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Commit 5dbe906f authored by Paul Blakey's avatar Paul Blakey Committed by Saeed Mahameed
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net/mlx5e: Use a slow path rule instead if vxlan neighbour isn't available 



When adding a vxlan tc rule, and a neighbour isn't available, we
don't insert any rule to hardware. Once we enable offloading flows
with multiple priorities, a packet that should have matched this rule
will continue in hardware pipeline and might match a wrong one.

This is unlike in tc software path where it will be matched and
forwarded to the vxlan device (which will cause a ARP lookup
eventually) and stop processing further tc filters.

To address that, when when a neighbour isn't available (EAGAIN from
attach_encap), or gets deleted, change the original action to be a
forward to slow path instead. Neighbour update will restore the original
action once the neighbour becomes available. This will be done atomically
so at any given time we will have a the correct match.

Signed-off-by: default avatarPaul Blakey <paulb@mellanox.com>
Reviewed-by: default avatarOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: default avatarSaeed Mahameed <saeedm@mellanox.com>
parent c92a0b94

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c

+82 −22
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ enum { 
	MLX5E_TC_FLOW_OFFLOADED	= BIT(MLX5E_TC_FLOW_BASE + 2),

	MLX5E_TC_FLOW_HAIRPIN	= BIT(MLX5E_TC_FLOW_BASE + 3),

	MLX5E_TC_FLOW_HAIRPIN_RSS = BIT(MLX5E_TC_FLOW_BASE + 4),

	MLX5E_TC_FLOW_SLOW	  = BIT(MLX5E_TC_FLOW_BASE + 5),

};



#define MLX5E_TC_MAX_SPLITS 1
@@ -82,7 +83,7 @@ struct mlx5e_tc_flow { 
	struct rhash_head	node;

	struct mlx5e_priv	*priv;

	u64			cookie;

	u8			flags;

	u16			flags;

	struct mlx5_flow_handle *rule[MLX5E_TC_MAX_SPLITS + 1];

	struct list_head	encap;   /* flows sharing the same encap ID */

	struct list_head	mod_hdr; /* flows sharing the same mod hdr ID */
@@ -860,6 +861,36 @@ mlx5e_tc_unoffload_fdb_rules(struct mlx5_eswitch *esw, 
	mlx5_eswitch_del_offloaded_rule(esw, flow->rule[0], attr);

}



static struct mlx5_flow_handle *

mlx5e_tc_offload_to_slow_path(struct mlx5_eswitch *esw,

			      struct mlx5e_tc_flow *flow,

			      struct mlx5_flow_spec *spec,

			      struct mlx5_esw_flow_attr *slow_attr)

{

	struct mlx5_flow_handle *rule;



	memcpy(slow_attr, flow->esw_attr, sizeof(*slow_attr));

	slow_attr->action = MLX5_FLOW_CONTEXT_ACTION_FWD_DEST,

	slow_attr->mirror_count = 0,

	slow_attr->dest_chain = FDB_SLOW_PATH_CHAIN,



	rule = mlx5e_tc_offload_fdb_rules(esw, flow, spec, slow_attr);

	if (!IS_ERR(rule))

		flow->flags |= MLX5E_TC_FLOW_SLOW;



	return rule;

}



static void

mlx5e_tc_unoffload_from_slow_path(struct mlx5_eswitch *esw,

				  struct mlx5e_tc_flow *flow,

				  struct mlx5_esw_flow_attr *slow_attr)

{

	memcpy(slow_attr, flow->esw_attr, sizeof(*slow_attr));

	mlx5e_tc_unoffload_fdb_rules(esw, flow, slow_attr);

	flow->flags &= ~MLX5E_TC_FLOW_SLOW;

}



static int

mlx5e_tc_add_fdb_flow(struct mlx5e_priv *priv,

		      struct mlx5e_tc_flow_parse_attr *parse_attr,
@@ -917,15 +948,21 @@ mlx5e_tc_add_fdb_flow(struct mlx5e_priv *priv, 
	/* we get here if (1) there's no error or when

	 * (2) there's an encap action and we're on -EAGAIN (no valid neigh)

	 */

	if (encap_err != -EAGAIN) {

	if (encap_err == -EAGAIN) {

		/* continue with goto slow path rule instead */

		struct mlx5_esw_flow_attr slow_attr;



		flow->rule[0] = mlx5e_tc_offload_to_slow_path(esw, flow, &parse_attr->spec, &slow_attr);

	} else {

		flow->rule[0] = mlx5e_tc_offload_fdb_rules(esw, flow, &parse_attr->spec, attr);

	}



	if (IS_ERR(flow->rule[0])) {

		err = PTR_ERR(flow->rule[0]);

		goto err_add_rule;

	}

	}



	return encap_err;

	return 0;



err_add_rule:

	mlx5_fc_destroy(esw->dev, counter);
@@ -946,9 +983,14 @@ static void mlx5e_tc_del_fdb_flow(struct mlx5e_priv *priv, 
{

	struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;

	struct mlx5_esw_flow_attr *attr = flow->esw_attr;

	struct mlx5_esw_flow_attr slow_attr;



	if (flow->flags & MLX5E_TC_FLOW_OFFLOADED)

		mlx5e_tc_unoffload_fdb_rules(esw, flow, flow->esw_attr);

	if (flow->flags & MLX5E_TC_FLOW_OFFLOADED) {

		if (flow->flags & MLX5E_TC_FLOW_SLOW)

			mlx5e_tc_unoffload_from_slow_path(esw, flow, &slow_attr);

		else

			mlx5e_tc_unoffload_fdb_rules(esw, flow, attr);

	}



	mlx5_eswitch_del_vlan_action(esw, attr);
@@ -968,7 +1010,7 @@ void mlx5e_tc_encap_flows_add(struct mlx5e_priv *priv, 
			      struct mlx5e_encap_entry *e)

{

	struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;

	struct mlx5_esw_flow_attr *esw_attr;

	struct mlx5_esw_flow_attr slow_attr, *esw_attr;

	struct mlx5_flow_handle *rule;

	struct mlx5_flow_spec *spec;

	struct mlx5e_tc_flow *flow;
@@ -991,6 +1033,7 @@ void mlx5e_tc_encap_flows_add(struct mlx5e_priv *priv, 
		esw_attr->encap_id = e->encap_id;

		spec = &esw_attr->parse_attr->spec;



		/* update from slow path rule to encap rule */

		rule = mlx5e_tc_offload_fdb_rules(esw, flow, spec, esw_attr);

		if (IS_ERR(rule)) {

			err = PTR_ERR(rule);
@@ -998,6 +1041,9 @@ void mlx5e_tc_encap_flows_add(struct mlx5e_priv *priv, 
				       err);

			continue;

		}



		mlx5e_tc_unoffload_from_slow_path(esw, flow, &slow_attr);

		flow->flags |= MLX5E_TC_FLOW_OFFLOADED; /* was unset when slow path rule removed */

		flow->rule[0] = rule;

	}

}
@@ -1006,11 +1052,28 @@ void mlx5e_tc_encap_flows_del(struct mlx5e_priv *priv, 
			      struct mlx5e_encap_entry *e)

{

	struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;

	struct mlx5_esw_flow_attr slow_attr;

	struct mlx5_flow_handle *rule;

	struct mlx5_flow_spec *spec;

	struct mlx5e_tc_flow *flow;

	int err;



	list_for_each_entry(flow, &e->flows, encap) {

		if (flow->flags & MLX5E_TC_FLOW_OFFLOADED)

		spec = &flow->esw_attr->parse_attr->spec;



		/* update from encap rule to slow path rule */

		rule = mlx5e_tc_offload_to_slow_path(esw, flow, spec, &slow_attr);



		if (IS_ERR(rule)) {

			err = PTR_ERR(rule);

			mlx5_core_warn(priv->mdev, "Failed to update slow path (encap) flow, %d\n",

				       err);

			continue;

		}



		mlx5e_tc_unoffload_fdb_rules(esw, flow, flow->esw_attr);

		flow->flags |= MLX5E_TC_FLOW_OFFLOADED; /* was unset when fast path rule removed */

		flow->rule[0] = rule;

	}



	if (e->flags & MLX5_ENCAP_ENTRY_VALID) {
@@ -2888,9 +2951,9 @@ static int parse_tc_fdb_actions(struct mlx5e_priv *priv, struct tcf_exts *exts, 
	return 0;

}



static void get_flags(int flags, u8 *flow_flags)

static void get_flags(int flags, u16 *flow_flags)

{

	u8 __flow_flags = 0;

	u16 __flow_flags = 0;



	if (flags & MLX5E_TC_INGRESS)

		__flow_flags |= MLX5E_TC_FLOW_INGRESS;
@@ -2921,7 +2984,7 @@ static struct rhashtable *get_tc_ht(struct mlx5e_priv *priv) 


static int

mlx5e_alloc_flow(struct mlx5e_priv *priv, int attr_size,

		 struct tc_cls_flower_offload *f, u8 flow_flags,

		 struct tc_cls_flower_offload *f, u16 flow_flags,

		 struct mlx5e_tc_flow_parse_attr **__parse_attr,

		 struct mlx5e_tc_flow **__flow)

{
@@ -2958,7 +3021,7 @@ mlx5e_alloc_flow(struct mlx5e_priv *priv, int attr_size, 
static int

mlx5e_add_fdb_flow(struct mlx5e_priv *priv,

		   struct tc_cls_flower_offload *f,

		   u8 flow_flags,

		   u16 flow_flags,

		   struct mlx5e_tc_flow **__flow)

{

	struct netlink_ext_ack *extack = f->common.extack;
@@ -2978,12 +3041,9 @@ mlx5e_add_fdb_flow(struct mlx5e_priv *priv, 
		goto err_free;



	err = mlx5e_tc_add_fdb_flow(priv, parse_attr, flow, extack);

	if (err && err != -EAGAIN)

	if (err)

		goto err_free;



	if (!err)

		flow->flags |= MLX5E_TC_FLOW_OFFLOADED;



	if (!(flow->esw_attr->action &

	      MLX5_FLOW_CONTEXT_ACTION_PACKET_REFORMAT))

		kvfree(parse_attr);
@@ -3002,7 +3062,7 @@ mlx5e_add_fdb_flow(struct mlx5e_priv *priv, 
static int

mlx5e_add_nic_flow(struct mlx5e_priv *priv,

		   struct tc_cls_flower_offload *f,

		   u8 flow_flags,

		   u16 flow_flags,

		   struct mlx5e_tc_flow **__flow)

{

	struct netlink_ext_ack *extack = f->common.extack;
@@ -3045,7 +3105,7 @@ mlx5e_tc_add_flow(struct mlx5e_priv *priv, 
		  struct mlx5e_tc_flow **flow)

{

	struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;

	u8 flow_flags;

	u16 flow_flags;

	int err;



	get_flags(flags, &flow_flags);