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From: Stanislav Fomichev <sdf@google.com>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
	martin.lau@linux.dev, song@kernel.org, yhs@fb.com,
	john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
	haoluo@google.com, jolsa@kernel.org, kuba@kernel.org,
	toke@kernel.org, willemb@google.com, dsahern@kernel.org,
	magnus.karlsson@intel.com, bjorn@kernel.org,
	maciej.fijalkowski@intel.com, hawk@kernel.org,
	yoong.siang.song@intel.com, netdev@vger.kernel.org,
	xdp-hints@xdp-project.net
Subject: [xdp-hints] [PATCH bpf-next v6 01/13] xsk: Support tx_metadata_len
Date: Mon, 27 Nov 2023 11:03:07 -0800	[thread overview]
Message-ID: <20231127190319.1190813-2-sdf@google.com> (raw)
In-Reply-To: <20231127190319.1190813-1-sdf@google.com>

For zerocopy mode, tx_desc->addr can point to an arbitrary offset
and carry some TX metadata in the headroom. For copy mode, there
is no way currently to populate skb metadata.

Introduce new tx_metadata_len umem config option that indicates how many
bytes to treat as metadata. Metadata bytes come prior to tx_desc address
(same as in RX case).

The size of the metadata has mostly the same constraints as XDP:
- less than 256 bytes
- 8-byte aligned (compared to 4-byte alignment on xdp, due to 8-byte
  timestamp in the completion)
- non-zero

This data is not interpreted in any way right now.

Reviewed-by: Song Yoong Siang <yoong.siang.song@intel.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
 include/net/xdp_sock.h            |  1 +
 include/net/xsk_buff_pool.h       |  1 +
 include/uapi/linux/if_xdp.h       |  1 +
 net/xdp/xdp_umem.c                |  4 ++++
 net/xdp/xsk.c                     | 12 +++++++++++-
 net/xdp/xsk_buff_pool.c           |  1 +
 net/xdp/xsk_queue.h               | 17 ++++++++++-------
 tools/include/uapi/linux/if_xdp.h |  1 +
 8 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h
index f83128007fb0..bcf765124f72 100644
--- a/include/net/xdp_sock.h
+++ b/include/net/xdp_sock.h
@@ -30,6 +30,7 @@ struct xdp_umem {
 	struct user_struct *user;
 	refcount_t users;
 	u8 flags;
+	u8 tx_metadata_len;
 	bool zc;
 	struct page **pgs;
 	int id;
diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
index b0bdff26fc88..1985ffaf9b0c 100644
--- a/include/net/xsk_buff_pool.h
+++ b/include/net/xsk_buff_pool.h
@@ -77,6 +77,7 @@ struct xsk_buff_pool {
 	u32 chunk_size;
 	u32 chunk_shift;
 	u32 frame_len;
+	u8 tx_metadata_len; /* inherited from umem */
 	u8 cached_need_wakeup;
 	bool uses_need_wakeup;
 	bool dma_need_sync;
diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h
index 8d48863472b9..2ecf79282c26 100644
--- a/include/uapi/linux/if_xdp.h
+++ b/include/uapi/linux/if_xdp.h
@@ -76,6 +76,7 @@ struct xdp_umem_reg {
 	__u32 chunk_size;
 	__u32 headroom;
 	__u32 flags;
+	__u32 tx_metadata_len;
 };
 
 struct xdp_statistics {
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index 06cead2b8e34..946a687fb8e8 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -199,6 +199,9 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
 	if (headroom >= chunk_size - XDP_PACKET_HEADROOM)
 		return -EINVAL;
 
+	if (mr->tx_metadata_len >= 256 || mr->tx_metadata_len % 8)
+		return -EINVAL;
+
 	umem->size = size;
 	umem->headroom = headroom;
 	umem->chunk_size = chunk_size;
@@ -207,6 +210,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
 	umem->pgs = NULL;
 	umem->user = NULL;
 	umem->flags = mr->flags;
+	umem->tx_metadata_len = mr->tx_metadata_len;
 
 	INIT_LIST_HEAD(&umem->xsk_dma_list);
 	refcount_set(&umem->users, 1);
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index ae9f8cb611f6..c904356e2800 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -1283,6 +1283,14 @@ struct xdp_umem_reg_v1 {
 	__u32 headroom;
 };
 
+struct xdp_umem_reg_v2 {
+	__u64 addr; /* Start of packet data area */
+	__u64 len; /* Length of packet data area */
+	__u32 chunk_size;
+	__u32 headroom;
+	__u32 flags;
+};
+
 static int xsk_setsockopt(struct socket *sock, int level, int optname,
 			  sockptr_t optval, unsigned int optlen)
 {
@@ -1326,8 +1334,10 @@ static int xsk_setsockopt(struct socket *sock, int level, int optname,
 
 		if (optlen < sizeof(struct xdp_umem_reg_v1))
 			return -EINVAL;
-		else if (optlen < sizeof(mr))
+		else if (optlen < sizeof(struct xdp_umem_reg_v2))
 			mr_size = sizeof(struct xdp_umem_reg_v1);
+		else if (optlen < sizeof(mr))
+			mr_size = sizeof(struct xdp_umem_reg_v2);
 
 		if (copy_from_sockptr(&mr, optval, mr_size))
 			return -EFAULT;
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index 49cb9f9a09be..386eddcdf837 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -85,6 +85,7 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
 		XDP_PACKET_HEADROOM;
 	pool->umem = umem;
 	pool->addrs = umem->addrs;
+	pool->tx_metadata_len = umem->tx_metadata_len;
 	INIT_LIST_HEAD(&pool->free_list);
 	INIT_LIST_HEAD(&pool->xskb_list);
 	INIT_LIST_HEAD(&pool->xsk_tx_list);
diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index 13354a1e4280..c74a1372bcb9 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -143,15 +143,17 @@ static inline bool xp_unused_options_set(u32 options)
 static inline bool xp_aligned_validate_desc(struct xsk_buff_pool *pool,
 					    struct xdp_desc *desc)
 {
-	u64 offset = desc->addr & (pool->chunk_size - 1);
+	u64 addr = desc->addr - pool->tx_metadata_len;
+	u64 len = desc->len + pool->tx_metadata_len;
+	u64 offset = addr & (pool->chunk_size - 1);
 
 	if (!desc->len)
 		return false;
 
-	if (offset + desc->len > pool->chunk_size)
+	if (offset + len > pool->chunk_size)
 		return false;
 
-	if (desc->addr >= pool->addrs_cnt)
+	if (addr >= pool->addrs_cnt)
 		return false;
 
 	if (xp_unused_options_set(desc->options))
@@ -162,16 +164,17 @@ static inline bool xp_aligned_validate_desc(struct xsk_buff_pool *pool,
 static inline bool xp_unaligned_validate_desc(struct xsk_buff_pool *pool,
 					      struct xdp_desc *desc)
 {
-	u64 addr = xp_unaligned_add_offset_to_addr(desc->addr);
+	u64 addr = xp_unaligned_add_offset_to_addr(desc->addr) - pool->tx_metadata_len;
+	u64 len = desc->len + pool->tx_metadata_len;
 
 	if (!desc->len)
 		return false;
 
-	if (desc->len > pool->chunk_size)
+	if (len > pool->chunk_size)
 		return false;
 
-	if (addr >= pool->addrs_cnt || addr + desc->len > pool->addrs_cnt ||
-	    xp_desc_crosses_non_contig_pg(pool, addr, desc->len))
+	if (addr >= pool->addrs_cnt || addr + len > pool->addrs_cnt ||
+	    xp_desc_crosses_non_contig_pg(pool, addr, len))
 		return false;
 
 	if (xp_unused_options_set(desc->options))
diff --git a/tools/include/uapi/linux/if_xdp.h b/tools/include/uapi/linux/if_xdp.h
index 73a47da885dc..34411a2e5b6c 100644
--- a/tools/include/uapi/linux/if_xdp.h
+++ b/tools/include/uapi/linux/if_xdp.h
@@ -76,6 +76,7 @@ struct xdp_umem_reg {
 	__u32 chunk_size;
 	__u32 headroom;
 	__u32 flags;
+	__u32 tx_metadata_len;
 };
 
 struct xdp_statistics {
-- 
2.43.0.rc1.413.gea7ed67945-goog


  reply	other threads:[~2023-11-27 19:04 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-27 19:03 [xdp-hints] [PATCH bpf-next v6 00/13] xsk: TX metadata Stanislav Fomichev
2023-11-27 19:03 ` Stanislav Fomichev [this message]
2023-11-28  3:09   ` [xdp-hints] Re: [PATCH bpf-next v6 01/13] xsk: Support tx_metadata_len Jakub Kicinski
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 02/13] xsk: Add TX timestamp and TX checksum offload support Stanislav Fomichev
2023-11-29 16:49   ` [xdp-hints] " Jakub Kicinski
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 03/13] tools: ynl: Print xsk-features from the sample Stanislav Fomichev
2023-11-29 16:47   ` [xdp-hints] " Jakub Kicinski
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 04/13] net/mlx5e: Implement AF_XDP TX timestamp and checksum offload Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 05/13] net: stmmac: Add Tx HWTS support to XDP ZC Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 06/13] xsk: Document tx_metadata_len layout Stanislav Fomichev
2023-12-02 17:09   ` [xdp-hints] " Simon Horman
2023-12-04 16:48     ` Stanislav Fomichev
2023-12-07 10:47       ` Simon Horman
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 07/13] xsk: Validate xsk_tx_metadata flags Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 08/13] xsk: Add option to calculate TX checksum in SW Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 09/13] selftests/xsk: Support tx_metadata_len Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 10/13] selftests/bpf: Add csum helpers Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 11/13] selftests/bpf: Add TX side to xdp_metadata Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 12/13] selftests/bpf: Convert xdp_hw_metadata to XDP_USE_NEED_WAKEUP Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 13/13] selftests/bpf: Add TX side to xdp_hw_metadata Stanislav Fomichev
2023-11-29 23:10 ` [xdp-hints] Re: [PATCH bpf-next v6 00/13] xsk: TX metadata patchwork-bot+netdevbpf

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