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xsk: Add TX timestamp and TX checksum offload support

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 what 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_TXMD_FLAGS_CHECKSUM: skb-style csum_start+csum_offset 2. XDP_TXMD_FLAGS_TIMESTAMP: writes TX timestamp back into metadata area upon completion (tx_timestamp field) XDP_TXMD_FLAGS_TIMESTAMP is also implemented for XDP_COPY mode: it 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.

Stanislav Fomichev committed 2 years ago

Commit 48eb03d1 parent 341ac9815 files · +348 −9Browse files

Unified · Split

15 files
  1. Documentation/netlink/specs/netdev.yaml +18 −1
  2. include/linux/netdevice.h +2 −0
  3. include/linux/skbuff.h +13 −1
  4. include/net/xdp_sock.h +110 −0
  5. include/net/xdp_sock_drv.h +13 −0
  6. include/net/xsk_buff_pool.h +6 −0
  7. include/uapi/linux/if_xdp.h +38 −0
  8. include/uapi/linux/netdev.h +16 −0
  9. net/core/netdev-genl.c +12 −1
  10. net/xdp/xsk.c +34 −0
  11. net/xdp/xsk_queue.h +1 −1
  12. tools/include/uapi/linux/if_xdp.h +47 −5
  13. tools/include/uapi/linux/netdev.h +16 −0
  14. tools/net/ynl/generated/netdev-user.c +19 −0
  15. tools/net/ynl/generated/netdev-user.h +3 −0
Documentation/netlink/specs/netdev.yaml+18−1
@@ -45,7 +45,6 @@ definitions: · 44 unmodified lines
4545 -
4646 type: flags
4747 name: xdp-rx-metadata
48− render-max: true
4948 entries:
5049 -
5150 name: timestamp
@@ -55,6 +54,18 @@ definitions: · 3 unmodified lines
5554 name: hash
5655 doc:
5756 Device is capable of exposing receive packet hash via bpf_xdp_metadata_rx_hash().
57+ -
58+ type: flags
59+ name: xsk-flags
60+ entries:
61+ -
62+ name: tx-timestamp
63+ doc:
64+ HW timestamping egress packets is supported by the driver.
65+ -
66+ name: tx-checksum
67+ doc:
68+ L3 checksum HW offload is supported by the driver.
5869
5970 attribute-sets:
6071 -
@@ -86,6 +97,11 @@ attribute-sets: · 25 unmodified lines
8697 See Documentation/networking/xdp-rx-metadata.rst for more details.
8798 type: u64
8899 enum: xdp-rx-metadata
100+ -
101+ name: xsk-features
102+ doc: Bitmask of enabled AF_XDP features.
103+ type: u64
104+ enum: xsk-flags
89105
90106 operations:
91107 list:
@@ -103,6 +119,7 @@ operations: · 11 unmodified lines
103119 - xdp-features
104120 - xdp-zc-max-segs
105121 - xdp-rx-metadata-features
122+ - xsk-features
106123 dump:
107124 reply: *dev-all
108125 -
include/linux/netdevice.h+2−0
@@ -1865,6 +1865,7 @@ enum netdev_stat_type { · 1864 unmodified lines
18651865 * @netdev_ops: Includes several pointers to callbacks,
18661866 * if one wants to override the ndo_*() functions
18671867 * @xdp_metadata_ops: Includes pointers to XDP metadata callbacks.
1868+ * @xsk_tx_metadata_ops: Includes pointers to AF_XDP TX metadata callbacks.
18681869 * @ethtool_ops: Management operations
18691870 * @l3mdev_ops: Layer 3 master device operations
18701871 * @ndisc_ops: Includes callbacks for different IPv6 neighbour
@@ -2128,6 +2129,7 @@ struct net_device { · 257 unmodified lines
21282129 unsigned long long priv_flags;
21292130 const struct net_device_ops *netdev_ops;
21302131 const struct xdp_metadata_ops *xdp_metadata_ops;
2132+ const struct xsk_tx_metadata_ops *xsk_tx_metadata_ops;
21312133 int ifindex;
21322134 unsigned short gflags;
21332135 unsigned short hard_header_len;
include/linux/skbuff.h+13−1
@@ -566,6 +566,15 @@ struct ubuf_info_msgzc { · 565 unmodified lines
566566 int mm_account_pinned_pages(struct mmpin *mmp, size_t size);
567567 void mm_unaccount_pinned_pages(struct mmpin *mmp);
568568
569+/* Preserve some data across TX submission and completion.
570+ *
571+ * Note, this state is stored in the driver. Extending the layout
572+ * might need some special care.
573+ */
574+struct xsk_tx_metadata_compl {
575+ __u64 *tx_timestamp;
576+};
577+
569578 /* This data is invariant across clones and lives at
570579 * the end of the header data, ie. at skb->end.
571580 */
@@ -578,7 +587,10 @@ struct skb_shared_info { · 6 unmodified lines
578587 /* Warning: this field is not always filled in (UFO)! */
579588 unsigned short gso_segs;
580589 struct sk_buff *frag_list;
581− struct skb_shared_hwtstamps hwtstamps;
590+ union {
591+ struct skb_shared_hwtstamps hwtstamps;
592+ struct xsk_tx_metadata_compl xsk_meta;
593+ };
582594 unsigned int gso_type;
583595 u32 tskey;
584596
include/net/xdp_sock.h+110−0
@@ -93,12 +93,105 @@ struct xdp_sock { · 92 unmodified lines
9393 struct xsk_queue *cq_tmp; /* Only as tmp storage before bind */
9494 };
9595
96+/*
97+ * AF_XDP TX metadata hooks for network devices.
98+ * The following hooks can be defined; unless noted otherwise, they are
99+ * optional and can be filled with a null pointer.
100+ *
101+ * void (*tmo_request_timestamp)(void *priv)
102+ * Called when AF_XDP frame requested egress timestamp.
103+ *
104+ * u64 (*tmo_fill_timestamp)(void *priv)
105+ * Called when AF_XDP frame, that had requested egress timestamp,
106+ * received a completion. The hook needs to return the actual HW timestamp.
107+ *
108+ * void (*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv)
109+ * Called when AF_XDP frame requested HW checksum offload. csum_start
110+ * indicates position where checksumming should start.
111+ * csum_offset indicates position where checksum should be stored.
112+ *
113+ */
114+struct xsk_tx_metadata_ops {
115+ void (*tmo_request_timestamp)(void *priv);
116+ u64 (*tmo_fill_timestamp)(void *priv);
117+ void (*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv);
118+};
119+
96120 #ifdef CONFIG_XDP_SOCKETS
97121
98122 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
99123 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp);
100124 void __xsk_map_flush(void);
101125
126+/**
127+ * xsk_tx_metadata_to_compl - Save enough relevant metadata information
128+ * to perform tx completion in the future.
129+ * @meta: pointer to AF_XDP metadata area
130+ * @compl: pointer to output struct xsk_tx_metadata_to_compl
131+ *
132+ * This function should be called by the networking device when
133+ * it prepares AF_XDP egress packet. The value of @compl should be stored
134+ * and passed to xsk_tx_metadata_complete upon TX completion.
135+ */
136+static inline void xsk_tx_metadata_to_compl(struct xsk_tx_metadata *meta,
137+ struct xsk_tx_metadata_compl *compl)
138+{
139+ if (!meta)
140+ return;
141+
142+ if (meta->flags & XDP_TXMD_FLAGS_TIMESTAMP)
143+ compl->tx_timestamp = &meta->completion.tx_timestamp;
144+ else
145+ compl->tx_timestamp = NULL;
146+}
147+
148+/**
149+ * xsk_tx_metadata_request - Evaluate AF_XDP TX metadata at submission
150+ * and call appropriate xsk_tx_metadata_ops operation.
151+ * @meta: pointer to AF_XDP metadata area
152+ * @ops: pointer to struct xsk_tx_metadata_ops
153+ * @priv: pointer to driver-private aread
154+ *
155+ * This function should be called by the networking device when
156+ * it prepares AF_XDP egress packet.
157+ */
158+static inline void xsk_tx_metadata_request(const struct xsk_tx_metadata *meta,
159+ const struct xsk_tx_metadata_ops *ops,
160+ void *priv)
161+{
162+ if (!meta)
163+ return;
164+
165+ if (ops->tmo_request_timestamp)
166+ if (meta->flags & XDP_TXMD_FLAGS_TIMESTAMP)
167+ ops->tmo_request_timestamp(priv);
168+
169+ if (ops->tmo_request_checksum)
170+ if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM)
171+ ops->tmo_request_checksum(meta->request.csum_start,
172+ meta->request.csum_offset, priv);
173+}
174+
175+/**
176+ * xsk_tx_metadata_complete - Evaluate AF_XDP TX metadata at completion
177+ * and call appropriate xsk_tx_metadata_ops operation.
178+ * @compl: pointer to completion metadata produced from xsk_tx_metadata_to_compl
179+ * @ops: pointer to struct xsk_tx_metadata_ops
180+ * @priv: pointer to driver-private aread
181+ *
182+ * This function should be called by the networking device upon
183+ * AF_XDP egress completion.
184+ */
185+static inline void xsk_tx_metadata_complete(struct xsk_tx_metadata_compl *compl,
186+ const struct xsk_tx_metadata_ops *ops,
187+ void *priv)
188+{
189+ if (!compl)
190+ return;
191+
192+ *compl->tx_timestamp = ops->tmo_fill_timestamp(priv);
193+}
194+
102195 #else
103196
104197 static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
@@ -115,6 +208,23 @@ static inline void __xsk_map_flush(void) · 10 unmodified lines
115208 {
116209 }
117210
211+static inline void xsk_tx_metadata_to_compl(struct xsk_tx_metadata *meta,
212+ struct xsk_tx_metadata_compl *compl)
213+{
214+}
215+
216+static inline void xsk_tx_metadata_request(struct xsk_tx_metadata *meta,
217+ const struct xsk_tx_metadata_ops *ops,
218+ void *priv)
219+{
220+}
221+
222+static inline void xsk_tx_metadata_complete(struct xsk_tx_metadata_compl *compl,
223+ const struct xsk_tx_metadata_ops *ops,
224+ void *priv)
225+{
226+}
227+
118228 #endif /* CONFIG_XDP_SOCKETS */
119229
120230 #if defined(CONFIG_XDP_SOCKETS) && defined(CONFIG_DEBUG_NET)
include/net/xdp_sock_drv.h+13−0
@@ -165,6 +165,14 @@ static inline void *xsk_buff_raw_get_data(struct xsk_buff_pool *pool, u64 addr) · 164 unmodified lines
165165 return xp_raw_get_data(pool, addr);
166166 }
167167
168+static inline struct xsk_tx_metadata *xsk_buff_get_metadata(struct xsk_buff_pool *pool, u64 addr)
169+{
170+ if (!pool->tx_metadata_len)
171+ return NULL;
172+
173+ return xp_raw_get_data(pool, addr) - pool->tx_metadata_len;
174+}
175+
168176 static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp, struct xsk_buff_pool *pool)
169177 {
170178 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) · 153 unmodified lines
324332 return NULL;
325333 }
326334
335+static inline struct xsk_tx_metadata *xsk_buff_get_metadata(struct xsk_buff_pool *pool, u64 addr)
336+{
337+ return NULL;
338+}
339+
327340 static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp, struct xsk_buff_pool *pool)
328341 {
329342 }
include/net/xsk_buff_pool.h+6−0
@@ -33,6 +33,7 @@ struct xdp_buff_xsk { · 32 unmodified lines
3333 };
3434
3535 #define XSK_CHECK_PRIV_TYPE(t) BUILD_BUG_ON(sizeof(t) > offsetofend(struct xdp_buff_xsk, cb))
36+#define XSK_TX_COMPL_FITS(t) BUILD_BUG_ON(sizeof(struct xsk_tx_metadata_compl) > sizeof(t))
3637
3738 struct xsk_dma_map {
3839 dma_addr_t *dma_pages;
@@ -234,4 +235,9 @@ static inline u64 xp_get_handle(struct xdp_buff_xsk *xskb) · 195 unmodified lines
234235 return xskb->orig_addr + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
235236 }
236237
238+static inline bool xp_tx_metadata_enabled(const struct xsk_buff_pool *pool)
239+{
240+ return pool->tx_metadata_len > 0;
241+}
242+
237243 #endif /* XSK_BUFF_POOL_H_ */
include/uapi/linux/if_xdp.h+38−0
@@ -106,6 +106,41 @@ struct xdp_options { · 105 unmodified lines
106106 #define XSK_UNALIGNED_BUF_ADDR_MASK \
107107 ((1ULL << XSK_UNALIGNED_BUF_OFFSET_SHIFT) - 1)
108108
109+/* Request transmit timestamp. Upon completion, put it into tx_timestamp
110+ * field of struct xsk_tx_metadata.
111+ */
112+#define XDP_TXMD_FLAGS_TIMESTAMP (1 << 0)
113+
114+/* Request transmit checksum offload. Checksum start position and offset
115+ * are communicated via csum_start and csum_offset fields of struct
116+ * xsk_tx_metadata.
117+ */
118+#define XDP_TXMD_FLAGS_CHECKSUM (1 << 1)
119+
120+/* AF_XDP offloads request. 'request' union member is consumed by the driver
121+ * when the packet is being transmitted. 'completion' union member is
122+ * filled by the driver when the transmit completion arrives.
123+ */
124+struct xsk_tx_metadata {
125+ __u64 flags;
126+
127+ union {
128+ struct {
129+ /* XDP_TXMD_FLAGS_CHECKSUM */
130+
131+ /* Offset from desc->addr where checksumming should start. */
132+ __u16 csum_start;
133+ /* Offset from csum_start where checksum should be stored. */
134+ __u16 csum_offset;
135+ } request;
136+
137+ struct {
138+ /* XDP_TXMD_FLAGS_TIMESTAMP */
139+ __u64 tx_timestamp;
140+ } completion;
141+ };
142+};
143+
109144 /* Rx/Tx descriptor */
110145 struct xdp_desc {
111146 __u64 addr;
@@ -122,4 +157,7 @@ struct xdp_desc { · 10 unmodified lines
122157 */
123158 #define XDP_PKT_CONTD (1 << 0)
124159
160+/* TX packet carries valid metadata. */
161+#define XDP_TX_METADATA (1 << 1)
162+
125163 #endif /* _LINUX_IF_XDP_H */
include/uapi/linux/netdev.h+16−0
@@ -53,12 +53,28 @@ enum netdev_xdp_rx_metadata { · 52 unmodified lines
5353 NETDEV_XDP_RX_METADATA_MASK = 3,
5454 };
5555
56+/**
57+ * enum netdev_xsk_flags
58+ * @NETDEV_XSK_FLAGS_TX_TIMESTAMP: HW timestamping egress packets is supported
59+ * by the driver.
60+ * @NETDEV_XSK_FLAGS_TX_CHECKSUM: L3 checksum HW offload is supported by the
61+ * driver.
62+ */
63+enum netdev_xsk_flags {
64+ NETDEV_XSK_FLAGS_TX_TIMESTAMP = 1,
65+ NETDEV_XSK_FLAGS_TX_CHECKSUM = 2,
66+
67+ /* private: */
68+ NETDEV_XSK_FLAGS_MASK = 3,
69+};
70+
5671 enum {
5772 NETDEV_A_DEV_IFINDEX = 1,
5873 NETDEV_A_DEV_PAD,
5974 NETDEV_A_DEV_XDP_FEATURES,
6075 NETDEV_A_DEV_XDP_ZC_MAX_SEGS,
6176 NETDEV_A_DEV_XDP_RX_METADATA_FEATURES,
77+ NETDEV_A_DEV_XSK_FEATURES,
6278
6379 __NETDEV_A_DEV_MAX,
6480 NETDEV_A_DEV_MAX = (__NETDEV_A_DEV_MAX - 1)
net/core/netdev-genl.c+12−1
@@ -6,6 +6,7 @@ · 5 unmodified lines
66 #include <net/net_namespace.h>
77 #include <net/sock.h>
88 #include <net/xdp.h>
9+#include <net/xdp_sock.h>
910
1011 #include "netdev-genl-gen.h"
1112
@@ -13,6 +14,7 @@ static int · 1 unmodified line
1314 netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp,
1415 const struct genl_info *info)
1516 {
17+ u64 xsk_features = 0;
1618 u64 xdp_rx_meta = 0;
1719 void *hdr;
1820
@@ -26,11 +28,20 @@ netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp, · 7 unmodified lines
2628 XDP_METADATA_KFUNC_xxx
2729 #undef XDP_METADATA_KFUNC
2830
31+ if (netdev->xsk_tx_metadata_ops) {
32+ if (netdev->xsk_tx_metadata_ops->tmo_fill_timestamp)
33+ xsk_features |= NETDEV_XSK_FLAGS_TX_TIMESTAMP;
34+ if (netdev->xsk_tx_metadata_ops->tmo_request_checksum)
35+ xsk_features |= NETDEV_XSK_FLAGS_TX_CHECKSUM;
36+ }
37+
2938 if (nla_put_u32(rsp, NETDEV_A_DEV_IFINDEX, netdev->ifindex) ||
3039 nla_put_u64_64bit(rsp, NETDEV_A_DEV_XDP_FEATURES,
3140 netdev->xdp_features, NETDEV_A_DEV_PAD) ||
3241 nla_put_u64_64bit(rsp, NETDEV_A_DEV_XDP_RX_METADATA_FEATURES,
33− xdp_rx_meta, NETDEV_A_DEV_PAD)) {
42+ xdp_rx_meta, NETDEV_A_DEV_PAD) ||
43+ nla_put_u64_64bit(rsp, NETDEV_A_DEV_XSK_FEATURES,
44+ xsk_features, NETDEV_A_DEV_PAD)) {
3445 genlmsg_cancel(rsp, hdr);
3546 return -EINVAL;
3647 }
net/xdp/xsk.c+34−0
@@ -571,6 +571,13 @@ static u32 xsk_get_num_desc(struct sk_buff *skb) · 570 unmodified lines
571571
572572 static void xsk_destruct_skb(struct sk_buff *skb)
573573 {
574+ struct xsk_tx_metadata_compl *compl = &skb_shinfo(skb)->xsk_meta;
575+
576+ if (compl->tx_timestamp) {
577+ /* sw completion timestamp, not a real one */
578+ *compl->tx_timestamp = ktime_get_tai_fast_ns();
579+ }
580+
574581 xsk_cq_submit_locked(xdp_sk(skb->sk), xsk_get_num_desc(skb));
575582 sock_wfree(skb);
576583 }
@@ -655,8 +662,10 @@ static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs, · 78 unmodified lines
655662 static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,
656663 struct xdp_desc *desc)
657664 {
665+ struct xsk_tx_metadata *meta = NULL;
658666 struct net_device *dev = xs->dev;
659667 struct sk_buff *skb = xs->skb;
668+ bool first_frag = false;
660669 int err;
661670
662671 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) {
@@ -687,6 +696,8 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, · 24 unmodified lines
687696 kfree_skb(skb);
688697 goto free_err;
689698 }
699+
700+ first_frag = true;
690701 } else {
691702 int nr_frags = skb_shinfo(skb)->nr_frags;
692703 struct page *page;
@@ -709,12 +720,35 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs, · 16 unmodified lines
709720
710721 skb_add_rx_frag(skb, nr_frags, page, 0, len, 0);
711722 }
723+
724+ if (first_frag && desc->options & XDP_TX_METADATA) {
725+ if (unlikely(xs->pool->tx_metadata_len == 0)) {
726+ err = -EINVAL;
727+ goto free_err;
728+ }
729+
730+ meta = buffer - xs->pool->tx_metadata_len;
731+
732+ if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM) {
733+ if (unlikely(meta->request.csum_start +
734+ meta->request.csum_offset +
735+ sizeof(__sum16) > len)) {
736+ err = -EINVAL;
737+ goto free_err;
738+ }
739+
740+ skb->csum_start = hr + meta->request.csum_start;
741+ skb->csum_offset = meta->request.csum_offset;
742+ skb->ip_summed = CHECKSUM_PARTIAL;
743+ }
744+ }
712745 }
713746
714747 skb->dev = dev;
715748 skb->priority = READ_ONCE(xs->sk.sk_priority);
716749 skb->mark = READ_ONCE(xs->sk.sk_mark);
717750 skb->destructor = xsk_destruct_skb;
751+ xsk_tx_metadata_to_compl(meta, &skb_shinfo(skb)->xsk_meta);
718752 xsk_set_destructor_arg(skb);
719753
720754 return skb;
net/xdp/xsk_queue.h+1−1
@@ -137,7 +137,7 @@ static inline bool xskq_cons_read_addr_unchecked(struct xsk_queue *q, u64 *addr) · 136 unmodified lines
137137
138138 static inline bool xp_unused_options_set(u32 options)
139139 {
140− return options & ~XDP_PKT_CONTD;
140+ return options & ~(XDP_PKT_CONTD | XDP_TX_METADATA);
141141 }
142142
143143 static inline bool xp_aligned_validate_desc(struct xsk_buff_pool *pool,
tools/include/uapi/linux/if_xdp.h+47−5
@@ -26,11 +26,11 @@ · 25 unmodified lines
2626 */
2727 #define XDP_USE_NEED_WAKEUP (1 << 3)
2828 /* By setting this option, userspace application indicates that it can
29− * handle multiple descriptors per packet thus enabling xsk core to split
29+ * handle multiple descriptors per packet thus enabling AF_XDP to split
3030 * multi-buffer XDP frames into multiple Rx descriptors. Without this set
31− * such frames will be dropped by xsk.
31+ * such frames will be dropped.
3232 */
33−#define XDP_USE_SG (1 << 4)
33+#define XDP_USE_SG (1 << 4)
3434
3535 /* Flags for xsk_umem_config flags */
3636 #define XDP_UMEM_UNALIGNED_CHUNK_FLAG (1 << 0)
@@ -106,6 +106,41 @@ struct xdp_options { · 69 unmodified lines
106106 #define XSK_UNALIGNED_BUF_ADDR_MASK \
107107 ((1ULL << XSK_UNALIGNED_BUF_OFFSET_SHIFT) - 1)
108108
109+/* Request transmit timestamp. Upon completion, put it into tx_timestamp
110+ * field of union xsk_tx_metadata.
111+ */
112+#define XDP_TXMD_FLAGS_TIMESTAMP (1 << 0)
113+
114+/* Request transmit checksum offload. Checksum start position and offset
115+ * are communicated via csum_start and csum_offset fields of union
116+ * xsk_tx_metadata.
117+ */
118+#define XDP_TXMD_FLAGS_CHECKSUM (1 << 1)
119+
120+/* AF_XDP offloads request. 'request' union member is consumed by the driver
121+ * when the packet is being transmitted. 'completion' union member is
122+ * filled by the driver when the transmit completion arrives.
123+ */
124+struct xsk_tx_metadata {
125+ __u64 flags;
126+
127+ union {
128+ struct {
129+ /* XDP_TXMD_FLAGS_CHECKSUM */
130+
131+ /* Offset from desc->addr where checksumming should start. */
132+ __u16 csum_start;
133+ /* Offset from csum_start where checksum should be stored. */
134+ __u16 csum_offset;
135+ } request;
136+
137+ struct {
138+ /* XDP_TXMD_FLAGS_TIMESTAMP */
139+ __u64 tx_timestamp;
140+ } completion;
141+ };
142+};
143+
109144 /* Rx/Tx descriptor */
110145 struct xdp_desc {
111146 __u64 addr;
@@ -113,9 +148,16 @@ struct xdp_desc { · 1 unmodified line
113148 __u32 options;
114149 };
115150
116−/* Flag indicating packet constitutes of multiple buffers*/
151+/* UMEM descriptor is __u64 */
152+
153+/* Flag indicating that the packet continues with the buffer pointed out by the
154+ * next frame in the ring. The end of the packet is signalled by setting this
155+ * bit to zero. For single buffer packets, every descriptor has 'options' set
156+ * to 0 and this maintains backward compatibility.
157+ */
117158 #define XDP_PKT_CONTD (1 << 0)
118159
119−/* UMEM descriptor is __u64 */
160+/* TX packet carries valid metadata. */
161+#define XDP_TX_METADATA (1 << 1)
120162
121163 #endif /* _LINUX_IF_XDP_H */
tools/include/uapi/linux/netdev.h+16−0
@@ -53,12 +53,28 @@ enum netdev_xdp_rx_metadata { · 52 unmodified lines
5353 NETDEV_XDP_RX_METADATA_MASK = 3,
5454 };
5555
56+/**
57+ * enum netdev_xsk_flags
58+ * @NETDEV_XSK_FLAGS_TX_TIMESTAMP: HW timestamping egress packets is supported
59+ * by the driver.
60+ * @NETDEV_XSK_FLAGS_TX_CHECKSUM: L3 checksum HW offload is supported by the
61+ * driver.
62+ */
63+enum netdev_xsk_flags {
64+ NETDEV_XSK_FLAGS_TX_TIMESTAMP = 1,
65+ NETDEV_XSK_FLAGS_TX_CHECKSUM = 2,
66+
67+ /* private: */
68+ NETDEV_XSK_FLAGS_MASK = 3,
69+};
70+
5671 enum {
5772 NETDEV_A_DEV_IFINDEX = 1,
5873 NETDEV_A_DEV_PAD,
5974 NETDEV_A_DEV_XDP_FEATURES,
6075 NETDEV_A_DEV_XDP_ZC_MAX_SEGS,
6176 NETDEV_A_DEV_XDP_RX_METADATA_FEATURES,
77+ NETDEV_A_DEV_XSK_FEATURES,
6278
6379 __NETDEV_A_DEV_MAX,
6480 NETDEV_A_DEV_MAX = (__NETDEV_A_DEV_MAX - 1)
tools/net/ynl/generated/netdev-user.c+19−0
@@ -58,6 +58,19 @@ const char *netdev_xdp_rx_metadata_str(enum netdev_xdp_rx_metadata value) · 57 unmodified lines
5858 return netdev_xdp_rx_metadata_strmap[value];
5959 }
6060
61+static const char * const netdev_xsk_flags_strmap[] = {
62+ [0] = "tx-timestamp",
63+ [1] = "tx-checksum",
64+};
65+
66+const char *netdev_xsk_flags_str(enum netdev_xsk_flags value)
67+{
68+ value = ffs(value) - 1;
69+ if (value < 0 || value >= (int)MNL_ARRAY_SIZE(netdev_xsk_flags_strmap))
70+ return NULL;
71+ return netdev_xsk_flags_strmap[value];
72+}
73+
6174 /* Policies */
6275 struct ynl_policy_attr netdev_dev_policy[NETDEV_A_DEV_MAX + 1] = {
6376 [NETDEV_A_DEV_IFINDEX] = { .name = "ifindex", .type = YNL_PT_U32, },
@@ -65,6 +78,7 @@ struct ynl_policy_attr netdev_dev_policy[NETDEV_A_DEV_MAX + 1] = { · 1 unmodified line
6578 [NETDEV_A_DEV_XDP_FEATURES] = { .name = "xdp-features", .type = YNL_PT_U64, },
6679 [NETDEV_A_DEV_XDP_ZC_MAX_SEGS] = { .name = "xdp-zc-max-segs", .type = YNL_PT_U32, },
6780 [NETDEV_A_DEV_XDP_RX_METADATA_FEATURES] = { .name = "xdp-rx-metadata-features", .type = YNL_PT_U64, },
81+ [NETDEV_A_DEV_XSK_FEATURES] = { .name = "xsk-features", .type = YNL_PT_U64, },
6882 };
6983
7084 struct ynl_policy_nest netdev_dev_nest = {
@@ -116,6 +130,11 @@ int netdev_dev_get_rsp_parse(const struct nlmsghdr *nlh, void *data) · 45 unmodified lines
116130 return MNL_CB_ERROR;
117131 dst->_present.xdp_rx_metadata_features = 1;
118132 dst->xdp_rx_metadata_features = mnl_attr_get_u64(attr);
133+ } else if (type == NETDEV_A_DEV_XSK_FEATURES) {
134+ if (ynl_attr_validate(yarg, attr))
135+ return MNL_CB_ERROR;
136+ dst->_present.xsk_features = 1;
137+ dst->xsk_features = mnl_attr_get_u64(attr);
119138 }
120139 }
121140
tools/net/ynl/generated/netdev-user.h+3−0
@@ -19,6 +19,7 @@ extern const struct ynl_family ynl_netdev_family; · 18 unmodified lines
1919 const char *netdev_op_str(int op);
2020 const char *netdev_xdp_act_str(enum netdev_xdp_act value);
2121 const char *netdev_xdp_rx_metadata_str(enum netdev_xdp_rx_metadata value);
22+const char *netdev_xsk_flags_str(enum netdev_xsk_flags value);
2223
2324 /* Common nested types */
2425 /* ============== NETDEV_CMD_DEV_GET ============== */
@@ -50,12 +51,14 @@ struct netdev_dev_get_rsp { · 25 unmodified lines
5051 __u32 xdp_features:1;
5152 __u32 xdp_zc_max_segs:1;
5253 __u32 xdp_rx_metadata_features:1;
54+ __u32 xsk_features:1;
5355 } _present;
5456
5557 __u32 ifindex;
5658 __u64 xdp_features;
5759 __u32 xdp_zc_max_segs;
5860 __u64 xdp_rx_metadata_features;
61+ __u64 xsk_features;
5962 };
6063
6164 void netdev_dev_get_rsp_free(struct netdev_dev_get_rsp *rsp);