[PATCH 4.14 068/118] drm/i915/gvt: Clear the shadow page table entry after post-sync

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Zhi Wang <zhi.a.wang@xxxxxxxxx>

commit 121d760d0788f95619049c63449d977065cab69d upstream.

A shadow page table entry needs to be cleared after being set as
post-sync. This patch fixes the recent error reported in Win7-32 test.

Fixes: 2707e4446688 ("drm/i915/gvt: vGPU graphics memory virtualization")
Signed-off-by: Zhi Wang <zhi.a.wang@xxxxxxxxx>
Signed-off-by: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/i915/gvt/gtt.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -1359,12 +1359,15 @@ static int ppgtt_handle_guest_write_page
 			return ret;
 	} else {
 		if (!test_bit(index, spt->post_shadow_bitmap)) {
+			int type = spt->shadow_page.type;
+
 			ppgtt_get_shadow_entry(spt, &se, index);
 			ret = ppgtt_handle_guest_entry_removal(gpt, &se, index);
 			if (ret)
 				return ret;
+			ops->set_pfn(&se, vgpu->gtt.scratch_pt[type].page_mfn);
+			ppgtt_set_shadow_entry(spt, &se, index);
 		}
-
 		ppgtt_set_post_shadow(spt, index);
 	}