From 48eb03dd26304c24f03bdbb9382e89c8564e71df Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Mon, 27 Nov 2023 11:03:08 -0800 Subject: 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 Signed-off-by: Stanislav Fomichev Acked-by: Jakub Kicinski Link: https://lore.kernel.org/r/20231127190319.1190813-3-sdf@google.com Signed-off-by: Alexei Starovoitov --- net/core/netdev-genl.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'net/core/netdev-genl.c') diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c index fe61f85bcf33..10f2124e9e23 100644 --- a/net/core/netdev-genl.c +++ b/net/core/netdev-genl.c @@ -6,6 +6,7 @@ #include #include #include +#include #include "netdev-genl-gen.h" @@ -13,6 +14,7 @@ static int netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp, const struct genl_info *info) { + u64 xsk_features = 0; u64 xdp_rx_meta = 0; void *hdr; @@ -26,11 +28,20 @@ netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp, XDP_METADATA_KFUNC_xxx #undef XDP_METADATA_KFUNC + if (netdev->xsk_tx_metadata_ops) { + if (netdev->xsk_tx_metadata_ops->tmo_fill_timestamp) + xsk_features |= NETDEV_XSK_FLAGS_TX_TIMESTAMP; + if (netdev->xsk_tx_metadata_ops->tmo_request_checksum) + xsk_features |= 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) || nla_put_u64_64bit(rsp, NETDEV_A_DEV_XDP_RX_METADATA_FEATURES, - xdp_rx_meta, NETDEV_A_DEV_PAD)) { + xdp_rx_meta, NETDEV_A_DEV_PAD) || + nla_put_u64_64bit(rsp, NETDEV_A_DEV_XSK_FEATURES, + xsk_features, NETDEV_A_DEV_PAD)) { genlmsg_cancel(rsp, hdr); return -EINVAL; } -- cgit v1.2.3