gve: Add flow steering device option

Add a new device option to signal to the driver that the device supports
flow steering. This device option also carries the maximum number of
flow steering rules that the device can store.
Signed-off-by: Jeroen de Borst <jeroendb@google.com>
Co-developed-by: Ziwei Xiao <ziweixiao@google.com>
Signed-off-by: Ziwei Xiao <ziweixiao@google.com>
Reviewed-by: Praveen Kaligineedi <pkaligineedi@google.com>
Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20240625001232.1476315-4-ziweixiao@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/google/gve/gve.h

@@ -786,6 +786,8 @@ struct gve_priv {
 
 	u16 header_buf_size; /* device configured, header-split supported if non-zero */
 	bool header_split_enabled; /* True if the header split is enabled by the user */
+
+	u32 max_flow_rules;
 };
 
 enum gve_service_task_flags_bit {

drivers/net/ethernet/google/gve/gve_adminq.c

@@ -44,6 +44,7 @@ void gve_parse_device_option(struct gve_priv *priv,
 			     struct gve_device_option_jumbo_frames **dev_op_jumbo_frames,
 			     struct gve_device_option_dqo_qpl **dev_op_dqo_qpl,
 			     struct gve_device_option_buffer_sizes **dev_op_buffer_sizes,
+			     struct gve_device_option_flow_steering **dev_op_flow_steering,
 			     struct gve_device_option_modify_ring **dev_op_modify_ring)
 {
 	u32 req_feat_mask = be32_to_cpu(option->required_features_mask);
@@ -189,6 +190,23 @@ void gve_parse_device_option(struct gve_priv *priv,
 		if (option_length == GVE_DEVICE_OPTION_NO_MIN_RING_SIZE)
 			priv->default_min_ring_size = true;
 		break;
+	case GVE_DEV_OPT_ID_FLOW_STEERING:
+		if (option_length < sizeof(**dev_op_flow_steering) ||
+		    req_feat_mask != GVE_DEV_OPT_REQ_FEAT_MASK_FLOW_STEERING) {
+			dev_warn(&priv->pdev->dev, GVE_DEVICE_OPTION_ERROR_FMT,
+				 "Flow Steering",
+				 (int)sizeof(**dev_op_flow_steering),
+				 GVE_DEV_OPT_REQ_FEAT_MASK_FLOW_STEERING,
+				 option_length, req_feat_mask);
+			break;
+		}
+
+		if (option_length > sizeof(**dev_op_flow_steering))
+			dev_warn(&priv->pdev->dev,
+				 GVE_DEVICE_OPTION_TOO_BIG_FMT,
+				 "Flow Steering");
+		*dev_op_flow_steering = (void *)(option + 1);
+		break;
 	default:
 		/* If we don't recognize the option just continue
 		 * without doing anything.
@@ -208,6 +226,7 @@ gve_process_device_options(struct gve_priv *priv,
 			   struct gve_device_option_jumbo_frames **dev_op_jumbo_frames,
 			   struct gve_device_option_dqo_qpl **dev_op_dqo_qpl,
 			   struct gve_device_option_buffer_sizes **dev_op_buffer_sizes,
+			   struct gve_device_option_flow_steering **dev_op_flow_steering,
 			   struct gve_device_option_modify_ring **dev_op_modify_ring)
 {
 	const int num_options = be16_to_cpu(descriptor->num_device_options);
@@ -230,7 +249,7 @@ gve_process_device_options(struct gve_priv *priv,
 					dev_op_gqi_rda, dev_op_gqi_qpl,
 					dev_op_dqo_rda, dev_op_jumbo_frames,
 					dev_op_dqo_qpl, dev_op_buffer_sizes,
-					dev_op_modify_ring);
+					dev_op_flow_steering, dev_op_modify_ring);
 		dev_opt = next_opt;
 	}
 
@@ -838,6 +857,8 @@ static void gve_enable_supported_features(struct gve_priv *priv,
 					  *dev_op_dqo_qpl,
 					  const struct gve_device_option_buffer_sizes
 					  *dev_op_buffer_sizes,
+					  const struct gve_device_option_flow_steering
+					  *dev_op_flow_steering,
 					  const struct gve_device_option_modify_ring
 					  *dev_op_modify_ring)
 {
@@ -890,10 +911,23 @@ static void gve_enable_supported_features(struct gve_priv *priv,
 			priv->min_tx_desc_cnt = be16_to_cpu(dev_op_modify_ring->min_tx_ring_size);
 		}
 	}
+
+	if (dev_op_flow_steering &&
+	    (supported_features_mask & GVE_SUP_FLOW_STEERING_MASK)) {
+		if (dev_op_flow_steering->max_flow_rules) {
+			priv->max_flow_rules =
+				be32_to_cpu(dev_op_flow_steering->max_flow_rules);
+			priv->dev->hw_features |= NETIF_F_NTUPLE;
+			dev_info(&priv->pdev->dev,
+				 "FLOW STEERING device option enabled with max rule limit of %u.\n",
+				 priv->max_flow_rules);
+		}
+	}
 }
 
 int gve_adminq_describe_device(struct gve_priv *priv)
 {
+	struct gve_device_option_flow_steering *dev_op_flow_steering = NULL;
 	struct gve_device_option_buffer_sizes *dev_op_buffer_sizes = NULL;
 	struct gve_device_option_jumbo_frames *dev_op_jumbo_frames = NULL;
 	struct gve_device_option_modify_ring *dev_op_modify_ring = NULL;
@@ -930,6 +964,7 @@ int gve_adminq_describe_device(struct gve_priv *priv)
 					 &dev_op_gqi_qpl, &dev_op_dqo_rda,
 					 &dev_op_jumbo_frames, &dev_op_dqo_qpl,
 					 &dev_op_buffer_sizes,
+					 &dev_op_flow_steering,
 					 &dev_op_modify_ring);
 	if (err)
 		goto free_device_descriptor;
@@ -991,7 +1026,8 @@ int gve_adminq_describe_device(struct gve_priv *priv)
 
 	gve_enable_supported_features(priv, supported_features_mask,
 				      dev_op_jumbo_frames, dev_op_dqo_qpl,
-				      dev_op_buffer_sizes, dev_op_modify_ring);
+				      dev_op_buffer_sizes, dev_op_flow_steering,
+				      dev_op_modify_ring);
 
 free_device_descriptor:
 	dma_pool_free(priv->adminq_pool, descriptor, descriptor_bus);

drivers/net/ethernet/google/gve/gve_adminq.h

@@ -146,6 +146,14 @@ struct gve_device_option_modify_ring {
 
 static_assert(sizeof(struct gve_device_option_modify_ring) == 12);
 
+struct gve_device_option_flow_steering {
+	__be32 supported_features_mask;
+	__be32 reserved;
+	__be32 max_flow_rules;
+};
+
+static_assert(sizeof(struct gve_device_option_flow_steering) == 12);
+
 /* Terminology:
  *
  * RDA - Raw DMA Addressing - Buffers associated with SKBs are directly DMA
@@ -163,6 +171,7 @@ enum gve_dev_opt_id {
 	GVE_DEV_OPT_ID_DQO_QPL			= 0x7,
 	GVE_DEV_OPT_ID_JUMBO_FRAMES		= 0x8,
 	GVE_DEV_OPT_ID_BUFFER_SIZES		= 0xa,
+	GVE_DEV_OPT_ID_FLOW_STEERING		= 0xb,
 };
 
 enum gve_dev_opt_req_feat_mask {
@@ -174,12 +183,14 @@ enum gve_dev_opt_req_feat_mask {
 	GVE_DEV_OPT_REQ_FEAT_MASK_DQO_QPL		= 0x0,
 	GVE_DEV_OPT_REQ_FEAT_MASK_BUFFER_SIZES		= 0x0,
 	GVE_DEV_OPT_REQ_FEAT_MASK_MODIFY_RING		= 0x0,
+	GVE_DEV_OPT_REQ_FEAT_MASK_FLOW_STEERING		= 0x0,
 };
 
 enum gve_sup_feature_mask {
 	GVE_SUP_MODIFY_RING_MASK	= 1 << 0,
 	GVE_SUP_JUMBO_FRAMES_MASK	= 1 << 2,
 	GVE_SUP_BUFFER_SIZES_MASK	= 1 << 4,
+	GVE_SUP_FLOW_STEERING_MASK	= 1 << 5,
 };
 
 #define GVE_DEV_OPT_LEN_GQI_RAW_ADDRESSING 0x0