diff --git a/MdePkg/Include/Protocol/SmmCpuIo.h b/MdePkg/Include/Protocol/SmmCpuIo.h
new file mode 100644
index 0000000000..90d0e93428
--- /dev/null
+++ b/MdePkg/Include/Protocol/SmmCpuIo.h
@@ -0,0 +1,87 @@
+/** @file
+  SMM CPU I/O protocol as defined in the PI 1.2 specification.
+
+  This protocol provides CPU I/O and memory access within SMM.
+
+  Copyright (c) 2009, Intel Corporation
+  All rights reserved. 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
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#ifndef _SMM_CPU_IO_H_
+#define _SMM_CPU_IO_H_
+
+#define EFI_SMM_CPU_IO_PROTOCOL_GUID \
+  { \
+    0x3242A9D8, 0xCE70, 0x4AA0, { 0x95, 0x5D, 0x5E, 0x7B, 0x14, 0x0D, 0xE4, 0xD2 } \
+  }
+
+typedef struct _EFI_SMM_CPU_IO_PROTOCOL  EFI_SMM_CPU_IO_PROTOCOL;
+
+///
+/// Width of the SMM CPU I/O operations
+///
+typedef enum {
+  SMM_IO_UINT8  = 0,
+  SMM_IO_UINT16 = 1,
+  SMM_IO_UINT32 = 2,
+  SMM_IO_UINT64 = 3
+} EFI_SMM_IO_WIDTH;
+
+/**
+  Provides the basic memory and I/O interfaces used toabstract accesses to devices.
+
+  The I/O operations are carried out exactly as requested.  The caller is responsible for any alignment 
+  and I/O width issues that the bus, device, platform, or type of I/O might require.
+
+  @param[in]      This           The EFI_SMM_CPU_IO_PROTOCOL instance.
+  @param[in]      Width          Signifies the width of the I/O operations.
+  @param[in]      Address        The base address of the I/O operations.
+                                 The caller is responsible for aligning the Address if required. 
+  @param[in]      Count          The number of I/O operations to perform.
+  @param[in,out]  Buffer         For read operations, the destination buffer to store the results.
+                                 For write operations, the source buffer from which to write data.
+
+  @retval EFI_SUCCESS            The data was read from or written to the device.
+  @retval EFI_UNSUPPORTED        The Address is not valid for this system.
+  @retval EFI_INVALID_PARAMETER  Width or Count, or both, were invalid.
+  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a lack of resources.
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EFI_SMM_CPU_IO)(
+  IN CONST EFI_SMM_CPU_IO_PROTOCOL  *This,
+  IN EFI_SMM_IO_WIDTH               Width,
+  IN UINT64                         Address,
+  IN UINTN                          Count,
+  IN OUT VOID                       *Buffer
+  );
+
+typedef struct {
+  ///
+  /// This service provides the various modalities of memory and I/O read.
+  ///
+  EFI_SMM_CPU_IO  Read;
+  ///
+  /// This service provides the various modalities of memory and I/O write.
+  ///
+  EFI_SMM_CPU_IO  Write;
+} EFI_SMM_IO_ACCESS;
+
+///
+/// SMM CPU I/O Protocol provides CPU I/O and memory access within SMM.
+///
+typedef struct _EFI_SMM_CPU_IO_PROTOCOL {
+  EFI_SMM_IO_ACCESS Mem;  ///< Allows reads and writes to memory-mapped I/O space.
+  EFI_SMM_IO_ACCESS Io;   ///< Allows reads and writes to I/O space.
+};
+
+extern EFI_GUID gEfiSmmCpuIoProtocolGuid;
+
+#endif
diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec
index 28cb07f0bf..b6c7ac37a4 100644
--- a/MdePkg/MdePkg.dec
+++ b/MdePkg/MdePkg.dec
@@ -573,8 +573,11 @@
   gEfiAcpiSdtProtocolGuid         = { 0xeb97088e, 0xcfdf, 0x49c6, { 0xbe, 0x4b, 0xd9, 0x6, 0xa5, 0xb2, 0xe, 0x86 }}
   
   ## Include/Protocol/SuperIo.h
-  gEfiSioProtocolGuid             = { 0x215fdd18, 0xbd50, 0x4feb, { 0x89, 0xb, 0x58, 0xca, 0xb, 0x47, 0x39, 0xe9 } }
+  gEfiSioProtocolGuid             = { 0x215fdd18, 0xbd50, 0x4feb, { 0x89, 0xb, 0x58, 0xca, 0xb, 0x47, 0x39, 0xe9 }}
   
+  ## Include/Protocol/SmmCpuIo.h
+  gEfiSmmCpuIoProtocolGuid        = { 0x3242a9d8, 0xce70, 0x4aa0, { 0x95, 0x5d, 0x5e, 0x7b, 0x14, 0x0d, 0xe4, 0xd2 }}
+
   #
   # Protocols defined in UEFI2.1/UEFI2.0/EFI1.1
   #