net: ethtool: require drivers to opt into the per-RSS ctx RXFH

RX Flow Hashing supports using different configuration for different
RSS contexts. Only two drivers seem to support it. Make sure we
uniformly error out for drivers which don't.

Reviewed-by: Joe Damato <joe@dama.to>
Link: https://patch.msgid.link/20250611145949.2674086-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
index 3cb8d3bf9044ca7e4baa358f3e15260b73e184e3..8b9ee8bac67412a8f1d36efdbe24da2be3281fd9 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
@@ -2616,6 +2616,7 @@ static void mlx5e_get_ts_stats(struct net_device *netdev,
 const struct ethtool_ops mlx5e_ethtool_ops = {
        .cap_link_lanes_supported = true,
        .cap_rss_ctx_supported  = true,
+       .rxfh_per_ctx_fields    = true,
        .rxfh_per_ctx_key       = true,
        .supported_coalesce_params = ETHTOOL_COALESCE_USECS |
                                     ETHTOOL_COALESCE_MAX_FRAMES |

diff --git a/drivers/net/ethernet/sfc/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
index 83d715544f7fb238c573687f9af235fe3a311f5e..afbedca63b29e05b21950cca8f79bc52ee9b64ac 100644 (file)
--- a/drivers/net/ethernet/sfc/ethtool.c
+++ b/drivers/net/ethernet/sfc/ethtool.c
@@ -262,6 +262,7 @@ const struct ethtool_ops efx_ethtool_ops = {
        .set_rxnfc              = efx_ethtool_set_rxnfc,
        .get_rxfh_indir_size    = efx_ethtool_get_rxfh_indir_size,
        .get_rxfh_key_size      = efx_ethtool_get_rxfh_key_size,
+       .rxfh_per_ctx_fields    = true,
        .rxfh_per_ctx_key       = true,
        .cap_rss_rxnfc_adds     = true,
        .rxfh_priv_size         = sizeof(struct efx_rss_context_priv),

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 90da1aee6e5692dadd8bd55da14699e007588c5e..1a6737721d7fe24b47199ab8c8e6c73ea813fe30 100644 (file)
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -855,6 +855,8 @@ struct kernel_ethtool_ts_info {
  * @cap_rss_ctx_supported: indicates if the driver supports RSS
  *     contexts via legacy API, drivers implementing @create_rxfh_context
  *     do not have to set this bit.
+ * @rxfh_per_ctx_fields: device supports selecting different header fields
+ *     for Rx hash calculation and RSS for each additional context.
  * @rxfh_per_ctx_key: device supports setting different RSS key for each
  *     additional context. Netlink API should report hfunc, key, and input_xfrm
  *     for every context, not just context 0.
@@ -1084,6 +1086,7 @@ struct ethtool_ops {
        u32     supported_input_xfrm:8;
        u32     cap_link_lanes_supported:1;
        u32     cap_rss_ctx_supported:1;
+       u32     rxfh_per_ctx_fields:1;
        u32     rxfh_per_ctx_key:1;
        u32     cap_rss_rxnfc_adds:1;
        u32     rxfh_indir_space;

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 33892099cdad23e20b85f9e897f582af635d9f6d..1a1705e900b3f503e28b2aa2a3552fb62ce113bb 100644 (file)
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1075,6 +1075,10 @@ ethtool_set_rxfh_fields(struct net_device *dev, u32 cmd, void __user *useraddr)
        if (rc)
                return rc;
 
+       if (info.flow_type & FLOW_RSS && info.rss_context &&
+           !ops->rxfh_per_ctx_fields)
+               return -EINVAL;
+
        if (ops->get_rxfh) {
                struct ethtool_rxfh_param rxfh = {};
 
@@ -1105,6 +1109,10 @@ ethtool_get_rxfh_fields(struct net_device *dev, u32 cmd, void __user *useraddr)
        if (ret)
                return ret;
 
+       if (info.flow_type & FLOW_RSS && info.rss_context &&
+           !ops->rxfh_per_ctx_fields)
+               return -EINVAL;
+
        ret = ops->get_rxnfc(dev, &info, NULL);
        if (ret < 0)
                return ret;