diff -r 8af26fef898c xen/arch/x86/acpi/cpu_idle.c
--- a/xen/arch/x86/acpi/cpu_idle.c	Fri Jul 24 12:08:54 2009 +0100
+++ b/xen/arch/x86/acpi/cpu_idle.c	Mon Jul 27 15:41:44 2009 +0100
@@ -442,6 +442,7 @@
     acpi_power->states[ACPI_STATE_C1].valid = 1;
 
     acpi_power->count = 2;
+    acpi_power->safe_state = &acpi_power->states[ACPI_STATE_C1];
 
     return 0;
 }