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48eb03dd26
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.
Reviewed-by: Song Yoong Siang <yoong.siang.song@intel.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20231127190319.1190813-3-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
93 lines
2.3 KiB
C
93 lines
2.3 KiB
C
/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
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/* Do not edit directly, auto-generated from: */
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/* Documentation/netlink/specs/netdev.yaml */
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/* YNL-GEN user header */
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#ifndef _LINUX_NETDEV_GEN_H
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#define _LINUX_NETDEV_GEN_H
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#include <stdlib.h>
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#include <string.h>
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#include <linux/types.h>
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#include <linux/netdev.h>
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struct ynl_sock;
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extern const struct ynl_family ynl_netdev_family;
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/* Enums */
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const char *netdev_op_str(int op);
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const char *netdev_xdp_act_str(enum netdev_xdp_act value);
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const char *netdev_xdp_rx_metadata_str(enum netdev_xdp_rx_metadata value);
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const char *netdev_xsk_flags_str(enum netdev_xsk_flags value);
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/* Common nested types */
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/* ============== NETDEV_CMD_DEV_GET ============== */
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/* NETDEV_CMD_DEV_GET - do */
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struct netdev_dev_get_req {
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struct {
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__u32 ifindex:1;
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} _present;
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__u32 ifindex;
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};
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static inline struct netdev_dev_get_req *netdev_dev_get_req_alloc(void)
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{
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return calloc(1, sizeof(struct netdev_dev_get_req));
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}
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void netdev_dev_get_req_free(struct netdev_dev_get_req *req);
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static inline void
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netdev_dev_get_req_set_ifindex(struct netdev_dev_get_req *req, __u32 ifindex)
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{
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req->_present.ifindex = 1;
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req->ifindex = ifindex;
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}
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struct netdev_dev_get_rsp {
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struct {
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__u32 ifindex:1;
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__u32 xdp_features:1;
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__u32 xdp_zc_max_segs:1;
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__u32 xdp_rx_metadata_features:1;
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__u32 xsk_features:1;
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} _present;
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__u32 ifindex;
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__u64 xdp_features;
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__u32 xdp_zc_max_segs;
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__u64 xdp_rx_metadata_features;
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__u64 xsk_features;
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};
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void netdev_dev_get_rsp_free(struct netdev_dev_get_rsp *rsp);
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/*
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* Get / dump information about a netdev.
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*/
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struct netdev_dev_get_rsp *
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netdev_dev_get(struct ynl_sock *ys, struct netdev_dev_get_req *req);
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/* NETDEV_CMD_DEV_GET - dump */
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struct netdev_dev_get_list {
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struct netdev_dev_get_list *next;
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struct netdev_dev_get_rsp obj __attribute__((aligned(8)));
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};
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void netdev_dev_get_list_free(struct netdev_dev_get_list *rsp);
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struct netdev_dev_get_list *netdev_dev_get_dump(struct ynl_sock *ys);
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/* NETDEV_CMD_DEV_GET - notify */
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struct netdev_dev_get_ntf {
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__u16 family;
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__u8 cmd;
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struct ynl_ntf_base_type *next;
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void (*free)(struct netdev_dev_get_ntf *ntf);
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struct netdev_dev_get_rsp obj __attribute__((aligned(8)));
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};
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void netdev_dev_get_ntf_free(struct netdev_dev_get_ntf *rsp);
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#endif /* _LINUX_NETDEV_GEN_H */
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