From: "Björn Töpel" <bjorn.topel@intel.com>
To: "Toke Høiland-Jørgensen" <toke@redhat.com>,
"Björn Töpel" <bjorn.topel@gmail.com>,
ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org,
bpf@vger.kernel.org
Cc: magnus.karlsson@intel.com, maciej.fijalkowski@intel.com,
kuba@kernel.org, jonathan.lemon@gmail.com, maximmi@nvidia.com,
davem@davemloft.net, hawk@kernel.org, john.fastabend@gmail.com,
ciara.loftus@intel.com, weqaar.a.janjua@intel.com,
Marek Majtyka <alardam@gmail.com>
Subject: Re: [PATCH bpf-next v2 5/8] libbpf, xsk: select AF_XDP BPF program based on kernel version
Date: Wed, 20 Jan 2021 15:49:45 +0100 [thread overview]
Message-ID: <6cda7383-663e-ed92-45dd-bbf87ca45eef@intel.com> (raw)
In-Reply-To: <6c7da700-700d-c7f6-fe0a-c42e55e81c8a@intel.com>
On 2021-01-20 14:25, Björn Töpel wrote:
> On 2021-01-20 13:52, Toke Høiland-Jørgensen wrote:
>> Björn Töpel <bjorn.topel@gmail.com> writes:
>>
>>> From: Björn Töpel <bjorn.topel@intel.com>
>>>
>>> Add detection for kernel version, and adapt the BPF program based on
>>> kernel support. This way, users will get the best possible performance
>>> from the BPF program.
>>
>> Please do explicit feature detection instead of relying on the kernel
>> version number; some distro kernels are known to have a creative notion
>> of their own version, which is not really related to the features they
>> actually support (I'm sure you know which one I'm referring to ;)).
>>
>
> Right. For a *new* helper, like bpf_redirect_xsk, we rely on rejection
> from the verifier to detect support. What about "bpf_redirect_map() now
> supports passing return value as flags"? Any ideas how to do that in a
> robust, non-version number-based scheme?
>
Just so that I understand this correctly. Red^WSome distro vendors
backport the world, and call that franken kernel, say, 3.10. Is that
interpretation correct? My hope was that wasn't the case. :-(
Would it make sense with some kind of BPF-specific "supported features"
mechanism? Something else with a bigger scope (whole kernel)?
Cheers,
Björn
next prev parent reply other threads:[~2021-01-20 15:37 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-19 15:50 [PATCH bpf-next v2 0/8] Introduce bpf_redirect_xsk() helper Björn Töpel
2021-01-19 15:50 ` [PATCH bpf-next v2 1/8] xdp: restructure redirect actions Björn Töpel
2021-01-20 12:44 ` Toke Høiland-Jørgensen
2021-01-20 13:40 ` Björn Töpel
2021-01-20 14:52 ` Toke Høiland-Jørgensen
2021-01-20 15:49 ` Björn Töpel
2021-01-20 16:30 ` Toke Høiland-Jørgensen
2021-01-20 17:26 ` Björn Töpel
2021-01-19 15:50 ` [PATCH bpf-next v2 2/8] xsk: remove explicit_free parameter from __xsk_rcv() Björn Töpel
2021-01-19 15:50 ` [PATCH bpf-next v2 3/8] xsk: fold xp_assign_dev and __xp_assign_dev Björn Töpel
2021-01-19 15:50 ` [PATCH bpf-next v2 4/8] xsk: register XDP sockets at bind(), and add new AF_XDP BPF helper Björn Töpel
2021-01-20 8:25 ` kernel test robot
2021-01-20 8:25 ` kernel test robot
2021-01-20 8:41 ` Björn Töpel
2021-01-20 8:41 ` Björn Töpel
2021-01-20 8:50 ` kernel test robot
2021-01-20 8:50 ` kernel test robot
2021-01-20 12:50 ` Toke Høiland-Jørgensen
2021-01-20 13:25 ` Björn Töpel
2021-01-20 14:54 ` Toke Høiland-Jørgensen
2021-01-20 15:18 ` Björn Töpel
2021-01-20 17:29 ` Toke Høiland-Jørgensen
2021-01-20 18:22 ` Björn Töpel
2021-01-20 20:26 ` Toke Høiland-Jørgensen
2021-01-20 21:15 ` Alexei Starovoitov
2021-01-21 8:18 ` Björn Töpel
2021-01-19 15:50 ` [PATCH bpf-next v2 5/8] libbpf, xsk: select AF_XDP BPF program based on kernel version Björn Töpel
2021-01-20 12:52 ` Toke Høiland-Jørgensen
2021-01-20 13:25 ` Björn Töpel
2021-01-20 14:49 ` Björn Töpel [this message]
2021-01-20 15:11 ` Toke Høiland-Jørgensen
2021-01-20 15:27 ` Björn Töpel
2021-01-20 17:30 ` Toke Høiland-Jørgensen
2021-01-20 18:25 ` Alexei Starovoitov
2021-01-20 18:30 ` Björn Töpel
2021-01-20 14:56 ` Toke Høiland-Jørgensen
2021-01-19 15:50 ` [PATCH bpf-next v2 6/8] libbpf, xsk: select bpf_redirect_xsk(), if supported Björn Töpel
2021-01-19 15:50 ` [PATCH bpf-next v2 7/8] selftest/bpf: add XDP socket tests for bpf_redirect_{xsk, map}() Björn Töpel
2021-01-21 7:39 ` Andrii Nakryiko
2021-01-21 12:31 ` Björn Töpel
2021-01-19 15:50 ` [PATCH bpf-next v2 8/8] selftest/bpf: remove a lot of ifobject casting in xdpxceiver Björn Töpel
2021-01-20 13:15 ` [PATCH bpf-next v2 0/8] Introduce bpf_redirect_xsk() helper Maxim Mikityanskiy
2021-01-20 13:27 ` Björn Töpel
2021-01-20 15:57 ` Jesper Dangaard Brouer
2021-01-20 16:19 ` Maciej Fijalkowski
2021-01-21 17:01 ` Jesper Dangaard Brouer
2021-01-22 8:59 ` Magnus Karlsson
2021-01-22 9:45 ` Maciej Fijalkowski
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