My system only goes to C3 because I have a dedicated NVIDIA GPU.
I have yet to see any 'normal' VM not make me lose all C-states. By 'normal,' I mean booting up Manjaro, Ubuntu, or Fedora without any kind of passthrough — with or without USB device passthrough.
I have two exceptions to the...
Oh man, thankfully I'm not crazy. It's the same over here, but unfortunately I cannot pass through the USB controller.
Hopefully, Proxmox devs see this thread and can fix this behavior!
Thank you.