Re: [RFC net-next 0/8] Introducing subdev bus and devlink extension

From: Yunsheng Lin
Date: Tue Jun 01 2021 - 03:33:15 EST


On 2021/6/1 13:37, Jakub Kicinski wrote:
> On Mon, 31 May 2021 18:36:12 +0800 moyufeng wrote:
>> Hi, Jiri & Jakub
>>
>> Generally, a devlink instance is created for each PF/VF. This
>> facilitates the query and configuration of the settings of each
>> function. But if some common objects, like the health status of
>> the entire ASIC, the data read by those instances will be duplicate.
>>
>> So I wonder do I just need to apply a public devlink instance for the
>> entire ASIC to avoid reading the same data? If so, then I can't set
>> parameters for each function individually. Or is there a better suggestion
>> to implement it?
>
> I don't think there is a great way to solve this today. In my mind
> devlink instances should be per ASIC, but I never had to solve this
> problem for a multi-function ASIC.

Is there a reason why it didn't have to be solved yet?
Is it because the devices currently supporting devlink do not have
this kind of problem, like single-function ASIC or multi-function
ASIC without sharing common resource?

Was there a discussion how to solved it in the past?

>
> Can you assume all functions are in the same control domain? Can they
> trust each other?

"same control domain" means if it is controlled by a single host, not
by multi hosts, right?

If the PF is not passed through to a vm using VFIO and other PF is still
in the host, then I think we can say it is controlled by a single host.

And each PF is trusted with each other right now, at least at the driver
level, but not between VF.

>
> .
>