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From: Jiri Pirko <jiri@resnulli.us>
To: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Parav Pandit <parav@mellanox.com>,
	alex.williamson@redhat.com, davem@davemloft.net,
	kvm@vger.kernel.org, netdev@vger.kernel.org, saeedm@mellanox.com,
	kwankhede@nvidia.com, leon@kernel.org, cohuck@redhat.com,
	jiri@mellanox.com, linux-rdma@vger.kernel.org,
	Or Gerlitz <gerlitz.or@gmail.com>
Subject: Re: [PATCH net-next 00/19] Mellanox, mlx5 sub function support
Date: Fri, 8 Nov 2019 13:12:33 +0100
Message-ID: <20191108121233.GJ6990@nanopsycho> (raw)
In-Reply-To: <20191107153234.0d735c1f@cakuba.netronome.com>

Thu, Nov 07, 2019 at 09:32:34PM CET, jakub.kicinski@netronome.com wrote:
>On Thu,  7 Nov 2019 10:04:48 -0600, Parav Pandit wrote:
>> Mellanox sub function capability allows users to create several hundreds
>> of networking and/or rdma devices without depending on PCI SR-IOV support.
>
>You call the new port type "sub function" but the devlink port flavour
>is mdev.
>
>As I'm sure you remember you nacked my patches exposing NFP's PCI 
>sub functions which are just regions of the BAR without any mdev
>capability. Am I in the clear to repost those now? Jiri?

Well question is, if it makes sense to have SFs without having them as
mdev? I mean, we discussed the modelling thoroughtly and eventually we
realized that in order to model this correctly, we need SFs on "a bus".
Originally we were thinking about custom bus, but mdev is already there
to handle this.

Our SFs are also just regions of the BAR, same thing as you have.

Can't you do the same for nfp SFs?
Then the "mdev" flavour is enough for all.


>
>> Overview:
>> ---------
>> Mellanox ConnectX sub functions are exposed to user as a mediated
>> device (mdev) [2] as discussed in RFC [3] and further during
>> netdevconf0x13 at [4].
>> 
>> mlx5 mediated device (mdev) enables users to create multiple netdevices
>> and/or RDMA devices from single PCI function.
>> 
>> Each mdev maps to a mlx5 sub function.
>> mlx5 sub function is similar to PCI VF. However it doesn't have its own
>> PCI function and MSI-X vectors.
>> 
>> mlx5 mdevs share common PCI resources such as PCI BAR region,
>> MSI-X interrupts.
>> 
>> Each mdev has its own window in the PCI BAR region, which is
>> accessible only to that mdev and applications using it.
>> 
>> Each mlx5 sub function has its own resource namespace for RDMA resources.
>> 
>> mdevs are supported when eswitch mode of the devlink instance
>> is in switchdev mode described in devlink documentation [5].
>
>So presumably the mdevs don't spawn their own devlink instance today,
>but once mapped via VIRTIO to a VM they will create one?

I don't think it is needed for anything. Maybe one day if there is a
need to create devlink instance for VF or SF, we can add it. But
currently, I don't see the need.


>
>It could be useful to specify.
>
>> Network side:
>> - By default the netdevice and the rdma device of mlx5 mdev cannot send or
>> receive any packets over the network or to any other mlx5 mdev.
>
>Does this mean the frames don't fall back to the repr by default?

That would be the sane default. If I up the representor, I should see
packets coming in from SF/VF and I should be able to send packets back.

  parent reply index

Thread overview: 132+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-07 16:04 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 [this message]
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
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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