diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
index 0858d8f4d7..db36a0ad3c 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
@@ -96,6 +96,11 @@ UINTN mNumberOfCpus = 1;
 //
 BOOLEAN mSmmReadyToLock = FALSE;
 
+//
+// S3 boot flag
+//
+BOOLEAN mSmmS3Flag = FALSE;
+
 //
 // Global used to cache PCD for SMM Code Access Check enable
 //
@@ -485,6 +490,8 @@ SmmRestoreCpu (
 
   DEBUG ((EFI_D_INFO, "SmmRestoreCpu()\n"));
 
+  mSmmS3Flag = TRUE;
+
   InitializeSpinLock (mMemoryMappedLock);
 
   //