@@ -227,6 +227,29 @@ static enum bp_state reserve_additional_memory(long credit)
balloon_hotplug = round_up(balloon_hotplug, PAGES_PER_SECTION);
nid = memory_add_physaddr_to_nid(hotplug_start_paddr);
+#ifdef CONFIG_XEN_HAVE_PVMMU
+ /*
+ * add_memory() will build page tables for the new memory so
+ * the p2m must contain invalid entries so the correct
+ * non-present PTEs will be written.
+ *
+ * If a failure occurs, the original (identity) p2m entries
+ * are not restored since this region is now known not to
+ * conflict with any devices.
+ */
+ if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ unsigned long pfn, i;
+
+ pfn = PFN_DOWN(hotplug_start_paddr);
+ for (i = 0; i < balloon_hotplug; i++) {
+ if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) {
+ pr_warn("set_phys_to_machine() failed, no memory added\n");
+ return BP_ECANCELED;
+ }
+ }
+ }
+#endif
+
rc = add_memory(nid, hotplug_start_paddr, balloon_hotplug << PAGE_SHIFT);
if (rc) {