[PATCH 5.11 143/210] net/mlx5e: Fix mapping of ct_label zero

Greg Kroah-Hartman
2021-04-12T09:43:37Z

From: Ariel Levkovich <lariel@nvidia.com>

[ Upstream commit d24f847e54214049814b9515771622eaab3f42ab ]

ct_label 0 is a default label each flow has and therefore
there can be rules that match on ct_label=0 without a prior
rule that set the ct_label to this value.

The ct_label value is not used directly in the HW rules and
instead it is mapped to some id within a defined range and this
id is used to set and match the metadata register which carries
the ct_label.

If we have a rule that matches on ct_label=0, the hw rule will
perform matching on a value that is != 0 because of the mapping
from label to id. Since the metadata register default value is
0 and it was never set before to anything else by an action that
sets the ct_label, there will always be a mismatch between that
register and the value in the rule.

To support such rule, a forced mapping of ct_label 0 to id=0
is done so that it will match the metadata register default
value of 0.

Fixes: 54b154ecfb8c ("net/mlx5e: CT: Map 128 bits labels to 32 bit map ID")
Signed-off-by: Ariel Levkovich <lariel@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../ethernet/mellanox/mlx5/core/en/tc_ct.c | 36 +++++++++++++++----
1 file changed, 29 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
index b42396df3111..0469f53dfb99 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
@@ -184,6 +184,28 @@ mlx5_tc_ct_entry_has_nat(struct mlx5_ct_entry *entry)
return !!(entry->tuple_nat_node.next);
}

+static int
+mlx5_get_label_mapping(struct mlx5_tc_ct_priv *ct_priv,
+ u32 *labels, u32 *id)
+{
+ if (!memchr_inv(labels, 0, sizeof(u32) * 4)) {
+ *id = 0;
+ return 0;
+ }
+
+ if (mapping_add(ct_priv->labels_mapping, labels, id))
+ return -EOPNOTSUPP;
+
+ return 0;
+}
+
+static void
+mlx5_put_label_mapping(struct mlx5_tc_ct_priv *ct_priv, u32 id)
+{
+ if (id)
+ mapping_remove(ct_priv->labels_mapping, id);
+}
+
static int
mlx5_tc_ct_rule_to_tuple(struct mlx5_ct_tuple *tuple, struct flow_rule *rule)
{
@@ -435,7 +457,7 @@ mlx5_tc_ct_entry_del_rule(struct mlx5_tc_ct_priv *ct_priv,
mlx5_tc_rule_delete(netdev_priv(ct_priv->netdev), zone_rule->rule, attr);
mlx5e_mod_hdr_detach(ct_priv->dev,
ct_priv->mod_hdr_tbl, zone_rule->mh);
- mapping_remove(ct_priv->labels_mapping, attr->ct_attr.ct_labels_id);
+ mlx5_put_label_mapping(ct_priv, attr->ct_attr.ct_labels_id);
kfree(attr);
}

@@ -638,8 +660,8 @@ mlx5_tc_ct_entry_create_mod_hdr(struct mlx5_tc_ct_priv *ct_priv,
if (!meta)
return -EOPNOTSUPP;

- err = mapping_add(ct_priv->labels_mapping, meta->ct_metadata.labels,
- &attr->ct_attr.ct_labels_id);
+ err = mlx5_get_label_mapping(ct_priv, meta->ct_metadata.labels,
+ &attr->ct_attr.ct_labels_id);
if (err)
return -EOPNOTSUPP;
if (nat) {
@@ -675,7 +697,7 @@ mlx5_tc_ct_entry_create_mod_hdr(struct mlx5_tc_ct_priv *ct_priv,

err_mapping:
dealloc_mod_hdr_actions(&mod_acts);
- mapping_remove(ct_priv->labels_mapping, attr->ct_attr.ct_labels_id);
+ mlx5_put_label_mapping(ct_priv, attr->ct_attr.ct_labels_id);
return err;
}

@@ -743,7 +765,7 @@ mlx5_tc_ct_entry_add_rule(struct mlx5_tc_ct_priv *ct_priv,
err_rule:
mlx5e_mod_hdr_detach(ct_priv->dev,
ct_priv->mod_hdr_tbl, zone_rule->mh);
- mapping_remove(ct_priv->labels_mapping, attr->ct_attr.ct_labels_id);
+ mlx5_put_label_mapping(ct_priv, attr->ct_attr.ct_labels_id);
err_mod_hdr:
kfree(attr);
err_attr:
@@ -1198,7 +1220,7 @@ void mlx5_tc_ct_match_del(struct mlx5_tc_ct_priv *priv, struct mlx5_ct_attr *ct_
if (!priv || !ct_attr->ct_labels_id)
return;

- mapping_remove(priv->labels_mapping, ct_attr->ct_labels_id);
+ mlx5_put_label_mapping(priv, ct_attr->ct_labels_id);
}

int
@@ -1276,7 +1298,7 @@ mlx5_tc_ct_match_add(struct mlx5_tc_ct_priv *priv,
ct_labels[1] = key->ct_labels[1] & mask->ct_labels[1];
ct_labels[2] = key->ct_labels[2] & mask->ct_labels[2];
ct_labels[3] = key->ct_labels[3] & mask->ct_labels[3];
- if (mapping_add(priv->labels_mapping, ct_labels, &ct_attr->ct_labels_id))
+ if (mlx5_get_label_mapping(priv, ct_labels, &ct_attr->ct_labels_id))
return -EOPNOTSUPP;
mlx5e_tc_match_to_reg_match(spec, LABELS_TO_REG, ct_attr->ct_labels_id,
MLX5_CT_LABELS_MASK);
--
2.30.2