Re: [PATCH 8/9] vfio/pci: use x86 naming instead of igd

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 08/02/2021 23:44, Max Gurtovoy wrote:
> 
> On 2/5/2021 2:42 AM, Alexey Kardashevskiy wrote:
>>
>>
>> On 04/02/2021 23:51, Jason Gunthorpe wrote:
>>> On Thu, Feb 04, 2021 at 12:05:22PM +1100, Alexey Kardashevskiy wrote:
>>>
>>>> It is system firmware (==bios) which puts stuff in the device tree. The
>>>> stuff is:
>>>> 1. emulated pci devices (custom pci bridges), one per nvlink, 
>>>> emulated by
>>>> the firmware, the driver is "ibmnpu" and it is a part on the nvidia 
>>>> driver;
>>>> these are basically config space proxies to the cpu's side of nvlink.
>>>> 2. interconnect information - which of 6 gpus nvlinks connected to 
>>>> which
>>>> nvlink on the cpu side, and memory ranges.
>>>
>>> So what is this vfio_nvlink driver supposed to be bound to?
>>>
>>> The "emulated pci devices"?
>>
>> Yes.
>>
>>> A real GPU function?
>>
>> Yes.
>>
>>> A real nvswitch function?
>>
>> What do you mean by this exactly? The cpu side of nvlink is "emulated 
>> pci devices", the gpu side is not in pci space at all, the nvidia 
>> driver manages it via the gpu's mmio or/and cfg space.
>>
>>> Something else?
>>
>> Nope :)
>> In this new scheme which you are proposing it should be 2 drivers, I 
>> guess.
> 
> I see.
> 
> So should it be nvidia_vfio_pci.ko ? and it will do the NVLINK stuff in 
> case the class code matches and otherwise just work as simple vfio_pci 
> GPU ?

"nvidia_vfio_pci" would be too generic, sounds like it is for every 
nvidia on every platform. powernv_nvidia_vfio_pci.ko may be.

> What about the second driver ? should it be called ibmnpu_vfio_pci.ko ?

This will do.


> 
>>
>>>
>>> Jason
>>>
>>

-- 
Alexey