UefiCpuPkg/CpuDxe: Add support for PCD PcdPteMemoryEncryptionAddressOrMask

This PCD holds the address mask for page table entries when memory
encryption is enabled on AMD processors supporting the Secure Encrypted
Virtualization (SEV) feature.

The mask is applied when page tables entries are created or modified.

CC: Jeff Fan <jeff.fan@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Leo Duran <leo.duran@amd.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>

UefiCpuPkg/CpuDxe/CpuDxe.inf

@@ -2,6 +2,8 @@
 #  CPU driver installs CPU Architecture Protocol and CPU MP protocol.
 #
 #  Copyright (c) 2008 - 2017, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
+#
 #  This program and the accompanying materials
 #  are licensed and made available under the terms and conditions of the BSD License
 #  which accompanies this distribution.  The full text of the license may be found at
@@ -77,6 +79,9 @@
   gEfiSecPlatformInformation2PpiGuid            ## UNDEFINED # HOB
   gEfiSecPlatformInformationPpiGuid             ## UNDEFINED # HOB
 
+[Pcd]
+  gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrMask    ## CONSUMES
+
 [Depex]
   TRUE