From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DC45E15B122; Wed, 28 Aug 2024 10:29:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.255 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724840996; cv=none; b=P/yZ3B5h4NXrE8WMoH6QePT2BXyn/mxOZYZGq1KmL5+w0k6zQ4+P2XXdSUDz7zY7zxQCrUWh8xliViRrZHpEtRjochWz7GgOlF9USULJF8lHOECJAcqnlu69oag1YBe1q7JmwZ7NoN5n3Yq+lxWBxECUjaJexP2x0hK36Yf1loc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724840996; c=relaxed/simple; bh=O4MXgpCagL+uFlh51r7eztf0GwKPpdu1twc3rJq1/Lw=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=Tm7+3pxqnczZJgluT2eQfaYbwPrKLwo4NHvB8jtdVIpsS4RWOj3x+QEV+Vjha3CkXKSV9q3+OEoSYL2/qEfdi3ICA/uHIF9wOGYk3ngNerRKNcVs6vmUP4L2aEpDTTGUW9QU3X9nXCXFkEUB4pOZnwzQHRcCE22W+PGARKlKLxg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.255 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.162.254]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Wv0y564mjz16PXv; Wed, 28 Aug 2024 18:29:01 +0800 (CST) Received: from kwepemg200003.china.huawei.com (unknown [7.202.181.30]) by mail.maildlp.com (Postfix) with ESMTPS id 02D6B180106; Wed, 28 Aug 2024 18:29:50 +0800 (CST) Received: from [10.174.176.93] (10.174.176.93) by kwepemg200003.china.huawei.com (7.202.181.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 28 Aug 2024 18:29:48 +0800 Message-ID: <1bb22ebe-3e54-465f-b076-229e999476a7@huawei.com> Date: Wed, 28 Aug 2024 18:29:48 +0800 Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next 0/4] Make SMC-R can work with rxe devices To: Jan Karcher , , , , CC: , , , , , , , , , , References: <20240809083148.1989912-1-liujian56@huawei.com> <0d5e2cec-dd0b-4920-99ff-9299e4df604f@linux.ibm.com> <20240821010324.GK103152@linux.alibaba.com> From: "liujian (CE)" In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemg200003.china.huawei.com (7.202.181.30) 在 2024/8/27 3:04, Jan Karcher 写道: > > > On 24/08/2024 12:04, liujian (CE) wrote: >> >> >> 在 2024/8/21 9:03, Dust Li 写道: >>> On 2024-08-20 15:16:57, Jan Karcher wrote: >>>> >>>> >>>> On 09/08/2024 10:31, Liu Jian wrote: >>>>> Make SMC-R can work with rxe devices. This allows us to easily test >>>>> and >>>>> learn the SMC-R protocol without relying on a physical RoCE NIC. >>>> >>>> Hi Liu, >>>> >>>> sorry for taking quite some time to answer. >>>> >>>> Looking into this i cannot accept this series at the given point of >>>> time. >>>> >>>> FWIU, RXE is mainly for testing and development and i agree that it >>>> would be >>>> a nice thing to have for SMC-R. >>>> The problem is that there is no clean layer for different RoCE devices >>>> currently. Adding RXE to it works but isn't clean. >>> >>> Hi jan, >>> >>>> Also we have no way to do a "test" build which would have such a device >>>> supported and a "prod" build which would not support it. >>>  > I don't quite understand what you mean here, Maybe I missed >>> something ? >>> IIUC, we can control whether to use RXE by simpling insmod or rmmod >>> rdma_rxe.ko > > Hi, > > Yes that enables RXE in general, but not the use of RXE in SMC. > >>> >> Yes, in the "prod" environment, we can completely turn off >> CONFIG_RDMA_RXE. > > Same as above + this is a compile time switch that is enabled for > distros like rh. Simply disabling it won't work here. > Got it, I misunderstood what you meant above. Thank you. >> >>> I believe having RXE support is beneficial for testing, especially in >>> simple physical networking setups where many corner cases are unlikely >>> to occur. By using RXE, we can easily configure unusual scenarios with >>> the existing iptables/netfilter infrastructure to simulate real-world >>> situations, such as packet dropping or network retransmission. This >>> approach can be advantageous for finding hidden bugs. >>> >> Yes, one of my main original intentions was to make testing smc-r >> easier. This change is relatively simple, mainly patch2 and patch4, >> and there are no logical changes. > > I agree with you. It would be beneficial for testing. > This is not a never, this is a not right now. > > If you want to push this forward as something you need now, feel free to > encapsulate it and introduce a vendor specific experimental option as > defined in the v2.1 protocol version [1] for it. This would be > compromise for me at the current time. > Got it, thanks. > Thanks > - Jan > > [1] > https://www.ibm.com/support/pages/system/files/inline-files/IBM%20Shared%20Memory%20Communications%20Version%202.1%20Emulated-ISM_0.pdf > >>> Best regards, >>> Dust >>> >>> >>>> >>>> Please give us time to investigate how to solve this in a neat way >>>> without >>>> building up to much technical debt. >>>> >>>> Thanks for your contribution and making us aware of this area of >>>> improvment. >>>> - Jan >>>> >>>>> >>>>> Liu Jian (4): >>>>>     rdma/device: export ib_device_get_netdev() >>>>>     net/smc: use ib_device_get_netdev() helper to get netdev info >>>>>     net/smc: fix one NULL pointer dereference in >>>>> smc_ib_is_sg_need_sync() >>>>>     RDMA/rxe: Set queue pair cur_qp_state when being queried >>>>> >>>>>    drivers/infiniband/core/core_priv.h   |  3 --- >>>>>    drivers/infiniband/core/device.c      |  1 + >>>>>    drivers/infiniband/sw/rxe/rxe_verbs.c |  2 ++ >>>>>    include/rdma/ib_verbs.h               |  2 ++ >>>>>    net/smc/smc_ib.c                      | 10 +++++----- >>>>>    net/smc/smc_pnet.c                    |  6 +----- >>>>>    6 files changed, 11 insertions(+), 13 deletions(-) >>>>>