[PATCH 4.10 011/111] net/mlx5: E-Switch, Dont allow changing inline mode when flows are configured

[Greg Kroah-Hartman]

4.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Roi Dayan <roid@xxxxxxxxxxxx>


[ Upstream commit 375f51e2b5b7b9a42b3139aea519cbb1bfc5d6ef ]

Changing the eswitch inline mode can potentially cause already configured
flows not to match the policy. E.g. set policy L4, add some L4 rules,
set policy to L2 --> bad! Hence we disallow it.

Keep track of how many offloaded rules are now set and refuse
inline mode changes if this isn't zero.

Fixes: bffaa916588e ("net/mlx5: E-Switch, Add control for inline mode")
Signed-off-by: Roi Dayan <roid@xxxxxxxxxxxx>
Reviewed-by: Or Gerlitz <ogerlitz@xxxxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlx5/core/eswitch.h          |    1 +
 drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c |    8 ++++++++
 2 files changed, 9 insertions(+)

--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
@@ -201,6 +201,7 @@ struct mlx5_esw_offload {
 	struct mlx5_eswitch_rep *vport_reps;
 	DECLARE_HASHTABLE(encap_tbl, 8);
 	u8 inline_mode;
+	u64 num_flows;
 };
 
 struct mlx5_eswitch {
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
@@ -93,6 +93,8 @@ mlx5_eswitch_add_offloaded_rule(struct m
 				   spec, &flow_act, dest, i);
 	if (IS_ERR(rule))
 		mlx5_fc_destroy(esw->dev, counter);
+	else
+		esw->offloads.num_flows++;
 
 	return rule;
 }
@@ -108,6 +110,7 @@ mlx5_eswitch_del_offloaded_rule(struct m
 		counter = mlx5_flow_rule_counter(rule);
 		mlx5_del_flow_rules(rule);
 		mlx5_fc_destroy(esw->dev, counter);
+		esw->offloads.num_flows--;
 	}
 }
 
@@ -919,6 +922,11 @@ int mlx5_devlink_eswitch_inline_mode_set
 	    MLX5_CAP_INLINE_MODE_VPORT_CONTEXT)
 		return -EOPNOTSUPP;
 
+	if (esw->offloads.num_flows > 0) {
+		esw_warn(dev, "Can't set inline mode when flows are configured\n");
+		return -EOPNOTSUPP;
+	}
+
 	err = esw_inline_mode_from_devlink(mode, &mlx5_mode);
 	if (err)
 		goto out;