diff -r 4b476378fc35 xen/arch/x86/smpboot.c
--- a/xen/arch/x86/smpboot.c	Mon Jan 21 17:03:10 2013 +0000
+++ b/xen/arch/x86/smpboot.c	Wed Jan 23 15:25:28 2013 +0000
@@ -837,7 +837,8 @@
     remove_siblinginfo(cpu);
 
     /* It's now safe to remove this processor from the online map */
-    cpumask_clear_cpu(cpu, cpupool0->cpu_valid);
+    if (system_state != SYS_STATE_suspend)
+        cpumask_clear_cpu(cpu, cpupool0->cpu_valid);
     cpumask_clear_cpu(cpu, &cpu_online_map);
     fixup_irqs();