It appears these tools do not work or gracefully report a useful error message if secure boot and the kernel lockdown=integrity option is enabled.
The relevant error output from
sudo ./nvidia_gpu_tools.py --gpu-bdf 0000:18 --query-cc-mode
is the following:
2025-08-23,22:03:14.042 ERROR Device /sys/bus/pci/devices/0000:18:00.0 broken [Errno 1] Operation not permitted
Topo:
Intel root port 0000:15:01.0
PciBridge 0000:16:00.0 c030:1000
PciBridge 0000:17:00.0 c030:1000
GPU 0000:18:00.0 ? 0x2335 BAR0 0x19c042000000
GPU 0000:18:00.0 [broken, cfg space working 1 bars configured 1]
2025-08-23,22:03:14.043 INFO Selected GPU 0000:18:00.0 [broken, cfg space working 1 bars configured 1]
Traceback (most recent call last):
If you look in kernel logs, you can also find this:
Lockdown: python3: direct PCI access is restricted; see man kernel_lockdown.7
It appears these tools do not work or gracefully report a useful error message if secure boot and the kernel lockdown=integrity option is enabled.
The relevant error output from
sudo ./nvidia_gpu_tools.py --gpu-bdf 0000:18 --query-cc-modeis the following:
If you look in kernel logs, you can also find this:
Lockdown: python3: direct PCI access is restricted; see man kernel_lockdown.7