kernel args (bootloader entry): nvidia_drm.modeset=1 amd_iommu=on iommu=pt video=efifb=off
"patched.rom" (actualy unmodified)
rom file="/var/lib/libvirt/images/patched.rom"/>
see https://github.com/QaidVoid/Complete-Single-GPU-Passthrough#vbios-patching
echo 1 > /sys/bus/pci/devices/0000:0c:00.0/rom
cat /sys/bus/pci/devices/0000:0c:00.0/rom > path/to/dump/vbios.rom