drm/i915/gvt: Pin vgpu dma address before using

diff --git a/drivers/gpu/drm/i915/gvt/dmabuf.c b/drivers/gpu/drm/i915/gvt/dmabuf.c
index c0347956f7cf..eae003605ebc 100644
--- a/drivers/gpu/drm/i915/gvt/dmabuf.c
+++ b/drivers/gpu/drm/i915/gvt/dmabuf.c
@@ -36,13 +36,32 @@ 
 
 #define GEN8_DECODE_PTE(pte) (pte & GENMASK_ULL(63, 12))
 
+static int vgpu_pin_dma_address(struct intel_vgpu *vgpu,
+				unsigned long size,
+				dma_addr_t dma_addr)
+{
+	int ret = 0;
+
+	if (intel_gvt_hypervisor_dma_pin_guest_page(vgpu, dma_addr))
+		ret = -EINVAL;
+
+	return ret;
+}
+
+static void vgpu_unpin_dma_address(struct intel_vgpu *vgpu,
+				   dma_addr_t dma_addr)
+{
+	intel_gvt_hypervisor_dma_unmap_guest_page(vgpu, dma_addr);
+}
+
 static int vgpu_gem_get_pages(
 		struct drm_i915_gem_object *obj)
 {
 	struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
+	struct intel_vgpu *vgpu;
 	struct sg_table *st;
 	struct scatterlist *sg;
-	int i, ret;
+	int i, j, ret;
 	gen8_pte_t __iomem *gtt_entries;
 	struct intel_vgpu_fb_info *fb_info;
 	u32 page_num;
@@ -51,6 +70,10 @@  static int vgpu_gem_get_pages(
 	if (WARN_ON(!fb_info))
 		return -ENODEV;
 
+	vgpu = fb_info->obj->vgpu;
+	if (WARN_ON(!vgpu))
+		return -ENODEV;
+
 	st = kmalloc(sizeof(*st), GFP_KERNEL);
 	if (unlikely(!st))
 		return -ENOMEM;
@@ -64,21 +87,53 @@  static int vgpu_gem_get_pages(
 	gtt_entries = (gen8_pte_t __iomem *)dev_priv->ggtt.gsm +
 		(fb_info->start >> PAGE_SHIFT);
 	for_each_sg(st->sgl, sg, page_num, i) {
+		dma_addr_t dma_addr =
+			GEN8_DECODE_PTE(readq(&gtt_entries[i]));
+		if (vgpu_pin_dma_address(vgpu, PAGE_SIZE, dma_addr)) {
+			ret = -EINVAL;
+			goto out;
+		}
+
 		sg->offset = 0;
 		sg->length = PAGE_SIZE;
-		sg_dma_address(sg) =
-			GEN8_DECODE_PTE(readq(&gtt_entries[i]));
 		sg_dma_len(sg) = PAGE_SIZE;
+		sg_dma_address(sg) = dma_addr;
 	}
 
 	__i915_gem_object_set_pages(obj, st, PAGE_SIZE);
+out:
+	if (ret) {
+		dma_addr_t dma_addr;
+
+		for_each_sg(st->sgl, sg, i, j) {
+			dma_addr = sg_dma_address(sg);
+			if (dma_addr)
+				vgpu_unpin_dma_address(vgpu, dma_addr);
+		}
+		sg_free_table(st);
+		kfree(st);
+	}
+
+	return ret;
 
-	return 0;
 }
 
 static void vgpu_gem_put_pages(struct drm_i915_gem_object *obj,
 		struct sg_table *pages)
 {
+	struct scatterlist *sg;
+
+	if (obj->base.dma_buf) {
+		struct intel_vgpu_fb_info *fb_info = obj->gvt_info;
+		struct intel_vgpu_dmabuf_obj *obj = fb_info->obj;
+		struct intel_vgpu *vgpu = obj->vgpu;
+		int i;
+
+		for_each_sg(pages->sgl, sg, fb_info->size, i)
+			vgpu_unpin_dma_address(vgpu,
+					       sg_dma_address(sg));
+	}
+
 	sg_free_table(pages);
 	kfree(pages);
 }
diff --git a/drivers/gpu/drm/i915/gvt/hypercall.h b/drivers/gpu/drm/i915/gvt/hypercall.h
index 4862fb12778e..b19a3b1ea4c1 100644
--- a/drivers/gpu/drm/i915/gvt/hypercall.h
+++ b/drivers/gpu/drm/i915/gvt/hypercall.h
@@ -62,6 +62,8 @@  struct intel_gvt_mpt {
 				  unsigned long size, dma_addr_t *dma_addr);
 	void (*dma_unmap_guest_page)(unsigned long handle, dma_addr_t dma_addr);
 
+	int (*dma_pin_guest_page)(unsigned long handle, dma_addr_t dma_addr);
+
 	int (*map_gfn_to_mfn)(unsigned long handle, unsigned long gfn,
 			      unsigned long mfn, unsigned int nr, bool map);
 	int (*set_trap_area)(unsigned long handle, u64 start, u64 end,
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 343d79c1cb7e..3571666ed403 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -1933,6 +1933,28 @@  static int kvmgt_dma_map_guest_page(unsigned long handle, unsigned long gfn,
 	return ret;
 }
 
+static int kvmgt_dma_pin_guest_page(unsigned long handle, dma_addr_t dma_addr)
+{
+	struct kvmgt_guest_info *info;
+	struct gvt_dma *entry;
+	int ret = 0;
+
+	if (!handle_valid(handle))
+		return -ENODEV;
+
+	info = (struct kvmgt_guest_info *)handle;
+
+	mutex_lock(&info->vgpu->vdev.cache_lock);
+	entry = __gvt_cache_find_dma_addr(info->vgpu, dma_addr);
+	if (entry)
+		kref_get(&entry->ref);
+	else
+		ret = -ENOMEM;
+	mutex_unlock(&info->vgpu->vdev.cache_lock);
+
+	return ret;
+}
+
 static void __gvt_dma_release(struct kref *ref)
 {
 	struct gvt_dma *entry = container_of(ref, typeof(*entry), ref);
@@ -2044,6 +2066,7 @@  static struct intel_gvt_mpt kvmgt_mpt = {
 	.gfn_to_mfn = kvmgt_gfn_to_pfn,
 	.dma_map_guest_page = kvmgt_dma_map_guest_page,
 	.dma_unmap_guest_page = kvmgt_dma_unmap_guest_page,
+	.dma_pin_guest_page = kvmgt_dma_pin_guest_page,
 	.set_opregion = kvmgt_set_opregion,
 	.set_edid = kvmgt_set_edid,
 	.get_vfio_device = kvmgt_get_vfio_device,
diff --git a/drivers/gpu/drm/i915/gvt/mpt.h b/drivers/gpu/drm/i915/gvt/mpt.h
index 0f9440128123..9ad224df9c68 100644
--- a/drivers/gpu/drm/i915/gvt/mpt.h
+++ b/drivers/gpu/drm/i915/gvt/mpt.h
@@ -254,6 +254,21 @@  static inline void intel_gvt_hypervisor_dma_unmap_guest_page(
 	intel_gvt_host.mpt->dma_unmap_guest_page(vgpu->handle, dma_addr);
 }
 
+/**
+ * intel_gvt_hypervisor_dma_pin_guest_page - pin guest dma buf
+ * @vgpu: a vGPU
+ * @dma_addr: guest dma addr
+ *
+ * Returns:
+ * 0 on success, negative error code if failed.
+ */
+static inline int
+intel_gvt_hypervisor_dma_pin_guest_page(struct intel_vgpu *vgpu,
+					dma_addr_t dma_addr)
+{
+	return intel_gvt_host.mpt->dma_pin_guest_page(vgpu->handle, dma_addr);
+}
+
 /**
  * intel_gvt_hypervisor_map_gfn_to_mfn - map a GFN region to MFN
  * @vgpu: a vGPU