net/mlx5: Correctly compare pkt reformat ids

struct mlx5_pkt_reformat contains a naked union of a u32 id and a
dr_action pointer which is used when the action is SW-managed (when
pkt_reformat.owner is set to MLX5_FLOW_RESOURCE_OWNER_SW). Using id
directly in that case is incorrect, as it maps to the least significant
32 bits of the 64-bit pointer in mlx5_fs_dr_action and not to the pkt
reformat id allocated in firmware.

For the purpose of comparing whether two rules are identical,
interpreting the least significant 32 bits of the mlx5_fs_dr_action
pointer as an id mostly works... until it breaks horribly and produces
the outcome described in [1].

This patch fixes mlx5_flow_dests_cmp to correctly compare ids using
mlx5_fs_dr_action_get_pkt_reformat_id for the SW-managed rules.

Link: https://lore.kernel.org/netdev/ea5264d6-6b55-4449-a602-214c6f509c1e@163.com/T/#u
Fixes: 6a48faeeca10 ("net/mlx5: Add direct rule fs_cmd implementation")
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/20240409190820.227554-6-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
index 2a9421342a50342f8f1cb5784cbb73cfc47f122d..cf085a478e3e4c69ffdd4ee9bb24f0036e27c66d 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
@@ -1664,6 +1664,16 @@ static int create_auto_flow_group(struct mlx5_flow_table *ft,
        return err;
 }
 
+static bool mlx5_pkt_reformat_cmp(struct mlx5_pkt_reformat *p1,
+                                 struct mlx5_pkt_reformat *p2)
+{
+       return p1->owner == p2->owner &&
+               (p1->owner == MLX5_FLOW_RESOURCE_OWNER_FW ?
+                p1->id == p2->id :
+                mlx5_fs_dr_action_get_pkt_reformat_id(p1) ==
+                mlx5_fs_dr_action_get_pkt_reformat_id(p2));
+}
+
 static bool mlx5_flow_dests_cmp(struct mlx5_flow_destination *d1,
                                struct mlx5_flow_destination *d2)
 {
@@ -1675,8 +1685,8 @@ static bool mlx5_flow_dests_cmp(struct mlx5_flow_destination *d1,
                     ((d1->vport.flags & MLX5_FLOW_DEST_VPORT_VHCA_ID) ?
                      (d1->vport.vhca_id == d2->vport.vhca_id) : true) &&
                     ((d1->vport.flags & MLX5_FLOW_DEST_VPORT_REFORMAT_ID) ?
-                     (d1->vport.pkt_reformat->id ==
-                      d2->vport.pkt_reformat->id) : true)) ||
+                     mlx5_pkt_reformat_cmp(d1->vport.pkt_reformat,
+                                           d2->vport.pkt_reformat) : true)) ||
                    (d1->type == MLX5_FLOW_DESTINATION_TYPE_FLOW_TABLE &&
                     d1->ft == d2->ft) ||
                    (d1->type == MLX5_FLOW_DESTINATION_TYPE_TIR &&