UefiCpuPkg/PiSmmCpuDxeSmm: Save and restore CR2 only if SmiProfile en…

…able

A page fault (#PF) that triggers an update to the page table only occurs
if SmiProfile is enabled. Therefore, it is necessary to save and restore
the CR2 register if SmiProfile is configured to be enabled.

Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>

UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c

@@ -851,7 +851,15 @@ SaveCr2 (
   OUT UINTN  *Cr2
   )
 {
-  *Cr2 = AsmReadCr2 ();
+  //
+  // A page fault (#PF) that triggers an update to the page
+  // table only occurs if SmiProfile is enabled. Therefore, it is
+  // necessary to save the CR2 register if SmiProfile is
+  // configured to be enabled.
+  //
+  if (mSmmProfileEnabled) {
+    *Cr2 = AsmReadCr2 ();
+  }
 }
 
 /**
@@ -864,5 +872,13 @@ RestoreCr2 (
   IN UINTN  Cr2
   )
 {
-  AsmWriteCr2 (Cr2);
+  //
+  // A page fault (#PF) that triggers an update to the page
+  // table only occurs if SmiProfile is enabled. Therefore, it is
+  // necessary to restore the CR2 register if SmiProfile is
+  // configured to be enabled.
+  //
+  if (mSmmProfileEnabled) {
+    AsmWriteCr2 (Cr2);
+  }
 }