Comment 12 for bug 1175155

Nope, you have to hide both from kernel. It's just, that listing 04:00.1 in config file is causing error. At least with xm stack.
Xen is attaching it anyway runtime, so it has to be hidden or you get "does not belong to pciback" error.

BTW atm im passing pci=['01:00.0','00:1a.0','04:00.0'] to the HVM, which stands for Radeon, one USB bus, and Audigy. And this works fine. But when I change to pci=['01:00.0','01:00.1','00:1a.0','04:00.0'], which adds HDMI from Radeon, then I get said "22 error".

I used to pass onboard Panther HDA, but after day or so sound was often garbled in Win7 VM, so I switched to SB.

Also Radeon is my secondary gpu, because I'm using i5-3570 gpu onboard asrock z77 pro4 for hypervisor/gnome display.