netdev - Re: [BUG] mlx5 have problems with ipv4-ipv6 tunnels in linux 4.4

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Message-ID: <CALzJLG8wWzfddbnbsjfMKPcsP-byCcKeWmmBYWvpfbDX1m6yqg@mail.gmail.com>
Date:   Mon, 9 Jul 2018 15:31:50 -0700
From:   Saeed Mahameed <saeedm@....mellanox.co.il>
To:     Konstantin Khlebnikov <khlebnikov@...dex-team.ru>
Cc:     netdev <netdev@...r.kernel.org>,
        Saeed Mahameed <saeedm@...lanox.com>,
        Or Gerlitz <ogerlitz@...lanox.com>,
        Tariq Toukan <tariqt@...lanox.com>,
        Gal Pressman <galp@...lanox.com>
Subject: Re: [BUG] mlx5 have problems with ipv4-ipv6 tunnels in linux 4.4

On Tue, Jul 3, 2018 at 10:45 PM, Konstantin Khlebnikov
<khlebnikov@...dex-team.ru> wrote:
> I'm seeing problems with tunnelled traffic with Mellanox Technologies
> MT27710 Family [ConnectX-4 Lx] using vanilla driver from linux 4.4.y
>
> Packets with payload bigger than 116 bytes are not exmited.
> Smaller packets and normal ipv6 works fine.
>

Hi Konstantin,

Is this true for all ipv6 traffic or just ipv4-ipv6 tunnels ?

what is the skb_network_offset(skb) for such packet ?

> In linux 4.9, 4.14 and out-of-tree driver everything seems fine for now.
> It's hard to guess or bisect commit: there are a lot of changes and
> something wrong with driver or swiotlb in 4.7..4.8.
> 4.6 is affected too - so this should be something between 4.6 and 4.9
>
> Probably this case was fixed indirectly by adding some kind of offload and
> non-offloaded path is still broken.
> Please give me a hint: which commit could it be.
>

I suspect it works in a newer kernel since we introduced on 4.7/4.8:

commit e3a19b53cbb0e6738b7a547f262179065b72e3fa
Author: Matthew Finlay <matt@...lanox.com>
Date:   Thu Jun 30 17:34:47 2016 +0300

    net/mlx5e: Copy all L2 headers into inline segment

    ConnectX4-Lx uses an inline wqe mode that currently defaults to
    requiring the entire L2 header be included in the wqe.
    This patch fixes mlx5e_get_inline_hdr_size() to account for
    all L2 headers (VLAN, QinQ, etc) using skb_network_offset(skb).

    Fixes: e586b3b0baee ("net/mlx5: Ethernet Datapath files")
    Signed-off-by: Matthew Finlay <matt@...lanox.com>
    Signed-off-by: Saeed Mahameed <saeedm@...lanox.com>
    Signed-off-by: David S. Miller <davem@...emloft.net>



commit ae76715d153e33c249b6850361e4d8d775388b5a
Author: Hadar Hen Zion <hadarh@...lanox.com>
Date:   Sun Jul 24 16:12:39 2016 +0300

    net/mlx5e: Check the minimum inline header mode before xmit

and then some fixes on top of it, such as:

commit f600c6088018d1dbc5777d18daa83660f7ea4a64
Author: Eran Ben Elisha <eranbe@...lanox.com>
Date:   Thu Jan 25 11:18:09 2018 +0200

    net/mlx5e: Verify inline header size do not exceed SKB linear size


anyhow, can you try the above patches one by one  on 4.4.y and see if it helps ?


Thanks,
Saeed