问题
I was wondering how to go about adding a virtual GPU into Qemu? I have been told it involves adding a new graphics output module that uses OpenGL?
回答1:
You probably refer to Create virtual hardware, kernel, qemu for Android Emulator in order to produce OpenGL graphics
The very first thing I suggest you do is reading the source code how commands to the virtual graphics adaptors already implemented are turned into graphical output. Then you should rewrite this, to use OpenGL commands instead. Once you got this you must literally invent a new, virtual GPU to offer the guest system. I'd not even attempt to emulate a GeForce or Radeon. GeForces are not publically documented anyway.
qemu doesn't provide a real kind of API for implementing a GPU. Of course there's some internal API for that, used to implement that VESA and S3 emulation, but a new GPU will require you to redo a lot of that again.
The virtual hardware should offer some I/O to pass drawing commands and data. In theory you could pass the full set OpenGL commands there. However OpenGL is hardware agnostic, whereas you actually implement "hardware", so you must find some balance there. Then in qemu you must implement that virtual hardware to execute the rendering commands apropriately.
Last but not least you must implement drivers for that virtual hardware, which will involve adding a new driver to Mesa and creating a driver for Xorg.
来源：https://stackoverflow.com/questions/5789418/how-do-i-add-a-virtual-gpu-into-qemu