diff --git a/xen/arch/x86/cpu/microcode/core.c b/xen/arch/x86/cpu/microcode/core.c
index e2d8ab8b24..e38e5eb7ff 100644
--- a/xen/arch/x86/cpu/microcode/core.c
+++ b/xen/arch/x86/cpu/microcode/core.c
@@ -376,7 +376,9 @@ static int secondary_nmi_work(void)
 {
     cpumask_set_cpu(smp_processor_id(), &cpu_callin_map);
 
-    return wait_for_state(LOADING_EXIT) ? 0 : -EBUSY;
+    wait_for_state(LOADING_EXIT);
+
+    return 0;
 }
 
 static int primary_thread_work(const struct microcode_patch *patch)
@@ -386,7 +388,7 @@ static int primary_thread_work(const struct microcode_patch *patch)
     cpumask_set_cpu(smp_processor_id(), &cpu_callin_map);
 
     if ( !wait_for_state(LOADING_ENTER) )
-        return -EBUSY;
+        return 0;
 
     ret = alternative_call(ucode_ops.apply_microcode, patch);
     if ( !ret )
@@ -427,7 +429,7 @@ static int cf_check microcode_nmi_callback(
 static int secondary_thread_fn(void)
 {
     if ( !wait_for_state(LOADING_CALLIN) )
-        return -EBUSY;
+        return 0;
 
     self_nmi();
 
@@ -449,7 +451,7 @@ static int secondary_thread_fn(void)
 static int primary_thread_fn(const struct microcode_patch *patch)
 {
     if ( !wait_for_state(LOADING_CALLIN) )
-        return -EBUSY;
+        return 0;
 
     if ( ucode_in_nmi )
     {