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Message-ID: <00bbbf48440c1889ecd16a590ebb746b820a4f48.camel@linux.ibm.com>
Subject: Re: [PATCH net-next] net/smc: add support for netdevice in
 containers.
From:   Niklas Schnelle <schnelle@linux.ibm.com>
To:     Albert Huang <huangjie.albert@bytedance.com>,
        Karsten Graul <kgraul@linux.ibm.com>,
        Wenjia Zhang <wenjia@linux.ibm.com>,
        Jan Karcher <jaka@linux.ibm.com>
Cc:     "D. Wythe" <alibuda@linux.alibaba.com>,
        Tony Lu <tonylu@linux.alibaba.com>,
        Wen Gu <guwen@linux.alibaba.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, linux-s390@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Thu, 28 Sep 2023 17:04:21 +0200
In-Reply-To: <20230925023546.9964-1-huangjie.albert@bytedance.com>
References: <20230925023546.9964-1-huangjie.albert@bytedance.com>
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On Mon, 2023-09-25 at 10:35 +0800, Albert Huang wrote:
> If the netdevice is within a container and communicates externally
> through network technologies like VXLAN, we won't be able to find
> routing information in the init_net namespace. To address this issue,
> we need to add a struct net parameter to the smc_ib_find_route function.
> This allow us to locate the routing information within the corresponding
> net namespace, ensuring the correct completion of the SMC CLC interaction.
>=20
> Signed-off-by: Albert Huang <huangjie.albert@bytedance.com>
> ---
>  net/smc/af_smc.c | 3 ++-
>  net/smc/smc_ib.c | 7 ++++---
>  net/smc/smc_ib.h | 2 +-
>  3 files changed, 7 insertions(+), 5 deletions(-)
>=20

I'm trying to test this patch on s390x but I'm running into the same
issue I ran into with the original SMC namespace
support:https://lore.kernel.org/netdev/8701fa4557026983a9ec687cfdd7ac5b3b85=
fd39.camel@linux.ibm.com/

Just like back then I'm using a server and a client network namespace
on the same system with two ConnectX-4 VFs from the same card and port.
Both TCP/IP traffic as well as user-space RDMA via "qperf =E2=80=A6 rc_bw" =
and
`qperf =E2=80=A6 rc_lat` work between namespaces and definitely go via the
card.

I did use "rdma system set netns exclusive" then moved the RDMA devices
into the namespaces with "rdma dev set <rdma_dev> netns <namespace>". I
also verified with "ip netns exec <namespace> rdma dev"
that the RDMA devices are in the network namespace and as seen by the
qperf runs normal RDMA does work.

For reference the smc_chck tool gives me the following output:

Server started on port 37373
[DEBUG] Interfaces to check: eno4378
Test with target IP 10.10.93.12 and port 37373
  Live test (SMC-D and SMC-R)
[DEBUG] Running client: smc_run /tmp/echo-clt.x0q8iO 10.10.93.12 -p
37373
[DEBUG] Client result: TCP 0x05000000/0x03030000
     Failed  (TCP fallback), reasons:
          Client:        0x05000000   Peer declined during handshake
          Server:        0x03030000   No SMC devices found (R and D)

I also checked that SMC is generally working, once I add an ISM device
I do get SMC-D between the namespaces. Any ideas what could break SMC-R
here?

Thanks,
Niklas