From: Jiri Pirko <jiri@resnulli.us>
To: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>,
Jason Gunthorpe <jgg@ziepe.ca>, Parav Pandit <parav@mellanox.com>,
David M <david.m.ertman@intel.com>,
"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"davem@davemloft.net" <davem@davemloft.net>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Saeed Mahameed <saeedm@mellanox.com>,
"kwankhede@nvidia.com" <kwankhede@nvidia.com>,
"leon@kernel.org" <leon@kernel.org>,
"cohuck@redhat.com" <cohuck@redhat.com>,
Jiri Pirko <jiri@mellanox.com>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
Or Gerlitz <gerlitz.or@gmail.com>
Subject: Re: [PATCH net-next 00/19] Mellanox, mlx5 sub function support
Date: Mon, 11 Nov 2019 15:37:14 +0100 [thread overview]
Message-ID: <20191111143714.GC2202@nanopsycho> (raw)
In-Reply-To: <20191111141430.GB585609@kroah.com>
Mon, Nov 11, 2019 at 03:14:30PM CET, gregkh@linuxfoundation.org wrote:
>On Mon, Nov 11, 2019 at 02:30:26PM +0100, Jiri Pirko wrote:
>> Mon, Nov 11, 2019 at 04:46:01AM CET, jakub.kicinski@netronome.com wrote:
>> >On Sun, 10 Nov 2019 10:18:55 +0100, gregkh@linuxfoundation.org wrote:
>> >> > What I'm missing is why is it so bad to have a driver register to
>> >> > multiple subsystems.
>> >>
>> >> Because these PCI devices seem to do "different" things all in one PCI
>> >> resource set. Blame the hardware designers :)
>> >
>> >See below, I don't think you can blame the HW designers in this
>> >particular case :)
>> >
>> >> > For the nfp I think the _real_ reason to have a bus was that it
>> >> > was expected to have some out-of-tree modules bind to it. Something
>> >> > I would not encourage :)
>> >>
>> >> That's not ok, and I agree with you.
>> >>
>> >> But there seems to be some more complex PCI devices that do lots of
>> >> different things all at once. Kind of like a PCI device that wants to
>> >> be both a keyboard and a storage device at the same time (i.e. a button
>> >> on a disk drive...)
>> >
>> >The keyboard which is also a storage device may be a clear cut case
>> >where multiple devices were integrated into one bus endpoint.
>>
>> Also, I think that very important differentiator between keyboard/button
>> and NIC is that keyboard/button is fixed. You have driver bus with 2
>> devices on constant addresses.
>>
>> However in case of NIC subfunctions. You have 0 at he beginning and user
>> instructs to create more (maybe hundreds). Now important questions
>> appear:
>>
>> 1) How to create devices (what API) - mdev has this figured out
>> 2) How to to do the addressing of the devices. Needs to be
>> predictable/defined by the user - mdev has this figured out
>> 3) Udev names of netdevices - udev names that according to the
>> bus/address. That is straightforeward with mdev.
>> I can't really see how to figure this one in particular with
>> per-driver busses :/
>
>Are network devices somehow only allowed to be on mdev busses?
Of course not. But there is a difference if we are talking about:
a) "the usual" network devices, like PF, VF. - They are well defined and
they have well defined lifecycle (pci probe, sriov sysfs for number
of VFs, etc). I this world all works fine. Even if a device has 100
static subdevices (bus or no bus).
b) dynamically created sub-bar-devices or subfunctions. Could be created
by user. This is not handled now in kernel, we have to find correct iface.
I don't really care it it is fakebus, driverbus, etc. I'm just concerned
about how to handle 1), 2), 3) above.
>
>No, don't be silly, userspace handles this just fine today on any type
>of bus, it's not an issue.
>
>You don't have to like individual "driver busses", but you had better
>not be using a fake platform device to use mdev. That's my main
>objection...
Okay, I understand your objection. Do you have suggestion how to handle
1) 2) 3) from above?
>
>thanks,
>
>greg k-h
next prev parent reply other threads:[~2019-11-11 14:37 UTC|newest]
Thread overview: 132+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-07 16:04 [PATCH net-next 00/19] Mellanox, mlx5 sub function support Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 01/19] net/mlx5: E-switch, Move devlink port close to eswitch port Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 02/19] net/mlx5: E-Switch, Add SF vport, vport-rep support Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 03/19] net/mlx5: Introduce SF table framework Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 04/19] net/mlx5: Introduce SF life cycle APIs to allocate/free Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 05/19] net/mlx5: E-Switch, Enable/disable SF's vport during SF life cycle Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 06/19] net/mlx5: Add support for mediated devices in switchdev mode Parav Pandit
2019-11-08 10:32 ` Jiri Pirko
2019-11-08 16:03 ` Parav Pandit
2019-11-08 16:22 ` Jiri Pirko
2019-11-08 16:29 ` Parav Pandit
2019-11-08 18:01 ` Jiri Pirko
2019-11-08 18:04 ` Jiri Pirko
2019-11-08 18:21 ` Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 07/19] vfio/mdev: Introduce sha1 based mdev alias Parav Pandit
2019-11-08 11:04 ` Jiri Pirko
2019-11-08 15:59 ` Parav Pandit
2019-11-08 16:28 ` Jiri Pirko
2019-11-08 11:10 ` Cornelia Huck
2019-11-08 16:03 ` Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 08/19] vfio/mdev: Make mdev alias unique among all mdevs Parav Pandit
2019-11-08 10:49 ` Jiri Pirko
2019-11-08 15:13 ` Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 09/19] vfio/mdev: Expose mdev alias in sysfs tree Parav Pandit
2019-11-08 13:22 ` Jiri Pirko
2019-11-08 18:03 ` Alex Williamson
2019-11-08 18:16 ` Jiri Pirko
2019-11-07 16:08 ` [PATCH net-next 10/19] vfio/mdev: Introduce an API mdev_alias Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 11/19] vfio/mdev: Improvise mdev life cycle and parent removal scheme Parav Pandit
2019-11-08 13:01 ` Cornelia Huck
2019-11-08 16:12 ` Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 12/19] devlink: Introduce mdev port flavour Parav Pandit
2019-11-07 20:38 ` Jakub Kicinski
2019-11-07 21:03 ` Parav Pandit
2019-11-08 1:17 ` Jakub Kicinski
2019-11-08 1:44 ` Parav Pandit
2019-11-08 2:20 ` Jakub Kicinski
2019-11-08 2:31 ` Parav Pandit
2019-11-08 9:46 ` Jiri Pirko
2019-11-08 15:45 ` Parav Pandit
2019-11-08 16:31 ` Jiri Pirko
2019-11-08 16:43 ` Parav Pandit
2019-11-08 18:11 ` Jiri Pirko
2019-11-08 18:23 ` Parav Pandit
2019-11-08 18:34 ` Jiri Pirko
2019-11-08 18:56 ` Parav Pandit
2019-11-08 9:30 ` Jiri Pirko
2019-11-08 15:41 ` Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 13/19] net/mlx5: Register SF devlink port Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 14/19] net/mlx5: Share irqs between SFs and parent PCI device Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 15/19] net/mlx5: Add load/unload routines for SF driver binding Parav Pandit
2019-11-08 9:48 ` Jiri Pirko
2019-11-08 11:13 ` Jiri Pirko
2019-11-07 16:08 ` [PATCH net-next 16/19] net/mlx5: Implement dma ops and params for mediated device Parav Pandit
2019-11-07 20:42 ` Jakub Kicinski
2019-11-07 21:30 ` Parav Pandit
2019-11-08 1:16 ` Jakub Kicinski
2019-11-08 6:37 ` Christoph Hellwig
2019-11-08 15:29 ` Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 17/19] net/mlx5: Add mdev driver to bind to mdev devices Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 18/19] Documentation: net: mlx5: Add mdev usage documentation Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 19/19] mtty: Optionally support mtty alias Parav Pandit
2019-11-08 6:26 ` Leon Romanovsky
2019-11-08 10:45 ` Jiri Pirko
2019-11-08 15:08 ` Parav Pandit
2019-11-08 15:15 ` Jiri Pirko
2019-11-08 13:46 ` Cornelia Huck
2019-11-08 15:10 ` Parav Pandit
2019-11-08 15:28 ` Cornelia Huck
2019-11-08 15:30 ` Parav Pandit
2019-11-08 17:54 ` Alex Williamson
2019-11-08 9:51 ` [PATCH net-next 01/19] net/mlx5: E-switch, Move devlink port close to eswitch port Jiri Pirko
2019-11-08 15:50 ` Parav Pandit
2019-11-07 17:03 ` [PATCH net-next 00/19] Mellanox, mlx5 sub function support Leon Romanovsky
2019-11-07 20:10 ` Parav Pandit
2019-11-08 6:20 ` Leon Romanovsky
2019-11-08 15:01 ` Parav Pandit
2019-11-07 20:32 ` Jakub Kicinski
2019-11-07 20:52 ` Parav Pandit
2019-11-08 1:16 ` Jakub Kicinski
2019-11-08 1:49 ` Parav Pandit
2019-11-08 2:12 ` Jakub Kicinski
2019-11-08 12:12 ` Jiri Pirko
2019-11-08 14:40 ` Jason Gunthorpe
2019-11-08 15:40 ` Parav Pandit
2019-11-08 19:12 ` Jakub Kicinski
2019-11-08 20:12 ` Jason Gunthorpe
2019-11-08 20:20 ` Parav Pandit
2019-11-08 20:32 ` Jason Gunthorpe
2019-11-08 20:52 ` gregkh
2019-11-08 20:34 ` Alex Williamson
2019-11-08 21:05 ` Jason Gunthorpe
2019-11-08 21:19 ` gregkh
2019-11-08 21:52 ` Alex Williamson
2019-11-08 22:48 ` Parav Pandit
2019-11-09 0:57 ` Jason Gunthorpe
2019-11-09 17:41 ` Jakub Kicinski
2019-11-10 19:04 ` Jason Gunthorpe
2019-11-10 19:48 ` Parav Pandit
2019-11-11 14:17 ` Jiri Pirko
2019-11-11 14:58 ` Parav Pandit
2019-11-11 15:06 ` Jiri Pirko
2019-11-19 4:51 ` Parav Pandit
2019-11-09 0:12 ` Jason Gunthorpe
2019-11-09 0:45 ` Parav Pandit
2019-11-11 2:19 ` Jason Wang
2019-11-08 21:45 ` Jakub Kicinski
2019-11-09 0:44 ` Jason Gunthorpe
2019-11-09 8:46 ` gregkh
2019-11-09 11:18 ` Jiri Pirko
2019-11-09 17:28 ` Jakub Kicinski
2019-11-10 9:16 ` gregkh
2019-11-09 17:27 ` Jakub Kicinski
2019-11-10 9:18 ` gregkh
2019-11-11 3:46 ` Jakub Kicinski
2019-11-11 5:18 ` Parav Pandit
2019-11-11 13:30 ` Jiri Pirko
2019-11-11 14:14 ` gregkh
2019-11-11 14:37 ` Jiri Pirko [this message]
2019-11-10 19:37 ` Jason Gunthorpe
2019-11-11 3:57 ` Jakub Kicinski
2019-11-08 16:06 ` Parav Pandit
2019-11-08 19:06 ` Jakub Kicinski
2019-11-08 19:34 ` Parav Pandit
2019-11-08 19:48 ` Jakub Kicinski
2019-11-08 19:41 ` Jiri Pirko
2019-11-08 20:40 ` Parav Pandit
2019-11-08 21:21 ` Jakub Kicinski
2019-11-08 21:39 ` Jiri Pirko
2019-11-08 21:51 ` Jakub Kicinski
2019-11-08 22:21 ` Jiri Pirko
2019-11-07 23:57 ` David Miller
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