AFAIK it's only the Microserver Gen8, many people running a Xeon with VT-d enable, including multiple models myself without issues, pretty sure I've also seen other users with different model HP servers running it without problems, of course can't guarantee there's won't be other models affected but seems unlikely, can also add that the issues start immediately after updating, since at least -rc4, so anyone affected would notice after a couple of hours or so, and if it was a more general issue we would have seen a lot of forum posts about it.