AMD Fusion GPU passthrough to KVM or Xen

Has anyone successfully gotten a passthrough working with the GPU portion of AMD's Fusion APUs (the E-350 is my target) on top of a Linux hypervisor? IE, I want to dedicate the GPU to one VM only, excluding all other VMs as well as the host. I know PCI passthrough can work with patches / kernel rebuilds for Xen and KVM. However, since the GPU is on the same chip, I don't know if the host OS will see it as PCI.

I know there are a number of tangential issues here, such as:

• Poor Fusion drivers in Linux at the moment
• Unsuccessful patching efforts seem common
• VT-d / IOMMU is required and (from my reading) is supported on the APU, but the motherboard may not offer it
• KVM doesn't appear to support primary graphics cards, only secondary graphics cards (described here)

However, I'd like to hear from anyone who has messed with this, even failed attempts. Fedora + KVM is my preferred virtualization platform but I'm willing to change that if it makes a difference.

EDIT: The goal is to do this for a Windows 7 guest (I know it's asking a lot). Regardless, just assume this is HVM, not PV.