From 53110232c95ff56067fd96c75a1a1c53d10dcd98 Mon Sep 17 00:00:00 2001 From: Cosmin Ratiu Date: Sun, 26 Oct 2025 22:20:19 +0200 Subject: [PATCH] net/mlx5: Don't zero user_count when destroying FDB tables esw->user_count tracks how many TC rules are added on an esw via mlx5e_configure_flower -> mlx5_esw_get -> atomic64_inc(&esw->user_count) esw.user_count was unconditionally set to 0 in esw_destroy_legacy_fdb_table and esw_destroy_offloads_fdb_tables. These two together can lead to the following sequence of events: 1. echo 1 > /sys/class/net/eth2/device/sriov_numvfs - mlx5_core_sriov_configure -...-> esw_create_legacy_table -> atomic64_set(&esw->user_count, 0) 2. tc qdisc add dev eth2 ingress && \ tc filter replace dev eth2 pref 1 protocol ip chain 0 ingress \ handle 1 flower action ct nat zone 64000 pipe - mlx5e_configure_flower -> mlx5_esw_get -> atomic64_inc(&esw->user_count) 3. echo 0 > /sys/class/net/eth2/device/sriov_numvfs - mlx5_core_sriov_configure -..-> esw_destroy_legacy_fdb_table -> atomic64_set(&esw->user_count, 0) 4. devlink dev eswitch set pci/0000:08:00.0 mode switchdev - mlx5_devlink_eswitch_mode_set -> mlx5_esw_try_lock -> atomic64_read(&esw->user_count) == 0 - then proceed to a WARN_ON in: esw_offloads_start -> mlx5_eswitch_enable_locke -> esw_offloads_enable -> mlx5_esw_offloads_rep_load -> mlx5e_vport_rep_load -> mlx5e_netdev_change_profile -> mlx5e_detach_netdev -> mlx5e_cleanup_nic_rx -> mlx5e_tc_nic_cleanup -> mlx5e_mod_hdr_tbl_destroy Fix this by not clearing out the user_count when destroying FDB tables, so that the check in mlx5_esw_try_lock can prevent the mode change when there are TC rules configured, as originally intended. Fixes: 2318b8bb94a3 ("net/mlx5: E-switch, Destroy legacy fdb table when needed") Signed-off-by: Cosmin Ratiu Reviewed-by: Dragos Tatulea Signed-off-by: Tariq Toukan Reviewed-by: Simon Horman Link: https://patch.msgid.link/1761510019-938772-1-git-send-email-tariqt@nvidia.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/mellanox/mlx5/core/esw/legacy.c | 1 - drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c | 1 - 2 files changed, 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/legacy.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/legacy.c index 76382626ad41d..929adeb50a98a 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/esw/legacy.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/legacy.c @@ -66,7 +66,6 @@ static void esw_destroy_legacy_fdb_table(struct mlx5_eswitch *esw) esw->fdb_table.legacy.addr_grp = NULL; esw->fdb_table.legacy.allmulti_grp = NULL; esw->fdb_table.legacy.promisc_grp = NULL; - atomic64_set(&esw->user_count, 0); } static int esw_create_legacy_fdb_table(struct mlx5_eswitch *esw) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c index 34749814f19b8..44a142a041b2f 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c @@ -1978,7 +1978,6 @@ static void esw_destroy_offloads_fdb_tables(struct mlx5_eswitch *esw) /* Holds true only as long as DMFS is the default */ mlx5_flow_namespace_set_mode(esw->fdb_table.offloads.ns, MLX5_FLOW_STEERING_MODE_DMFS); - atomic64_set(&esw->user_count, 0); } static int esw_get_nr_ft_offloads_steering_src_ports(struct mlx5_eswitch *esw) -- 2.47.3