MdeModulePkg/VarCheckPolicyLib: implement standalone MM version

This commit adds the VarCheckPolicyLib that will be able to
execute in the context of standalone MM.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Co-authored-by: Kun Qin <kun.q@outlook.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Supreeth Venkatesh <supreeth.venkatesh@arm.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>

MdeModulePkg/Library/VarCheckPolicyLib/VarCheckPolicyLibTraditional.c

@@ -0,0 +1,50 @@
+/** @file -- VarCheckPolicyLibTraditional.c
+This is an instance of a VarCheck lib constructor for traditional SMM.
+
+Copyright (c) Microsoft Corporation. All rights reserved.
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/SmmMemLib.h>
+
+#include "VarCheckPolicyLib.h"
+
+/**
+  Traditional constructor function of VarCheckPolicyLib to invoke common
+  constructor routine.
+
+  @param[in] ImageHandle    The firmware allocated handle for the EFI image.
+  @param[in] SystemTable    A pointer to the EFI System Table.
+
+  @retval EFI_SUCCESS       The constructor executed correctly.
+
+**/
+EFI_STATUS
+EFIAPI
+VarCheckPolicyLibTraditionalConstructor (
+  IN EFI_HANDLE             ImageHandle,
+  IN EFI_SYSTEM_TABLE       *SystemTable
+  )
+{
+  return VarCheckPolicyLibCommonConstructor ();
+}
+
+/**
+  This function is wrapper function to validate the buffer.
+
+  @param Buffer  The buffer start address to be checked.
+  @param Length  The buffer length to be checked.
+
+  @retval TRUE  This buffer is valid per processor architecture and not overlap with SMRAM.
+  @retval FALSE This buffer is not valid per processor architecture or overlap with SMRAM.
+**/
+BOOLEAN
+EFIAPI
+VarCheckPolicyIsBufferOutsideValid (
+  IN EFI_PHYSICAL_ADDRESS  Buffer,
+  IN UINT64                Length
+  )
+{
+  return SmmIsBufferOutsideSmmValid (Buffer, Length);
+}