История изменений

do not want to pass the APU R7 250 w/2GB (V)RAM
APU passed to guest

Never tried, never heard about that. It is even possible?

Is the UEFI necessary for the new way of passing-throug?

If video bios is EFI-based — yes.

http://vfio.blogspot.com/2014/08/does-my-graphics-card-rom-support-efi.html

do not want to pass the APU R7 250 w/2GB (V)RAM
APU passed to guest

Never tried, never heard about that. It is even possible?

Is the UEFI necessary for the new way of passing-throug?

If video bios id EFI-based — yes.

http://vfio.blogspot.com/2014/08/does-my-graphics-card-rom-support-efi.html