Subject: [net V2 3/9] net/mlx5: E-switch, Change flow rule destination checking

From: Saeed Mahameed <[email-masked]>
Date: Fri, 1 Mar 2024 23:03:12 -0800

From: Jianbo Liu <[email-masked]>

The checking in the cited commit is not accurate. In the common case,
VF destination is internal, and uplink destination is external.
However, uplink destination with packet reformat is considered as
internal because firmware uses LB+hairpin to support it. Update the
checking so header rewrite rules with both internal and external
destinations are not allowed.

Fixes: e0e22d59b47a ("net/mlx5: E-switch, Add checking for flow rule destinations")
Signed-off-by: Jianbo Liu <[email-masked]>
Reviewed-by: Rahul Rameshbabu <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 .../mellanox/mlx5/core/eswitch_offloads.c     | 23 +++++++++++--------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
index 14b3bd3c5e2f..baaae628b0a0 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
@@ -535,21 +535,26 @@ esw_src_port_rewrite_supported(struct mlx5_eswitch *esw)
 }
 
 static bool
-esw_dests_to_vf_pf_vports(struct mlx5_flow_destination *dests, int max_dest)
+esw_dests_to_int_external(struct mlx5_flow_destination *dests, int max_dest)
 {
-	bool vf_dest = false, pf_dest = false;
+	bool internal_dest = false, external_dest = false;
 	int i;
 
 	for (i = 0; i < max_dest; i++) {
-		if (dests[i].type != MLX5_FLOW_DESTINATION_TYPE_VPORT)
+		if (dests[i].type != MLX5_FLOW_DESTINATION_TYPE_VPORT &&
+		    dests[i].type != MLX5_FLOW_DESTINATION_TYPE_UPLINK)
 			continue;
 
-		if (dests[i].vport.num == MLX5_VPORT_UPLINK)
-			pf_dest = true;
+		/* Uplink dest is external, but considered as internal
+		 * if there is reformat because firmware uses LB+hairpin to support it.
+		 */
+		if (dests[i].vport.num == MLX5_VPORT_UPLINK &&
+		    !(dests[i].vport.flags & MLX5_FLOW_DEST_VPORT_REFORMAT_ID))
+			external_dest = true;
 		else
-			vf_dest = true;
+			internal_dest = true;
 
-		if (vf_dest && pf_dest)
+		if (internal_dest && external_dest)
 			return true;
 	}
 
@@ -695,9 +700,9 @@ mlx5_eswitch_add_offloaded_rule(struct mlx5_eswitch *esw,
 
 		/* Header rewrite with combined wire+loopback in FDB is not allowed */
 		if ((flow_act.action & MLX5_FLOW_CONTEXT_ACTION_MOD_HDR) &&
-		    esw_dests_to_vf_pf_vports(dest, i)) {
+		    esw_dests_to_int_external(dest, i)) {
 			esw_warn(esw->dev,
-				 "FDB: Header rewrite with forwarding to both PF and VF is not allowed\n");
+				 "FDB: Header rewrite with forwarding to both internal and external dests is not allowed\n");
 			rule = ERR_PTR(-EINVAL);
 			goto err_esw_get;
 		}
-- 
2.44.0