Please be sure to run a very recent version of Qemu, 3.2 or later IIRC and specify the PCIe link width and speed. By default NVidia cards on a root port in a q35 machine will only report a x1 link and the NVidia driver will configure the SOC for it. Please see this thread for more information: Increasing VFIO VGA Performance
Wow! I am glad to have LG as part of the lecture, I am truly honoured 
Most certainly, LG is one of those projects that requires multiple combinations of hardware to test and develop against. It’s near impossible to profile a performance issue without the hardware on hand.