[PATCH] drm/i915/gvt: clear the vGPU reset logic

[Ping Gao]

Releasing shadow PPGTT pages is not enough when vGPU reset, the
guest page table tracking data should has same life-cycle with
all the shadow PPGTT pages; Otherwise there is no chance to
re-shadow the PPGTT pages without free the guest page table
tracking data.

This patch clear the PPGTT reset logic and make the vGPU reset in
working order.

Signed-off-by: Ping Gao <ping.a.gao at intel.com>
---
 drivers/gpu/drm/i915/gvt/gtt.c | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
index 28c9234..77fe681 100644
--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -2309,6 +2309,36 @@ void intel_vgpu_reset_ggtt(struct intel_vgpu *vgpu)
 }
 
 /**
+ * intel_vgpu_reset_ppgtt - free all the ppgtt entries and the
+ * guest page table tracking data.
+ * @vgpu: a vGPU
+ *
+ * This function is called during vGPU reset.
+ *
+ */
+static void intel_vgpu_reset_ppgtt(struct intel_vgpu *vgpu)
+{
+	struct list_head *pos, *n;
+	struct intel_vgpu_mm *mm;
+
+	ppgtt_free_all_shadow_page(vgpu);
+
+	/* The guest page table tracking data should free also after
+	 * free all the shadow pages, otherwise there is no chance
+	 * to create those shadow pages again when it's need.
+	 */
+	list_for_each_safe(pos, n, &vgpu->gtt.mm_list_head) {
+		mm = container_of(pos, struct intel_vgpu_mm, list);
+		if (mm->type == INTEL_GVT_MM_PPGTT) {
+			vgpu->gvt->gtt.mm_free_page_table(mm);
+			list_del(&mm->list);
+			list_del(&mm->lru_list);
+			kfree(mm);
+		}
+	}
+}
+
+/**
  * 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
@@ -2321,7 +2351,8 @@ void intel_vgpu_reset_gtt(struct intel_vgpu *vgpu, bool dmlr)
 {
 	int i;
 
-	ppgtt_free_all_shadow_page(vgpu);
+	intel_vgpu_reset_ppgtt(vgpu);
+
 	if (!dmlr)
 		return;
 
-- 
2.7.4