diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index ab5947f1c1..10d57dfb82 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -366,7 +366,9 @@ void asmlinkage start_secondary(void *unused)
 
     cpu_init();
 
-    initialize_cpu_data(cpu);
+    /* During resume, must not clear previously collected data. */
+    if ( system_state != SYS_STATE_resume )
+        initialize_cpu_data(cpu);
 
     microcode_update_one();