From: Jakub Kicinski <kuba@kernel.org>
To: Yunsheng Lin <linyunsheng@huawei.com>
Cc: moyufeng <moyufeng@huawei.com>,
Jakub Kicinski <jakub.kicinski@netronome.com>,
Jiri Pirko <jiri@resnulli.us>, Parav Pandit <parav@mellanox.com>,
Or Gerlitz <gerlitz.or@gmail.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"michal.lkml@markovi.net" <michal.lkml@markovi.net>,
"davem@davemloft.net" <davem@davemloft.net>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
Jiri Pirko <jiri@mellanox.com>,
Salil Mehta <salil.mehta@huawei.com>,
"lipeng (Y)" <lipeng321@huawei.com>,
Guangbin Huang <huangguangbin2@huawei.com>,
<shenjian15@huawei.com>,
"chenhao (DY)" <chenhao288@hisilicon.com>,
Jiaran Zhang <zhangjiaran@huawei.com>
Subject: Re: [RFC net-next 0/8] Introducing subdev bus and devlink extension
Date: Mon, 7 Jun 2021 12:46:43 -0700 [thread overview]
Message-ID: <20210607124643.1bb1c6a1@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> (raw)
In-Reply-To: <4e7a41ed-3f4d-d55d-8302-df3bc42dedd4@huawei.com>
On Mon, 7 Jun 2021 09:36:38 +0800 Yunsheng Lin wrote:
> On 2021/6/5 2:41, Jakub Kicinski wrote:
> > On Fri, 4 Jun 2021 09:18:04 +0800 Yunsheng Lin wrote:
> >> My initial thinking is a id from a global IDA pool, which indeed may
> >> change on every boot.
> >>
> >> I am not really thinking much deeper about the controller id, just
> >> mirroring the bus identifiers for pcie device and ifindex for netdev,
> >
> > devlink instance id seems fine, but there's already a controller
> > concept in devlink so please steer clear of that naming.
> I am not sure if controller concept already existed is reusable for
> the devlink instance representing problem for multi-function which
> shares common resource in the same ASIC. If not, we do need to pick
> up other name.
>
> Another thing I am not really think throught is how is the VF represented
> by the devlink instance when VF is passed through to a VM.
> I was thinking about VF is represented as devlink port, just like PF(with
> different port flavour), and VF devlink port only exist on the same host
> as PF(which assumes PF is never passed through to a VM), so it may means
> the PF is responsible for creating the devlink port for VF when VF is passed
> through to a VM?
>
> Or do we need to create a devlink instance for VF in the VM too when the
> VF is passed through to a VM? Or more specificly, does user need to query
> or configure devlink info or configuration in a VM? If not, then devlink
> instance in VM seems unnecessary?
I believe the current best practice is to create a devlink instance for
the VF with a devlink port of type "virtual". Such instance represents
a "virtualized" view of the device.
> >> which may change too if the device is pluged into different pci slot
> >> on every boot?
> >
> > Heh. What is someone reflashes the part to change it's serial number? :)
> > pci slot is reasonably stable, as proven by years of experience trying
> > to find stable naming for netdevs.
>
> I suppose that requires a booting to take effect and a vendor tool
> to reflash the serial number, it seems reasonable the vendor/user will
> try their best to not mess the serial number, otherwise service and
> maintenance based on serial number will not work?
> I was thinking about adding the vendor name besides the serial number
> to indicate a devlink instance, to avoid that case that two hw from
> different vendor having the same serial number accidentally.
I'm not opposed to the use of attributes such as serial number for
selecting instance, in principle. I was just trying to prove that PCI
slot/PCI device name is as stable as any other attribute.
In fact for mass-produced machines using PCI slot is far more
convenient than globally unique identifiers because it can be used
to talk to a specific device in a server for all machines of a given
model, hence easing automation.
> >> We could still allow devlink instances to have multiple names,
> >> which seems to be more like devlink tool problem?
> >>
> >> For example, devlink tool could use the id or the vendor_info/
> >> serial_number to indicate a devlink instance according to user's
> >> request.
> >
> > Typing serial numbers seems pretty painful.
> >
> >> Aliase could be allowed too as long as devlink core provide a
> >> field and ops to set/get the field mirroring the ifalias for
> >> netdevice?
> >
> > I don't understand.
>
> I meant we could still allow the user to provide a more meaningful
> name to indicate a devlink instance besides the id.
To clarify/summarize my statement above serial number may be a useful
addition but PCI device names should IMHO remain the primary
identifiers, even if it means devlink instances with multiple names.
In addition I don't think that user-controlled names/aliases are
necessarily a great idea for devlink.
next prev parent reply other threads:[~2021-06-07 19:46 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-01 5:37 [RFC net-next 0/8] Introducing subdev bus and devlink extension Parav Pandit
2019-03-01 5:37 ` [RFC net-next 1/8] subdev: Introducing subdev bus Parav Pandit
2019-03-01 7:17 ` Greg KH
2019-03-01 16:35 ` Parav Pandit
2019-03-01 17:00 ` Greg KH
2019-03-26 11:48 ` Lorenzo Pieralisi
2019-03-01 5:37 ` [RFC net-next 2/8] subdev: Introduce pm callbacks Parav Pandit
2019-03-01 5:37 ` [RFC net-next 3/8] modpost: Add support for subdev device id table Parav Pandit
2019-03-01 5:37 ` [RFC net-next 4/8] devlink: Introduce and use devlink_init/cleanup() in alloc/free Parav Pandit
2019-03-01 5:37 ` [RFC net-next 5/8] devlink: Add variant of devlink_register/unregister Parav Pandit
2019-03-01 5:37 ` [RFC net-next 6/8] devlink: Add support for devlink subdev lifecycle Parav Pandit
2019-03-01 5:37 ` [RFC net-next 7/8] net/mlx5: Add devlink subdev life cycle command support Parav Pandit
2019-03-01 7:18 ` Greg KH
2019-03-01 16:04 ` Parav Pandit
2019-03-01 5:37 ` [RFC net-next 8/8] net/mlx5: Add subdev driver to bind to subdev devices Parav Pandit
2019-03-01 7:21 ` Greg KH
2019-03-01 17:21 ` Parav Pandit
2019-03-05 7:13 ` Greg KH
2019-03-05 17:57 ` Parav Pandit
2019-03-05 19:27 ` Greg KH
2019-03-05 21:37 ` Parav Pandit
2019-03-01 22:12 ` Saeed Mahameed
2019-03-04 16:45 ` Parav Pandit
2019-03-01 20:03 ` [RFC net-next 0/8] Introducing subdev bus and devlink extension Jakub Kicinski
2019-03-04 4:41 ` Parav Pandit
2019-03-05 1:35 ` Jakub Kicinski
2019-03-05 19:46 ` Parav Pandit
2019-03-05 22:39 ` Kirti Wankhede
2019-03-05 23:17 ` Parav Pandit
2019-03-05 23:44 ` Parav Pandit
2019-03-06 0:44 ` Parav Pandit
2019-03-06 3:51 ` Kirti Wankhede
2019-03-06 5:42 ` Parav Pandit
2019-03-07 19:04 ` Kirti Wankhede
2019-03-07 20:27 ` Parav Pandit
2019-03-07 20:53 ` Kirti Wankhede
2019-03-07 21:02 ` Parav Pandit
2019-03-07 21:07 ` Kirti Wankhede
2019-03-07 21:21 ` Parav Pandit
2019-03-07 22:01 ` Kirti Wankhede
2019-03-07 22:31 ` Parav Pandit
2019-03-08 12:19 ` Kirti Wankhede
2019-03-08 17:09 ` Parav Pandit
2019-03-05 1:45 ` Jakub Kicinski
2019-03-05 16:52 ` Parav Pandit
2021-05-31 10:36 ` moyufeng
2021-06-01 5:37 ` Jakub Kicinski
2021-06-01 7:33 ` Yunsheng Lin
2021-06-01 21:34 ` Jakub Kicinski
2021-06-02 2:24 ` Yunsheng Lin
2021-06-02 16:34 ` Jakub Kicinski
2021-06-03 3:46 ` Yunsheng Lin
2021-06-03 17:53 ` Jakub Kicinski
2021-06-04 1:18 ` Yunsheng Lin
2021-06-04 18:41 ` Jakub Kicinski
2021-06-07 1:36 ` Yunsheng Lin
2021-06-07 19:46 ` Jakub Kicinski [this message]
2021-06-08 12:10 ` Yunsheng Lin
2021-06-08 17:29 ` Jakub Kicinski
2021-06-09 9:16 ` Yunsheng Lin
2021-06-09 9:38 ` Parav Pandit
2021-06-09 11:05 ` Yunsheng Lin
2021-06-09 11:59 ` Parav Pandit
2021-06-09 12:30 ` Yunsheng Lin
2021-06-09 13:45 ` Parav Pandit
2021-06-10 7:04 ` Yunsheng Lin
2021-06-10 7:17 ` Parav Pandit
2021-06-09 16:40 ` Jakub Kicinski
2021-06-10 6:52 ` Yunsheng Lin
2021-06-09 9:52 ` Parav Pandit
2021-06-09 11:16 ` Yunsheng Lin
2021-06-09 12:00 ` Parav Pandit
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