[PATCH net-next v4 10/11] net/mlx5e: Support ethtool tcp-data-split settings

Mark Bloch
2025-06-10T15:12:07Z

From: Saeed Mahameed <saeedm@nvidia.com>

In mlx5, tcp header-data split requires HW GRO to be on.

Enabling it fails when HW GRO is off.
mlx5e_fix_features now keeps HW GRO on when tcp data split is enabled.
Finally, when tcp data split is disabled, features are updated to maybe
remove the forced HW GRO.

Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
---
.../ethernet/mellanox/mlx5/core/en_ethtool.c | 33 ++++++++++++++++---
.../net/ethernet/mellanox/mlx5/core/en_main.c | 8 +++++
2 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
index ea078c9f5d15..21005cc4eb06 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
@@ -32,6 +32,7 @@

#include <linux/dim.h>
#include <linux/ethtool_netlink.h>
+#include <net/netdev_queues.h>

#include "en.h"
#include "en/channels.h"
@@ -366,11 +367,6 @@ void mlx5e_ethtool_get_ringparam(struct mlx5e_priv *priv,
param->tx_max_pending = 1 << MLX5E_PARAMS_MAXIMUM_LOG_SQ_SIZE;
param->rx_pending = 1 << priv->channels.params.log_rq_mtu_frames;
param->tx_pending = 1 << priv->channels.params.log_sq_size;
-
- kernel_param->tcp_data_split =
- (priv->channels.params.packet_merge.type == MLX5E_PACKET_MERGE_SHAMPO) ?
- ETHTOOL_TCP_DATA_SPLIT_ENABLED :
- ETHTOOL_TCP_DATA_SPLIT_DISABLED;
}

static void mlx5e_get_ringparam(struct net_device *dev,
@@ -383,6 +379,27 @@ static void mlx5e_get_ringparam(struct net_device *dev,
mlx5e_ethtool_get_ringparam(priv, param, kernel_param);
}

+static bool mlx5e_ethtool_set_tcp_data_split(struct mlx5e_priv *priv,
+ u8 tcp_data_split,
+ struct netlink_ext_ack *extack)
+{
+ struct net_device *dev = priv->netdev;
+
+ if (tcp_data_split == ETHTOOL_TCP_DATA_SPLIT_ENABLED &&
+ !(dev->features & NETIF_F_GRO_HW)) {
+ NL_SET_ERR_MSG(extack,
+ "TCP-data-split is not supported when GRO HW is disabled\n");
+ return false; /* GRO HW is not enabled */
+ }
+
+ /* Might need to disable HW-GRO if it was kept on due to hds. */
+ if (tcp_data_split == ETHTOOL_TCP_DATA_SPLIT_DISABLED &&
+ dev->cfg->hds_config == ETHTOOL_TCP_DATA_SPLIT_ENABLED)
+ netdev_update_features(priv->netdev);
+
+ return true;
+}
+
int mlx5e_ethtool_set_ringparam(struct mlx5e_priv *priv,
struct ethtool_ringparam *param,
struct netlink_ext_ack *extack)
@@ -441,6 +458,11 @@ static int mlx5e_set_ringparam(struct net_device *dev,
{
struct mlx5e_priv *priv = netdev_priv(dev);

+ if (!mlx5e_ethtool_set_tcp_data_split(priv,
+ kernel_param->tcp_data_split,
+ extack))
+ return -EINVAL;
+
return mlx5e_ethtool_set_ringparam(priv, param, extack);
}

@@ -2625,6 +2647,7 @@ const struct ethtool_ops mlx5e_ethtool_ops = {
ETHTOOL_COALESCE_USE_ADAPTIVE |
ETHTOOL_COALESCE_USE_CQE,
.supported_input_xfrm = RXH_XFRM_SYM_OR_XOR,
+ .supported_ring_params = ETHTOOL_RING_USE_TCP_DATA_SPLIT,
.get_drvinfo = mlx5e_get_drvinfo,
.get_link = ethtool_op_get_link,
.get_link_ext_state = mlx5e_get_link_ext_state,
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 90687392545c..026bd479c6dd 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -4413,6 +4413,7 @@ static netdev_features_t mlx5e_fix_uplink_rep_features(struct net_device *netdev
static netdev_features_t mlx5e_fix_features(struct net_device *netdev,
netdev_features_t features)
{
+ struct netdev_config *cfg = netdev->cfg_pending;
struct mlx5e_priv *priv = netdev_priv(netdev);
struct mlx5e_vlan_table *vlan;
struct mlx5e_params *params;
@@ -4479,6 +4480,13 @@ static netdev_features_t mlx5e_fix_features(struct net_device *netdev,
}
}

+ /* The header-data split ring param requires HW GRO to stay enabled. */
+ if (cfg && cfg->hds_config == ETHTOOL_TCP_DATA_SPLIT_ENABLED &&
+ !(features & NETIF_F_GRO_HW)) {
+ netdev_warn(netdev, "Keeping HW-GRO enabled, TCP header-data split depends on it\n");
+ features |= NETIF_F_GRO_HW;
+ }
+
if (mlx5e_is_uplink_rep(priv)) {
features = mlx5e_fix_uplink_rep_features(netdev, features);
netdev->netns_immutable = true;
--
2.34.1