Xilinx now offically supports their virtual cable driver!

[tmbinc]

... that's the good news, though.

For the rest, read https://github.com/Xilinx/XilinxVirtualCable/issues/1. I didn't want to make a big drama out of it (in fact, I retroactively licensed my code as CC0, i.e. Public Domain), but their response made me angry.

(TL;DR: Xilinx took my code, made an Appnote out of it, and didn't attribute. When asked, they accused me of breaking their copyright to justify their screwup.)