENOMEM;
+		goto err_alloc_pcpu_stats;
+	}
+
+	INIT_DELAYED_WORK(&lb_priv->ex->stats.refresh_dw, lb_stats_refresh);
+
+	err = team_options_register(team, lb_options, ARRAY_SIZE(lb_options));
+	if (err)
+		goto err_options_register;
+	return 0;
+
+err_options_register:
+	free_percpu(lb_priv->pcpu_stats);
+err_alloc_pcpu_stats:
+	kfree(lb_priv->ex);
+	return err;
 }
 
 static void lb_exit(struct team *team)
 {
+	struct lb_priv *lb_priv = get_lb_priv(team);
+
 	team_options_unregister(team, lb_options,
 				ARRAY_SIZE(lb_options));
+	cancel_delayed_work_sync(&lb_priv->ex->stats.refresh_dw);
+	free_percpu(lb_priv->pcpu_stats);
+	kfree(lb_priv->ex);
+}
+
+static int lb_port_enter(struct team *team, struct team_port *port)
+{
+	struct lb_port_priv *lb_port_priv = get_lb_port_priv(port);
+
+	lb_port_priv->pcpu_stats = alloc_percpu(struct lb_stats);
+	if (!lb_port_priv->pcpu_stats)
+		return -ENOMEM;
+	return 0;
+}
+
+static void lb_port_leave(struct team *team, struct team_port *port)
+{
+	struct lb_port_priv *lb_port_priv = get_lb_port_priv(port);
+
+	free_percpu(lb_port_priv->pcpu_stats);
+}
+
+static void lb_port_disabled(struct team *team, struct team_port *port)
+{
+	lb_tx_hash_to_port_mapping_null_port(team, port);
 }
 
 static const struct team_mode_ops lb_mode_ops = {
 	.init			= lb_init,
 	.exit			= lb_exit,
+	.port_enter		= lb_port_enter,
+	.port_leave		= lb_port_leave,
+	.port_disabled		= lb_port_disabled,
 	.transmit		= lb_transmit,
 };
 
@@ -161,6 +643,7 @@ static const struct team_mode lb_mode = {
 	.kind		= "loadbalance",
 	.owner		= THIS_MODULE,
 	.priv_size	= sizeof(struct lb_priv),
+	.port_priv_size	= sizeof(struct lb_port_priv),
 	.ops		= &lb_mode_ops,
 };