From 7422064883398612b5921bf26b15bd9b0dd6c325 Mon Sep 17 00:00:00 2001
From: Zhi Wang <zhi.a.wang@intel.com>
Date: Tue, 10 Oct 2017 17:14:13 +0800
Subject: [PATCH] drm/i915/gvt: Fix a bug of unexpectedly clear scratch page table
Git-commit: 7422064883398612b5921bf26b15bd9b0dd6c325
Patch-mainline: v4.16-rc1
References: FATE#322643 bsc#1055900

During a vGPU reset, the scratch page table shouldn't be cleared, what
needs to be cleared should be the scratch page.

Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/gvt/gtt.c |    9 ---------
 1 file changed, 9 deletions(-)

--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -2398,8 +2398,6 @@ void intel_vgpu_reset_ggtt(struct intel_
  */
 void intel_vgpu_reset_gtt(struct intel_vgpu *vgpu)
 {
-	int i;
-
 	ppgtt_free_all_shadow_page(vgpu);
 
 	/* Shadow pages are only created when there is no page
@@ -2409,11 +2407,4 @@ void intel_vgpu_reset_gtt(struct intel_v
 	intel_vgpu_free_mm(vgpu, INTEL_GVT_MM_PPGTT);
 
 	intel_vgpu_reset_ggtt(vgpu);
-
-	/* clear scratch page for security */
-	for (i = GTT_TYPE_PPGTT_PTE_PT; i < GTT_TYPE_MAX; i++) {
-		if (vgpu->gtt.scratch_pt[i].page != NULL)
-			memset(page_address(vgpu->gtt.scratch_pt[i].page),
-				0, PAGE_SIZE);
-	}
 }