Nouveau - Oct 2024 - [RFC 06/29] nvkm/vgpu: set RMSetSriovMode when NVIDIA vGPU is enabled

On Sun, Sep 22, 2024 at 05:49:28AM -0700, Zhi Wang
wrote:
> The registry object "RMSetSriovMode" is required to be set when
vGPU is
> enabled.
> 
> Set "RMSetSriovMode" to 1 when nvkm is loading the GSP firmware
and
> initialize the GSP registry objects, if vGPU is enabled.
Also really weird, this sounds like what the PCI sriov enable is for.

Jason

On 27/09/2024 1.53, Jason Gunthorpe wrote:
> On Sun, Sep 22, 2024 at 05:49:28AM -0700, Zhi Wang wrote:
>> The registry object "RMSetSriovMode" is required to be set
when vGPU is
>> enabled.
>>
>> Set "RMSetSriovMode" to 1 when nvkm is loading the GSP
firmware and
>> initialize the GSP registry objects, if vGPU is enabled.
> 
> Also really weird, this sounds like what the PCI sriov enable is for.
> 
As what has been explained in PATCH 4's reply, the concept of vGPU and 
VF are not identically equal. PCI SRIOV VF is the HW interface of 
reaching a vGPU and there were generations in which HW didn't have SRIOV 
VFs and a vGPU is reached via other means.

The "RMSetSriovMode" here is not equal to PCI SRIOV enable, which 
activates the VFs and let them present on PCI bus. It is to tell the GSP 
FW to enable the mode of "vGPUs are reached by VFs".
> Jason