v4.19.13 snapshot.
diff --git a/include/xen/balloon.h b/include/xen/balloon.h
new file mode 100644
index 0000000..4914b93
--- /dev/null
+++ b/include/xen/balloon.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/******************************************************************************
+ * Xen balloon functionality
+ */
+
+#define RETRY_UNLIMITED 0
+
+struct balloon_stats {
+ /* We aim for 'current allocation' == 'target allocation'. */
+ unsigned long current_pages;
+ unsigned long target_pages;
+ unsigned long target_unpopulated;
+ /* Number of pages in high- and low-memory balloons. */
+ unsigned long balloon_low;
+ unsigned long balloon_high;
+ unsigned long total_pages;
+ unsigned long schedule_delay;
+ unsigned long max_schedule_delay;
+ unsigned long retry_count;
+ unsigned long max_retry_count;
+};
+
+extern struct balloon_stats balloon_stats;
+
+void balloon_set_new_target(unsigned long target);
+
+int alloc_xenballooned_pages(int nr_pages, struct page **pages);
+void free_xenballooned_pages(int nr_pages, struct page **pages);
+
+struct device;
+#ifdef CONFIG_XEN_SELFBALLOONING
+extern int register_xen_selfballooning(struct device *dev);
+#else
+static inline int register_xen_selfballooning(struct device *dev)
+{
+ return -ENOSYS;
+}
+#endif
+
+#ifdef CONFIG_XEN_BALLOON
+void xen_balloon_init(void);
+#else
+static inline void xen_balloon_init(void)
+{
+}
+#endif