From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E57CEC43381 for ; Thu, 21 Mar 2019 13:05:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A882B218E2 for ; Thu, 21 Mar 2019 13:05:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="uTRL9kn4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728217AbfCUNFC (ORCPT ); Thu, 21 Mar 2019 09:05:02 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:42496 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727870AbfCUNFB (ORCPT ); Thu, 21 Mar 2019 09:05:01 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x2LCx2He101921; Thu, 21 Mar 2019 13:04:46 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=content-type : mime-version : subject : from : in-reply-to : date : cc : content-transfer-encoding : message-id : references : to; s=corp-2018-07-02; bh=KdAZh92z1cBWjR/Jbjxa183Wd97YQ67Eny5Zbor2CDE=; b=uTRL9kn4cALLqDbWy8KlV2ODaNIPjBh69r+KCLchyZytoSBm7KCVcqu9zbBpVFvvWkN/ zCBbrKWmM/cvkI/byVrH5jhM9mI7u1GOox05JjaaaewpYHBFFv6clxNwNmJb004otbNb eSq8H7nFeMpfkXr2+PQ2ENgk9UznIERTTg4I8TZGMmvGvOuaA3BSqB1XNIevXogM8a3X ShVJk1znhk3CtCCMHOx3kb7Ok9vbhuuxu2UBRCCilDXzX/ArlHVrFofp5mtczUyyDN02 WxRPvooKonW7Ns35jVXzyhzVWhfmOdCBvDtrINXQVuRslY/QiIpNfRAs3uS8vmdkDqlL Tw== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2130.oracle.com with ESMTP id 2r8rjv0a6j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 21 Mar 2019 13:04:46 +0000 Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id x2LD4jfn020820 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 21 Mar 2019 13:04:45 GMT Received: from abhmp0008.oracle.com (abhmp0008.oracle.com [141.146.116.14]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x2LD4hCP017946; Thu, 21 Mar 2019 13:04:43 GMT Received: from [10.30.3.18] (/213.57.127.2) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 21 Mar 2019 06:04:43 -0700 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 11.1 \(3445.4.7\)) Subject: Re: [summary] virtio network device failover writeup From: Liran Alon In-Reply-To: <20190321085159-mutt-send-email-mst@kernel.org> Date: Thu, 21 Mar 2019 15:04:37 +0200 Cc: Stephen Hemminger , Si-Wei Liu , Sridhar Samudrala , Alexander Duyck , Jakub Kicinski , Jiri Pirko , David Miller , Netdev , virtualization@lists.linux-foundation.org, boris.ostrovsky@oracle.com, vijay.balakrishna@oracle.com, jfreimann@redhat.com, ogerlitz@mellanox.com, vuhuong@mellanox.com Content-Transfer-Encoding: quoted-printable Message-Id: <2939FB15-720A-4C9E-92B7-2DBA139DDE0F@oracle.com> References: <20190320061632-mutt-send-email-mst@kernel.org> <20190320100747-mutt-send-email-mst@kernel.org> <36772E22-7A8F-4C42-A731-398E3204B418@oracle.com> <20190320180641-mutt-send-email-mst@kernel.org> <20190321044920-mutt-send-email-mst@kernel.org> <20190321082532-mutt-send-email-mst@kernel.org> <20190321085159-mutt-send-email-mst@kernel.org> To: "Michael S. Tsirkin" X-Mailer: Apple Mail (2.3445.4.7) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9201 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1903210094 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > On 21 Mar 2019, at 14:57, Michael S. Tsirkin wrote: >=20 > On Thu, Mar 21, 2019 at 02:47:50PM +0200, Liran Alon wrote: >>=20 >>=20 >>> On 21 Mar 2019, at 14:37, Michael S. Tsirkin wrote: >>>=20 >>> On Thu, Mar 21, 2019 at 12:07:57PM +0200, Liran Alon wrote: >>>>>>>> 2) It brings non-intuitive customer experience. For example, a = customer may attempt to analyse connectivity issue by checking the = connectivity >>>>>>>> on a net-failover slave (e.g. the VF) but will see no = connectivity when in-fact checking the connectivity on the net-failover = master netdev shows correct connectivity. >>>>>>>>=20 >>>>>>>> The set of changes I vision to fix our issues are: >>>>>>>> 1) Hide net-failover slaves in a different netns created and = managed by the kernel. But that user can enter to it and manage the = netdevs there if wishes to do so explicitly. >>>>>>>> (E.g. Configure the net-failover VF slave in some special way). >>>>>>>> 2) Match the virtio-net and the VF based on a PV attribute = instead of MAC. (Similar to as done in NetVSC). E.g. Provide a = virtio-net interface to get PCI slot where the matching VF will be = hot-plugged by hypervisor. >>>>>>>> 3) Have an explicit virtio-net control message to command = hypervisor to switch data-path from virtio-net to VF and vice-versa. = Instead of relying on intercepting the PCI master enable-bit >>>>>>>> as an indicator on when VF is about to be set up. (Similar to = as done in NetVSC). >>>>>>>>=20 >>>>>>>> Is there any clear issue we see regarding the above suggestion? >>>>>>>>=20 >>>>>>>> -Liran >>>>>>>=20 >>>>>>> The issue would be this: how do we avoid conflicting with = namespaces >>>>>>> created by users? >>>>>>=20 >>>>>> This is kinda controversial, but maybe separate netns names into = 2 groups: hidden and normal. >>>>>> To reference a hidden netns, you need to do it explicitly.=20 >>>>>> Hidden and normal netns names can collide as they will be = maintained in different namespaces (Yes I=E2=80=99m overloading the term = namespace here=E2=80=A6). >>>>>=20 >>>>> Maybe it's an unnamed namespace. Hidden until userspace gives it a = name? >>>>=20 >>>> This is also a good idea that will solve the issue. Yes. >>>>=20 >>>>>=20 >>>>>> Does this seems reasonable? >>>>>>=20 >>>>>> -Liran >>>>>=20 >>>>> Reasonable I'd say yes, easy to implement probably no. But maybe I >>>>> missed a trick or two. >>>>=20 >>>> BTW, from a practical point of view, I think that even until we = figure out a solution on how to implement this, >>>> it was better to create an kernel auto-generated name (e.g. = =E2=80=9Ckernel_net_failover_slaves") >>>> that will break only userspace workloads that by a very rare-chance = have a netns that collides with this then >>>> the breakage we have today for the various userspace components. >>>>=20 >>>> -Liran >>>=20 >>> It seems quite easy to supply that as a module parameter. Do we need = two >>> namespaces though? Won't some userspace still be confused by the two >>> slaves sharing the MAC address? >>=20 >> That=E2=80=99s one reasonable option. >> Another one is that we will indeed change the mechanism by which we = determine a VF should be bonded with a virtio-net device. >> i.e. Expose a new virtio-net property that specify the PCI slot of = the VF to be bonded with. >>=20 >> The second seems cleaner but I don=E2=80=99t have a strong opinion on = this. Both seem reasonable to me and your suggestion is faster to = implement from current state of things. >>=20 >> -Liran >=20 > OK. Now what happens if master is moved to another namespace? Do we = need > to move the slaves too? No. Why would we move the slaves? The whole point is to make most = customer ignore the net-failover slaves and remain them =E2=80=9Chidden=E2= =80=9D in their dedicated netns. We won=E2=80=99t prevent customer from explicitly moving the = net-failover slaves out of this netns, but we will not move them out of = there automatically. >=20 > Also siwei's patch is then kind of extraneous right? > Attempts to rename a slave will now fail as it's in a namespace=E2=80=A6= I=E2=80=99m not sure actually. Isn't udev/systemd netns-aware? I would expect it to be able to provide names also to netdevs in netns = different than default netns. If that=E2=80=99s the case, Si-Wei patch to be able to rename a = net-failover slave when it is already open is still required. As the = race-condition still exists. -Liran >=20 >>>=20 >>> --=20 >>> MST