public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Jamal Hadi Salim <jhs@mojatatu•com>
To: Florian Fainelli <f.fainelli@gmail•com>, Jiri Pirko <jiri@resnulli•us>
Cc: netdev <netdev@vger•kernel.org>,
	David Miller <davem@davemloft•net>,
	Neil Horman <nhorman@tuxdriver•com>,
	andy@greyhouse•net, tgraf@suug•ch, dborkman@redhat•com,
	ogerlitz@mellanox•com, jesse@nicira•com, pshelar@nicira•com,
	azhou@nicira•com, Ben Hutchings <ben@decadent•org.uk>,
	Stephen Hemminger <stephen@networkplumber•org>,
	jeffrey.t.kirsher@intel•com, vyasevic <vyasevic@redhat•com>,
	Cong Wang <xiyou.wangcong@gmail•com>,
	John Fastabend <john.r.fastabend@intel•com>,
	Eric Dumazet <edumazet@google•com>,
	Scott Feldman <sfeldma@cumulusnetworks•com>,
	Lennert Buytenhek <buytenh@wantstofly•org>
Subject: Re: [patch net-next RFC 0/4] introduce infrastructure for support of switch chip datapath
Date: Fri, 21 Mar 2014 08:04:20 -0400	[thread overview]
Message-ID: <532C2AC4.7080303@mojatatu.com> (raw)
In-Reply-To: <CAGVrzcbqQGGYb2Wkkekei7ivGd2XOnE+5GthLUv6_nD_oicrSQ@mail.gmail.com>

On 03/20/14 13:21, Florian Fainelli wrote:
> 2014-03-20 5:40 GMT-07:00 Jiri Pirko <jiri@resnulli•us>:
>> Thu, Mar 20, 2014 at 12:49:07PM CET, jhs@mojatatu•com wrote:
>>> Hi Jiri,
>>>

>>>
>>> I think the abstraction should be a netdev and to be specific the
>>> bridge - not openvswitch. Our current tools like ifconfig, iproute2,
>>> bridge etc should continue to work.
>>
>> That is exactly the case. Nothing is specific to OVS. OVS is just a one
>> method to access the switchdev api.
>>
>> Abstraction is netdev. One netdev per each switch port and one netdev as
>> a master on the top of that representing the switch itself.
>>

Ok, so that is what a bridge is.

>> I think that the problem is that each solution serves different purpose.
>> For example DSA is for switches connected as a PHY to a MAC. That is
>> completely different case to what my switchdev API is trying to handle.
>
> I agree with Jamal here, we should try to find a solution that fits
> most users here,

Indeed. We have too many splinters already and each has its own way
of being addressed. [Did you know MacVLAN is now also a L2 device that
does bridging and a crap load of other things? A long way off from
what the original intent was.]

I think we are saying the same thing, but:
This means need for a consistent interface and abstraction.
My favorite abstraction in the kernel that i consider to be immortal
is the netdev. I can have a netdev that is implemented as a physical
ethernet port or as a tuntap or as a tunnel etc. They mostly use the
same abstraction with small differences depending on the type, f.e
a tuntap  with uid, gid etc is mostly no different than my laptop
realtek ethernet port. I can control any of those the same way I
control a CAN device on a vehicle with iproute2 and the same way i
control  a dummy device, ifb, veth, etc.
In otherwords, how packet processing happens (whether the netdev is
used to toast bread) or what tables or constructs a specific kind of
netdev needs (to slice bread) is only relevant to the implementation.
 From user space i dont need to have 15 different APIs to manage/control
things (ok, there is ethtool - but that is just one more interface; but
we have matured enough such that if you try to use /proc or /sysfs
people will yell at you).

In my view: that (immortal) device for L2/bridging is the bridge or
maybe a more barebone version of the bridge (since it has gained a
little more weight in recent times).

>it seems to me like there are 3 switches categories:
>
> - entreprise built-in switches in NICs that support VF/PF
> - embedded/entreprise switches that support tagging (Marvell eDSA/DSA,
> Broadcom tags)
> - embedded switches that only support 802.1q VLANs
>

I had started documenting this stuff to provide some context for an
abstraction, but i had too many pre-emptions, so the document is not
complete. Both John and Vlad had provided inputs to shape it. I
could post it and take patches to it.

> The first category is more flow-oriented than control-oriented,
> whereas the last two are more "event and control" oriented where you
> usually have a system where the switch will be configured not to flood
> the CPU port if possible, but when it does, this is to perform
> specific configuration (address learning, port protection, snooping,
> authorization...).
>
 >
> DSA is not designed specifically for switches which are connected to a
> MAC and appear as a regular PHY, this is how it first started, but
> nothing prevents you from using DSA with a switch that is e.g: memory
> mapped into your CPU register space, MDIO is just the transport for
> the control part.

Your view is more detail oriented than mine. My focus is to more from
a control/management abstraction level. From that perspective this
is a healthy discussion - thank you.

> For instance, if my switches support a N-bytes tag that will give me a
> reason code for receiving this frame, and a bitmap representing the
> originating port, how would you imagine this fitting into the
> openvswitch/switchdev model, aside from the netdev per-port? Do you
> think we could easily migrate existing DSA users to
> openvswitch/switchdev by handling the custom switch tag?
>

I dont think so. I think we need to have this discussion to come
up with a reasonable conclusion.

cheers,
jamal

  reply	other threads:[~2014-03-21 12:04 UTC|newest]

Thread overview: 125+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-19 15:33 [patch net-next RFC 0/4] introduce infrastructure for support of switch chip datapath Jiri Pirko
2014-03-19 15:33 ` [patch net-next RFC 1/4] openvswitch: split flow structures into ovs specific and generic ones Jiri Pirko
2014-03-20 13:04   ` Thomas Graf
2014-03-19 15:33 ` [patch net-next RFC 2/4] net: introduce switchdev API Jiri Pirko
2014-03-20 13:59   ` Thomas Graf
2014-03-20 14:18     ` Jiri Pirko
2014-03-20 14:43   ` Nikolay Aleksandrov
2014-03-20 15:42     ` Jiri Pirko
2014-03-19 15:33 ` [patch net-next RFC 3/4] openvswitch: Introduce support for switchdev based datapath Jiri Pirko
2014-03-19 15:33 ` [patch net-next RFC 4/4] net: introduce dummy switch Jiri Pirko
2014-03-20 11:49 ` [patch net-next RFC 0/4] introduce infrastructure for support of switch chip datapath Jamal Hadi Salim
2014-03-20 12:40   ` Jiri Pirko
2014-03-20 17:21     ` Florian Fainelli
2014-03-21 12:04       ` Jamal Hadi Salim [this message]
2014-03-22  9:48         ` Jiri Pirko
2014-03-24 23:07           ` Jamal Hadi Salim
2014-03-25 17:39             ` Neil Horman
2014-03-25 18:00               ` Thomas Graf
2014-03-25 19:35                 ` Neil Horman
2014-03-25 20:11                   ` Florian Fainelli
2014-03-25 20:31                     ` Neil Horman
2014-03-25 21:22                       ` Jamal Hadi Salim
2014-03-25 21:26                     ` Thomas Graf
2014-03-25 21:42                       ` Florian Fainelli
2014-03-25 21:54                         ` Thomas Graf
2014-03-26 10:55                           ` Neil Horman
2014-03-26  5:37                     ` Roopa Prabhu
2014-03-26 10:54                       ` Jamal Hadi Salim
2014-03-26 15:31                         ` John W. Linville
2014-03-26 16:54                         ` Roopa Prabhu
2014-03-26 16:59                           ` Jiri Pirko
2014-03-26 17:29                             ` Florian Fainelli
2014-03-26 17:35                               ` Jiri Pirko
2014-03-26 17:58                                 ` Florian Fainelli
2014-03-26 18:14                                   ` Jiri Pirko
2014-03-26 18:29                                     ` Hannes Frederic Sowa
2014-03-26 18:30                                     ` Florian Fainelli
2014-03-26 21:51                                     ` Jamal Hadi Salim
2014-03-26 22:22                                       ` Florian Fainelli
2014-03-26 22:53                                         ` Jamal Hadi Salim
2014-03-26 23:16                                           ` Florian Fainelli
2014-03-27  6:56                                         ` Jiri Pirko
2014-03-27 10:39                                           ` Jamal Hadi Salim
2014-03-27 10:50                                             ` Jiri Pirko
2014-03-27 11:12                                               ` Jamal Hadi Salim
2014-03-27 11:16                                                 ` Jiri Pirko
2014-03-27 14:10                                           ` Sergey Ryazanov
2014-03-27 16:41                                             ` Florian Fainelli
2014-03-27 16:57                                               ` Jiri Pirko
2014-03-27 16:59                                               ` Thomas Graf
2014-03-27 20:32                                               ` Sergey Ryazanov
2014-03-27 21:20                                                 ` Florian Fainelli
2014-03-27 21:55                                                   ` Jamal Hadi Salim
2014-03-28  6:28                                                   ` Jiri Pirko
2014-03-30 12:08                                                     ` Alon Harel
2014-03-27 21:41                                               ` Jamal Hadi Salim
2014-03-27 16:55                                             ` Jiri Pirko
2014-03-27 19:58                                               ` Sergey Ryazanov
2014-03-27 20:01                                                 ` Florian Fainelli
2014-03-27 20:04                                                   ` Sergey Ryazanov
2014-03-27 21:47                                                   ` Jamal Hadi Salim
2014-03-27 21:54                                                     ` Florian Fainelli
2014-03-27 21:59                                                       ` Jamal Hadi Salim
2014-03-27 22:19                                                         ` Florian Fainelli
2014-03-27 23:42                                                         ` Thomas Graf
2014-03-27 23:46                                                           ` Florian Fainelli
2014-03-26 17:57                               ` Roopa Prabhu
2014-03-26 18:09                                 ` Florian Fainelli
2014-03-27 13:46                                   ` John W. Linville
2014-03-26 17:47                             ` Roopa Prabhu
2014-03-26 18:03                               ` Jiri Pirko
2014-03-26 21:27                                 ` Roopa Prabhu
2014-03-26 21:31                                   ` Jiri Pirko
2014-03-27 15:35                                     ` Roopa Prabhu
2014-03-27 16:10                                       ` Jiri Pirko
2014-04-01 19:13                                 ` Scott Feldman
2014-04-02  6:41                                   ` Jiri Pirko
2014-04-02 15:37                                     ` Scott Feldman
2014-04-02 14:32                                   ` Andy Gospodarek
2014-04-02 15:25                                     ` John W. Linville
2014-04-02 16:15                                       ` Scott Feldman
2014-04-02 16:47                                         ` Florian Fainelli
2014-04-02 21:52                                           ` Thomas Graf
2014-04-02 19:29                                         ` John W. Linville
2014-04-02 19:54                                           ` Scott Feldman
2014-04-02 20:06                                             ` John W. Linville
2014-04-02 20:04                                           ` Stephen Hemminger
2014-04-02 20:23                                             ` Jiri Pirko
2014-04-02 20:38                                               ` John W. Linville
2014-04-02 21:36                                                 ` Thomas Graf
2014-03-25 20:56                   ` Jamal Hadi Salim
2014-03-25 21:19                     ` Thomas Graf
2014-03-25 21:24                       ` Jamal Hadi Salim
2014-03-26  7:21                       ` Jiri Pirko
2014-03-26 11:00                         ` Jamal Hadi Salim
2014-03-26 11:06                           ` Jamal Hadi Salim
2014-03-26 11:31                             ` Jamal Hadi Salim
2014-03-26 13:20                             ` Jiri Pirko
2014-03-26 13:23                               ` Jamal Hadi Salim
2014-03-26 13:17                           ` Jiri Pirko
2014-03-26 11:10                     ` Neil Horman
2014-03-26 11:29                       ` Thomas Graf
2014-03-26 12:58                         ` Jamal Hadi Salim
2014-03-26 15:22                         ` John W. Linville
2014-03-26 21:36                           ` Jamal Hadi Salim
2014-03-26 18:21                         ` Neil Horman
2014-03-26 19:11                           ` Florian Fainelli
2014-03-26 22:44                             ` Jamal Hadi Salim
2014-03-26 23:15                               ` Thomas Graf
2014-03-26 23:21                                 ` Florian Fainelli
2014-03-27 15:26                               ` Neil Horman
2014-03-27 21:33                                 ` Jamal Hadi Salim
2014-03-26 19:24                           ` Hannes Frederic Sowa
2014-03-27 13:43                           ` John W. Linville
2014-03-26 12:19                       ` Jamal Hadi Salim
2014-03-26 15:27                       ` John W. Linville
2014-03-25 18:33               ` Florian Fainelli
2014-03-25 19:40                 ` Neil Horman
2014-03-25 20:00                   ` Florian Fainelli
2014-03-25 21:39                     ` tgraf
2014-03-25 22:08                       ` Jamal Hadi Salim
2014-03-26  5:48                         ` Roopa Prabhu
2014-03-25 20:46               ` Jamal Hadi Salim
2014-03-26  7:24               ` Jiri Pirko
2014-03-22  9:40       ` Jiri Pirko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=532C2AC4.7080303@mojatatu.com \
    --to=jhs@mojatatu$(echo .)com \
    --cc=andy@greyhouse$(echo .)net \
    --cc=azhou@nicira$(echo .)com \
    --cc=ben@decadent$(echo .)org.uk \
    --cc=buytenh@wantstofly$(echo .)org \
    --cc=davem@davemloft$(echo .)net \
    --cc=dborkman@redhat$(echo .)com \
    --cc=edumazet@google$(echo .)com \
    --cc=f.fainelli@gmail$(echo .)com \
    --cc=jeffrey.t.kirsher@intel$(echo .)com \
    --cc=jesse@nicira$(echo .)com \
    --cc=jiri@resnulli$(echo .)us \
    --cc=john.r.fastabend@intel$(echo .)com \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=nhorman@tuxdriver$(echo .)com \
    --cc=ogerlitz@mellanox$(echo .)com \
    --cc=pshelar@nicira$(echo .)com \
    --cc=sfeldma@cumulusnetworks$(echo .)com \
    --cc=stephen@networkplumber$(echo .)org \
    --cc=tgraf@suug$(echo .)ch \
    --cc=vyasevic@redhat$(echo .)com \
    --cc=xiyou.wangcong@gmail$(echo .)com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox