diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index b48b586dc28755ceceb0ee6e7011bb786ffb5a76..057f905b25b0376ed949bd1dc82e8bced4c6e104 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -27,6 +27,7 @@
 #include <drm/drmP.h>
 #include <drm/i915_drm.h>
 #include "i915_drv.h"
+#include "i915_vgpu.h"
 #include "i915_trace.h"
 #include "intel_drv.h"
 
@@ -1756,6 +1757,16 @@ static int i915_gem_setup_global_gtt(struct drm_device *dev,
 
 	/* Subtract the guard page ... */
 	drm_mm_init(&ggtt_vm->mm, start, end - start - PAGE_SIZE);
+
+	dev_priv->gtt.base.start = start;
+	dev_priv->gtt.base.total = end - start;
+
+	if (intel_vgpu_active(dev)) {
+		ret = intel_vgt_balloon(dev);
+		if (ret)
+			return ret;
+	}
+
 	if (!HAS_LLC(dev))
 		dev_priv->gtt.base.mm.color_adjust = i915_gtt_color_adjust;
 
@@ -1775,9 +1786,6 @@ static int i915_gem_setup_global_gtt(struct drm_device *dev,
 		vma->bound |= GLOBAL_BIND;
 	}
 
-	dev_priv->gtt.base.start = start;
-	dev_priv->gtt.base.total = end - start;
-
 	/* Clear any non-preallocated blocks */
 	drm_mm_for_each_hole(entry, &ggtt_vm->mm, hole_start, hole_end) {
 		DRM_DEBUG_KMS("clearing unused GTT space: [%lx, %lx]\n",
@@ -1829,6 +1837,9 @@ void i915_global_gtt_cleanup(struct drm_device *dev)
 	}
 
 	if (drm_mm_initialized(&vm->mm)) {
+		if (intel_vgpu_active(dev))
+			intel_vgt_deballoon();
+
 		drm_mm_takedown(&vm->mm);
 		list_del(&vm->global_link);
 	}
diff --git a/drivers/gpu/drm/i915/i915_vgpu.c b/drivers/gpu/drm/i915/i915_vgpu.c
index 995a6003ed7836ad99880f040abf126a57240287..5eee75bff1701133caaf903b3fbe74a3b11dcb60 100644
--- a/drivers/gpu/drm/i915/i915_vgpu.c
+++ b/drivers/gpu/drm/i915/i915_vgpu.c
@@ -84,3 +84,181 @@ void i915_check_vgpu(struct drm_device *dev)
 	dev_priv->vgpu.active = true;
 	DRM_INFO("Virtual GPU for Intel GVT-g detected.\n");
 }
+
+struct _balloon_info_ {
+	/*
+	 * There are up to 2 regions per mappable/unmappable graphic
+	 * memory that might be ballooned. Here, index 0/1 is for mappable
+	 * graphic memory, 2/3 for unmappable graphic memory.
+	 */
+	struct drm_mm_node space[4];
+};
+
+static struct _balloon_info_ bl_info;
+
+/**
+ * intel_vgt_deballoon - deballoon reserved graphics address trunks
+ *
+ * This function is called to deallocate the ballooned-out graphic memory, when
+ * driver is unloaded or when ballooning fails.
+ */
+void intel_vgt_deballoon(void)
+{
+	int i;
+
+	DRM_DEBUG("VGT deballoon.\n");
+
+	for (i = 0; i < 4; i++) {
+		if (bl_info.space[i].allocated)
+			drm_mm_remove_node(&bl_info.space[i]);
+	}
+
+	memset(&bl_info, 0, sizeof(bl_info));
+}
+
+static int vgt_balloon_space(struct drm_mm *mm,
+			     struct drm_mm_node *node,
+			     unsigned long start, unsigned long end)
+{
+	unsigned long size = end - start;
+
+	if (start == end)
+		return -EINVAL;
+
+	DRM_INFO("balloon space: range [ 0x%lx - 0x%lx ] %lu KiB.\n",
+		 start, end, size / 1024);
+
+	node->start = start;
+	node->size = size;
+
+	return drm_mm_reserve_node(mm, node);
+}
+
+/**
+ * intel_vgt_balloon - balloon out reserved graphics address trunks
+ * @dev: drm device
+ *
+ * This function is called at the initialization stage, to balloon out the
+ * graphic address space allocated to other vGPUs, by marking these spaces as
+ * reserved. The ballooning related knowledge(starting address and size of
+ * the mappable/unmappable graphic memory) is described in the vgt_if structure
+ * in a reserved mmio range.
+ *
+ * To give an example, the drawing below depicts one typical scenario after
+ * ballooning. Here the vGPU1 has 2 pieces of graphic address spaces ballooned
+ * out each for the mappable and the non-mappable part. From the vGPU1 point of
+ * view, the total size is the same as the physical one, with the start address
+ * of its graphic space being zero. Yet there are some portions ballooned out(
+ * the shadow part, which are marked as reserved by drm allocator). From the
+ * host point of view, the graphic address space is partitioned by multiple
+ * vGPUs in different VMs.
+ *
+ *                        vGPU1 view         Host view
+ *             0 ------> +-----------+     +-----------+
+ *               ^       |///////////|     |   vGPU3   |
+ *               |       |///////////|     +-----------+
+ *               |       |///////////|     |   vGPU2   |
+ *               |       +-----------+     +-----------+
+ *        mappable GM    | available | ==> |   vGPU1   |
+ *               |       +-----------+     +-----------+
+ *               |       |///////////|     |           |
+ *               v       |///////////|     |   Host    |
+ *               +=======+===========+     +===========+
+ *               ^       |///////////|     |   vGPU3   |
+ *               |       |///////////|     +-----------+
+ *               |       |///////////|     |   vGPU2   |
+ *               |       +-----------+     +-----------+
+ *      unmappable GM    | available | ==> |   vGPU1   |
+ *               |       +-----------+     +-----------+
+ *               |       |///////////|     |           |
+ *               |       |///////////|     |   Host    |
+ *               v       |///////////|     |           |
+ * total GM size ------> +-----------+     +-----------+
+ *
+ * Returns:
+ * zero on success, non-zero if configuration invalid or ballooning failed
+ */
+int intel_vgt_balloon(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct i915_address_space *ggtt_vm = &dev_priv->gtt.base;
+	unsigned long ggtt_vm_end = ggtt_vm->start + ggtt_vm->total;
+
+	unsigned long mappable_base, mappable_size, mappable_end;
+	unsigned long unmappable_base, unmappable_size, unmappable_end;
+	int ret;
+
+	mappable_base = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.base));
+	mappable_size = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.size));
+	unmappable_base = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.base));
+	unmappable_size = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.size));
+
+	mappable_end = mappable_base + mappable_size;
+	unmappable_end = unmappable_base + unmappable_size;
+
+	DRM_INFO("VGT ballooning configuration:\n");
+	DRM_INFO("Mappable graphic memory: base 0x%lx size %ldKiB\n",
+		 mappable_base, mappable_size / 1024);
+	DRM_INFO("Unmappable graphic memory: base 0x%lx size %ldKiB\n",
+		 unmappable_base, unmappable_size / 1024);
+
+	if (mappable_base < ggtt_vm->start ||
+	    mappable_end > dev_priv->gtt.mappable_end ||
+	    unmappable_base < dev_priv->gtt.mappable_end ||
+	    unmappable_end > ggtt_vm_end) {
+		DRM_ERROR("Invalid ballooning configuration!\n");
+		return -EINVAL;
+	}
+
+	/* Unmappable graphic memory ballooning */
+	if (unmappable_base > dev_priv->gtt.mappable_end) {
+		ret = vgt_balloon_space(&ggtt_vm->mm,
+					&bl_info.space[2],
+					dev_priv->gtt.mappable_end,
+					unmappable_base);
+
+		if (ret)
+			goto err;
+	}
+
+	/*
+	 * No need to partition out the last physical page,
+	 * because it is reserved to the guard page.
+	 */
+	if (unmappable_end < ggtt_vm_end - PAGE_SIZE) {
+		ret = vgt_balloon_space(&ggtt_vm->mm,
+					&bl_info.space[3],
+					unmappable_end,
+					ggtt_vm_end - PAGE_SIZE);
+		if (ret)
+			goto err;
+	}
+
+	/* Mappable graphic memory ballooning */
+	if (mappable_base > ggtt_vm->start) {
+		ret = vgt_balloon_space(&ggtt_vm->mm,
+					&bl_info.space[0],
+					ggtt_vm->start, mappable_base);
+
+		if (ret)
+			goto err;
+	}
+
+	if (mappable_end < dev_priv->gtt.mappable_end) {
+		ret = vgt_balloon_space(&ggtt_vm->mm,
+					&bl_info.space[1],
+					mappable_end,
+					dev_priv->gtt.mappable_end);
+
+		if (ret)
+			goto err;
+	}
+
+	DRM_INFO("VGT balloon successfully\n");
+	return 0;
+
+err:
+	DRM_ERROR("VGT balloon fail\n");
+	intel_vgt_deballoon();
+	return ret;
+}
diff --git a/drivers/gpu/drm/i915/i915_vgpu.h b/drivers/gpu/drm/i915/i915_vgpu.h
index aa72e146d6c8868b12340db6d43ad4273e143235..3ed01a7ac48e95c21fc61033dbb328bd143b278d 100644
--- a/drivers/gpu/drm/i915/i915_vgpu.h
+++ b/drivers/gpu/drm/i915/i915_vgpu.h
@@ -81,5 +81,7 @@ struct vgt_if {
 	(VGT_PVINFO_PAGE + (long)&((struct vgt_if *)NULL)->x)
 
 extern void i915_check_vgpu(struct drm_device *dev);
+extern int intel_vgt_balloon(struct drm_device *dev);
+extern void intel_vgt_deballoon(void);
 
 #endif /* _I915_VGPU_H_ */