vm: object: implement object cleanup

vm/vm-object.c

@@ -15,10 +15,30 @@
 		(p) += VM_PAGE_SIZE;                                           \
 	}
 
+static kern_status_t vm_object_cleanup(struct object *obj, struct queue *q)
+{
+	struct vm_object *vmo = vm_object_cast(obj);
+	struct btree_node *cur = btree_first(&vmo->vo_pages);
+	while (cur) {
+		struct vm_page *pg
+			= BTREE_CONTAINER(struct vm_page, p_bnode, cur);
+		struct btree_node *next = btree_next(cur);
+		btree_delete(&vmo->vo_pages, cur);
+
+		vm_page_free(pg);
+		cur = next;
+	}
+
+	return KERN_OK;
+}
+
 static struct object_type vm_object_type = {
 	.ob_name = "vm-object",
 	.ob_size = sizeof(struct vm_object),
 	.ob_header_offset = offsetof(struct vm_object, vo_base),
+	.ob_ops = {
+		.destroy = vm_object_cleanup,
+	},
 };
 
 struct object_iterator {