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net/mlx5e: Support offloading TC NIC hairpin flows
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We refer to TC NIC rule that involves forwarding as "hairpin".

All hairpin rules from the current NIC device (called "func" in
the code) to a given NIC device ("peer") are steered into the
same hairpin RQ/SQ pair.

The hairpin pair is set on demand and removed when there are no
TC rules that need it.

Here's a TC rule that matches on icmp, does header re-write of the
dst mac and hairpin from RX/enp1s2f1 to TX/enp1s2f2 (enp1s2f1/2 are
two mlx5 devices):

tc filter add dev enp1s2f1 protocol ip parent ffff: prio 2
    flower skip_sw ip_proto icmp
     action pedit ex munge eth dst set 10:22:33:44:55:66 pipe
     action mirred egress redirect dev enp1s2f2

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
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Or Gerlitz authored and Saeed Mahameed committed Jan 9, 2018
1 parent 77ab67b commit 5c65c56
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Showing 2 changed files with 172 additions and 12 deletions.
1 change: 1 addition & 0 deletions drivers/net/ethernet/mellanox/mlx5/core/en.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -659,6 +659,7 @@ struct mlx5e_tc_table {
struct rhashtable ht;

DECLARE_HASHTABLE(mod_hdr_tbl, 8);
DECLARE_HASHTABLE(hairpin_tbl, 8);
};

struct mlx5e_vlan_table {
Expand Down
183 changes: 171 additions & 12 deletions drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -56,12 +56,14 @@ struct mlx5_nic_flow_attr {
u32 action;
u32 flow_tag;
u32 mod_hdr_id;
u32 hairpin_tirn;
};

enum {
MLX5E_TC_FLOW_ESWITCH = BIT(0),
MLX5E_TC_FLOW_NIC = BIT(1),
MLX5E_TC_FLOW_OFFLOADED = BIT(2),
MLX5E_TC_FLOW_HAIRPIN = BIT(3),
};

struct mlx5e_tc_flow {
Expand All @@ -71,6 +73,7 @@ struct mlx5e_tc_flow {
struct mlx5_flow_handle *rule;
struct list_head encap; /* flows sharing the same encap ID */
struct list_head mod_hdr; /* flows sharing the same mod hdr ID */
struct list_head hairpin; /* flows sharing the same hairpin */
union {
struct mlx5_esw_flow_attr esw_attr[0];
struct mlx5_nic_flow_attr nic_attr[0];
Expand Down Expand Up @@ -101,6 +104,17 @@ struct mlx5e_hairpin {
u32 tirn;
};

struct mlx5e_hairpin_entry {
/* a node of a hash table which keeps all the hairpin entries */
struct hlist_node hairpin_hlist;

/* flows sharing the same hairpin */
struct list_head flows;

int peer_ifindex;
struct mlx5e_hairpin *hp;
};

struct mod_hdr_key {
int num_actions;
void *actions;
Expand Down Expand Up @@ -319,14 +333,106 @@ static void mlx5e_hairpin_destroy(struct mlx5e_hairpin *hp)
kvfree(hp);
}

static struct mlx5e_hairpin_entry *mlx5e_hairpin_get(struct mlx5e_priv *priv,
int peer_ifindex)
{
struct mlx5e_hairpin_entry *hpe;

hash_for_each_possible(priv->fs.tc.hairpin_tbl, hpe,
hairpin_hlist, peer_ifindex) {
if (hpe->peer_ifindex == peer_ifindex)
return hpe;
}

return NULL;
}

static int mlx5e_hairpin_flow_add(struct mlx5e_priv *priv,
struct mlx5e_tc_flow *flow,
struct mlx5e_tc_flow_parse_attr *parse_attr)
{
int peer_ifindex = parse_attr->mirred_ifindex;
struct mlx5_hairpin_params params;
struct mlx5e_hairpin_entry *hpe;
struct mlx5e_hairpin *hp;
int err;

if (!MLX5_CAP_GEN(priv->mdev, hairpin)) {
netdev_warn(priv->netdev, "hairpin is not supported\n");
return -EOPNOTSUPP;
}

hpe = mlx5e_hairpin_get(priv, peer_ifindex);
if (hpe)
goto attach_flow;

hpe = kzalloc(sizeof(*hpe), GFP_KERNEL);
if (!hpe)
return -ENOMEM;

INIT_LIST_HEAD(&hpe->flows);
hpe->peer_ifindex = peer_ifindex;

params.log_data_size = 15;
params.log_data_size = min_t(u8, params.log_data_size,
MLX5_CAP_GEN(priv->mdev, log_max_hairpin_wq_data_sz));
params.log_data_size = max_t(u8, params.log_data_size,
MLX5_CAP_GEN(priv->mdev, log_min_hairpin_wq_data_sz));
params.q_counter = priv->q_counter;

hp = mlx5e_hairpin_create(priv, &params, peer_ifindex);
if (IS_ERR(hp)) {
err = PTR_ERR(hp);
goto create_hairpin_err;
}

netdev_dbg(priv->netdev, "add hairpin: tirn %x rqn %x peer %s sqn %x log data size %d\n",
hp->tirn, hp->pair->rqn, hp->pair->peer_mdev->priv.name,
hp->pair->sqn, params.log_data_size);

hpe->hp = hp;
hash_add(priv->fs.tc.hairpin_tbl, &hpe->hairpin_hlist, peer_ifindex);

attach_flow:
flow->nic_attr->hairpin_tirn = hpe->hp->tirn;
list_add(&flow->hairpin, &hpe->flows);
return 0;

create_hairpin_err:
kfree(hpe);
return err;
}

static void mlx5e_hairpin_flow_del(struct mlx5e_priv *priv,
struct mlx5e_tc_flow *flow)
{
struct list_head *next = flow->hairpin.next;

list_del(&flow->hairpin);

/* no more hairpin flows for us, release the hairpin pair */
if (list_empty(next)) {
struct mlx5e_hairpin_entry *hpe;

hpe = list_entry(next, struct mlx5e_hairpin_entry, flows);

netdev_dbg(priv->netdev, "del hairpin: peer %s\n",
hpe->hp->pair->peer_mdev->priv.name);

mlx5e_hairpin_destroy(hpe->hp);
hash_del(&hpe->hairpin_hlist);
kfree(hpe);
}
}

static struct mlx5_flow_handle *
mlx5e_tc_add_nic_flow(struct mlx5e_priv *priv,
struct mlx5e_tc_flow_parse_attr *parse_attr,
struct mlx5e_tc_flow *flow)
{
struct mlx5_nic_flow_attr *attr = flow->nic_attr;
struct mlx5_core_dev *dev = priv->mdev;
struct mlx5_flow_destination dest = {};
struct mlx5_flow_destination dest[2] = {};
struct mlx5_flow_act flow_act = {
.action = attr->action,
.flow_tag = attr->flow_tag,
Expand All @@ -335,18 +441,33 @@ mlx5e_tc_add_nic_flow(struct mlx5e_priv *priv,
struct mlx5_fc *counter = NULL;
struct mlx5_flow_handle *rule;
bool table_created = false;
int err;
int err, dest_ix = 0;

if (attr->action & MLX5_FLOW_CONTEXT_ACTION_FWD_DEST) {
dest.type = MLX5_FLOW_DESTINATION_TYPE_FLOW_TABLE;
dest.ft = priv->fs.vlan.ft.t;
} else if (attr->action & MLX5_FLOW_CONTEXT_ACTION_COUNT) {
counter = mlx5_fc_create(dev, true);
if (IS_ERR(counter))
return ERR_CAST(counter);
if (flow->flags & MLX5E_TC_FLOW_HAIRPIN) {
err = mlx5e_hairpin_flow_add(priv, flow, parse_attr);
if (err) {
rule = ERR_PTR(err);
goto err_add_hairpin_flow;
}
dest[dest_ix].type = MLX5_FLOW_DESTINATION_TYPE_TIR;
dest[dest_ix].tir_num = attr->hairpin_tirn;
} else {
dest[dest_ix].type = MLX5_FLOW_DESTINATION_TYPE_FLOW_TABLE;
dest[dest_ix].ft = priv->fs.vlan.ft.t;
}
dest_ix++;
}

dest.type = MLX5_FLOW_DESTINATION_TYPE_COUNTER;
dest.counter = counter;
if (attr->action & MLX5_FLOW_CONTEXT_ACTION_COUNT) {
counter = mlx5_fc_create(dev, true);
if (IS_ERR(counter)) {
rule = ERR_CAST(counter);
goto err_fc_create;
}
dest[dest_ix].type = MLX5_FLOW_DESTINATION_TYPE_COUNTER;
dest[dest_ix].counter = counter;
dest_ix++;
}

if (attr->action & MLX5_FLOW_CONTEXT_ACTION_MOD_HDR) {
Expand Down Expand Up @@ -389,7 +510,7 @@ mlx5e_tc_add_nic_flow(struct mlx5e_priv *priv,

parse_attr->spec.match_criteria_enable = MLX5_MATCH_OUTER_HEADERS;
rule = mlx5_add_flow_rules(priv->fs.tc.t, &parse_attr->spec,
&flow_act, &dest, 1);
&flow_act, dest, dest_ix);

if (IS_ERR(rule))
goto err_add_rule;
Expand All @@ -406,7 +527,10 @@ mlx5e_tc_add_nic_flow(struct mlx5e_priv *priv,
mlx5e_detach_mod_hdr(priv, flow);
err_create_mod_hdr_id:
mlx5_fc_destroy(dev, counter);

err_fc_create:
if (flow->flags & MLX5E_TC_FLOW_HAIRPIN)
mlx5e_hairpin_flow_del(priv, flow);
err_add_hairpin_flow:
return rule;
}

Expand All @@ -427,6 +551,9 @@ static void mlx5e_tc_del_nic_flow(struct mlx5e_priv *priv,

if (attr->action & MLX5_FLOW_CONTEXT_ACTION_MOD_HDR)
mlx5e_detach_mod_hdr(priv, flow);

if (flow->flags & MLX5E_TC_FLOW_HAIRPIN)
mlx5e_hairpin_flow_del(priv, flow);
}

static void mlx5e_detach_encap(struct mlx5e_priv *priv,
Expand Down Expand Up @@ -1519,6 +1646,20 @@ static bool actions_match_supported(struct mlx5e_priv *priv,
return true;
}

static bool same_hw_devs(struct mlx5e_priv *priv, struct mlx5e_priv *peer_priv)
{
struct mlx5_core_dev *fmdev, *pmdev;
u16 func_id, peer_id;

fmdev = priv->mdev;
pmdev = peer_priv->mdev;

func_id = (u16)((fmdev->pdev->bus->number << 8) | PCI_SLOT(fmdev->pdev->devfn));
peer_id = (u16)((pmdev->pdev->bus->number << 8) | PCI_SLOT(pmdev->pdev->devfn));

return (func_id == peer_id);
}

static int parse_tc_nic_actions(struct mlx5e_priv *priv, struct tcf_exts *exts,
struct mlx5e_tc_flow_parse_attr *parse_attr,
struct mlx5e_tc_flow *flow)
Expand Down Expand Up @@ -1563,6 +1704,23 @@ static int parse_tc_nic_actions(struct mlx5e_priv *priv, struct tcf_exts *exts,
return -EOPNOTSUPP;
}

if (is_tcf_mirred_egress_redirect(a)) {
struct net_device *peer_dev = tcf_mirred_dev(a);

if (priv->netdev->netdev_ops == peer_dev->netdev_ops &&
same_hw_devs(priv, netdev_priv(peer_dev))) {
parse_attr->mirred_ifindex = peer_dev->ifindex;
flow->flags |= MLX5E_TC_FLOW_HAIRPIN;
attr->action |= MLX5_FLOW_CONTEXT_ACTION_FWD_DEST |
MLX5_FLOW_CONTEXT_ACTION_COUNT;
} else {
netdev_warn(priv->netdev, "device %s not on same HW, can't offload\n",
peer_dev->name);
return -EINVAL;
}
continue;
}

if (is_tcf_skbedit_mark(a)) {
u32 mark = tcf_skbedit_mark(a);

Expand Down Expand Up @@ -2285,6 +2443,7 @@ int mlx5e_tc_init(struct mlx5e_priv *priv)
struct mlx5e_tc_table *tc = &priv->fs.tc;

hash_init(tc->mod_hdr_tbl);
hash_init(tc->hairpin_tbl);

tc->ht_params = mlx5e_tc_flow_ht_params;
return rhashtable_init(&tc->ht, &tc->ht_params);
Expand Down

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