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From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: Martin KaFai Lau <martin.lau@linux.dev>,
	Stanislav Fomichev <sdf@google.com>
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
	song@kernel.org, yhs@fb.com, john.fastabend@gmail.com,
	kpsingh@kernel.org, haoluo@google.com, jolsa@kernel.org,
	bpf@vger.kernel.org
Subject: Re: [PATCH bpf-next v4 06/15] bpf: Support consuming XDP HW metadata from fext programs
Date: Wed, 14 Dec 2022 11:41:51 +0100	[thread overview]
Message-ID: <87cz8mgtcg.fsf@toke.dk> (raw)
In-Reply-To: <1a0436c5-2198-0c69-1306-872454d2fb13@linux.dev>

Martin KaFai Lau <martin.lau@linux.dev> writes:

> On 12/12/22 6:35 PM, Stanislav Fomichev wrote:
>> From: Toke Høiland-Jørgensen <toke@redhat.com>
>> 
>> Instead of rejecting the attaching of PROG_TYPE_EXT programs to XDP
>> programs that consume HW metadata, implement support for propagating the
>> offload information. The extension program doesn't need to set a flag or
>> ifindex, it these will just be propagated from the target by the verifier.
>
> s/it/because/ ... these will just be propagated....

Yeah, or just drop 'it' :)

>> We need to create a separate offload object for the extension program,
>> though, since it can be reattached to a different program later (which
>> means we can't just inhering the offload information from the target).
>
> hmm.... inheriting?

Think I meant to write "we can't just inherit"

>> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
>> index 11c558be4992..8686475f0dbe 100644
>> --- a/kernel/bpf/syscall.c
>> +++ b/kernel/bpf/syscall.c
>> @@ -3021,6 +3021,14 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog,
>>   			goto out_put_prog;
>>   		}
>>   
>> +		if (bpf_prog_is_dev_bound(prog->aux) &&
>
>
>> +		    (bpf_prog_is_offloaded(tgt_prog->aux) ||
>> +		     !bpf_prog_is_dev_bound(tgt_prog->aux) ||
>> +		     !bpf_offload_dev_match(prog, tgt_prog->aux->offload->netdev))) {
>
> hmm... tgt_prog->aux->offload does not look safe without taking bpf_devs_lock. 
> offload could be NULL, no?
>
> It probably needs a bpf_prog_dev_bound_match(prog, tgt_prog) which takes the lock.

Hmm, right, I was kinda expecting that this would not go away while
tgt_prog was alive, but I see now that's not the case due to the
unregister hook. So yeah, needs locking (same below) :)

-Toke


  reply	other threads:[~2022-12-14 10:42 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-13  2:35 [PATCH bpf-next v4 00/15] xdp: hints via kfuncs Stanislav Fomichev
2022-12-13  2:35 ` [PATCH bpf-next v4 01/15] bpf: Document XDP RX metadata Stanislav Fomichev
2022-12-13 16:37   ` David Vernet
2022-12-13 20:42     ` Stanislav Fomichev
2022-12-14 10:34       ` [xdp-hints] " Toke Høiland-Jørgensen
2022-12-14 18:42         ` Stanislav Fomichev
2022-12-14 23:46           ` Toke Høiland-Jørgensen
2022-12-15  3:48             ` Stanislav Fomichev
2022-12-15 14:04               ` Toke Høiland-Jørgensen
2022-12-14 23:46   ` [xdp-hints] " Toke Høiland-Jørgensen
2022-12-17  4:20   ` kernel test robot
2022-12-13  2:35 ` [PATCH bpf-next v4 02/15] bpf: Rename bpf_{prog,map}_is_dev_bound to is_offloaded Stanislav Fomichev
2022-12-13  2:35 ` [PATCH bpf-next v4 03/15] bpf: Introduce device-bound XDP programs Stanislav Fomichev
2022-12-13 23:25   ` Martin KaFai Lau
2022-12-14 18:42     ` Stanislav Fomichev
2022-12-13  2:35 ` [PATCH bpf-next v4 04/15] selftests/bpf: Update expected test_offload.py messages Stanislav Fomichev
2022-12-13  2:35 ` [PATCH bpf-next v4 05/15] bpf: XDP metadata RX kfuncs Stanislav Fomichev
2022-12-13 17:00   ` David Vernet
2022-12-13 20:42     ` Stanislav Fomichev
2022-12-13 21:45       ` David Vernet
2022-12-14  1:53   ` Martin KaFai Lau
2022-12-14 18:43     ` Stanislav Fomichev
2022-12-14 10:54   ` [xdp-hints] " Toke Høiland-Jørgensen
2022-12-14 18:43     ` Stanislav Fomichev
2022-12-13  2:35 ` [PATCH bpf-next v4 06/15] bpf: Support consuming XDP HW metadata from fext programs Stanislav Fomichev
2022-12-14  1:45   ` Martin KaFai Lau
2022-12-14 10:41     ` Toke Høiland-Jørgensen [this message]
2022-12-14 18:43       ` Stanislav Fomichev
2022-12-14 22:19         ` Toke Høiland-Jørgensen
2022-12-13  2:35 ` [PATCH bpf-next v4 07/15] veth: Introduce veth_xdp_buff wrapper for xdp_buff Stanislav Fomichev
2022-12-13  2:35 ` [PATCH bpf-next v4 08/15] veth: Support RX XDP metadata Stanislav Fomichev
2022-12-13 15:55   ` Jesper Dangaard Brouer
2022-12-13 20:42     ` Stanislav Fomichev
2022-12-14  9:48       ` Jesper Dangaard Brouer
2022-12-14 10:47         ` [xdp-hints] " Toke Høiland-Jørgensen
2022-12-14 18:09           ` Martin KaFai Lau
2022-12-14 18:44             ` Stanislav Fomichev
2022-12-13  2:35 ` [PATCH bpf-next v4 09/15] selftests/bpf: Verify xdp_metadata xdp->af_xdp path Stanislav Fomichev
2022-12-13  2:36 ` [PATCH bpf-next v4 10/15] net/mlx4_en: Introduce wrapper for xdp_buff Stanislav Fomichev
2022-12-13  8:56   ` Tariq Toukan
2022-12-13  2:36 ` [PATCH bpf-next v4 11/15] net/mlx4_en: Support RX XDP metadata Stanislav Fomichev
2022-12-13  8:56   ` Tariq Toukan
2022-12-13  2:36 ` [PATCH bpf-next v4 12/15] xsk: Add cb area to struct xdp_buff_xsk Stanislav Fomichev
2022-12-13  2:36 ` [PATCH bpf-next v4 13/15] net/mlx5e: Introduce wrapper for xdp_buff Stanislav Fomichev
2022-12-13  2:36 ` [PATCH bpf-next v4 14/15] net/mlx5e: Support RX XDP metadata Stanislav Fomichev
2022-12-13  2:36 ` [PATCH bpf-next v4 15/15] selftests/bpf: Simple program to dump XDP RX metadata Stanislav Fomichev

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