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

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Message-ID: <CAJ3xEMje3rnWLWSw5o98OEP_wsKdWKjZXY5EAEGMJpkdtSW4WA@mail.gmail.com>
Date:   Thu, 12 Jul 2018 21:03:04 +0300
From:   Or Gerlitz <gerlitz.or@...il.com>
To:     Konstantin Khlebnikov <khlebnikov@...dex-team.ru>,
        Saeed Mahameed <saeedm@...lanox.com>
Cc:     Saeed Mahameed <saeedm@....mellanox.co.il>,
        netdev <netdev@...r.kernel.org>,
        Or Gerlitz <ogerlitz@...lanox.com>,
        Tariq Toukan <tariqt@...lanox.com>
Subject: Re: [BUG] mlx5 have problems with ipv4-ipv6 tunnels in linux 4.4

On Tue, Jul 10, 2018 at 12:19 PM, Konstantin Khlebnikov
<khlebnikov@...dex-team.ru> wrote:
> On 10.07.2018 01:31, Saeed Mahameed wrote:
>>
>> 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:
>
>
> Yes, this works. Thank you.
>
> Problem was with VLAN rather than tunnel.
>
> This hunk from first patch is enough:
> -#define MLX5E_MIN_INLINE ETH_HLEN
> +#define MLX5E_MIN_INLINE (ETH_HLEN + VLAN_HLEN)


so... what should we do to fix 4.4-stable? just push there the 1st path?

Saeed, 4.4 is LTS, lets fix it there..

Or.


> In my case full data path looks like
>
> ( tcp -> ipip6 -> veth ) -> netns-to-host -> ( veth -> vlan at mlx5 )
>
> Tunnelled traffic also goes to vlan, while most of other traffic goes
> through non-tagged interface and worked fine.
>
> max_inline is 226 so (226 - vlan - ethernet - ipv6 - ipv4 - tcp)
> leaves exactly 116 bytes for payload.
>
>
>>
>> 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
>>
>