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From:   Andrii Nakryiko <andrii.nakryiko@gmail.com>
Date:   Wed, 24 Aug 2022 13:52:10 -0700
Message-ID: <CAEf4Bza=Ra8uC3HuQgcaDx4s78mdRtrD+z7=qStCX5MTnJ7fOg@mail.gmail.com>
Subject: Re: [PATCH v3 1/4] bpf: Define new BPF_MAP_TYPE_USER_RINGBUF map type
To:     David Vernet <void@manifault.com>
Cc:     bpf@vger.kernel.org, ast@kernel.org, andrii@kernel.org,
        daniel@iogearbox.net, kernel-team@fb.com, martin.lau@linux.dev,
        song@kernel.org, yhs@fb.com, john.fastabend@gmail.com,
        kpsingh@kernel.org, sdf@google.com, haoluo@google.com,
        jolsa@kernel.org, joannelkoong@gmail.com, tj@kernel.org,
        linux-kernel@vger.kernel.org
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On Thu, Aug 18, 2022 at 3:12 PM David Vernet <void@manifault.com> wrote:
>
> We want to support a ringbuf map type where samples are published from
> user-space, to be consumed by BPF programs. BPF currently supports a kernel
> -> user-space circular ringbuffer via the BPF_MAP_TYPE_RINGBUF map type.
> We'll need to define a new map type for user-space -> kernel, as none of
> the helpers exported for BPF_MAP_TYPE_RINGBUF will apply to a user-space
> producer ringbuffer, and we'll want to add one or more helper functions
> that would not apply for a kernel-producer ringbuffer.
>
> This patch therefore adds a new BPF_MAP_TYPE_USER_RINGBUF map type
> definition. The map type is useless in its current form, as there is no way
> to access or use it for anything until we one or more BPF helpers. A
> follow-on patch will therefore add a new helper function that allows BPF
> programs to run callbacks on samples that are published to the ringbuffer.
>
> Signed-off-by: David Vernet <void@manifault.com>
> ---

LGTM.

Acked-by: Andrii Nakryiko <andrii@kernel.org>

>  include/linux/bpf_types.h      |  1 +
>  include/uapi/linux/bpf.h       |  1 +
>  kernel/bpf/ringbuf.c           | 62 ++++++++++++++++++++++++++++++----
>  kernel/bpf/verifier.c          |  3 ++
>  tools/include/uapi/linux/bpf.h |  1 +
>  tools/lib/bpf/libbpf.c         |  1 +
>  6 files changed, 63 insertions(+), 6 deletions(-)

[...]