XLVM

I recently upgraded my server from Intel 6th gen (6700) to 12th gen (12700K), I noticed that my Windows VM now prevents my system to go to even C2 state on idle. On the previous system with the Windows VM on, it could still go to C2 for 40-55%. Weird thing is that on the new system with Ubuntu VM on, it can still reach even C3 state when idle. Seems like GPU PCIe passthrough related after some investigation. After turning off the Windows VM, the GPU (RTX 3060 Ti) halts the system to be at C2. Only after running auto-tune command again or changing the tunables for that GPU allow the system to go to C3 state again. I actually had similar experience with the Ubuntu VM initially. I added eGPU (T600) and it prevents the system to go on lower C states until I finished installing the nvidia drivers, then it works fine. I did clean install on nvidia drivers for the Windows VM but seems like it does not fix the issue. It's quite a thorn on my side as turning on VM prevents CPU on lower C state, but then turning it off cause the GPU to not go on low power mode because of no drivers. I could install the nvidia plugin and run the script as SpaceinvaderOne's guide but I assume I need to uninstall the plugin before turning on the VM since the note on the plugin says that it shouldn't be installed if the GPU is going the be put to passthrough. Anyone has similar thing occurring on your system? Or any suggestion on where this behaviour could be from? Or is it just a Windows 11 thing....?