From: Jakub Kicinski <jakub.kicinski@netronome.com>
To: Jiri Pirko <jiri@resnulli.us>
Cc: netdev@vger.kernel.org, davem@davemloft.net, mlxsw@mellanox.com
Subject: Re: [patch net-next rfc 00/15] netdevsim: impement proper device model
Date: Mon, 15 Apr 2019 12:27:09 -0700 [thread overview]
Message-ID: <20190415122709.45dd4b09@cakuba.netronome.com> (raw)
In-Reply-To: <20190413162112.8203-1-jiri@resnulli.us>
On Sat, 13 Apr 2019 18:20:57 +0200, Jiri Pirko wrote:
> From: Jiri Pirko <jiri@mellanox.com>
>
> Currently the model of netdevsim is a bit odd in multiple ways.
> 1) devlink instance is not in any way related with actual netdevsim
> netdevices. Instead, it is created per-namespace.
> 2) multi-port netdevsim device is done using "link" attribute.
> 3) netdevsim bus is there only to have something to bind the netdev to,
> it really does not act as a bus.
Nope, it's there to expose SR-IOV ops :)
> 4) netdevsim instances are created by "ip link add" which is great for
> soft devices with no hw backend. The rtnl core allocates netdev and
> calls into driver holding rtnl mutex. For hw-backed devices, this
> flow is wrong as it breaks order in which things are done.
>
> This patchset adjust netdevsim to fix all above.
>
> In order to support proper devlink and devlink port instances and to be
> able to emulate real devices, there is need to implement bus probe and
> instantiate everything from there. User can specify device id and port
> count to be instantianted. For example:
>
> echo "10 4" > /sys/bus/netdevsim/new_device
I really don't like the design where ID has to be allocated by user
space. It's a step back.
I also dislike declaring ports from the start. In real drivers ports
are never "atomically" registered, they are crated and destroyed one
by one, and a lot of races/UAFs/bugs lie in those small periods of
time where one netdev got unregistered, but other are still around...
> Then devlink shows this:
>
> $ devlink dev
> netdevsim/netdevsim10
>
> $ devlink port
> netdevsim/netdevsim10/0: type eth netdev netdevsim10p1 flavour physical
> netdevsim/netdevsim10/1: type eth netdev netdevsim10p2 flavour physical
> netdevsim/netdevsim10/2: type eth netdev netdevsim10p3 flavour physical
> netdevsim/netdevsim10/3: type eth netdev netdevsim10p4 flavour physical
>
> Debugfs topology is also adjusted a bit. The rest stays the same as
> before.
>
> TODO:
> - teach udev to rename netdevsim netdevices similarly to pci netdevices
So we can test udev as well?
> - fix tools/testing/selftests/bpf/test_offload.py to work with new iface
That'd step 0 :)
BTW are you testing all this with the various sysfs/kobject debug
checks? I don't remember all the deets now, but there were certainly
ordering considerations coming from there.
next prev parent reply other threads:[~2019-04-15 19:27 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-13 16:20 [patch net-next rfc 00/15] netdevsim: impement proper device model Jiri Pirko
2019-04-13 16:20 ` [patch net-next rfc 01/15] netdevsim: move device registration on bus to be done earlier in init Jiri Pirko
2019-04-13 16:20 ` [patch net-next rfc 02/15] netdevsim: create devlink instance per netdevsim instance Jiri Pirko
2019-04-15 2:24 ` David Ahern
2019-04-15 5:41 ` Jiri Pirko
2019-04-15 15:07 ` David Ahern
2019-04-15 15:39 ` Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 03/15] netdevsim: rename devlink.c to dev.c to contain per-dev(asic) items Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 04/15] netdevsim: put netdevsim bus code into separate file Jiri Pirko
2019-04-14 20:27 ` David Miller
2019-04-15 5:40 ` Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 05/15] netdevsim: move device registration and related code to bus.c Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 06/15] netdevsim: add stub netdevsim driver implementation Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 07/15] netdevsim: use ida for bus device ids Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 08/15] netdevsim: add bus attributes to add new and delete devices Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 09/15] netdevsim: rename dev_init/exit() functions and make them independent on ns Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 10/15] netdevsim: merge sdev into dev Jiri Pirko
2019-04-15 20:49 ` Jakub Kicinski
2019-04-16 8:49 ` Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 11/15] netdevsim: generate random switch id instead of using dev id Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 12/15] netdevsim: change debugfs tree topology Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 13/15] netdevsim: implement dev probe/remove skeleton with port initialization Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 14/15] netdevsim: move netdev creation/destruction to dev probe Jiri Pirko
2019-04-13 16:21 ` [patch net-next rfc 15/15] netdevsim: implement ndo_get_devlink_port Jiri Pirko
2019-04-15 19:27 ` Jakub Kicinski [this message]
2019-04-16 8:53 ` [patch net-next rfc 00/15] netdevsim: impement proper device model Jiri Pirko
2019-04-16 17:58 ` Jakub Kicinski
2019-04-16 8:59 ` Jiri Pirko
2019-04-16 18:04 ` Jakub Kicinski
2019-04-18 7:22 ` Jiri Pirko
2019-04-18 17:07 ` Jakub Kicinski
2019-04-19 5:25 ` Jiri Pirko
2019-04-19 21:00 ` Jakub Kicinski
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