[PATCH bpf-next v2 3/3] xsk: Add Tx GSO type and size offload support

[Muyang Tian <tianmuyang@huawei.com>]

This change extends the xsk_tx_metadata struct with
GSO type and size fields.
A new offload XDP_TX_METADATA_GSO is defined, which
offloads gso_type and gso_size in skb_shared_info to XDP.

Signed-off-by: Muyang Tian <tianmuyang@huawei.com>
---
 Documentation/netlink/specs/netdev.yaml |  4 ++++
 include/net/xdp_sock.h                  |  8 ++++++++
 include/net/xdp_sock_drv.h              |  1 +
 include/uapi/linux/if_xdp.h             | 11 +++++++++++
 include/uapi/linux/netdev.h             |  2 ++
 net/xdp/xsk.c                           |  5 +++++
 tools/include/uapi/linux/if_xdp.h       | 11 +++++++++++
 tools/include/uapi/linux/netdev.h       |  2 ++
 8 files changed, 44 insertions(+)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 5beee7c8e7cf..f4aa04eba54c 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -78,6 +78,10 @@ definitions:
         name: tx-checksum
         doc:
           L3 checksum HW offload is supported by the driver.
+      -
+        name: tx-gso
+        doc:
+          GSO type and size is supported by the driver.
   -
     name: queue-type
     type: enum
diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h
index bfe625b55d55..e5acb27c3e07 100644
--- a/include/net/xdp_sock.h
+++ b/include/net/xdp_sock.h
@@ -110,11 +110,14 @@ struct xdp_sock {
  *     indicates position where checksumming should start.
  *     csum_offset indicates position where checksum should be stored.
  *
+ * void (*tmo_request_gso)(u32 gso_type, u16 gso_size, void *priv)
+ *     Called when AF_XDP frame requested GSO info.
  */
 struct xsk_tx_metadata_ops {
 	void	(*tmo_request_timestamp)(void *priv);
 	u64	(*tmo_fill_timestamp)(void *priv);
 	void	(*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv);
+	void	(*tmo_request_gso)(u32 gso_type, u16 gso_size, void *priv);
 };
 
 #ifdef CONFIG_XDP_SOCKETS
@@ -170,6 +173,11 @@ static inline void xsk_tx_metadata_request(const struct xsk_tx_metadata *meta,
 		if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM)
 			ops->tmo_request_checksum(meta->request.csum_start,
 						  meta->request.csum_offset, priv);
+
+	if (ops->tmo_request_gso)
+		if (meta->flags & XDP_TXMD_FLAGS_GSO)
+			ops->tmo_request_gso(meta->request.gso_type,
+						  meta->request.gso_size, priv);
 }
 
 /**
diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h
index 0a5dca2b2b3f..b192dab2b835 100644
--- a/include/net/xdp_sock_drv.h
+++ b/include/net/xdp_sock_drv.h
@@ -198,6 +198,7 @@ static inline void *xsk_buff_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
 #define XDP_TXMD_FLAGS_VALID ( \
 		XDP_TXMD_FLAGS_TIMESTAMP | \
 		XDP_TXMD_FLAGS_CHECKSUM | \
+		XDP_TXMD_FLAGS_GSO | \
 	0)
 
 static inline bool xsk_buff_valid_tx_metadata(struct xsk_tx_metadata *meta)
diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h
index 42ec5ddaab8d..c3ea368bf613 100644
--- a/include/uapi/linux/if_xdp.h
+++ b/include/uapi/linux/if_xdp.h
@@ -127,6 +127,11 @@ struct xdp_options {
  */
 #define XDP_TXMD_FLAGS_CHECKSUM			(1 << 1)
 
+/* Request transmit GSO info. GSO type and size are communicated via
+ * csum_start and csum_offset fields of struct xsk_tx_metadata.
+ */
+#define XDP_TXMD_FLAGS_GSO				(1 << 2)
+
 /* AF_XDP offloads request. 'request' union member is consumed by the driver
  * when the packet is being transmitted. 'completion' union member is
  * filled by the driver when the transmit completion arrives.
@@ -142,6 +147,12 @@ struct xsk_tx_metadata {
 			__u16 csum_start;
 			/* Offset from csum_start where checksum should be stored. */
 			__u16 csum_offset;
+
+			/* XDP_TXMD_FLAGS_GSO */
+			/* Identical to skb_shared_info.gso_type*/
+			__u32 gso_type;
+			/* Identical to skb_shared_info.gso_size*/
+			__u16 gso_size;
 		} request;
 
 		struct {
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 1e711d6a4c6b..bd175afb3c6b 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -65,10 +65,12 @@ enum netdev_xdp_rx_metadata {
  *   by the driver.
  * @NETDEV_XSK_FLAGS_TX_CHECKSUM: L3 checksum HW offload is supported by the
  *   driver.
+ * @NETDEV_XSK_FLAGS_TX_GSO: GSO type and size is supported by the driver.
  */
 enum netdev_xsk_flags {
 	NETDEV_XSK_FLAGS_TX_TIMESTAMP = 1,
 	NETDEV_XSK_FLAGS_TX_CHECKSUM = 2,
+	NETDEV_XSK_FLAGS_TX_GSO = 4,
 };
 
 enum netdev_queue_type {
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 1140b2a120ca..5a19edfce16c 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -745,6 +745,11 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,
 						goto free_err;
 				}
 			}
+
+			if (meta->flags & XDP_TXMD_FLAGS_GSO) {
+				skb_shinfo(skb)->gso_type = meta->request.gso_type;
+				skb_shinfo(skb)->gso_size = meta->request.gso_size;
+			}
 		}
 	}
 
diff --git a/tools/include/uapi/linux/if_xdp.h b/tools/include/uapi/linux/if_xdp.h
index 2f082b01ff22..5714d0be8c53 100644
--- a/tools/include/uapi/linux/if_xdp.h
+++ b/tools/include/uapi/linux/if_xdp.h
@@ -127,6 +127,11 @@ struct xdp_options {
  */
 #define XDP_TXMD_FLAGS_CHECKSUM			(1 << 1)
 
+/* Request transmit GSO info. GSO type and size are communicated via
+ * csum_start and csum_offset fields of struct xsk_tx_metadata.
+ */
+#define XDP_TXMD_FLAGS_GSO				(1 << 2)
+
 /* AF_XDP offloads request. 'request' union member is consumed by the driver
  * when the packet is being transmitted. 'completion' union member is
  * filled by the driver when the transmit completion arrives.
@@ -142,6 +147,12 @@ struct xsk_tx_metadata {
 			__u16 csum_start;
 			/* Offset from csum_start where checksum should be stored. */
 			__u16 csum_offset;
+
+			/* XDP_TXMD_FLAGS_GSO */
+			/* Identical to skb_shared_info.gso_type*/
+			__u32 gso_type;
+			/* Identical to skb_shared_info.gso_size*/
+			__u16 gso_size;
 		} request;
 
 		struct {
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index 1e711d6a4c6b..bd175afb3c6b 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -65,10 +65,12 @@ enum netdev_xdp_rx_metadata {
  *   by the driver.
  * @NETDEV_XSK_FLAGS_TX_CHECKSUM: L3 checksum HW offload is supported by the
  *   driver.
+ * @NETDEV_XSK_FLAGS_TX_GSO: GSO type and size is supported by the driver.
  */
 enum netdev_xsk_flags {
 	NETDEV_XSK_FLAGS_TX_TIMESTAMP = 1,
 	NETDEV_XSK_FLAGS_TX_CHECKSUM = 2,
+	NETDEV_XSK_FLAGS_TX_GSO = 4,
 };
 
 enum netdev_queue_type {
-- 
2.41.0