I'd like to add a 'me too' to this subject.
unRAID version 6.3.5
Hardware:
Mobo: Asus X99 Sabertooth
Processor: Intel 6800k
RAM: 64GB
VM OS: Debian 9.3
I just did something similar with a VMDK containing a Linux image, which was even easier.
I didn't edit the XML but just selected 'SATA' instead of IDE under advanced when creating the VM (IDE was not allowed), and selected BIOS instead of the default EFI.