drm/i915/gvt: Refine the intel_vgpu_reset_gtt reset function

When doing the VGPU reset, we don't need to do the gtt/ppgtt reset.
This will make the GVT to do the ppgtt shadow every time for
a workload and caused really bad performance after a VGPU reset.
This patch will make sure ppgtt clean only happen at device module
level reset to fix this.

Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

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

@@ -2352,13 +2352,12 @@ void intel_vgpu_reset_ggtt(struct intel_vgpu *vgpu)
 /**
  * intel_vgpu_reset_gtt - reset the all GTT related status
  * @vgpu: a vGPU
- * @dmlr: true for vGPU Device Model Level Reset, false for GT Reset
  *
  * This function is called from vfio core to reset reset all
  * GTT related status, including GGTT, PPGTT, scratch page.
  *
  */
-void intel_vgpu_reset_gtt(struct intel_vgpu *vgpu, bool dmlr)
+void intel_vgpu_reset_gtt(struct intel_vgpu *vgpu)
 {
 	int i;
 
@@ -2370,9 +2369,6 @@ void intel_vgpu_reset_gtt(struct intel_vgpu *vgpu, bool dmlr)
 	 */
 	intel_vgpu_free_mm(vgpu, INTEL_GVT_MM_PPGTT);
 
-	if (!dmlr)
-		return;
-
 	intel_vgpu_reset_ggtt(vgpu);
 
 	/* clear scratch page for security */

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

@@ -212,7 +212,7 @@ extern void intel_vgpu_clean_gtt(struct intel_vgpu *vgpu);
 void intel_vgpu_reset_ggtt(struct intel_vgpu *vgpu);
 
 extern int intel_gvt_init_gtt(struct intel_gvt *gvt);
-extern void intel_vgpu_reset_gtt(struct intel_vgpu *vgpu, bool dmlr);
+void intel_vgpu_reset_gtt(struct intel_vgpu *vgpu);
 extern void intel_gvt_clean_gtt(struct intel_gvt *gvt);
 
 extern struct intel_vgpu_mm *intel_gvt_find_ppgtt_mm(struct intel_vgpu *vgpu,

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

@@ -502,11 +502,11 @@ void intel_gvt_reset_vgpu_locked(struct intel_vgpu *vgpu, bool dmlr,
 	/* full GPU reset or device model level reset */
 	if (engine_mask == ALL_ENGINES || dmlr) {
 
-		intel_vgpu_reset_gtt(vgpu, dmlr);
-
 		/*fence will not be reset during virtual reset */
-		if (dmlr)
+		if (dmlr) {
+			intel_vgpu_reset_gtt(vgpu);
 			intel_vgpu_reset_resource(vgpu);
+		}
 
 		intel_vgpu_reset_mmio(vgpu, dmlr);
 		populate_pvinfo_page(vgpu);