From: Lorenzo Bianconi <lorenzo@kernel.org>
To: Jakub Kicinski <kuba@kernel.org>
Cc: Donald Hunter <donald.hunter@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>, Simon Horman <horms@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Jesper Dangaard Brouer <hawk@kernel.org>,
John Fastabend <john.fastabend@gmail.com>,
Stanislav Fomichev <sdf@fomichev.me>,
Andrew Lunn <andrew+netdev@lunn.ch>,
Tony Nguyen <anthony.l.nguyen@intel.com>,
Przemek Kitszel <przemyslaw.kitszel@intel.com>,
Alexander Lobakin <aleksander.lobakin@intel.com>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
KP Singh <kpsingh@kernel.org>, Hao Luo <haoluo@google.com>,
Jiri Olsa <jolsa@kernel.org>, Shuah Khan <shuah@kernel.org>,
Maciej Fijalkowski <maciej.fijalkowski@intel.com>,
Jakub Sitnicki <jakub@cloudflare.com>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
intel-wired-lan@lists.osuosl.org,
linux-kselftest@vger.kernel.org
Subject: Re: [PATCH bpf-next v3 1/5] netlink: specs: Add XDP RX checksum capability to XDP metadata specs
Date: Thu, 19 Feb 2026 12:04:56 +0100 [thread overview]
Message-ID: <aZbuWBnmh_SQJyVf@lore-desk> (raw)
In-Reply-To: <20260218174742.62a4074f@kernel.org>
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> On Tue, 17 Feb 2026 09:33:56 +0100 Lorenzo Bianconi wrote:
> > + * In case of success, ``ip_summed`` is set to the RX checksum result. Possible
> > + * values are:
> > + * ``XDP_CHECKSUM_NONE``
> > + * ``XDP_CHECKSUM_UNNECESSARY``
> > + * ``XDP_CHECKSUM_COMPLETE``
> > + *
> > + * In case of success, ``cksum_meta`` contains the hw computed checksum value
> > + * for ``XDP_CHECKSUM_COMPLETE`` or the ``csum_level`` for
> > + * ``XDP_CHECKSUM_UNNECESSARY``. It is set to 0 for ``XDP_CHECKSUM_NONE``
>
> It's fairly common for NICs to report both csum complete and
> unnecessary. Which one should the driver return in that case?
Do you mean what is value for cksum_meta if we do not report csum_level for
XDP_CHECKSUM_UNNECESSARY/CHECKSUM_UNNECESSARY use-case? (as suggested by
Stanislav).
My original idea is:
- if the hw reports CHECKSUM_COMPLETE:
- ip_summed = XDP_CHECKSUM_COMPLETE
- cksum_meta contains the checksum computed by the hw
- if the hw reports CHECKSUM_UNNECESSARY
- ip_summed = XDP_CHECKSUM_UNNECESSARY
- cksum_meta = csum_level <-- Stanislav suggests to drop this one
- if the hw reports CHECKSUM_NONE
- ip_summed = XDP_CHECKSUM_NONE
- cksum_meta = 0
Regards,
Lorenzo
> What if the user prefers the other one?..
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next prev parent reply other threads:[~2026-02-19 11:04 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-17 8:33 [PATCH bpf-next v3 0/5] Add the the capability to load HW RX checsum in eBPF programs Lorenzo Bianconi
2026-02-17 8:33 ` [PATCH bpf-next v3 1/5] netlink: specs: Add XDP RX checksum capability to XDP metadata specs Lorenzo Bianconi
2026-02-18 1:01 ` Stanislav Fomichev
2026-02-18 10:58 ` Jesper Dangaard Brouer
2026-02-19 1:47 ` Jakub Kicinski
2026-02-19 11:04 ` Lorenzo Bianconi [this message]
2026-02-19 17:13 ` Jakub Kicinski
2026-02-23 17:11 ` Lorenzo Bianconi
2026-02-23 23:18 ` Jakub Kicinski
2026-02-27 13:21 ` Lorenzo Bianconi
2026-02-27 23:32 ` Jakub Kicinski
2026-02-28 11:58 ` Lorenzo Bianconi
2026-02-17 8:33 ` [PATCH bpf-next v3 2/5] net: veth: Add xmo_rx_checksum callback to veth driver Lorenzo Bianconi
2026-02-17 8:33 ` [PATCH bpf-next v3 3/5] net: ice: Add xmo_rx_checksum callback Lorenzo Bianconi
2026-02-17 8:33 ` [PATCH bpf-next v3 4/5] selftests/bpf: Add selftest support for bpf_xdp_metadata_rx_checksum Lorenzo Bianconi
2026-02-17 9:17 ` bot+bpf-ci
2026-02-17 8:34 ` [PATCH bpf-next v3 5/5] selftests/bpf: Add bpf_xdp_metadata_rx_checksum support to xdp_hw_metadat prog Lorenzo Bianconi
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