From patchwork Mon Jul 24 23:59:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 13325434 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1F5E614260 for ; Tue, 25 Jul 2023 00:00:07 +0000 (UTC) Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DFB651729 for ; Mon, 24 Jul 2023 17:00:04 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id 41be03b00d2f7-5637a108d02so1786444a12.2 for ; Mon, 24 Jul 2023 17:00:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1690243204; x=1690848004; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=LZitIKEGHOUJcKGa5imxxibILXWHECIO3+E2QgXBYx4=; b=fCEApc3K/Gk9sLGq0Edwz4wQJ/ExAzVaf/I7mHAaozgnLNkBIjytyamCWbD9+FAWTR yRmBeGFiKiT/v7GgAvX/0TJfOJoroOkjS1e9NoyT76+u3xnjXKklXvY5/LTuRnUoZlqI AwTyOXS5XhQPIgPMKeUhvHnmHqZyV2poeZ08dCs/fwPtqHROTsYar+T0fteVhEgfQOFM ePIjcxqjomFoWubbr4pOX3JHdAeYCqcQp+9jyY6S3PFZkNu8Ye7j5NIUVYmIy/yEF6p+ HBBT/5NuBua8MlJIrv81FKTmHQPiAcYfH3rA50rIBOvarAUS8ar1qbz3xx3/HGZIOPaI LC1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690243204; x=1690848004; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=LZitIKEGHOUJcKGa5imxxibILXWHECIO3+E2QgXBYx4=; b=doj8SYGni1+vA9NN5OdbFRmtlKURaZE7wH43dz468Xpzd8p3pz86ckF+4RvlcaDVQU hH815koF7fInZtRVA9t7MrclZF5vpw8LGdxJ2K6/RhSLczEtrwnd/73jqfdUp67ic7Dd uA+yr6CIrM3Mv5KhanjNbdkxHeK643bnTTHdLCVWsaZYNbjiPbA8Xb+q5zswhrKfJMnT 6F+KNCfMGiEB9kvtGCOqmAiWcV9gnl/NnvJIwJ0sKtJFAQMVPMPuOxfCAXBnjmehuTqW wtYm3gKIkAomVxilDnRnx8v0Z1lfgKtc/1yaMnMWxPKlpDb8T5IBp766iS8QFZyZ/mEL 9IKw== X-Gm-Message-State: ABy/qLbajX4rOgH6iJle9lxDPn0TRNoJWHJLERGrT9qvejM44KuR3XH9 IrKUcWkoZAjjqIU8W1DADdGV4cC0q2bJOcNWq99hRNOWke+lG/6G9qwBia5MWFk/OMAR1Vh290W Aj5dg4o4GOTIsJ6ljXcaFVLrvtUZ6u9iKWM61Da5AVuZJfc7grA== X-Google-Smtp-Source: APBJJlGy3Nz+k5GT9X9wvFeUyrorRpVRZGHJ8SWTchnCCXPJPV9E7z9nZOCSwkMYcnQqi6yJsobvfEY= X-Received: from sdf.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5935]) (user=sdf job=sendgmr) by 2002:a63:330b:0:b0:563:3c98:cdae with SMTP id z11-20020a63330b000000b005633c98cdaemr43542pgz.4.1690243203028; Mon, 24 Jul 2023 17:00:03 -0700 (PDT) Date: Mon, 24 Jul 2023 16:59:51 -0700 In-Reply-To: <20230724235957.1953861-1-sdf@google.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20230724235957.1953861-1-sdf@google.com> X-Mailer: git-send-email 2.41.0.487.g6d72f3e995-goog Message-ID: <20230724235957.1953861-3-sdf@google.com> Subject: [RFC net-next v4 2/8] xsk: add TX timestamp and TX checksum offload support From: Stanislav Fomichev 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, netdev@vger.kernel.org, xdp-hints@xdp-project.net X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC This change actually defines the (initial) metadata layout that should be used by AF_XDP userspace (xsk_tx_metadata). The first field is flags which requests appropriate offloads, followed by the offload-specific fields. The supported per-device offloads are exported via netlink (new xsk-flags). The offloads themselves are still implemented in a bit of a framework-y fashion that's left from my initial kfunc attempt. I'm introducing new xsk_tx_metadata_ops which drivers are supposed to implement. The drivers are also supposed to call xsk_tx_metadata_request/xsk_tx_metadata_complete in the right places. Since xsk_tx_metadata_{request,_complete} are static inline, we don't incur any extra overhead doing indirect calls. The benefit of this scheme is as follows: - keeps all metadata layout parsing away from driver code - makes it easy to grep and see which drivers implement what - don't need any extra flags to maintain to keep track of that offloads are implemented; if the callback is implemented - the offload is supported (used by netlink reporting code) Two offloads are defined right now: 1. XDP_TX_METADATA_CHECKSUM: skb-style csum_start+csum_offset 2. XDP_TX_METADATA_TIMESTAMP: writes TX timestamp back into metadata area upon completion (tx_timestamp field) The offloads are also implemented for copy mode: 1. Extra XDP_TX_METADATA_CHECKSUM_SW to trigger skb_checksum_help; this might be useful as a reference implementation and for testing 2. XDP_TX_METADATA_TIMESTAMP writes SW timestamp from the skb destructor (note I'm reusing hwtstamps to pass metadata pointer) The struct is forward-compatible and can be extended in the future by appending more fields. Signed-off-by: Stanislav Fomichev --- Documentation/netlink/specs/netdev.yaml | 19 ++++++++ include/linux/netdevice.h | 27 +++++++++++ include/linux/skbuff.h | 5 ++- include/net/xdp_sock.h | 60 +++++++++++++++++++++++++ include/net/xdp_sock_drv.h | 13 ++++++ include/uapi/linux/if_xdp.h | 35 +++++++++++++++ include/uapi/linux/netdev.h | 15 +++++++ net/core/netdev-genl.c | 12 ++++- net/xdp/xsk.c | 38 ++++++++++++++++ net/xdp/xsk_queue.h | 2 +- tools/include/uapi/linux/if_xdp.h | 50 ++++++++++++++++++--- 11 files changed, 268 insertions(+), 8 deletions(-) diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml index e41015310a6e..bf9c1cc32614 100644 --- a/Documentation/netlink/specs/netdev.yaml +++ b/Documentation/netlink/specs/netdev.yaml @@ -42,6 +42,19 @@ name: netdev doc: This feature informs if netdev implements non-linear XDP buffer support in ndo_xdp_xmit callback. + - + type: flags + name: xsk-flags + render-max: true + entries: + - + name: tx-timestamp + doc: + HW timestamping egress packets is supported by the driver. + - + name: tx-checksum + doc: + L3 checksum HW offload is supported by the driver. attribute-sets: - @@ -68,6 +81,12 @@ name: netdev type: u32 checks: min: 1 + - + name: xsk-features + doc: Bitmask of enabled AF_XDP features. + type: u64 + enum: xsk-flags + enum-as-flags: true operations: list: diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 11652e464f5d..8b40c80557aa 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1660,6 +1660,31 @@ struct xdp_metadata_ops { enum xdp_rss_hash_type *rss_type); }; +/* + * This structure defines the AF_XDP TX metadata hooks for network devices. + * The following hooks can be defined; unless noted otherwise, they are + * optional and can be filled with a null pointer. + * + * int (*tmo_request_timestamp)(void *priv) + * This function is called when AF_XDP frame requested egress timestamp. + * + * int (*tmo_fill_timestamp)(void *priv) + * This function is called when AF_XDP frame, that had requested + * egress timestamp, received a completion. The hook needs to return + * the actual HW timestamp. + * + * int (*tmo_request_timestamp)(u16 csum_start, u16 csum_offset, void *priv) + * This function is called when AF_XDP frame requested HW checksum + * offload. csum_start indicates position where checksumming should start. + * csum_offset indicates position where checksum should be stored. + * + */ +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); +}; + /** * enum netdev_priv_flags - &struct net_device priv_flags * @@ -1844,6 +1869,7 @@ enum netdev_ml_priv_type { * @netdev_ops: Includes several pointers to callbacks, * if one wants to override the ndo_*() functions * @xdp_metadata_ops: Includes pointers to XDP metadata callbacks. + * @xsk_tx_metadata_ops: Includes pointers to AF_XDP TX metadata callbacks. * @ethtool_ops: Management operations * @l3mdev_ops: Layer 3 master device operations * @ndisc_ops: Includes callbacks for different IPv6 neighbour @@ -2100,6 +2126,7 @@ struct net_device { unsigned long long priv_flags; const struct net_device_ops *netdev_ops; const struct xdp_metadata_ops *xdp_metadata_ops; + const struct xsk_tx_metadata_ops *xsk_tx_metadata_ops; int ifindex; unsigned short gflags; unsigned short hard_header_len; diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index faaba050f843..5febc1a5131e 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -581,7 +581,10 @@ struct skb_shared_info { /* Warning: this field is not always filled in (UFO)! */ unsigned short gso_segs; struct sk_buff *frag_list; - struct skb_shared_hwtstamps hwtstamps; + union { + struct skb_shared_hwtstamps hwtstamps; + struct xsk_tx_metadata *xsk_meta; + }; unsigned int gso_type; u32 tskey; diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index 467b9fb56827..288fa58c4665 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -90,6 +90,54 @@ int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp); int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp); void __xsk_map_flush(void); +/** + * xsk_tx_metadata_request - Evaluate AF_XDP TX metadata at submission + * and call appropriate xsk_tx_metadata_ops operation. + * @meta: pointer to AF_XDP metadata area + * @ops: pointer to struct xsk_tx_metadata_ops + * @priv: pointer to driver-private aread + * + * This function should be called by the networking device when + * it prepares AF_XDP egress packet. + */ +static inline void xsk_tx_metadata_request(const struct xsk_tx_metadata *meta, + const struct xsk_tx_metadata_ops *ops, + void *priv) +{ + if (!meta) + return; + + if (ops->tmo_request_timestamp) + if (meta->flags & XDP_TX_METADATA_TIMESTAMP) + ops->tmo_request_timestamp(priv); + + if (ops->tmo_request_checksum) + if (meta->flags & XDP_TX_METADATA_CHECKSUM) + ops->tmo_request_checksum(meta->csum_start, meta->csum_offset, priv); +} + +/** + * xsk_tx_metadata_complete - Evaluate AF_XDP TX metadata at completion + * and call appropriate xsk_tx_metadata_ops operation. + * @meta: pointer to AF_XDP metadata area + * @ops: pointer to struct xsk_tx_metadata_ops + * @priv: pointer to driver-private aread + * + * This function should be called by the networking device upon + * AF_XDP egress completion. + */ +static inline void xsk_tx_metadata_complete(struct xsk_tx_metadata *meta, + const struct xsk_tx_metadata_ops *ops, + void *priv) +{ + if (!meta) + return; + + if (ops->tmo_fill_timestamp) + if (meta->flags & XDP_TX_METADATA_TIMESTAMP) + meta->tx_timestamp = ops->tmo_fill_timestamp(priv); +} + #else static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) @@ -106,6 +154,18 @@ static inline void __xsk_map_flush(void) { } +static inline void xsk_tx_metadata_request(struct xsk_tx_metadata *meta, + const struct xsk_tx_metadata_ops *ops, + void *priv) +{ +} + +static inline void xsk_tx_metadata_complete(struct xsk_tx_metadata *meta, + const struct xsk_tx_metadata_ops *ops, + void *priv) +{ +} + #endif /* CONFIG_XDP_SOCKETS */ #endif /* _LINUX_XDP_SOCK_H */ diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h index 1f6fc8c7a84c..e2558ac3e195 100644 --- a/include/net/xdp_sock_drv.h +++ b/include/net/xdp_sock_drv.h @@ -165,6 +165,14 @@ static inline void *xsk_buff_raw_get_data(struct xsk_buff_pool *pool, u64 addr) return xp_raw_get_data(pool, addr); } +static inline struct xsk_tx_metadata *xsk_buff_get_metadata(struct xsk_buff_pool *pool, u64 addr) +{ + if (!pool->tx_metadata_len) + return NULL; + + return xp_raw_get_data(pool, addr) - pool->tx_metadata_len; +} + static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp, struct xsk_buff_pool *pool) { struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp); @@ -324,6 +332,11 @@ static inline void *xsk_buff_raw_get_data(struct xsk_buff_pool *pool, u64 addr) return NULL; } +static inline struct xsk_tx_metadata *xsk_buff_get_metadata(struct xsk_buff_pool *pool, u64 addr) +{ + return NULL; +} + static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp, struct xsk_buff_pool *pool) { } diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h index b37b50102e1c..b9b1b2c4108a 100644 --- a/include/uapi/linux/if_xdp.h +++ b/include/uapi/linux/if_xdp.h @@ -106,6 +106,38 @@ struct xdp_options { #define XSK_UNALIGNED_BUF_ADDR_MASK \ ((1ULL << XSK_UNALIGNED_BUF_OFFSET_SHIFT) - 1) +/* Request transmit timestamp. Upon completion, put it into tx_timestamp + * field of struct xsk_tx_metadata. + */ +#define XDP_TX_METADATA_TIMESTAMP (1 << 0) + +/* Request transmit checksum offload. Checksum start position and offset + * are communicated via csum_start and csum_offset fields of struct + * xsk_tx_metadata. + */ +#define XDP_TX_METADATA_CHECKSUM (1 << 1) + +/* Force checksum calculation in software. Can be used for testing or + * working around potential HW issues. This option causes performance + * degradation and only works in XDP_COPY mode. + */ +#define XDP_TX_METADATA_CHECKSUM_SW (1 << 2) + +struct xsk_tx_metadata { + __u32 flags; + + /* XDP_TX_METADATA_CHECKSUM */ + + /* Offset from desc->addr where checksumming should start. */ + __u16 csum_start; + /* Offset from csum_start where checksum should be stored. */ + __u16 csum_offset; + + /* XDP_TX_METADATA_TIMESTAMP */ + + __u64 tx_timestamp; +}; + /* Rx/Tx descriptor */ struct xdp_desc { __u64 addr; @@ -122,4 +154,7 @@ struct xdp_desc { */ #define XDP_PKT_CONTD (1 << 0) +/* TX packet carries valid metadata. */ +#define XDP_TX_METADATA (1 << 1) + #endif /* _LINUX_IF_XDP_H */ diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h index bf71698a1e82..cf1e11c76339 100644 --- a/include/uapi/linux/netdev.h +++ b/include/uapi/linux/netdev.h @@ -37,11 +37,26 @@ enum netdev_xdp_act { NETDEV_XDP_ACT_MASK = 127, }; +/** + * enum netdev_xsk_flags + * @NETDEV_XSK_FLAGS_TX_TIMESTAMP: HW timestamping egress packets is supported + * by the driver. + * @NETDEV_XSK_FLAGS_TX_CHECKSUM: L3 checksum HW offload is supported by the + * driver. + */ +enum netdev_xsk_flags { + NETDEV_XSK_FLAGS_TX_TIMESTAMP = 1, + NETDEV_XSK_FLAGS_TX_CHECKSUM = 2, + + NETDEV_XSK_FLAGS_MASK = 3, +}; + enum { NETDEV_A_DEV_IFINDEX = 1, NETDEV_A_DEV_PAD, NETDEV_A_DEV_XDP_FEATURES, NETDEV_A_DEV_XDP_ZC_MAX_SEGS, + NETDEV_A_DEV_XSK_FEATURES, __NETDEV_A_DEV_MAX, NETDEV_A_DEV_MAX = (__NETDEV_A_DEV_MAX - 1) diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c index 65ef4867fc49..9e8c1f3caf36 100644 --- a/net/core/netdev-genl.c +++ b/net/core/netdev-genl.c @@ -12,15 +12,25 @@ static int netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp, u32 portid, u32 seq, int flags, u32 cmd) { + u64 xsk_flags = 0; void *hdr; hdr = genlmsg_put(rsp, portid, seq, &netdev_nl_family, flags, cmd); if (!hdr) return -EMSGSIZE; + if (netdev->xsk_tx_metadata_ops) { + if (netdev->xsk_tx_metadata_ops->tmo_fill_timestamp) + xsk_flags |= NETDEV_XSK_FLAGS_TX_TIMESTAMP; + if (netdev->xsk_tx_metadata_ops->tmo_request_checksum) + xsk_flags |= NETDEV_XSK_FLAGS_TX_CHECKSUM; + } + if (nla_put_u32(rsp, NETDEV_A_DEV_IFINDEX, netdev->ifindex) || nla_put_u64_64bit(rsp, NETDEV_A_DEV_XDP_FEATURES, - netdev->xdp_features, NETDEV_A_DEV_PAD)) { + netdev->xdp_features, NETDEV_A_DEV_PAD) || + nla_put_u64_64bit(rsp, NETDEV_A_DEV_XSK_FEATURES, + xsk_flags, NETDEV_A_DEV_PAD)) { genlmsg_cancel(rsp, hdr); return -EINVAL; } diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 81106e4d6e0f..9a5c4e63898d 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -542,6 +542,15 @@ static u32 xsk_get_num_desc(struct sk_buff *skb) static void xsk_destruct_skb(struct sk_buff *skb) { + struct xsk_tx_metadata *meta = skb_shinfo(skb)->xsk_meta; + + if (meta) { + if (meta->flags & XDP_TX_METADATA_TIMESTAMP) { + /* sw completion timestamp, not a real one */ + meta->tx_timestamp = ktime_get_tai_fast_ns(); + } + } + xsk_cq_submit_locked(xdp_sk(skb->sk), xsk_get_num_desc(skb)); sock_wfree(skb); } @@ -626,6 +635,7 @@ static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, struct xdp_desc *desc) { + struct xsk_tx_metadata *meta = NULL; struct net_device *dev = xs->dev; struct sk_buff *skb = xs->skb; int err; @@ -678,12 +688,40 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, skb_add_rx_frag(skb, nr_frags, page, 0, len, 0); } + + if (desc->options & XDP_TX_METADATA) { + if (unlikely(xs->tx_metadata_len == 0)) { + err = -EINVAL; + goto free_err; + } + + meta = buffer - xs->tx_metadata_len; + + if (meta->flags & XDP_TX_METADATA_CHECKSUM) { + if (unlikely(meta->csum_start + meta->csum_offset + + sizeof(__sum16) > len)) { + err = -EINVAL; + goto free_err; + } + + skb->csum_start = hr + meta->csum_start; + skb->csum_offset = meta->csum_offset; + skb->ip_summed = CHECKSUM_PARTIAL; + + if (unlikely(meta->flags & XDP_TX_METADATA_CHECKSUM_SW)) { + err = skb_checksum_help(skb); + if (err) + goto free_err; + } + } + } } skb->dev = dev; skb->priority = xs->sk.sk_priority; skb->mark = xs->sk.sk_mark; skb->destructor = xsk_destruct_skb; + skb_shinfo(skb)->xsk_meta = meta; xsk_set_destructor_arg(skb); return skb; diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h index c74a1372bcb9..6f2d1621c992 100644 --- a/net/xdp/xsk_queue.h +++ b/net/xdp/xsk_queue.h @@ -137,7 +137,7 @@ static inline bool xskq_cons_read_addr_unchecked(struct xsk_queue *q, u64 *addr) static inline bool xp_unused_options_set(u32 options) { - return options & ~XDP_PKT_CONTD; + return options & ~(XDP_PKT_CONTD | XDP_TX_METADATA); } static inline bool xp_aligned_validate_desc(struct xsk_buff_pool *pool, diff --git a/tools/include/uapi/linux/if_xdp.h b/tools/include/uapi/linux/if_xdp.h index 73a47da885dc..b9b1b2c4108a 100644 --- a/tools/include/uapi/linux/if_xdp.h +++ b/tools/include/uapi/linux/if_xdp.h @@ -26,11 +26,11 @@ */ #define XDP_USE_NEED_WAKEUP (1 << 3) /* By setting this option, userspace application indicates that it can - * handle multiple descriptors per packet thus enabling xsk core to split + * handle multiple descriptors per packet thus enabling AF_XDP to split * multi-buffer XDP frames into multiple Rx descriptors. Without this set - * such frames will be dropped by xsk. + * such frames will be dropped. */ -#define XDP_USE_SG (1 << 4) +#define XDP_USE_SG (1 << 4) /* Flags for xsk_umem_config flags */ #define XDP_UMEM_UNALIGNED_CHUNK_FLAG (1 << 0) @@ -69,6 +69,7 @@ struct xdp_mmap_offsets { #define XDP_UMEM_COMPLETION_RING 6 #define XDP_STATISTICS 7 #define XDP_OPTIONS 8 +#define XDP_TX_METADATA_LEN 9 struct xdp_umem_reg { __u64 addr; /* Start of packet data area */ @@ -105,6 +106,38 @@ struct xdp_options { #define XSK_UNALIGNED_BUF_ADDR_MASK \ ((1ULL << XSK_UNALIGNED_BUF_OFFSET_SHIFT) - 1) +/* Request transmit timestamp. Upon completion, put it into tx_timestamp + * field of struct xsk_tx_metadata. + */ +#define XDP_TX_METADATA_TIMESTAMP (1 << 0) + +/* Request transmit checksum offload. Checksum start position and offset + * are communicated via csum_start and csum_offset fields of struct + * xsk_tx_metadata. + */ +#define XDP_TX_METADATA_CHECKSUM (1 << 1) + +/* Force checksum calculation in software. Can be used for testing or + * working around potential HW issues. This option causes performance + * degradation and only works in XDP_COPY mode. + */ +#define XDP_TX_METADATA_CHECKSUM_SW (1 << 2) + +struct xsk_tx_metadata { + __u32 flags; + + /* XDP_TX_METADATA_CHECKSUM */ + + /* Offset from desc->addr where checksumming should start. */ + __u16 csum_start; + /* Offset from csum_start where checksum should be stored. */ + __u16 csum_offset; + + /* XDP_TX_METADATA_TIMESTAMP */ + + __u64 tx_timestamp; +}; + /* Rx/Tx descriptor */ struct xdp_desc { __u64 addr; @@ -112,9 +145,16 @@ struct xdp_desc { __u32 options; }; -/* Flag indicating packet constitutes of multiple buffers*/ +/* UMEM descriptor is __u64 */ + +/* Flag indicating that the packet continues with the buffer pointed out by the + * next frame in the ring. The end of the packet is signalled by setting this + * bit to zero. For single buffer packets, every descriptor has 'options' set + * to 0 and this maintains backward compatibility. + */ #define XDP_PKT_CONTD (1 << 0) -/* UMEM descriptor is __u64 */ +/* TX packet carries valid metadata. */ +#define XDP_TX_METADATA (1 << 1) #endif /* _LINUX_IF_XDP_H */