--- linux-2.6.32.x86_64/drivers/xen/balloon.c.orig	2010-06-05 22:43:11.000000000 +0100
+++ linux-2.6.32.x86_64/drivers/xen/balloon.c	2010-06-05 22:47:03.000000000 +0100
@@ -340,7 +340,7 @@
 				discontig_free = 1;
 
 			set_phys_to_machine(lpfn, INVALID_P2M_ENTRY);
-			if (!PageHighMem(page)) {
+			if (!PageHighMem(pfn_to_page(lpfn))) {
 				ret = HYPERVISOR_update_va_mapping(
 					(unsigned long)__va(lpfn << PAGE_SHIFT),
 					__pte_ma(0), 0);