[PATCH net-next v3 4/4] net/mlx5e: Return -EOPNOTSUPP when attempting to offload an unsupported action

[xiangxia . m . yue]

From: Tonghao Zhang <xiangxia.m....@gmail.com>

* Now the encapsulation is not supported for mlx5 VFs. When we try to
offload that action, the -EINVAL is returned, but not -EOPNOTSUPP.
This patch changes the returned value and ignore to confuse user.
The command is shown as below [1].

* When max modify header action is zero, we return -EOPNOTSUPP
directly. In this way, we can ignore wrong message info (e.g.
"mlx5: parsed 0 pedit actions, can't do more"). This happens when
offloading pedit actions on mlx(cx4) VFs. The command is shown as below [2].

For example: (p2p1_0 is VF net device)
[1]
$ tc filter add dev p2p1_0 protocol ip  parent ffff: prio 1 flower skip_sw \
    src_mac e4:11:22:33:44:01    \
    action tunnel_key set        \
    src_ip 1.1.1.100        \
    dst_ip 1.1.1.200        \
    dst_port 4789 id 100        \
    action mirred egress redirect dev vxlan0

[2]
$ tc filter add dev p2p1_0 parent ffff: protocol ip prio 1 \
    flower skip_sw dst_mac 00:10:56:fb:64:e8 \
    dst_ip 1.1.1.100 src_ip 1.1.1.200 \
    action pedit ex munge eth src set 00:10:56:b4:5d:20

Signed-off-by: Tonghao Zhang <xiangxia.m....@gmail.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c 
b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 56ac50d..3a02b22 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -2035,7 +2035,7 @@ static int parse_tc_pedit_action(struct mlx5e_priv *priv,
                                 struct netlink_ext_ack *extack)
 {
        u8 cmd = (act->id == FLOW_ACTION_MANGLE) ? 0 : 1;
-       int err = -EOPNOTSUPP;
+       int max_actions, err = -EOPNOTSUPP;
        u32 mask, val, offset;
        u8 htype;
 
@@ -2047,6 +2047,17 @@ static int parse_tc_pedit_action(struct mlx5e_priv *priv,
                goto out_err;
        }
 
+        if (namespace == MLX5_FLOW_NAMESPACE_FDB) /* FDB offloading */
+                max_actions = MLX5_CAP_ESW_FLOWTABLE_FDB(priv->mdev, 
max_modify_header_actions);
+        else /* namespace is MLX5_FLOW_NAMESPACE_KERNEL - NIC offloading */
+                max_actions = MLX5_CAP_FLOWTABLE_NIC_RX(priv->mdev, 
max_modify_header_actions);
+
+       if (!max_actions) {
+               NL_SET_ERR_MSG_MOD(extack,
+                                  "don't support pedit actions, can't 
offload");
+               goto out_err;
+       }
+
        mask = act->mangle.mask;
        val = act->mangle.val;
        offset = act->mangle.offset;
@@ -2294,7 +2305,8 @@ static int parse_tc_nic_actions(struct mlx5e_priv *priv,
                        }
                        break;
                default:
-                       return -EINVAL;
+                       NL_SET_ERR_MSG_MOD(extack, "The offload action is not 
supported");
+                       return -EOPNOTSUPP;
                }
        }
 
@@ -2616,7 +2628,8 @@ static int parse_tc_fdb_actions(struct mlx5e_priv *priv,
                        break;
                        }
                default:
-                       return -EINVAL;
+                       NL_SET_ERR_MSG_MOD(extack, "The offload action is not 
supported");
+                       return -EOPNOTSUPP;
                }
        }
 
-- 
1.8.3.1