drm/i915/gvt: vGPU MMIO virtualization

This patch introduces the generic vGPU MMIO emulation intercept
framework.  The MPT modules will request GVT-g core logic to
emulate MMIO read/write through IO emulation operations
callback when hypervisor trapped a guest GTTMMIO read/write.

Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/gvt/debug.h

@@ -36,4 +36,7 @@
 #define gvt_dbg_mm(fmt, args...) \
 	DRM_DEBUG_DRIVER("gvt: mm: "fmt, ##args)
 
+#define gvt_dbg_mmio(fmt, args...) \
+	DRM_DEBUG_DRIVER("gvt: mmio: "fmt, ##args)
+
 #endif