Just want to let you know this also allows me to passthrough on an x470 platform which doesn't yet have the ABBA bios update:   MSI x470 Carbon running the Sep9 2019 bios update, booting in Legacy+UEFI The patched kernel seen above. Ryzen 3900x Saphire rx 480 and a VBIOS file from tech powerup ending(Sapphire.RX480.8192.160921.rom), and has to be in a secondary slot, not the primary.