diff options
author | Stanislav Fomichev <sdf@google.com> | 2023-11-27 11:03:08 -0800 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2023-11-29 14:59:40 -0800 |
commit | 48eb03dd26304c24f03bdbb9382e89c8564e71df (patch) | |
tree | ac572d4d71fa6012c7267efc03d17c18bcb11e5c /tools | |
parent | 341ac980eab90ac1f6c22ee9f9da83ed9604d899 (diff) |
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.
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>
Diffstat (limited to 'tools')
-rw-r--r-- | tools/include/uapi/linux/if_xdp.h | 52 | ||||
-rw-r--r-- | tools/include/uapi/linux/netdev.h | 16 | ||||
-rw-r--r-- | tools/net/ynl/generated/netdev-user.c | 19 | ||||
-rw-r--r-- | tools/net/ynl/generated/netdev-user.h | 3 |
4 files changed, 85 insertions, 5 deletions
diff --git a/tools/include/uapi/linux/if_xdp.h b/tools/include/uapi/linux/if_xdp.h index 34411a2e5b6c..d0882edc1642 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) @@ -106,6 +106,41 @@ 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 union xsk_tx_metadata. + */ +#define XDP_TXMD_FLAGS_TIMESTAMP (1 << 0) + +/* Request transmit checksum offload. Checksum start position and offset + * are communicated via csum_start and csum_offset fields of union + * xsk_tx_metadata. + */ +#define XDP_TXMD_FLAGS_CHECKSUM (1 << 1) + +/* 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. + */ +struct xsk_tx_metadata { + __u64 flags; + + union { + struct { + /* XDP_TXMD_FLAGS_CHECKSUM */ + + /* Offset from desc->addr where checksumming should start. */ + __u16 csum_start; + /* Offset from csum_start where checksum should be stored. */ + __u16 csum_offset; + } request; + + struct { + /* XDP_TXMD_FLAGS_TIMESTAMP */ + __u64 tx_timestamp; + } completion; + }; +}; + /* Rx/Tx descriptor */ struct xdp_desc { __u64 addr; @@ -113,9 +148,16 @@ 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 */ diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h index 2943a151d4f1..48d5477a668c 100644 --- a/tools/include/uapi/linux/netdev.h +++ b/tools/include/uapi/linux/netdev.h @@ -53,12 +53,28 @@ enum netdev_xdp_rx_metadata { NETDEV_XDP_RX_METADATA_MASK = 3, }; +/** + * 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, + + /* private: */ + 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_XDP_RX_METADATA_FEATURES, + NETDEV_A_DEV_XSK_FEATURES, __NETDEV_A_DEV_MAX, NETDEV_A_DEV_MAX = (__NETDEV_A_DEV_MAX - 1) diff --git a/tools/net/ynl/generated/netdev-user.c b/tools/net/ynl/generated/netdev-user.c index b5ffe8cd1144..6283d87dad37 100644 --- a/tools/net/ynl/generated/netdev-user.c +++ b/tools/net/ynl/generated/netdev-user.c @@ -58,6 +58,19 @@ const char *netdev_xdp_rx_metadata_str(enum netdev_xdp_rx_metadata value) return netdev_xdp_rx_metadata_strmap[value]; } +static const char * const netdev_xsk_flags_strmap[] = { + [0] = "tx-timestamp", + [1] = "tx-checksum", +}; + +const char *netdev_xsk_flags_str(enum netdev_xsk_flags value) +{ + value = ffs(value) - 1; + if (value < 0 || value >= (int)MNL_ARRAY_SIZE(netdev_xsk_flags_strmap)) + return NULL; + return netdev_xsk_flags_strmap[value]; +} + /* Policies */ struct ynl_policy_attr netdev_dev_policy[NETDEV_A_DEV_MAX + 1] = { [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] = { [NETDEV_A_DEV_XDP_FEATURES] = { .name = "xdp-features", .type = YNL_PT_U64, }, [NETDEV_A_DEV_XDP_ZC_MAX_SEGS] = { .name = "xdp-zc-max-segs", .type = YNL_PT_U32, }, [NETDEV_A_DEV_XDP_RX_METADATA_FEATURES] = { .name = "xdp-rx-metadata-features", .type = YNL_PT_U64, }, + [NETDEV_A_DEV_XSK_FEATURES] = { .name = "xsk-features", .type = YNL_PT_U64, }, }; struct ynl_policy_nest netdev_dev_nest = { @@ -116,6 +130,11 @@ int netdev_dev_get_rsp_parse(const struct nlmsghdr *nlh, void *data) return MNL_CB_ERROR; dst->_present.xdp_rx_metadata_features = 1; dst->xdp_rx_metadata_features = mnl_attr_get_u64(attr); + } else if (type == NETDEV_A_DEV_XSK_FEATURES) { + if (ynl_attr_validate(yarg, attr)) + return MNL_CB_ERROR; + dst->_present.xsk_features = 1; + dst->xsk_features = mnl_attr_get_u64(attr); } } diff --git a/tools/net/ynl/generated/netdev-user.h b/tools/net/ynl/generated/netdev-user.h index 4fafac879df3..39af1908444b 100644 --- a/tools/net/ynl/generated/netdev-user.h +++ b/tools/net/ynl/generated/netdev-user.h @@ -19,6 +19,7 @@ extern const struct ynl_family ynl_netdev_family; const char *netdev_op_str(int op); const char *netdev_xdp_act_str(enum netdev_xdp_act value); const char *netdev_xdp_rx_metadata_str(enum netdev_xdp_rx_metadata value); +const char *netdev_xsk_flags_str(enum netdev_xsk_flags value); /* Common nested types */ /* ============== NETDEV_CMD_DEV_GET ============== */ @@ -50,12 +51,14 @@ struct netdev_dev_get_rsp { __u32 xdp_features:1; __u32 xdp_zc_max_segs:1; __u32 xdp_rx_metadata_features:1; + __u32 xsk_features:1; } _present; __u32 ifindex; __u64 xdp_features; __u32 xdp_zc_max_segs; __u64 xdp_rx_metadata_features; + __u64 xsk_features; }; void netdev_dev_get_rsp_free(struct netdev_dev_get_rsp *rsp); |