The command and statusMost register of the PCI header require hardwareare either constant values or require
accessemulation anyway. All other register of the PCI headThe command and status register are fixed values or requirethe only exception which
require hardware access. So, we're adding an emulation anyways.handler for all
GPU passthrough requires the emulation of some specialother register. It will
be implemented in another source file. For that reason, export theAs this emulation handler will be reused by some future features like
emulation handlersGPU passthrough, we directly export it.