I succeeded in accomplishing the Intel IGD GPU-passthrough for Qemu/KVM, with fully working guests, after close to 3 years of distributed independent research and development, back in early 2016, so I am updating here for the interested folks. Below are the complete demonstrations showing successful bring-up of separate instances of Windows, Ubuntu and Android-x86, one after another, within Qemu/KVM using the Intel IGD physical GPU that was passed through Qemu/KVM using PCI-passthrough mechanism. They include all the technical details involving the finding of compatible host kernel, Qemu/KVM source code modifications to be able to successfully offer the Intel IGD physical GPU for the guest to render its graphics, and all the guest debugging.
Related project : With the above success in achieving successful and fully working guests with Intel IGD GPU-passthrough for Qemu/KVM, specifically for Android, I reworked on my Master's thesis on Android Sensor Emulation research project with this Intel IGD GPU-passthrough work to be able to demonstrate all the graphics-intense games equipped with a plethora of emulated sensors being driven by hardware sensor readings over WiFi in real-time, thus allowing the user to play Android games on PC using Android Smartphone as a joystick or in other words, as like a PlayStation controller. For those interested in this work related to Intel IGD GPU-passthrough, below is the complete demonstration of the same.
Note: As such my Android Sensor Emulation doesn't depend on any GPU-passthrough support. The Intel IGD GPU-passthrough was only necessary for advanced and graphics-intense Android games like Need For Speed, Asphalt, etc which required at least OpenGLES 3.0+ as opposed to OpenGLES 1.0/1.1 that Qemu/KVM emulated graphics card came with. So, to demonstrate the full potential of my Android Sensor Emulation work from end user perspective, I chose these advanced graphics games which were controlled by motion sensors(such as gyroscope, accelerometer, etc) readings which were actually provided by my Android Sensor Emulation logic.
Cheers.