Okay, so it looks like I made it work. Removed the whole "args: -device 'vfio-pci,host=00:02.0,addr=0x02,x-igd-gms=1'" line from the VM config. Added "hostpci0: 00:02.0,pcie=1,rombar=0,x-vga=1"
Rebooted into BIOS, enabled UEFI boot for storage and PCI-E. Rebooted and it suddenly worked.