drm/i915/gvt: Add verbose gtt shadow logs

This add a new macro gvt_vdbg_mm() to print more verbose logs for
gtt shadowing. The added verbose logs are very useful for debugging.
gvt_vdbg_mm() only comes into effect if VERBOSE_DEBUG is defined by
the developer.
Signed-off-by: Changbin Du <changbin.du@intel.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/gvt/gtt.c

@@ -38,6 +38,12 @@
 #include "i915_pvinfo.h"
 #include "trace.h"
 
+#if defined(VERBOSE_DEBUG)
+#define gvt_vdbg_mm(fmt, args...) gvt_dbg_mm(fmt, ##args)
+#else
+#define gvt_vdbg_mm(fmt, args...)
+#endif
+
 static bool enable_out_of_sync = false;
 static int preallocated_oos_pages = 8192;
 
@@ -582,6 +588,9 @@ static inline int ppgtt_spt_get_entry(
 		return ret;
 
 	ops->test_pse(e);
+
+	gvt_vdbg_mm("read ppgtt entry, spt type %d, entry type %d, index %lu, value %llx\n",
+		    type, e->type, index, e->val64);
 	return 0;
 }
 
@@ -597,6 +606,9 @@ static inline int ppgtt_spt_set_entry(
 	if (WARN(!gtt_type_is_entry(e->type), "invalid entry type\n"))
 		return -EINVAL;
 
+	gvt_vdbg_mm("set ppgtt entry, spt type %d, entry type %d, index %lu, value %llx\n",
+		    type, e->type, index, e->val64);
+
 	return ops->set_entry(page_table, e, index, guest,
 			spt->guest_page.track.gfn << I915_GTT_PAGE_SHIFT,
 			spt->vgpu);
@@ -1109,6 +1121,9 @@ static int ppgtt_handle_guest_entry_removal(struct intel_vgpu_guest_page *gpt,
 	trace_gpt_change(spt->vgpu->id, "remove", spt, sp->type, se->val64,
 			 index);
 
+	gvt_vdbg_mm("destroy old shadow entry, type %d, index %lu, value %llx\n",
+		    se->type, index, se->val64);
+
 	if (!ops->test_present(se))
 		return 0;
 
@@ -1147,6 +1162,9 @@ static int ppgtt_handle_guest_entry_add(struct intel_vgpu_guest_page *gpt,
 	trace_gpt_change(spt->vgpu->id, "add", spt, sp->type,
 		we->val64, index);
 
+	gvt_vdbg_mm("add shadow entry: type %d, index %lu, value %llx\n",
+		    we->type, index, we->val64);
+
 	if (gtt_type_is_pt(get_next_pt_type(we->type))) {
 		s = ppgtt_populate_shadow_page_by_guest_entry(vgpu, we);
 		if (IS_ERR(s)) {