Well it worked.
Passing the AMD HD 5450 to a Windows 8 domU was a bit trickier than passing the primary Intel VGA but still achievable though I found the driver installation awkward.
- The integrated Intel i7-3770 HD 4000 GPU needed to be set as the Primary Display Adapter in the BIOS thus the AMD HD 5450 was setup as the Secondary Display Adapter.
- Wheezy domU with stock Linux kernel and Xen 4.1.3 were used alongside the xm toolstack.
- The domU was installed over VNC.
- The HDMI audio function of the graphics card also needs to be passed.
- Installing AMD Catalyst froze the VM and required a reboot of the dom0 to restart the Windows 8 domU properly. I worked around this by installing only the drivers with Catalyst Control Center.
- Windows 8 assigned drivers to the AMD HD 5450 that were faster in Windows Performance Score, Counter Strike Source Video Stress and Unigine than AMD 12.8 drivers (!)
- AMD HD 5450 performance is crappy compared to Intel HD 4000 however it's more than fine for Windows 8 non-gaming tasks.
- AMD HD 5450 Team Fortress 2 gameplay was crappy with ~30 FPS.
- I wasn't able to successfully passthrough my 2nd Intel NIC as the VM refused to start and spat out errors.
- I'm too hooked on FT2 having scored 50h since early September which is totally sucked my free time...
- 2 concurrent Windows 8 domUs one running the integrated HD 4000 and the other the AMD HD 5450.
- Clean up the benchmarks I've run on bare metal, HD 4000 and AMD HD 5450 domU.
- Clean up my notes and publish as HowTo on linux-bsd-sharing.blogspot.com.
- Setup Linux domUs with VGA passthrough.