From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: [PATCH net-next 6/6] netdevsim: Add simple FIB resource controller via devlink Date: Fri, 6 Apr 2018 15:22:29 -0600 Message-ID: References: <20180328012200.15175-1-dsa@cumulusnetworks.com> <20180328012200.15175-7-dsa@cumulusnetworks.com> <20180405172718.GA9125@nanopsycho> <20180406055255.GB19345@nanopsycho> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, davem@davemloft.net, roopa@cumulusnetworks.com, shm@cumulusnetworks.com, jiri@mellanox.com, idosch@mellanox.com, jakub.kicinski@netronome.com, andy.roulin@gmail.com To: Jiri Pirko Return-path: Received: from mail-pf0-f173.google.com ([209.85.192.173]:46260 "EHLO mail-pf0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751384AbeDFVWJ (ORCPT ); Fri, 6 Apr 2018 17:22:09 -0400 Received: by mail-pf0-f173.google.com with SMTP id h69so1623597pfe.13 for ; Fri, 06 Apr 2018 14:22:09 -0700 (PDT) In-Reply-To: <20180406055255.GB19345@nanopsycho> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 4/5/18 11:52 PM, Jiri Pirko wrote: > Thu, Apr 05, 2018 at 11:06:41PM CEST, dsa@cumulusnetworks.com wrote: >> On 4/5/18 2:10 PM, David Ahern wrote: >>> >>> The ASIC here is the kernel tables in a namespace. It does not make >>> sense to have 2 devlink instances for a single namespace. >> >> I put this example controller in netdevsim per a suggestion from Ido. >> The netdevsim seemed like a good idea given that modules intention -- >> testing network facilities. Perhaps I should have done this as a >> completely standalone module ... >> >> The intention is to treat the kernel's tables *per namespace* as a >> standalone entity that can be managed very similar to ASIC resources. > > So you say you want to treat a namespace as an ASIC? That sounds very > odd to me :/ Why? The kernel has forwarding tables, acl's, etc just like the ASIC, and each namespace is a separate set of tables. If you think about it, userspace "programs" the kernel just like mlxsw and userspace SDKs "program" an asic. >> Given that I can add a resource controller module >> (drivers/net/kern_res_mgr.c?) that creates a 'struct device' per network >> namespace with a devlink instance. In this case the device would very >> much be tied to the namespace 1:1. > > That sounds more reasonable and accurate, yet still odd. You would not > have any netdevices there? Any ports? > Sure, what ever ports are assigned to or created in the namespace. Nothing about the devlink API says it has to be a real h/w device. Nothing about the devlink API says it can only be used for real h/w that has ports represented by netdevices that the devlink instance some how has "control" over. As the netdevsim demo shows, I can build an L3 resource controller for the kernel tables using just the devlink API and the in-kernel notifiers.