From: Jakub Kicinski <kuba@kernel.org>
To: Stanislav Fomichev <sdf@google.com>
Cc: bpf@vger.kernel.org, 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,
haoluo@google.com, jolsa@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,
yoong.siang.song@intel.com, netdev@vger.kernel.org,
xdp-hints@xdp-project.net
Subject: [xdp-hints] Re: [PATCH bpf-next v6 02/13] xsk: Add TX timestamp and TX checksum offload support
Date: Wed, 29 Nov 2023 08:49:13 -0800 [thread overview]
Message-ID: <20231129084913.01dc63c2@kernel.org> (raw)
In-Reply-To: <20231127190319.1190813-3-sdf@google.com>
On Mon, 27 Nov 2023 11:03:08 -0800 Stanislav Fomichev wrote:
> 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.
Acked-by: Jakub Kicinski <kuba@kernel.org>
next prev parent reply other threads:[~2023-11-29 16:49 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-27 19:03 [xdp-hints] [PATCH bpf-next v6 00/13] xsk: TX metadata Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 01/13] xsk: Support tx_metadata_len Stanislav Fomichev
2023-11-28 3:09 ` [xdp-hints] " Jakub Kicinski
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 02/13] xsk: Add TX timestamp and TX checksum offload support Stanislav Fomichev
2023-11-29 16:49 ` Jakub Kicinski [this message]
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 03/13] tools: ynl: Print xsk-features from the sample Stanislav Fomichev
2023-11-29 16:47 ` [xdp-hints] " Jakub Kicinski
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 04/13] net/mlx5e: Implement AF_XDP TX timestamp and checksum offload Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 05/13] net: stmmac: Add Tx HWTS support to XDP ZC Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 06/13] xsk: Document tx_metadata_len layout Stanislav Fomichev
2023-12-02 17:09 ` [xdp-hints] " Simon Horman
2023-12-04 16:48 ` Stanislav Fomichev
2023-12-07 10:47 ` Simon Horman
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 07/13] xsk: Validate xsk_tx_metadata flags Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 08/13] xsk: Add option to calculate TX checksum in SW Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 09/13] selftests/xsk: Support tx_metadata_len Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 10/13] selftests/bpf: Add csum helpers Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 11/13] selftests/bpf: Add TX side to xdp_metadata Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 12/13] selftests/bpf: Convert xdp_hw_metadata to XDP_USE_NEED_WAKEUP Stanislav Fomichev
2023-11-27 19:03 ` [xdp-hints] [PATCH bpf-next v6 13/13] selftests/bpf: Add TX side to xdp_hw_metadata Stanislav Fomichev
2023-11-29 23:10 ` [xdp-hints] Re: [PATCH bpf-next v6 00/13] xsk: TX metadata patchwork-bot+netdevbpf
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