[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 <r...@mellanox.com>


[ 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 <r...@mellanox.com>
Reviewed-by: Or Gerlitz <ogerl...@mellanox.com>
Signed-off-by: Saeed Mahameed <sae...@mellanox.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 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;