diff --git a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/BmDma.c b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/BmDma.c
index 7a5f3619a4..e8685666e7 100644
--- a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/BmDma.c
+++ b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/BmDma.c
@@ -300,7 +300,7 @@ IoMmuUnmap (
 
   @retval EFI_SUCCESS           The requested memory pages were allocated.
   @retval EFI_UNSUPPORTED       Attributes is unsupported. The only legal attribute bits are
-                                MEMORY_WRITE_COMBINE and MEMORY_CACHED.
+                                MEMORY_WRITE_COMBINE, MEMORY_CACHED and DUAL_ADDRESS_CYCLE.
   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
   @retval EFI_OUT_OF_RESOURCES  The memory pages could not be allocated.
 
diff --git a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/IntelVTdDxe.c b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/IntelVTdDxe.c
index 64693a8c6e..89d9bea3fc 100644
--- a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/IntelVTdDxe.c
+++ b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/IntelVTdDxe.c
@@ -87,7 +87,7 @@ IoMmuUnmap (
 
   @retval EFI_SUCCESS           The requested memory pages were allocated.
   @retval EFI_UNSUPPORTED       Attributes is unsupported. The only legal attribute bits are
-                                MEMORY_WRITE_COMBINE and MEMORY_CACHED.
+                                MEMORY_WRITE_COMBINE, MEMORY_CACHED and DUAL_ADDRESS_CYCLE.
   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
   @retval EFI_OUT_OF_RESOURCES  The memory pages could not be allocated.
 
diff --git a/IntelSiliconPkg/Feature/VTd/IntelVTdPmrPei/IntelVTdPmrPei.c b/IntelSiliconPkg/Feature/VTd/IntelVTdPmrPei/IntelVTdPmrPei.c
index 240a6d2817..7147a19f53 100644
--- a/IntelSiliconPkg/Feature/VTd/IntelVTdPmrPei/IntelVTdPmrPei.c
+++ b/IntelSiliconPkg/Feature/VTd/IntelVTdPmrPei/IntelVTdPmrPei.c
@@ -284,7 +284,7 @@ PeiIoMmuUnmap (
 
   @retval EFI_SUCCESS           The requested memory pages were allocated.
   @retval EFI_UNSUPPORTED       Attributes is unsupported. The only legal attribute bits are
-                                MEMORY_WRITE_COMBINE and MEMORY_CACHED.
+                                MEMORY_WRITE_COMBINE, MEMORY_CACHED and DUAL_ADDRESS_CYCLE.
   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
   @retval EFI_OUT_OF_RESOURCES  The memory pages could not be allocated.