who creates /dev/nvidia0

[lremember]

Thank you very much for your answer. The problem I encountered is: I can get the PCI device number of NVIDIA graphics card, such as (81:00.0). I want to use this device number to correspond to my local device name (/dev/nvidia0). What is the connection between the PCI device number and the device name.
BR!

[aritger]

To answer the question in your subject line, it is the program nvidia-modprobe that creates the /dev/nvidiaN device files. This is a little backwards, but IIRC the in-kernel interface to creating device files isn't available to the non-GPL nvidia.ko, and the open nvidia.ko inherited that behavior.

For how to map between PCI bus ID and /dev/nvidiaN number, the GPU enumeration code in the driver is probably a bit more complicated than necessary. Relevant functions include:

nv-pci.c:nv_pci_probe()
nv.c:nv_linux_add_device_locked()
nv.c:nvidia_read_card_info()

Once nvidia.ko is loaded, I think you can look at /proc/driver/nvidia/gpus/${busid}/information. The "Device Minor" number in that file is the /dev/nvidiaN N number.

I hope that helps.

[lremember]

Thank you very much for your help. Your suggestions are very helpful to me! thank you very much！