Re: [PATCH v2 05/19] net/xsc: add ioctl command interface

[fengchengwen <fengchengwen@huawei.com>]

On 2024/9/14 10:54, Stephen Hemminger wrote:
> On Fri, 13 Sep 2024 10:55:08 +0800
> "WanRenyong" <wanry@yunsilicon.com> wrote:
> 
>>>  
>>>> Ioctl API is used for interaction between PMD and kernel driver. As you
>>>> said, ioctl is
>>>>
>>>> the worst API, should I consider using read and write instead?  
>>> It seemed the ioctl couldn't handle VF located in VM, and interact 
>>> with PF driver which run in host kernel.  
>>>> If not, could you please give me some advice?  
>>> If your NIC support firmware, could consider use firmware as mid-man between DPDK and kernel.
>>>  
>>>>  
>> Hello, fengchenwen,
>>
>> Thanks for your reply.
>> Sorry for not describing it clearly. We know how to implement the 
>> bifurcation functionality. The main issue is that ioctl is used 
>> forcommunication with the kernel driver by PMD, but ioctl is not 
>> considered a good API, we need to find a better approach. Implemented 
>> via firmware might be a good idea, but it's complex, we can think about 
>> it in the further.Recently shoud I consider using read and write 
>> instead?  Is there any advise?
> 
> 
> There are already several pre-existing ways to do bifurcation in drivers.
> 1. RDMA which is used by mlx5 and mana drivers.
> 2. using SR-IOV and queue steering. (Intel did this but not sure if it still exists)
> 3. BPF
> 
> It seems unlikely a new approach using ioctl() that only works on your device
> would be accepted by the netdev developers.

I just "grep -rn ioctl | wc -l" and found there are 518.
Some of them are net driver which open char device.

Ioctl could be an option as long as it meets current and future needs.