Merge branch 'gve-jumbo-frame'

Jeroen de Borst says:

====================
gve: Add jumbo-frame support for GQ

This patchset introduces jumbo-frame support for the GQ queue format.
The device already supports jumbo-frames on TX. This introduces
multi-descriptor RX packets using a packet continuation bit.

A widely deployed driver has a bug with causes it to fail to load
when a MTU greater than 2048 bytes is configured. A jumbo-frame device
option is introduced to pass a jumbo-frame MTU only to drivers that
support it.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -142,6 +142,19 @@ struct gve_index_list {
 	s16 tail;
 };
 
+/* A single received packet split across multiple buffers may be
+ * reconstructed using the information in this structure.
+ */
+struct gve_rx_ctx {
+	/* head and tail of skb chain for the current packet or NULL if none */
+	struct sk_buff *skb_head;
+	struct sk_buff *skb_tail;
+	u16 total_expected_size;
+	u8 expected_frag_cnt;
+	u8 curr_frag_cnt;
+	u8 reuse_frags;
+};
+
 /* Contains datapath state used to represent an RX queue. */
 struct gve_rx_ring {
 	struct gve_priv *gve;
@@ -153,6 +166,7 @@ struct gve_rx_ring {
 
 			/* threshold for posting new buffs and descs */
 			u32 db_threshold;
+			u16 packet_buffer_size;
 		};
 
 		/* DQO fields. */
@@ -200,15 +214,16 @@ struct gve_rx_ring {
 	u64 rx_skb_alloc_fail; /* free-running count of skb alloc fails */
 	u64 rx_buf_alloc_fail; /* free-running count of buffer alloc fails */
 	u64 rx_desc_err_dropped_pkt; /* free-running count of packets dropped by descriptor error */
+	u64 rx_cont_packet_cnt; /* free-running multi-fragment packets received */
+	u64 rx_frag_flip_cnt; /* free-running count of rx segments where page_flip was used */
+	u64 rx_frag_copy_cnt; /* free-running count of rx segments copied into skb linear portion */
 	u32 q_num; /* queue index */
 	u32 ntfy_id; /* notification block index */
 	struct gve_queue_resources *q_resources; /* head and tail pointer idx */
 	dma_addr_t q_resources_bus; /* dma address for the queue resources */
 	struct u64_stats_sync statss; /* sync stats for 32bit archs */
 
-	/* head and tail of skb chain for the current packet or NULL if none */
-	struct sk_buff *skb_head;
-	struct sk_buff *skb_tail;
+	struct gve_rx_ctx ctx; /* Info for packet currently being processed in this ring. */
 };
 
 /* A TX desc ring entry */

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

@@ -38,7 +38,8 @@ void gve_parse_device_option(struct gve_priv *priv,
 			     struct gve_device_option *option,
 			     struct gve_device_option_gqi_rda **dev_op_gqi_rda,
 			     struct gve_device_option_gqi_qpl **dev_op_gqi_qpl,
-			     struct gve_device_option_dqo_rda **dev_op_dqo_rda)
+			     struct gve_device_option_dqo_rda **dev_op_dqo_rda,
+			     struct gve_device_option_jumbo_frames **dev_op_jumbo_frames)
 {
 	u32 req_feat_mask = be32_to_cpu(option->required_features_mask);
 	u16 option_length = be16_to_cpu(option->option_length);
@@ -111,6 +112,24 @@ void gve_parse_device_option(struct gve_priv *priv,
 		}
 		*dev_op_dqo_rda = (void *)(option + 1);
 		break;
+	case GVE_DEV_OPT_ID_JUMBO_FRAMES:
+		if (option_length < sizeof(**dev_op_jumbo_frames) ||
+		    req_feat_mask != GVE_DEV_OPT_REQ_FEAT_MASK_JUMBO_FRAMES) {
+			dev_warn(&priv->pdev->dev, GVE_DEVICE_OPTION_ERROR_FMT,
+				 "Jumbo Frames",
+				 (int)sizeof(**dev_op_jumbo_frames),
+				 GVE_DEV_OPT_REQ_FEAT_MASK_JUMBO_FRAMES,
+				 option_length, req_feat_mask);
+			break;
+		}
+
+		if (option_length > sizeof(**dev_op_jumbo_frames)) {
+			dev_warn(&priv->pdev->dev,
+				 GVE_DEVICE_OPTION_TOO_BIG_FMT,
+				 "Jumbo Frames");
+		}
+		*dev_op_jumbo_frames = (void *)(option + 1);
+		break;
 	default:
 		/* If we don't recognize the option just continue
 		 * without doing anything.
@@ -126,7 +145,8 @@ gve_process_device_options(struct gve_priv *priv,
 			   struct gve_device_descriptor *descriptor,
 			   struct gve_device_option_gqi_rda **dev_op_gqi_rda,
 			   struct gve_device_option_gqi_qpl **dev_op_gqi_qpl,
-			   struct gve_device_option_dqo_rda **dev_op_dqo_rda)
+			   struct gve_device_option_dqo_rda **dev_op_dqo_rda,
+			   struct gve_device_option_jumbo_frames **dev_op_jumbo_frames)
 {
 	const int num_options = be16_to_cpu(descriptor->num_device_options);
 	struct gve_device_option *dev_opt;
@@ -146,7 +166,7 @@ gve_process_device_options(struct gve_priv *priv,
 
 		gve_parse_device_option(priv, descriptor, dev_opt,
 					dev_op_gqi_rda, dev_op_gqi_qpl,
-					dev_op_dqo_rda);
+					dev_op_dqo_rda, dev_op_jumbo_frames);
 		dev_opt = next_opt;
 	}
 
@@ -530,6 +550,7 @@ static int gve_adminq_create_rx_queue(struct gve_priv *priv, u32 queue_index)
 			cpu_to_be64(rx->data.data_bus),
 		cmd.create_rx_queue.index = cpu_to_be32(queue_index);
 		cmd.create_rx_queue.queue_page_list_id = cpu_to_be32(qpl_id);
+		cmd.create_rx_queue.packet_buffer_size = cpu_to_be16(rx->packet_buffer_size);
 	} else {
 		cmd.create_rx_queue.rx_ring_size =
 			cpu_to_be16(priv->rx_desc_cnt);
@@ -660,12 +681,31 @@ gve_set_desc_cnt_dqo(struct gve_priv *priv,
 	return 0;
 }
 
+static void gve_enable_supported_features(struct gve_priv *priv,
+					  u32 supported_features_mask,
+					  const struct gve_device_option_jumbo_frames
+						  *dev_op_jumbo_frames)
+{
+	/* Before control reaches this point, the page-size-capped max MTU from
+	 * the gve_device_descriptor field has already been stored in
+	 * priv->dev->max_mtu. We overwrite it with the true max MTU below.
+	 */
+	if (dev_op_jumbo_frames &&
+	    (supported_features_mask & GVE_SUP_JUMBO_FRAMES_MASK)) {
+		dev_info(&priv->pdev->dev,
+			 "JUMBO FRAMES device option enabled.\n");
+		priv->dev->max_mtu = be16_to_cpu(dev_op_jumbo_frames->max_mtu);
+	}
+}
+
 int gve_adminq_describe_device(struct gve_priv *priv)
 {
+	struct gve_device_option_jumbo_frames *dev_op_jumbo_frames = NULL;
 	struct gve_device_option_gqi_rda *dev_op_gqi_rda = NULL;
 	struct gve_device_option_gqi_qpl *dev_op_gqi_qpl = NULL;
 	struct gve_device_option_dqo_rda *dev_op_dqo_rda = NULL;
 	struct gve_device_descriptor *descriptor;
+	u32 supported_features_mask = 0;
 	union gve_adminq_command cmd;
 	dma_addr_t descriptor_bus;
 	int err = 0;
@@ -689,7 +729,8 @@ int gve_adminq_describe_device(struct gve_priv *priv)
 		goto free_device_descriptor;
 
 	err = gve_process_device_options(priv, descriptor, &dev_op_gqi_rda,
-					 &dev_op_gqi_qpl, &dev_op_dqo_rda);
+					 &dev_op_gqi_qpl, &dev_op_dqo_rda,
+					 &dev_op_jumbo_frames);
 	if (err)
 		goto free_device_descriptor;
 
@@ -704,12 +745,19 @@ int gve_adminq_describe_device(struct gve_priv *priv)
 		priv->queue_format = GVE_DQO_RDA_FORMAT;
 		dev_info(&priv->pdev->dev,
 			 "Driver is running with DQO RDA queue format.\n");
+		supported_features_mask =
+			be32_to_cpu(dev_op_dqo_rda->supported_features_mask);
 	} else if (dev_op_gqi_rda) {
 		priv->queue_format = GVE_GQI_RDA_FORMAT;
 		dev_info(&priv->pdev->dev,
 			 "Driver is running with GQI RDA queue format.\n");
+		supported_features_mask =
+			be32_to_cpu(dev_op_gqi_rda->supported_features_mask);
 	} else {
 		priv->queue_format = GVE_GQI_QPL_FORMAT;
+		if (dev_op_gqi_qpl)
+			supported_features_mask =
+				be32_to_cpu(dev_op_gqi_qpl->supported_features_mask);
 		dev_info(&priv->pdev->dev,
 			 "Driver is running with GQI QPL queue format.\n");
 	}
@@ -746,6 +794,9 @@ int gve_adminq_describe_device(struct gve_priv *priv)
 	}
 	priv->default_num_queues = be16_to_cpu(descriptor->default_num_queues);
 
+	gve_enable_supported_features(priv, supported_features_mask,
+				      dev_op_jumbo_frames);
+
 free_device_descriptor:
 	dma_free_coherent(&priv->pdev->dev, PAGE_SIZE, descriptor,
 			  descriptor_bus);

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

@@ -108,6 +108,14 @@ struct gve_device_option_dqo_rda {
 
 static_assert(sizeof(struct gve_device_option_dqo_rda) == 8);
 
+struct gve_device_option_jumbo_frames {
+	__be32 supported_features_mask;
+	__be16 max_mtu;
+	u8 padding[2];
+};
+
+static_assert(sizeof(struct gve_device_option_jumbo_frames) == 8);
+
 /* Terminology:
  *
  * RDA - Raw DMA Addressing - Buffers associated with SKBs are directly DMA
@@ -121,13 +129,19 @@ enum gve_dev_opt_id {
 	GVE_DEV_OPT_ID_GQI_RDA = 0x2,
 	GVE_DEV_OPT_ID_GQI_QPL = 0x3,
 	GVE_DEV_OPT_ID_DQO_RDA = 0x4,
+	GVE_DEV_OPT_ID_JUMBO_FRAMES = 0x8,
 };
 
 enum gve_dev_opt_req_feat_mask {
 	GVE_DEV_OPT_REQ_FEAT_MASK_GQI_RAW_ADDRESSING = 0x0,
 	GVE_DEV_OPT_REQ_FEAT_MASK_GQI_RDA = 0x0,
 	GVE_DEV_OPT_REQ_FEAT_MASK_GQI_QPL = 0x0,
 	GVE_DEV_OPT_REQ_FEAT_MASK_DQO_RDA = 0x0,
+	GVE_DEV_OPT_REQ_FEAT_MASK_JUMBO_FRAMES = 0x0,
+};
+
+enum gve_sup_feature_mask {
+	GVE_SUP_JUMBO_FRAMES_MASK = 1 << 2,
 };
 
 #define GVE_DEV_OPT_LEN_GQI_RAW_ADDRESSING 0x0

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

@@ -90,12 +90,13 @@ union gve_rx_data_slot {
 
 /* GVE Recive Packet Descriptor Flags */
 #define GVE_RXFLG(x)	cpu_to_be16(1 << (3 + (x)))
-#define	GVE_RXF_FRAG	GVE_RXFLG(3)	/* IP Fragment			*/
-#define	GVE_RXF_IPV4	GVE_RXFLG(4)	/* IPv4				*/
-#define	GVE_RXF_IPV6	GVE_RXFLG(5)	/* IPv6				*/
-#define	GVE_RXF_TCP	GVE_RXFLG(6)	/* TCP Packet			*/
-#define	GVE_RXF_UDP	GVE_RXFLG(7)	/* UDP Packet			*/
-#define	GVE_RXF_ERR	GVE_RXFLG(8)	/* Packet Error Detected	*/
+#define	GVE_RXF_FRAG		GVE_RXFLG(3)	/* IP Fragment			*/
+#define	GVE_RXF_IPV4		GVE_RXFLG(4)	/* IPv4				*/
+#define	GVE_RXF_IPV6		GVE_RXFLG(5)	/* IPv6				*/
+#define	GVE_RXF_TCP		GVE_RXFLG(6)	/* TCP Packet			*/
+#define	GVE_RXF_UDP		GVE_RXFLG(7)	/* UDP Packet			*/
+#define	GVE_RXF_ERR		GVE_RXFLG(8)	/* Packet Error Detected	*/
+#define	GVE_RXF_PKT_CONT	GVE_RXFLG(10)	/* Multi Fragment RX packet	*/
 
 /* GVE IRQ */
 #define GVE_IRQ_ACK	BIT(31)

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

@@ -43,6 +43,7 @@ static const char gve_gstrings_main_stats[][ETH_GSTRING_LEN] = {
 
 static const char gve_gstrings_rx_stats[][ETH_GSTRING_LEN] = {
 	"rx_posted_desc[%u]", "rx_completed_desc[%u]", "rx_bytes[%u]",
+	"rx_cont_packet_cnt[%u]", "rx_frag_flip_cnt[%u]", "rx_frag_copy_cnt[%u]",
 	"rx_dropped_pkt[%u]", "rx_copybreak_pkt[%u]", "rx_copied_pkt[%u]",
 	"rx_queue_drop_cnt[%u]", "rx_no_buffers_posted[%u]",
 	"rx_drops_packet_over_mru[%u]", "rx_drops_invalid_checksum[%u]",
@@ -265,6 +266,9 @@ gve_get_ethtool_stats(struct net_device *netdev,
 			} while (u64_stats_fetch_retry(&priv->rx[ring].statss,
 						       start));
 			data[i++] = tmp_rx_bytes;
+			data[i++] = rx->rx_cont_packet_cnt;
+			data[i++] = rx->rx_frag_flip_cnt;
+			data[i++] = rx->rx_frag_copy_cnt;
 			/* rx dropped packets */
 			data[i++] = tmp_rx_skb_alloc_fail +
 				tmp_rx_buf_alloc_fail +

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

@@ -1371,14 +1371,6 @@ static int gve_init_priv(struct gve_priv *priv, bool skip_describe_device)
 			"Could not get device information: err=%d\n", err);
 		goto err;
 	}
-	if (gve_is_gqi(priv) && priv->dev->max_mtu > PAGE_SIZE) {
-		priv->dev->max_mtu = PAGE_SIZE;
-		err = gve_adminq_set_mtu(priv, priv->dev->mtu);
-		if (err) {
-			dev_err(&priv->pdev->dev, "Could not set mtu");
-			goto err;
-		}
-	}
 	priv->dev->mtu = priv->dev->max_mtu;
 	num_ntfy = pci_msix_vec_count(priv->pdev);
 	if (num_ntfy <= 0) {