From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: [RFC PATCH net-next v5 3/4] virtio_net: Extend virtio to use VF datapath when available Date: Tue, 10 Apr 2018 12:55:04 +0200 Message-ID: <20180410105504.GA2028@nanopsycho> References: <1522962503-3963-1-git-send-email-sridhar.samudrala@intel.com> <1522962503-3963-4-git-send-email-sridhar.samudrala@intel.com> <20180406124814.GA24525@nanopsycho> <20180409080751.GE19345@nanopsycho> <16b2e531-7bfa-7f25-2702-f3f8069663ee@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: mst@redhat.com, stephen@networkplumber.org, davem@davemloft.net, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, virtio-dev@lists.oasis-open.org, jesse.brandeburg@intel.com, alexander.h.duyck@intel.com, kubakici@wp.pl, jasowang@redhat.com, loseweigh@gmail.com To: "Samudrala, Sridhar" Return-path: Received: from mail-wm0-f65.google.com ([74.125.82.65]:54990 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751737AbeDJKzG (ORCPT ); Tue, 10 Apr 2018 06:55:06 -0400 Received: by mail-wm0-f65.google.com with SMTP id r191so25122050wmg.4 for ; Tue, 10 Apr 2018 03:55:06 -0700 (PDT) Content-Disposition: inline In-Reply-To: <16b2e531-7bfa-7f25-2702-f3f8069663ee@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: Mon, Apr 09, 2018 at 08:47:06PM CEST, sridhar.samudrala@intel.com wrote: >On 4/9/2018 1:07 AM, Jiri Pirko wrote: >> Sat, Apr 07, 2018 at 12:59:14AM CEST, sridhar.samudrala@intel.com wrote: >> > On 4/6/2018 5:48 AM, Jiri Pirko wrote: >> > > Thu, Apr 05, 2018 at 11:08:22PM CEST, sridhar.samudrala@intel.com wrote: >> [...] >> >> > > > +static int virtnet_bypass_join_child(struct net_device *bypass_netdev, >> > > > + struct net_device *child_netdev) >> > > > +{ >> > > > + struct virtnet_bypass_info *vbi; >> > > > + bool backup; >> > > > + >> > > > + vbi = netdev_priv(bypass_netdev); >> > > > + backup = (child_netdev->dev.parent == bypass_netdev->dev.parent); >> > > > + if (backup ? rtnl_dereference(vbi->backup_netdev) : >> > > > + rtnl_dereference(vbi->active_netdev)) { >> > > > + netdev_info(bypass_netdev, >> > > > + "%s attempting to join bypass dev when %s already present\n", >> > > > + child_netdev->name, backup ? "backup" : "active"); >> > > Bypass module should check if there is already some other netdev >> > > enslaved and refuse right there. >> > This will work for virtio-net with 3 netdev model, but this check has to be done by netvsc >> > as its bypass_netdev is same as the backup_netdev. >> > Will add a flag while registering with the bypass module to indicate if the driver is doing >> > a 2 netdev or 3 netdev model and based on that flag this check can be done in bypass module >> > for 3 netdev scenario. >> Just let me undestand it clearly. What I expect the difference would be >> between 2netdev and3 netdev model is this: >> 2netdev: >> bypass_master >> / >> / >> VF_slave >> >> 3netdev: >> bypass_master >> / \ >> / \ >> VF_slave backup_slave >> >> Is that correct? If not, how does it look like? >> >> >Looks correct. >VF_slave and backup_slave are the original netdevs and are present in both the models. >In the 3 netdev model, bypass_master netdev is created and VF_slave and backup_slave are >marked as the 2 slaves of this new netdev. You say it looks correct and in another sentence you provide completely different description. Could you please look again? [...]