[PATCH v6 5/7] SecurityPkg: Tcg2Smm: Separate Tcg2Smm into 2 modules

["Kun Qin" <kun.q@outlook.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3169

This change separated the original Tcg2Smm module into 2 drivers: the
SMM driver that registers callback for physical presence and memory
clear; the Tcg2Acpi driver that patches and publishes ACPI table for
runtime use.

Tcg2Smm introduced an SMI root handler to allow Tcg2Acpi to communicate
the NVS region used by Tpm.asl and exchange the registered SwSmiValue.

Lastly, Tcg2Smm driver will publish gTcg2MmSwSmiRegisteredGuid at the end
of entrypoint to ensure Tcg2Acpi to load after Tcg2Smm is ready to
communicate.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Qi Zhang <qi1.zhang@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>

Signed-off-by: Kun Qin <kun.q@outlook.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
---

Notes:
    v6:
    - Updated Tcg2Acpi driver entrypoint function description.
    
    v5:
    - Previously reviewed, no change.
    
    v4:
    - Previously reviewed, no change.
    
    v3:
    - Added review-by tag. [Jiewen]
    - Added expected usage in driver header.
    - Initialized pointer variables to null at entrypoint.
    
    v2:
    - Newly added.

 SecurityPkg/Tcg/{Tcg2Smm/Tcg2Smm.c => Tcg2Acpi/Tcg2Acpi.c}     | 356 ++++----
 SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c                              | 853 ++++----------------
 SecurityPkg/Tcg/Tcg2Smm/Tcg2TraditionalMm.c                    |  82 ++
 SecurityPkg/Include/Guid/TpmNvsMm.h                            |  68 ++
 SecurityPkg/SecurityPkg.dec                                    |   7 +
 SecurityPkg/SecurityPkg.dsc                                    |   1 +
 SecurityPkg/Tcg/{Tcg2Smm/Tcg2Smm.inf => Tcg2Acpi/Tcg2Acpi.inf} |  34 +-
 SecurityPkg/Tcg/{Tcg2Smm => Tcg2Acpi}/Tpm.asl                  |   0
 SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.h                              | 119 +--
 SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.inf                            |  25 +-
 10 files changed, 551 insertions(+), 994 deletions(-)

diff --git a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c b/SecurityPkg/Tcg/Tcg2Acpi/Tcg2Acpi.c
similarity index 72%
copy from SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c
copy to SecurityPkg/Tcg/Tcg2Acpi/Tcg2Acpi.c
index 08105c3692ba..924c3b4edda6 100644
--- a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c
+++ b/SecurityPkg/Tcg/Tcg2Acpi/Tcg2Acpi.c
@@ -1,20 +1,76 @@
 /** @file
-  It updates TPM2 items in ACPI table and registers SMI2 callback
-  functions for Tcg2 physical presence, ClearMemory, and sample
-  for dTPM StartMethod.
+  This driver implements TPM 2.0 definition block in ACPI table and
+  populates registered SMI callback functions for Tcg2 physical presence
+  and MemoryClear to handle the requests for ACPI method. It needs to be
+  used together with Tcg2 MM drivers to exchange information on registered
+  SwSmiValue and allocated NVS region address.
 
   Caution: This module requires additional review when modified.
   This driver will have external input - variable and ACPINvs data in SMM mode.
   This external input must be validated carefully to avoid security issue.
 
-  PhysicalPresenceCallback() and MemoryClearCallback() will receive untrusted input and do some check.
-
 Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) Microsoft Corporation.
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
 
-#include "Tcg2Smm.h"
+#include <PiDxe.h>
+
+#include <IndustryStandard/Tpm2Acpi.h>
+
+#include <Guid/TpmInstance.h>
+#include <Guid/TpmNvsMm.h>
+#include <Guid/PiSmmCommunicationRegionTable.h>
+
+#include <Protocol/AcpiTable.h>
+#include <Protocol/Tcg2Protocol.h>
+#include <Protocol/MmCommunication.h>
+
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DxeServicesLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/DebugLib.h>
+#include <Library/PcdLib.h>
+#include <Library/PrintLib.h>
+#include <Library/TpmMeasurementLib.h>
+#include <Library/Tpm2DeviceLib.h>
+#include <Library/Tpm2CommandLib.h>
+#include <Library/UefiLib.h>
+
+//
+// Physical Presence Interface Version supported by Platform
+//
+#define PHYSICAL_PRESENCE_VERSION_TAG                              "$PV"
+#define PHYSICAL_PRESENCE_VERSION_SIZE                             4
+
+//
+// PNP _HID for TPM2 device
+//
+#define TPM_HID_TAG                                                "NNNN0000"
+#define TPM_HID_PNP_SIZE                                           8
+#define TPM_HID_ACPI_SIZE                                          9
+
+#define TPM_PRS_RESL                                               "RESL"
+#define TPM_PRS_RESS                                               "RESS"
+#define TPM_PRS_RES_NAME_SIZE                                      4
+//
+// Minimum PRS resource template size
+//  1 byte    for  BufferOp
+//  1 byte    for  PkgLength
+//  2 bytes   for  BufferSize
+//  12 bytes  for  Memory32Fixed descriptor
+//  5 bytes   for  Interrupt descriptor
+//  2 bytes   for  END Tag
+//
+#define TPM_POS_RES_TEMPLATE_MIN_SIZE                              (1 + 1 + 2 + 12 + 5 + 2)
+
+//
+// Max Interrupt buffer size for PRS interrupt resource
+// Now support 15 interrupts in maxmum
+//
+#define MAX_PRS_INT_BUF_SIZE                                       (15*4)
 
 #pragma pack(1)
 
@@ -49,142 +105,8 @@ EFI_TPM2_ACPI_TABLE_V4  mTpm2AcpiTemplate = {
   EFI_TPM2_ACPI_TABLE_START_METHOD_TIS, // StartMethod
 };
 
-EFI_SMM_VARIABLE_PROTOCOL  *mSmmVariable;
 TCG_NVS                    *mTcgNvs;
 
-/**
-  Software SMI callback for TPM physical presence which is called from ACPI method.
-
-  Caution: This function may receive untrusted input.
-  Variable and ACPINvs are external input, so this function will validate
-  its data structure to be valid value.
-
-  @param[in]      DispatchHandle  The unique handle assigned to this handler by SmiHandlerRegister().
-  @param[in]      Context         Points to an optional handler context which was specified when the
-                                  handler was registered.
-  @param[in, out] CommBuffer      A pointer to a collection of data in memory that will
-                                  be conveyed from a non-SMM environment into an SMM environment.
-  @param[in, out] CommBufferSize  The size of the CommBuffer.
-
-  @retval EFI_SUCCESS             The interrupt was handled successfully.
-
-**/
-EFI_STATUS
-EFIAPI
-PhysicalPresenceCallback (
-  IN EFI_HANDLE                  DispatchHandle,
-  IN CONST VOID                  *Context,
-  IN OUT VOID                    *CommBuffer,
-  IN OUT UINTN                   *CommBufferSize
-  )
-{
-  UINT32                MostRecentRequest;
-  UINT32                Response;
-  UINT32                OperationRequest;
-  UINT32                RequestParameter;
-
-
-  if (mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_RETURN_REQUEST_RESPONSE_TO_OS) {
-    mTcgNvs->PhysicalPresence.ReturnCode = Tcg2PhysicalPresenceLibReturnOperationResponseToOsFunction (
-                                             &MostRecentRequest,
-                                             &Response
-                                             );
-    mTcgNvs->PhysicalPresence.LastRequest = MostRecentRequest;
-    mTcgNvs->PhysicalPresence.Response = Response;
-    return EFI_SUCCESS;
-  } else if ((mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_SUBMIT_REQUEST_TO_BIOS)
-          || (mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_SUBMIT_REQUEST_TO_BIOS_2)) {
-
-    OperationRequest = mTcgNvs->PhysicalPresence.Request;
-    RequestParameter = mTcgNvs->PhysicalPresence.RequestParameter;
-    mTcgNvs->PhysicalPresence.ReturnCode = Tcg2PhysicalPresenceLibSubmitRequestToPreOSFunctionEx (
-                                             &OperationRequest,
-                                             &RequestParameter
-                                             );
-    mTcgNvs->PhysicalPresence.Request = OperationRequest;
-    mTcgNvs->PhysicalPresence.RequestParameter = RequestParameter;
-  } else if (mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_GET_USER_CONFIRMATION_STATUS_FOR_REQUEST) {
-    mTcgNvs->PhysicalPresence.ReturnCode = Tcg2PhysicalPresenceLibGetUserConfirmationStatusFunction (mTcgNvs->PPRequestUserConfirm);
-  }
-
-  return EFI_SUCCESS;
-}
-
-
-/**
-  Software SMI callback for MemoryClear which is called from ACPI method.
-
-  Caution: This function may receive untrusted input.
-  Variable and ACPINvs are external input, so this function will validate
-  its data structure to be valid value.
-
-  @param[in]      DispatchHandle  The unique handle assigned to this handler by SmiHandlerRegister().
-  @param[in]      Context         Points to an optional handler context which was specified when the
-                                  handler was registered.
-  @param[in, out] CommBuffer      A pointer to a collection of data in memory that will
-                                  be conveyed from a non-SMM environment into an SMM environment.
-  @param[in, out] CommBufferSize  The size of the CommBuffer.
-
-  @retval EFI_SUCCESS             The interrupt was handled successfully.
-
-**/
-EFI_STATUS
-EFIAPI
-MemoryClearCallback (
-  IN EFI_HANDLE                  DispatchHandle,
-  IN CONST VOID                  *Context,
-  IN OUT VOID                    *CommBuffer,
-  IN OUT UINTN                   *CommBufferSize
-  )
-{
-  EFI_STATUS                     Status;
-  UINTN                          DataSize;
-  UINT8                          MorControl;
-
-  mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_SUCCESS;
-  if (mTcgNvs->MemoryClear.Parameter == ACPI_FUNCTION_DSM_MEMORY_CLEAR_INTERFACE) {
-    MorControl = (UINT8) mTcgNvs->MemoryClear.Request;
-  } else if (mTcgNvs->MemoryClear.Parameter == ACPI_FUNCTION_PTS_CLEAR_MOR_BIT) {
-    DataSize = sizeof (UINT8);
-    Status = mSmmVariable->SmmGetVariable (
-                             MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME,
-                             &gEfiMemoryOverwriteControlDataGuid,
-                             NULL,
-                             &DataSize,
-                             &MorControl
-                             );
-    if (EFI_ERROR (Status)) {
-      mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
-      DEBUG ((EFI_D_ERROR, "[TPM] Get MOR variable failure! Status = %r\n", Status));
-      return EFI_SUCCESS;
-    }
-
-    if (MOR_CLEAR_MEMORY_VALUE (MorControl) == 0x0) {
-      return EFI_SUCCESS;
-    }
-    MorControl &= ~MOR_CLEAR_MEMORY_BIT_MASK;
-  } else {
-    mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
-    DEBUG ((EFI_D_ERROR, "[TPM] MOR Parameter error! Parameter = %x\n", mTcgNvs->MemoryClear.Parameter));
-    return EFI_SUCCESS;
-  }
-
-  DataSize = sizeof (UINT8);
-  Status = mSmmVariable->SmmSetVariable (
-                           MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME,
-                           &gEfiMemoryOverwriteControlDataGuid,
-                           EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
-                           DataSize,
-                           &MorControl
-                           );
-  if (EFI_ERROR (Status)) {
-    mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
-    DEBUG ((EFI_D_ERROR, "[TPM] Set MOR variable failure! Status = %r\n", Status));
-  }
-
-  return EFI_SUCCESS;
-}
-
 /**
   Find the operation region in TCG ACPI table by given Name and Size,
   and initialize it if the region is found.
@@ -232,6 +154,103 @@ AssignOpRegion (
   return (VOID *) (UINTN) MemoryAddress;
 }
 
+/**
+  Locate the MM communication buffer and protocol, then use it to exchange information with
+  Tcg2StandaloneMmm on NVS address and SMI value.
+
+  @param[in, out] TcgNvs         The NVS subject to send to MM environment.
+
+  @return                        The status for locating MM common buffer, communicate to MM, etc.
+
+**/
+EFI_STATUS
+EFIAPI
+ExchangeCommonBuffer (
+  IN OUT  TCG_NVS                 *TcgNvs
+)
+{
+  EFI_STATUS                                Status;
+  EFI_MM_COMMUNICATION_PROTOCOL             *MmCommunication;
+  EDKII_PI_SMM_COMMUNICATION_REGION_TABLE   *PiSmmCommunicationRegionTable;
+  EFI_MEMORY_DESCRIPTOR                     *MmCommMemRegion;
+  EFI_MM_COMMUNICATE_HEADER                 *CommHeader;
+  TPM_NVS_MM_COMM_BUFFER                    *CommBuffer;
+  UINTN                                     CommBufferSize;
+  UINTN                                     Index;
+
+  // Step 0: Sanity check for input argument
+  if (TcgNvs == NULL) {
+    DEBUG ((DEBUG_ERROR, "%a - Input argument is NULL!\n", __FUNCTION__));
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Step 1: Grab the common buffer header
+  Status = EfiGetSystemConfigurationTable (&gEdkiiPiSmmCommunicationRegionTableGuid, (VOID**) &PiSmmCommunicationRegionTable);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a - Failed to locate SMM communciation common buffer - %r!\n", __FUNCTION__, Status));
+    return Status;
+  }
+
+  // Step 2: Grab one that is large enough to hold TPM_NVS_MM_COMM_BUFFER, the IPL one should be sufficient
+  CommBufferSize = 0;
+  MmCommMemRegion = (EFI_MEMORY_DESCRIPTOR*) (PiSmmCommunicationRegionTable + 1);
+  for (Index = 0; Index < PiSmmCommunicationRegionTable->NumberOfEntries; Index++) {
+    if (MmCommMemRegion->Type == EfiConventionalMemory) {
+      CommBufferSize = EFI_PAGES_TO_SIZE ((UINTN)MmCommMemRegion->NumberOfPages);
+      if (CommBufferSize >= (sizeof (TPM_NVS_MM_COMM_BUFFER) + OFFSET_OF (EFI_MM_COMMUNICATE_HEADER, Data))) {
+        break;
+      }
+    }
+    MmCommMemRegion = (EFI_MEMORY_DESCRIPTOR*)((UINT8*)MmCommMemRegion + PiSmmCommunicationRegionTable->DescriptorSize);
+  }
+
+  if (Index >= PiSmmCommunicationRegionTable->NumberOfEntries) {
+    // Could not find one that meets our goal...
+    DEBUG ((DEBUG_ERROR, "%a - Could not find a common buffer that is big enough for NVS!\n", __FUNCTION__));
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  // Step 3: Start to populate contents
+  // Step 3.1: MM Communication common header
+  CommHeader = (EFI_MM_COMMUNICATE_HEADER *) (UINTN) MmCommMemRegion->PhysicalStart;
+  CommBufferSize = sizeof (TPM_NVS_MM_COMM_BUFFER) + OFFSET_OF (EFI_MM_COMMUNICATE_HEADER, Data);
+  ZeroMem (CommHeader, CommBufferSize);
+  CopyGuid (&CommHeader->HeaderGuid, &gTpmNvsMmGuid);
+  CommHeader->MessageLength = sizeof (TPM_NVS_MM_COMM_BUFFER);
+
+  // Step 3.2: TPM_NVS_MM_COMM_BUFFER content per our needs
+  CommBuffer = (TPM_NVS_MM_COMM_BUFFER *) (CommHeader->Data);
+  CommBuffer->Function = TpmNvsMmExchangeInfo;
+  CommBuffer->TargetAddress = (EFI_PHYSICAL_ADDRESS) (UINTN) TcgNvs;
+
+  // Step 4: Locate the protocol and signal Mmi.
+  Status = gBS->LocateProtocol (&gEfiMmCommunicationProtocolGuid, NULL, (VOID**) &MmCommunication);
+  if (!EFI_ERROR (Status)) {
+    Status = MmCommunication->Communicate (MmCommunication, CommHeader, &CommBufferSize);
+    DEBUG ((DEBUG_INFO, "%a - Communicate() = %r\n", __FUNCTION__, Status));
+  }
+  else {
+    DEBUG ((DEBUG_ERROR, "%a - Failed to locate MmCommunication protocol - %r\n", __FUNCTION__, Status));
+    return Status;
+  }
+
+  // Step 5: If everything goes well, populate the channel number
+  if (!EFI_ERROR (CommBuffer->ReturnStatus)) {
+    // Need to demote to UINT8 according to SMI value definition
+    TcgNvs->PhysicalPresence.SoftwareSmi = (UINT8) CommBuffer->RegisteredPpSwiValue;
+    TcgNvs->MemoryClear.SoftwareSmi = (UINT8) CommBuffer->RegisteredMcSwiValue;
+    DEBUG ((
+      DEBUG_INFO,
+      "%a Communication returned software SMI value. PP: 0x%x; MC: 0x%x.\n",
+      __FUNCTION__,
+      TcgNvs->PhysicalPresence.SoftwareSmi,
+      TcgNvs->MemoryClear.SoftwareSmi
+      ));
+  }
+
+  return (EFI_STATUS) CommBuffer->ReturnStatus;
+}
+
 /**
   Patch version string of Physical Presence interface supported by platform. The initial string tag in TPM
 ACPI table is "$PV".
@@ -259,7 +278,7 @@ UpdatePPVersion (
        DataPtr += 1) {
     if (AsciiStrCmp((CHAR8 *)DataPtr,  PHYSICAL_PRESENCE_VERSION_TAG) == 0) {
       Status = AsciiStrCpyS((CHAR8 *)DataPtr, PHYSICAL_PRESENCE_VERSION_SIZE, PPVer);
-      DEBUG((EFI_D_INFO, "TPM2 Physical Presence Interface Version update status 0x%x\n", Status));
+      DEBUG((DEBUG_INFO, "TPM2 Physical Presence Interface Version update status 0x%x\n", Status));
       return Status;
     }
   }
@@ -548,7 +567,7 @@ UpdateHID (
   //
   Status = Tpm2GetCapabilityManufactureID(&ManufacturerID);
   if (!EFI_ERROR(Status)) {
-    DEBUG((EFI_D_INFO, "TPM_PT_MANUFACTURER 0x%08x\n", ManufacturerID));
+    DEBUG((DEBUG_INFO, "TPM_PT_MANUFACTURER 0x%08x\n", ManufacturerID));
     //
     // ManufacturerID defined in TCG Vendor ID Registry
     // may tailed with 0x00 or 0x20
@@ -568,15 +587,15 @@ UpdateHID (
       PnpHID = FALSE;
     }
   } else {
-    DEBUG ((EFI_D_ERROR, "Get TPM_PT_MANUFACTURER failed %x!\n", Status));
+    DEBUG ((DEBUG_ERROR, "Get TPM_PT_MANUFACTURER failed %x!\n", Status));
     ASSERT(FALSE);
     return Status;
   }
 
   Status = Tpm2GetCapabilityFirmwareVersion(&FirmwareVersion1, &FirmwareVersion2);
   if (!EFI_ERROR(Status)) {
-    DEBUG((EFI_D_INFO, "TPM_PT_FIRMWARE_VERSION_1 0x%x\n", FirmwareVersion1));
-    DEBUG((EFI_D_INFO, "TPM_PT_FIRMWARE_VERSION_2 0x%x\n", FirmwareVersion2));
+    DEBUG((DEBUG_INFO, "TPM_PT_FIRMWARE_VERSION_1 0x%x\n", FirmwareVersion1));
+    DEBUG((DEBUG_INFO, "TPM_PT_FIRMWARE_VERSION_2 0x%x\n", FirmwareVersion2));
     //
     //   #### is Firmware Version 1
     //
@@ -587,7 +606,7 @@ UpdateHID (
     }
 
   } else {
-    DEBUG ((EFI_D_ERROR, "Get TPM_PT_FIRMWARE_VERSION_X failed %x!\n", Status));
+    DEBUG ((DEBUG_ERROR, "Get TPM_PT_FIRMWARE_VERSION_X failed %x!\n", Status));
     ASSERT(FALSE);
     return Status;
   }
@@ -615,7 +634,7 @@ UpdateHID (
     }
   }
 
-  DEBUG((EFI_D_ERROR, "TPM2 ACPI HID TAG for patch not found!\n"));
+  DEBUG((DEBUG_ERROR, "TPM2 ACPI HID TAG for patch not found!\n"));
   return EFI_NOT_FOUND;
 }
 
@@ -716,6 +735,8 @@ PublishAcpiTable (
   mTcgNvs->TpmIrqNum            = PcdGet32(PcdTpm2CurrentIrqNum);
   mTcgNvs->IsShortFormPkgLength = IsShortFormPkgLength;
 
+  Status = ExchangeCommonBuffer (mTcgNvs);
+
   //
   // Publish the TPM ACPI table. Table is re-checksummed.
   //
@@ -806,7 +827,7 @@ PublishTpm2 (
   case Tpm2PtpInterfaceTis:
     break;
   default:
-    DEBUG((EFI_D_ERROR, "TPM2 InterfaceType get error! %d\n", InterfaceType));
+    DEBUG((DEBUG_ERROR, "TPM2 InterfaceType get error! %d\n", InterfaceType));
     break;
   }
 
@@ -837,8 +858,8 @@ PublishTpm2 (
 /**
   The driver's entry point.
 
-  It install callbacks for TPM physical presence and MemoryClear, and locate
-  SMM variable to be used in the callback function.
+  It patches and installs ACPI tables used for handling TPM physical presence
+  and Memory Clear requests through ACPI method.
 
   @param[in] ImageHandle  The firmware allocated handle for the EFI image.
   @param[in] SystemTable  A pointer to the EFI System Table.
@@ -849,58 +870,27 @@ PublishTpm2 (
 **/
 EFI_STATUS
 EFIAPI
-InitializeTcgSmm (
+InitializeTcgAcpi (
   IN EFI_HANDLE                  ImageHandle,
   IN EFI_SYSTEM_TABLE            *SystemTable
   )
 {
   EFI_STATUS                     Status;
-  EFI_SMM_SW_DISPATCH2_PROTOCOL  *SwDispatch;
-  EFI_SMM_SW_REGISTER_CONTEXT    SwContext;
-  EFI_HANDLE                     SwHandle;
 
   if (!CompareGuid (PcdGetPtr(PcdTpmInstanceGuid), &gEfiTpmDeviceInstanceTpm20DtpmGuid)){
-    DEBUG ((EFI_D_ERROR, "No TPM2 DTPM instance required!\n"));
+    DEBUG ((DEBUG_ERROR, "No TPM2 DTPM instance required!\n"));
     return EFI_UNSUPPORTED;
   }
 
   Status = PublishAcpiTable ();
   ASSERT_EFI_ERROR (Status);
 
-  //
-  // Get the Sw dispatch protocol and register SMI callback functions.
-  //
-  Status = gMmst->MmLocateProtocol (&gEfiSmmSwDispatch2ProtocolGuid, NULL, (VOID**)&SwDispatch);
-  ASSERT_EFI_ERROR (Status);
-  SwContext.SwSmiInputValue = (UINTN) -1;
-  Status = SwDispatch->Register (SwDispatch, PhysicalPresenceCallback, &SwContext, &SwHandle);
-  ASSERT_EFI_ERROR (Status);
-  if (EFI_ERROR (Status)) {
-    return Status;
-  }
-  mTcgNvs->PhysicalPresence.SoftwareSmi = (UINT8) SwContext.SwSmiInputValue;
-
-  SwContext.SwSmiInputValue = (UINTN) -1;
-  Status = SwDispatch->Register (SwDispatch, MemoryClearCallback, &SwContext, &SwHandle);
-  ASSERT_EFI_ERROR (Status);
-  if (EFI_ERROR (Status)) {
-    return Status;
-  }
-  mTcgNvs->MemoryClear.SoftwareSmi = (UINT8) SwContext.SwSmiInputValue;
-
-  //
-  // Locate SmmVariableProtocol.
-  //
-  Status = gMmst->MmLocateProtocol (&gEfiSmmVariableProtocolGuid, NULL, (VOID**)&mSmmVariable);
-  ASSERT_EFI_ERROR (Status);
-
   //
   // Set TPM2 ACPI table
   //
   Status = PublishTpm2 ();
   ASSERT_EFI_ERROR (Status);
 
-
   return EFI_SUCCESS;
 }
 
diff --git a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c b/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c
index 08105c3692ba..589c08794bcf 100644
--- a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c
+++ b/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c
@@ -10,47 +10,95 @@
   PhysicalPresenceCallback() and MemoryClearCallback() will receive untrusted input and do some check.
 
 Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) Microsoft Corporation.
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
 
 #include "Tcg2Smm.h"
 
-#pragma pack(1)
-
-typedef struct {
-  EFI_ACPI_DESCRIPTION_HEADER Header;
-  // Flags field is replaced in version 4 and above
-  //    BIT0~15:  PlatformClass      This field is only valid for version 4 and above
-  //    BIT16~31: Reserved
-  UINT32                      Flags;
-  UINT64                      AddressOfControlArea;
-  UINT32                      StartMethod;
-  UINT8                       PlatformSpecificParameters[12];  // size up to 12
-  UINT32                      Laml;                          // Optional
-  UINT64                      Lasa;                          // Optional
-} EFI_TPM2_ACPI_TABLE_V4;
-
-#pragma pack()
-
-EFI_TPM2_ACPI_TABLE_V4  mTpm2AcpiTemplate = {
-  {
-    EFI_ACPI_5_0_TRUSTED_COMPUTING_PLATFORM_2_TABLE_SIGNATURE,
-    sizeof (mTpm2AcpiTemplate),
-    EFI_TPM2_ACPI_TABLE_REVISION,
-    //
-    // Compiler initializes the remaining bytes to 0
-    // These fields should be filled in in production
-    //
-  },
-  0, // BIT0~15:  PlatformClass
-     // BIT16~31: Reserved
-  0, // Control Area
-  EFI_TPM2_ACPI_TABLE_START_METHOD_TIS, // StartMethod
-};
-
-EFI_SMM_VARIABLE_PROTOCOL  *mSmmVariable;
-TCG_NVS                    *mTcgNvs;
+EFI_SMM_VARIABLE_PROTOCOL  *mSmmVariable = NULL;
+TCG_NVS                    *mTcgNvs = NULL;
+UINTN                       mPpSoftwareSmi;
+UINTN                       mMcSoftwareSmi;
+EFI_HANDLE                  mReadyToLockHandle;
+
+/**
+  Communication service SMI Handler entry.
+
+  This handler takes requests to exchange Mmi channel and Nvs address between MM and DXE.
+
+  Caution: This function may receive untrusted input.
+  Communicate buffer and buffer size are external input, so this function will do basic validation.
+
+  @param[in]      DispatchHandle    The unique handle assigned to this handler by SmiHandlerRegister().
+  @param[in]      RegisterContext   Points to an optional handler context which was specified when the
+                                    handler was registered.
+  @param[in, out] CommBuffer        A pointer to a collection of data in memory that will
+                                    be conveyed from a non-SMM environment into an SMM environment.
+  @param[in, out] CommBufferSize    The size of the CommBuffer.
+
+  @retval EFI_SUCCESS               The interrupt was handled and quiesced. No other handlers
+                                    should still be called.
+  @retval EFI_UNSUPPORTED           An unknown test function was requested.
+  @retval EFI_ACCESS_DENIED         Part of the communication buffer lies in an invalid region.
+
+**/
+EFI_STATUS
+EFIAPI
+TpmNvsCommunciate (
+  IN     EFI_HANDLE                   DispatchHandle,
+  IN     CONST VOID                   *RegisterContext,
+  IN OUT VOID                         *CommBuffer,
+  IN OUT UINTN                        *CommBufferSize
+  )
+{
+  EFI_STATUS                Status;
+  UINTN                     TempCommBufferSize;
+  TPM_NVS_MM_COMM_BUFFER    *CommParams;
+
+  DEBUG ((DEBUG_VERBOSE, "%a()\n", __FUNCTION__));
+
+  //
+  // If input is invalid, stop processing this SMI
+  //
+  if (CommBuffer == NULL || CommBufferSize == NULL) {
+    return EFI_SUCCESS;
+  }
+
+  TempCommBufferSize = *CommBufferSize;
+
+  if(TempCommBufferSize != sizeof (TPM_NVS_MM_COMM_BUFFER)) {
+    DEBUG ((DEBUG_ERROR, "[%a] MM Communication buffer size is invalid for this handler!\n", __FUNCTION__));
+    return EFI_ACCESS_DENIED;
+  }
+  if (!IsBufferOutsideMmValid ((UINTN) CommBuffer, TempCommBufferSize)) {
+    DEBUG ((DEBUG_ERROR, "[%a] - MM Communication buffer in invalid location!\n", __FUNCTION__));
+    return EFI_ACCESS_DENIED;
+  }
+
+  //
+  // Farm out the job to individual functions based on what was requested.
+  //
+  CommParams = (TPM_NVS_MM_COMM_BUFFER*) CommBuffer;
+  Status = EFI_SUCCESS;
+  switch (CommParams->Function) {
+    case TpmNvsMmExchangeInfo:
+      DEBUG ((DEBUG_VERBOSE, "[%a] - Function requested: MM_EXCHANGE_NVS_INFO\n", __FUNCTION__));
+      CommParams->RegisteredPpSwiValue = mPpSoftwareSmi;
+      CommParams->RegisteredMcSwiValue = mMcSoftwareSmi;
+      mTcgNvs = (TCG_NVS*) (UINTN) CommParams->TargetAddress;
+      break;
+
+    default:
+      DEBUG ((DEBUG_INFO, "[%a] - Unknown function %d!\n", __FUNCTION__, CommParams->Function));
+      Status = EFI_UNSUPPORTED;
+      break;
+  }
+
+  CommParams->ReturnStatus = (UINT64) Status;
+  return EFI_SUCCESS;
+}
 
 /**
   Software SMI callback for TPM physical presence which is called from ACPI method.
@@ -186,721 +234,140 @@ MemoryClearCallback (
 }
 
 /**
-  Find the operation region in TCG ACPI table by given Name and Size,
-  and initialize it if the region is found.
+  Notification for SMM ReadyToLock protocol.
 
-  @param[in, out] Table          The TPM item in ACPI table.
-  @param[in]      Name           The name string to find in TPM table.
-  @param[in]      Size           The size of the region to find.
+  @param[in] Protocol   Points to the protocol's unique identifier.
+  @param[in] Interface  Points to the interface instance.
+  @param[in] Handle     The handle on which the interface was installed.
 
-  @return                        The allocated address for the found region.
-
-**/
-VOID *
-AssignOpRegion (
-  EFI_ACPI_DESCRIPTION_HEADER    *Table,
-  UINT32                         Name,
-  UINT16                         Size
-  )
-{
-  EFI_STATUS                     Status;
-  AML_OP_REGION_32_8             *OpRegion;
-  EFI_PHYSICAL_ADDRESS           MemoryAddress;
-
-  MemoryAddress = SIZE_4GB - 1;
-
-  //
-  // Patch some pointers for the ASL code before loading the SSDT.
-  //
-  for (OpRegion  = (AML_OP_REGION_32_8 *) (Table + 1);
-       OpRegion <= (AML_OP_REGION_32_8 *) ((UINT8 *) Table + Table->Length);
-       OpRegion  = (AML_OP_REGION_32_8 *) ((UINT8 *) OpRegion + 1)) {
-    if ((OpRegion->OpRegionOp  == AML_EXT_REGION_OP) &&
-        (OpRegion->NameString  == Name) &&
-        (OpRegion->DWordPrefix == AML_DWORD_PREFIX) &&
-        (OpRegion->BytePrefix  == AML_BYTE_PREFIX)) {
-
-      Status = gBS->AllocatePages(AllocateMaxAddress, EfiACPIMemoryNVS, EFI_SIZE_TO_PAGES (Size), &MemoryAddress);
-      ASSERT_EFI_ERROR (Status);
-      ZeroMem ((VOID *)(UINTN)MemoryAddress, Size);
-      OpRegion->RegionOffset = (UINT32) (UINTN) MemoryAddress;
-      OpRegion->RegionLen    = (UINT8) Size;
-      break;
-    }
-  }
-
-  return (VOID *) (UINTN) MemoryAddress;
-}
-
-/**
-  Patch version string of Physical Presence interface supported by platform. The initial string tag in TPM
-ACPI table is "$PV".
-
-  @param[in, out] Table          The TPM item in ACPI table.
-  @param[in]      PPVer          Version string of Physical Presence interface supported by platform.
-
-  @return                        The allocated address for the found region.
-
-**/
-EFI_STATUS
-UpdatePPVersion (
-  EFI_ACPI_DESCRIPTION_HEADER    *Table,
-  CHAR8                          *PPVer
-  )
-{
-  EFI_STATUS  Status;
-  UINT8       *DataPtr;
-
-  //
-  // Patch some pointers for the ASL code before loading the SSDT.
-  //
-  for (DataPtr  = (UINT8 *)(Table + 1);
-       DataPtr <= (UINT8 *) ((UINT8 *) Table + Table->Length - PHYSICAL_PRESENCE_VERSION_SIZE);
-       DataPtr += 1) {
-    if (AsciiStrCmp((CHAR8 *)DataPtr,  PHYSICAL_PRESENCE_VERSION_TAG) == 0) {
-      Status = AsciiStrCpyS((CHAR8 *)DataPtr, PHYSICAL_PRESENCE_VERSION_SIZE, PPVer);
-      DEBUG((EFI_D_INFO, "TPM2 Physical Presence Interface Version update status 0x%x\n", Status));
-      return Status;
-    }
-  }
-
-  return EFI_NOT_FOUND;
-}
-
-/**
-  Patch interrupt resources returned by TPM _PRS. ResourceTemplate to patch is determined by input
-  interrupt buffer size. BufferSize, PkgLength and interrupt descriptor in ByteList need to be patched
-
-  @param[in, out] Table            The TPM item in ACPI table.
-  @param[in]      IrqBuffer        Input new IRQ buffer.
-  @param[in]      IrqBuffserSize   Input new IRQ buffer size.
-  @param[out]     IsShortFormPkgLength   If _PRS returns Short length Package(ACPI spec 20.2.4).
-
-  @return                          patch status.
-
-**/
-EFI_STATUS
-UpdatePossibleResource (
-  IN OUT  EFI_ACPI_DESCRIPTION_HEADER    *Table,
-  IN      UINT32                         *IrqBuffer,
-  IN      UINT32                         IrqBuffserSize,
-  OUT     BOOLEAN                        *IsShortFormPkgLength
-  )
-{
-  UINT8       *DataPtr;
-  UINT8       *DataEndPtr;
-  UINT32      NewPkgLength;
-  UINT32      OrignalPkgLength;
-
-  NewPkgLength     = 0;
-  OrignalPkgLength = 0;
-  DataEndPtr       = NULL;
-
-  //
-  // Follow ACPI spec
-  //           6.4.3   Extend Interrupt Descriptor.
-  //           19.3.3 ASL Resource Template
-  //           20      AML specification
-  // to patch TPM ACPI object _PRS returned ResourceTemplate() containing 2 resource descriptors and an auto appended End Tag
-  //
-  //  AML data is organized by following rule.
-  //  Code need to patch BufferSize and PkgLength and interrupt descriptor in ByteList
-  //
-  // =============  Buffer ====================
-  //           DefBuffer := BufferOp PkgLength BufferSize ByteList
-  //            BufferOp := 0x11
-  //
-  // ==============PkgLength==================
-  //          PkgLength := PkgLeadByte |
-  //                              <PkgLeadByte ByteData> |
-  //                              <PkgLeadByte ByteData ByteData> |
-  //                              <PkgLeadByte ByteData ByteData ByteData>
-  //
-  //       PkgLeadByte := <bit 7-6: ByteData count that follows (0-3)>
-  //                               <bit 5-4: Only used if PkgLength <= 63 >
-  //                               <bit 3-0: Least significant package length nybble>
-  //
-  //==============BufferSize==================
-  //        BufferSize := Integer
-  //           Integer := ByteConst|WordConst|DwordConst....
-  //
-  //           ByteConst := BytePrefix ByteData
-  //
-  //==============ByteList===================
-  //          ByteList := ByteData ByteList
-  //
-  //=========================================
-
-  //
-  // 1. Check TPM_PRS_RESS with PkgLength <=63 can hold the input interrupt number buffer for patching
-  //
-  for (DataPtr  = (UINT8 *)(Table + 1);
-       DataPtr < (UINT8 *) ((UINT8 *) Table + Table->Length - (TPM_PRS_RES_NAME_SIZE + TPM_POS_RES_TEMPLATE_MIN_SIZE));
-       DataPtr += 1) {
-    if (CompareMem(DataPtr, TPM_PRS_RESS, TPM_PRS_RES_NAME_SIZE) == 0) {
-      //
-      // Jump over object name & BufferOp
-      //
-      DataPtr += TPM_PRS_RES_NAME_SIZE + 1;
-
-      if ((*DataPtr & (BIT7|BIT6)) == 0) {
-        OrignalPkgLength = (UINT32)*DataPtr;
-        DataEndPtr       = DataPtr + OrignalPkgLength;
-
-        //
-        // Jump over PkgLength = PkgLeadByte only
-        //
-        NewPkgLength++;
-
-        //
-        // Jump over BufferSize
-        //
-        if (*(DataPtr + 1) == AML_BYTE_PREFIX) {
-          NewPkgLength += 2;
-        } else if (*(DataPtr + 1) == AML_WORD_PREFIX) {
-          NewPkgLength += 3;
-        } else if (*(DataPtr + 1) == AML_DWORD_PREFIX) {
-          NewPkgLength += 5;
-        } else {
-          ASSERT(FALSE);
-          return EFI_UNSUPPORTED;
-        }
-      } else {
-        ASSERT(FALSE);
-        return EFI_UNSUPPORTED;
-      }
-
-      //
-      // Include Memory32Fixed Descriptor (12 Bytes) + Interrupt Descriptor header(5 Bytes) + End Tag(2 Bytes)
-      //
-      NewPkgLength += 19 + IrqBuffserSize;
-      if (NewPkgLength > 63) {
-        break;
-      }
-
-      if (NewPkgLength > OrignalPkgLength) {
-        ASSERT(FALSE);
-        return EFI_INVALID_PARAMETER;
-      }
-
-      //
-      // 1.1 Patch PkgLength
-      //
-      *DataPtr = (UINT8)NewPkgLength;
-
-      //
-      // 1.2 Patch BufferSize = sizeof(Memory32Fixed Descriptor + Interrupt Descriptor + End Tag).
-      //      It is Little endian. So only patch lowest byte of BufferSize due to current interrupt number limit.
-      //
-      *(DataPtr + 2) = (UINT8)(IrqBuffserSize + 19);
-
-      //
-      // Notify _PRS to report short formed ResourceTemplate
-      //
-      *IsShortFormPkgLength = TRUE;
-
-      break;
-    }
-  }
-
-  //
-  // 2. Use TPM_PRS_RESL with PkgLength > 63 to hold longer input interrupt number buffer for patching
-  //
-  if (NewPkgLength > 63) {
-    NewPkgLength     = 0;
-    OrignalPkgLength = 0;
-    for (DataPtr  = (UINT8 *)(Table + 1);
-         DataPtr < (UINT8 *) ((UINT8 *) Table + Table->Length - (TPM_PRS_RES_NAME_SIZE + TPM_POS_RES_TEMPLATE_MIN_SIZE));
-         DataPtr += 1) {
-      if (CompareMem(DataPtr, TPM_PRS_RESL, TPM_PRS_RES_NAME_SIZE) == 0) {
-        //
-        // Jump over object name & BufferOp
-        //
-        DataPtr += TPM_PRS_RES_NAME_SIZE + 1;
-
-        if ((*DataPtr & (BIT7|BIT6)) != 0) {
-          OrignalPkgLength = (UINT32)(*(DataPtr + 1) << 4) + (*DataPtr & 0x0F);
-          DataEndPtr       = DataPtr + OrignalPkgLength;
-          //
-          // Jump over PkgLength = PkgLeadByte + ByteData length
-          //
-          NewPkgLength += 1 + ((*DataPtr & (BIT7|BIT6)) >> 6);
-
-          //
-          // Jump over BufferSize
-          //
-          if (*(DataPtr + NewPkgLength) == AML_BYTE_PREFIX) {
-            NewPkgLength += 2;
-          } else if (*(DataPtr + NewPkgLength) == AML_WORD_PREFIX) {
-            NewPkgLength += 3;
-          } else if (*(DataPtr + NewPkgLength) == AML_DWORD_PREFIX) {
-            NewPkgLength += 5;
-          } else {
-            ASSERT(FALSE);
-            return EFI_UNSUPPORTED;
-          }
-        } else {
-          ASSERT(FALSE);
-          return EFI_UNSUPPORTED;
-        }
-
-        //
-        // Include Memory32Fixed Descriptor (12 Bytes) + Interrupt Descriptor header(5 Bytes) + End Tag(2  Bytes)
-        //
-        NewPkgLength += 19 + IrqBuffserSize;
-
-        if (NewPkgLength > OrignalPkgLength) {
-          ASSERT(FALSE);
-          return EFI_INVALID_PARAMETER;
-        }
-
-        //
-        // 2.1 Patch PkgLength. Only patch PkgLeadByte and first ByteData
-        //
-        *DataPtr = (UINT8)((*DataPtr) & 0xF0) | (NewPkgLength & 0x0F);
-        *(DataPtr + 1) = (UINT8)((NewPkgLength & 0xFF0) >> 4);
-
-        //
-        // 2.2 Patch BufferSize = sizeof(Memory32Fixed Descriptor + Interrupt Descriptor + End Tag).
-        //     It is Little endian. Only patch lowest byte of BufferSize due to current interrupt number limit.
-        //
-        *(DataPtr + 2 + ((*DataPtr & (BIT7|BIT6)) >> 6)) = (UINT8)(IrqBuffserSize + 19);
-
-        //
-        // Notify _PRS to report long formed ResourceTemplate
-        //
-        *IsShortFormPkgLength = FALSE;
-        break;
-      }
-    }
-  }
-
-  if (DataPtr >= (UINT8 *) ((UINT8 *) Table + Table->Length - (TPM_PRS_RES_NAME_SIZE + TPM_POS_RES_TEMPLATE_MIN_SIZE))) {
-    return EFI_NOT_FOUND;
-  }
-
-  //
-  // 3. Move DataPtr to Interrupt descriptor header and patch interrupt descriptor.
-  //     5 bytes for interrupt descriptor header, 2 bytes for End Tag
-  //
-  DataPtr += NewPkgLength - (5 + IrqBuffserSize + 2);
-  //
-  //   3.1 Patch Length bit[7:0] of Interrupt descriptor patch interrupt descriptor
-  //
-  *(DataPtr + 1) = (UINT8)(2 + IrqBuffserSize);
-  //
-  //   3.2 Patch Interrupt Table Length
-  //
-  *(DataPtr + 4) = (UINT8)(IrqBuffserSize / sizeof(UINT32));
-  //
-  //   3.3 Copy patched InterruptNumBuffer
-  //
-  CopyMem(DataPtr + 5, IrqBuffer, IrqBuffserSize);
-
-  //
-  // 4. Jump over Interrupt descriptor and Patch END Tag, set Checksum field to 0
-  //
-  DataPtr       += 5 + IrqBuffserSize;
-  *DataPtr       = ACPI_END_TAG_DESCRIPTOR;
-  *(DataPtr + 1) = 0;
-
-  //
-  // 5. Jump over new ResourceTemplate. Stuff rest bytes to NOOP
-  //
-  DataPtr += 2;
-  if (DataPtr < DataEndPtr) {
-    SetMem(DataPtr, (UINTN)DataEndPtr - (UINTN)DataPtr, AML_NOOP_OP);
-  }
-
-  return EFI_SUCCESS;
-}
-
-/**
-  Patch TPM2 device HID string.  The initial string tag in TPM2 ACPI table is "NNN0000".
-
-  @param[in, out] Table          The TPM2 SSDT ACPI table.
-
-  @return                               HID Update status.
-
-**/
-EFI_STATUS
-UpdateHID (
-  EFI_ACPI_DESCRIPTION_HEADER    *Table
-  )
-{
-  EFI_STATUS  Status;
-  UINT8       *DataPtr;
-  CHAR8       Hid[TPM_HID_ACPI_SIZE];
-  UINT32      ManufacturerID;
-  UINT32      FirmwareVersion1;
-  UINT32      FirmwareVersion2;
-  BOOLEAN     PnpHID;
-
-  PnpHID = TRUE;
-
-  //
-  // Initialize HID with Default PNP string
-  //
-  ZeroMem(Hid, TPM_HID_ACPI_SIZE);
-
-  //
-  // Get Manufacturer ID
-  //
-  Status = Tpm2GetCapabilityManufactureID(&ManufacturerID);
-  if (!EFI_ERROR(Status)) {
-    DEBUG((EFI_D_INFO, "TPM_PT_MANUFACTURER 0x%08x\n", ManufacturerID));
-    //
-    // ManufacturerID defined in TCG Vendor ID Registry
-    // may tailed with 0x00 or 0x20
-    //
-    if ((ManufacturerID >> 24) == 0x00 || ((ManufacturerID >> 24) == 0x20)) {
-      //
-      //  HID containing PNP ID "NNN####"
-      //   NNN is uppercase letter for Vendor ID specified by manufacturer
-      //
-      CopyMem(Hid, &ManufacturerID, 3);
-    } else {
-      //
-      //  HID containing ACP ID "NNNN####"
-      //   NNNN is uppercase letter for Vendor ID specified by manufacturer
-      //
-      CopyMem(Hid, &ManufacturerID, 4);
-      PnpHID = FALSE;
-    }
-  } else {
-    DEBUG ((EFI_D_ERROR, "Get TPM_PT_MANUFACTURER failed %x!\n", Status));
-    ASSERT(FALSE);
-    return Status;
-  }
-
-  Status = Tpm2GetCapabilityFirmwareVersion(&FirmwareVersion1, &FirmwareVersion2);
-  if (!EFI_ERROR(Status)) {
-    DEBUG((EFI_D_INFO, "TPM_PT_FIRMWARE_VERSION_1 0x%x\n", FirmwareVersion1));
-    DEBUG((EFI_D_INFO, "TPM_PT_FIRMWARE_VERSION_2 0x%x\n", FirmwareVersion2));
-    //
-    //   #### is Firmware Version 1
-    //
-    if (PnpHID) {
-      AsciiSPrint(Hid + 3, TPM_HID_PNP_SIZE - 3, "%02d%02d", ((FirmwareVersion1 & 0xFFFF0000) >> 16), (FirmwareVersion1 & 0x0000FFFF));
-    } else {
-      AsciiSPrint(Hid + 4, TPM_HID_ACPI_SIZE - 4, "%02d%02d", ((FirmwareVersion1 & 0xFFFF0000) >> 16), (FirmwareVersion1 & 0x0000FFFF));
-    }
-
-  } else {
-    DEBUG ((EFI_D_ERROR, "Get TPM_PT_FIRMWARE_VERSION_X failed %x!\n", Status));
-    ASSERT(FALSE);
-    return Status;
-  }
-
-  //
-  // Patch HID in ASL code before loading the SSDT.
-  //
-  for (DataPtr  = (UINT8 *)(Table + 1);
-       DataPtr <= (UINT8 *) ((UINT8 *) Table + Table->Length - TPM_HID_PNP_SIZE);
-       DataPtr += 1) {
-    if (AsciiStrCmp((CHAR8 *)DataPtr,  TPM_HID_TAG) == 0) {
-      if (PnpHID) {
-        CopyMem(DataPtr, Hid, TPM_HID_PNP_SIZE);
-        //
-        // if HID is PNP ID, patch the last byte in HID TAG to Noop
-        //
-        *(DataPtr + TPM_HID_PNP_SIZE) = AML_NOOP_OP;
-      } else {
-
-        CopyMem(DataPtr, Hid, TPM_HID_ACPI_SIZE);
-      }
-      DEBUG((DEBUG_INFO, "TPM2 ACPI _HID is patched to %a\n", DataPtr));
-
-      return Status;
-    }
-  }
-
-  DEBUG((EFI_D_ERROR, "TPM2 ACPI HID TAG for patch not found!\n"));
-  return EFI_NOT_FOUND;
-}
-
-/**
-  Initialize and publish TPM items in ACPI table.
-
-  @retval   EFI_SUCCESS     The TCG ACPI table is published successfully.
-  @retval   Others          The TCG ACPI table is not published.
-
-**/
-EFI_STATUS
-PublishAcpiTable (
-  VOID
-  )
-{
-  EFI_STATUS                     Status;
-  EFI_ACPI_TABLE_PROTOCOL        *AcpiTable;
-  UINTN                          TableKey;
-  EFI_ACPI_DESCRIPTION_HEADER    *Table;
-  UINTN                          TableSize;
-  UINT32                         *PossibleIrqNumBuf;
-  UINT32                         PossibleIrqNumBufSize;
-  BOOLEAN                        IsShortFormPkgLength;
-
-  IsShortFormPkgLength = FALSE;
-
-  Status = GetSectionFromFv (
-             &gEfiCallerIdGuid,
-             EFI_SECTION_RAW,
-             0,
-             (VOID **) &Table,
-             &TableSize
-             );
-  ASSERT_EFI_ERROR (Status);
-
-  //
-  // Measure to PCR[0] with event EV_POST_CODE ACPI DATA.
-  // The measurement has to be done before any update.
-  // Otherwise, the PCR record would be different after TPM FW update
-  // or the PCD configuration change.
-  //
-  TpmMeasureAndLogData(
-    0,
-    EV_POST_CODE,
-    EV_POSTCODE_INFO_ACPI_DATA,
-    ACPI_DATA_LEN,
-    Table,
-    TableSize
-    );
-
-  //
-  // Update Table version before measuring it to PCR
-  //
-  Status = UpdatePPVersion(Table, (CHAR8 *)PcdGetPtr(PcdTcgPhysicalPresenceInterfaceVer));
-  ASSERT_EFI_ERROR (Status);
-
-  DEBUG ((
-    DEBUG_INFO,
-    "Current physical presence interface version - %a\n",
-    (CHAR8 *) PcdGetPtr(PcdTcgPhysicalPresenceInterfaceVer)
-    ));
-
-  //
-  // Update TPM2 HID after measuring it to PCR
-  //
-  Status = UpdateHID(Table);
-  if (EFI_ERROR(Status)) {
-    return Status;
-  }
-
-  if (PcdGet32(PcdTpm2CurrentIrqNum) != 0) {
-    //
-    // Patch _PRS interrupt resource only when TPM interrupt is supported
-    //
-    PossibleIrqNumBuf     = (UINT32 *)PcdGetPtr(PcdTpm2PossibleIrqNumBuf);
-    PossibleIrqNumBufSize = (UINT32)PcdGetSize(PcdTpm2PossibleIrqNumBuf);
-
-    if (PossibleIrqNumBufSize <= MAX_PRS_INT_BUF_SIZE && (PossibleIrqNumBufSize % sizeof(UINT32)) == 0) {
-      Status = UpdatePossibleResource(Table, PossibleIrqNumBuf, PossibleIrqNumBufSize, &IsShortFormPkgLength);
-      DEBUG ((
-        DEBUG_INFO,
-        "UpdatePossibleResource status - %x. TPM2 service may not ready in OS.\n",
-        Status
-        ));
-    } else {
-      DEBUG ((
-        DEBUG_INFO,
-        "PcdTpm2PossibleIrqNumBuf size %x is not correct. TPM2 service may not ready in OS.\n",
-        PossibleIrqNumBufSize
-      ));
-    }
-  }
-
-  ASSERT (Table->OemTableId == SIGNATURE_64 ('T', 'p', 'm', '2', 'T', 'a', 'b', 'l'));
-  CopyMem (Table->OemId, PcdGetPtr (PcdAcpiDefaultOemId), sizeof (Table->OemId) );
-  mTcgNvs = AssignOpRegion (Table, SIGNATURE_32 ('T', 'N', 'V', 'S'), (UINT16) sizeof (TCG_NVS));
-  ASSERT (mTcgNvs != NULL);
-  mTcgNvs->TpmIrqNum            = PcdGet32(PcdTpm2CurrentIrqNum);
-  mTcgNvs->IsShortFormPkgLength = IsShortFormPkgLength;
-
-  //
-  // Publish the TPM ACPI table. Table is re-checksummed.
-  //
-  Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL, (VOID **) &AcpiTable);
-  ASSERT_EFI_ERROR (Status);
-
-  TableKey = 0;
-  Status = AcpiTable->InstallAcpiTable (
-                        AcpiTable,
-                        Table,
-                        TableSize,
-                        &TableKey
-                        );
-  ASSERT_EFI_ERROR (Status);
-
-  return Status;
-}
-
-/**
-  Publish TPM2 ACPI table
-
-  @retval   EFI_SUCCESS     The TPM2 ACPI table is published successfully.
-  @retval   Others          The TPM2 ACPI table is not published.
+  @retval EFI_SUCCESS   Notification runs successfully.
 
 **/
 EFI_STATUS
-PublishTpm2 (
-  VOID
-  )
+EFIAPI
+TcgMmReadyToLock (
+  IN CONST EFI_GUID  *Protocol,
+  IN VOID            *Interface,
+  IN EFI_HANDLE      Handle
+)
 {
-  EFI_STATUS                     Status;
-  EFI_ACPI_TABLE_PROTOCOL        *AcpiTable;
-  UINTN                          TableKey;
-  UINT64                         OemTableId;
-  EFI_TPM2_ACPI_CONTROL_AREA     *ControlArea;
-  TPM2_PTP_INTERFACE_TYPE        InterfaceType;
-
-  //
-  // Measure to PCR[0] with event EV_POST_CODE ACPI DATA.
-  // The measurement has to be done before any update.
-  // Otherwise, the PCR record would be different after event log update
-  // or the PCD configuration change.
-  //
-  TpmMeasureAndLogData(
-    0,
-    EV_POST_CODE,
-    EV_POSTCODE_INFO_ACPI_DATA,
-    ACPI_DATA_LEN,
-    &mTpm2AcpiTemplate,
-    mTpm2AcpiTemplate.Header.Length
-    );
-
-  mTpm2AcpiTemplate.Header.Revision = PcdGet8(PcdTpm2AcpiTableRev);
-  DEBUG((DEBUG_INFO, "Tpm2 ACPI table revision is %d\n", mTpm2AcpiTemplate.Header.Revision));
-
-  //
-  // PlatformClass is only valid for version 4 and above
-  //    BIT0~15:  PlatformClass
-  //    BIT16~31: Reserved
-  //
-  if (mTpm2AcpiTemplate.Header.Revision >= EFI_TPM2_ACPI_TABLE_REVISION_4) {
-    mTpm2AcpiTemplate.Flags = (mTpm2AcpiTemplate.Flags & 0xFFFF0000) | PcdGet8(PcdTpmPlatformClass);
-    DEBUG((DEBUG_INFO, "Tpm2 ACPI table PlatformClass is %d\n", (mTpm2AcpiTemplate.Flags & 0x0000FFFF)));
-  }
-
-  mTpm2AcpiTemplate.Laml = PcdGet32(PcdTpm2AcpiTableLaml);
-  mTpm2AcpiTemplate.Lasa = PcdGet64(PcdTpm2AcpiTableLasa);
-  if ((mTpm2AcpiTemplate.Header.Revision < EFI_TPM2_ACPI_TABLE_REVISION_4) ||
-      (mTpm2AcpiTemplate.Laml == 0) || (mTpm2AcpiTemplate.Lasa == 0)) {
-    //
-    // If version is smaller than 4 or Laml/Lasa is not valid, rollback to original Length.
-    //
-    mTpm2AcpiTemplate.Header.Length = sizeof(EFI_TPM2_ACPI_TABLE);
-  }
+  EFI_STATUS Status;
 
-  InterfaceType = PcdGet8(PcdActiveTpmInterfaceType);
-  switch (InterfaceType) {
-  case Tpm2PtpInterfaceCrb:
-    mTpm2AcpiTemplate.StartMethod = EFI_TPM2_ACPI_TABLE_START_METHOD_COMMAND_RESPONSE_BUFFER_INTERFACE;
-    mTpm2AcpiTemplate.AddressOfControlArea = PcdGet64 (PcdTpmBaseAddress) + 0x40;
-    ControlArea = (EFI_TPM2_ACPI_CONTROL_AREA *)(UINTN)mTpm2AcpiTemplate.AddressOfControlArea;
-    ControlArea->CommandSize  = 0xF80;
-    ControlArea->ResponseSize = 0xF80;
-    ControlArea->Command      = PcdGet64 (PcdTpmBaseAddress) + 0x80;
-    ControlArea->Response     = PcdGet64 (PcdTpmBaseAddress) + 0x80;
-    break;
-  case Tpm2PtpInterfaceFifo:
-  case Tpm2PtpInterfaceTis:
-    break;
-  default:
-    DEBUG((EFI_D_ERROR, "TPM2 InterfaceType get error! %d\n", InterfaceType));
-    break;
+  if (mReadyToLockHandle != NULL) {
+    Status = gMmst->MmiHandlerUnRegister (mReadyToLockHandle);
+    mReadyToLockHandle = NULL;
   }
-
-  CopyMem (mTpm2AcpiTemplate.Header.OemId, PcdGetPtr (PcdAcpiDefaultOemId), sizeof (mTpm2AcpiTemplate.Header.OemId));
-  OemTableId = PcdGet64 (PcdAcpiDefaultOemTableId);
-  CopyMem (&mTpm2AcpiTemplate.Header.OemTableId, &OemTableId, sizeof (UINT64));
-  mTpm2AcpiTemplate.Header.OemRevision      = PcdGet32 (PcdAcpiDefaultOemRevision);
-  mTpm2AcpiTemplate.Header.CreatorId        = PcdGet32 (PcdAcpiDefaultCreatorId);
-  mTpm2AcpiTemplate.Header.CreatorRevision  = PcdGet32 (PcdAcpiDefaultCreatorRevision);
-
-  //
-  // Construct ACPI table
-  //
-  Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL, (VOID **) &AcpiTable);
-  ASSERT_EFI_ERROR (Status);
-
-  Status = AcpiTable->InstallAcpiTable (
-                        AcpiTable,
-                        &mTpm2AcpiTemplate,
-                        mTpm2AcpiTemplate.Header.Length,
-                        &TableKey
-                        );
-  ASSERT_EFI_ERROR (Status);
-
   return Status;
 }
 
 /**
-  The driver's entry point.
+  The driver's common initialization routine.
 
   It install callbacks for TPM physical presence and MemoryClear, and locate
   SMM variable to be used in the callback function.
 
-  @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 entry point is executed successfully.
   @retval Others          Some error occurs when executing this entry point.
 
 **/
 EFI_STATUS
-EFIAPI
-InitializeTcgSmm (
-  IN EFI_HANDLE                  ImageHandle,
-  IN EFI_SYSTEM_TABLE            *SystemTable
+InitializeTcgCommon (
+  VOID
   )
 {
   EFI_STATUS                     Status;
   EFI_SMM_SW_DISPATCH2_PROTOCOL  *SwDispatch;
   EFI_SMM_SW_REGISTER_CONTEXT    SwContext;
-  EFI_HANDLE                     SwHandle;
+  EFI_HANDLE                     PpSwHandle;
+  EFI_HANDLE                     McSwHandle;
+  EFI_HANDLE                     NotifyHandle;
 
   if (!CompareGuid (PcdGetPtr(PcdTpmInstanceGuid), &gEfiTpmDeviceInstanceTpm20DtpmGuid)){
     DEBUG ((EFI_D_ERROR, "No TPM2 DTPM instance required!\n"));
     return EFI_UNSUPPORTED;
   }
 
-  Status = PublishAcpiTable ();
+  // Initialize variables first
+  mReadyToLockHandle = NULL;
+  SwDispatch = NULL;
+  PpSwHandle = NULL;
+  McSwHandle = NULL;
+  NotifyHandle = NULL;
+
+  // Register a root handler to communicate the NVS region and SMI channel between MM and DXE
+  Status = gMmst->MmiHandlerRegister (TpmNvsCommunciate, &gTpmNvsMmGuid, &mReadyToLockHandle);
   ASSERT_EFI_ERROR (Status);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "[%a] Failed to register NVS communicate as root MM handler - %r!\n", __FUNCTION__, Status));
+    goto Cleanup;
+  }
 
   //
   // Get the Sw dispatch protocol and register SMI callback functions.
   //
   Status = gMmst->MmLocateProtocol (&gEfiSmmSwDispatch2ProtocolGuid, NULL, (VOID**)&SwDispatch);
   ASSERT_EFI_ERROR (Status);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "[%a] Failed to locate Sw dispatch protocol - %r!\n", __FUNCTION__, Status));
+    goto Cleanup;
+  }
+
   SwContext.SwSmiInputValue = (UINTN) -1;
-  Status = SwDispatch->Register (SwDispatch, PhysicalPresenceCallback, &SwContext, &SwHandle);
+  Status = SwDispatch->Register (SwDispatch, PhysicalPresenceCallback, &SwContext, &PpSwHandle);
   ASSERT_EFI_ERROR (Status);
   if (EFI_ERROR (Status)) {
-    return Status;
+    DEBUG ((DEBUG_ERROR, "[%a] Failed to register PP callback as SW MM handler - %r!\n", __FUNCTION__, Status));
+    goto Cleanup;
   }
-  mTcgNvs->PhysicalPresence.SoftwareSmi = (UINT8) SwContext.SwSmiInputValue;
+  mPpSoftwareSmi = SwContext.SwSmiInputValue;
 
   SwContext.SwSmiInputValue = (UINTN) -1;
-  Status = SwDispatch->Register (SwDispatch, MemoryClearCallback, &SwContext, &SwHandle);
+  Status = SwDispatch->Register (SwDispatch, MemoryClearCallback, &SwContext, &McSwHandle);
   ASSERT_EFI_ERROR (Status);
   if (EFI_ERROR (Status)) {
-    return Status;
+    DEBUG ((DEBUG_ERROR, "[%a] Failed to register MC callback as SW MM handler - %r!\n", __FUNCTION__, Status));
+    goto Cleanup;
   }
-  mTcgNvs->MemoryClear.SoftwareSmi = (UINT8) SwContext.SwSmiInputValue;
+  mMcSoftwareSmi = SwContext.SwSmiInputValue;
 
   //
   // Locate SmmVariableProtocol.
   //
   Status = gMmst->MmLocateProtocol (&gEfiSmmVariableProtocolGuid, NULL, (VOID**)&mSmmVariable);
   ASSERT_EFI_ERROR (Status);
+  if (EFI_ERROR (Status)) {
+    // Should not happen
+    DEBUG ((DEBUG_ERROR, "[%a] Failed to locate SMM variable protocol - %r!\n", __FUNCTION__, Status));
+    goto Cleanup;
+  }
 
-  //
-  // Set TPM2 ACPI table
-  //
-  Status = PublishTpm2 ();
+  // Turn off the light before leaving the room... at least, take a remote...
+  Status = gMmst->MmRegisterProtocolNotify (&gEfiMmReadyToLockProtocolGuid, TcgMmReadyToLock, &NotifyHandle);
   ASSERT_EFI_ERROR (Status);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "[%a] Failed to register ready to lock notification - %r!\n", __FUNCTION__, Status));
+    goto Cleanup;
+  }
 
+  Tcg2NotifyMmReady ();
 
-  return EFI_SUCCESS;
+Cleanup:
+  if (EFI_ERROR (Status)) {
+    // Something is whacked, clean up the mess...
+    if (NotifyHandle != NULL) {
+      gMmst->MmRegisterProtocolNotify (&gEfiMmReadyToLockProtocolGuid, NULL, &NotifyHandle);
+    }
+    if (McSwHandle != NULL && SwDispatch != NULL) {
+      SwDispatch->UnRegister (SwDispatch, McSwHandle);
+    }
+    if (PpSwHandle != NULL && SwDispatch != NULL) {
+      SwDispatch->UnRegister (SwDispatch, PpSwHandle);
+    }
+    if (mReadyToLockHandle != NULL) {
+      gMmst->MmiHandlerUnRegister (mReadyToLockHandle);
+    }
+  }
+
+  return Status;
 }
 
diff --git a/SecurityPkg/Tcg/Tcg2Smm/Tcg2TraditionalMm.c b/SecurityPkg/Tcg/Tcg2Smm/Tcg2TraditionalMm.c
new file mode 100644
index 000000000000..5930090b4e46
--- /dev/null
+++ b/SecurityPkg/Tcg/Tcg2Smm/Tcg2TraditionalMm.c
@@ -0,0 +1,82 @@
+/** @file
+  TCG2 SMM driver that updates TPM2 items in ACPI table and registers
+  SMI2 callback functions for Tcg2 physical presence, ClearMemory, and
+  sample for dTPM StartMethod.
+
+  Caution: This module requires additional review when modified.
+  This driver will have external input - variable and ACPINvs data in SMM mode.
+  This external input must be validated carefully to avoid security issue.
+
+  PhysicalPresenceCallback() and MemoryClearCallback() will receive untrusted input and do some check.
+
+Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) Microsoft Corporation.
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "Tcg2Smm.h"
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/SmmMemLib.h>
+
+/**
+  Notify the system that the SMM variable driver is ready.
+**/
+VOID
+Tcg2NotifyMmReady (
+  VOID
+  )
+{
+  EFI_STATUS            Status;
+  EFI_HANDLE            Handle;
+
+  Handle = NULL;
+  Status = gBS->InstallProtocolInterface (
+                  &Handle,
+                  &gTcg2MmSwSmiRegisteredGuid,
+                  EFI_NATIVE_INTERFACE,
+                  NULL
+                  );
+  ASSERT_EFI_ERROR (Status);
+}
+
+/**
+  This function is an abstraction layer for implementation specific Mm buffer validation routine.
+
+  @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
+IsBufferOutsideMmValid (
+  IN EFI_PHYSICAL_ADDRESS  Buffer,
+  IN UINT64                Length
+  )
+{
+  return SmmIsBufferOutsideSmmValid (Buffer, Length);
+}
+
+/**
+  The driver's entry point.
+
+  It install callbacks for TPM physical presence and MemoryClear, and locate
+  SMM variable to be used in the callback function.
+
+  @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 entry point is executed successfully.
+  @retval Others          Some error occurs when executing this entry point.
+
+**/
+EFI_STATUS
+EFIAPI
+InitializeTcgSmm (
+  IN EFI_HANDLE                  ImageHandle,
+  IN EFI_SYSTEM_TABLE            *SystemTable
+  )
+{
+  return InitializeTcgCommon ();
+}
diff --git a/SecurityPkg/Include/Guid/TpmNvsMm.h b/SecurityPkg/Include/Guid/TpmNvsMm.h
new file mode 100644
index 000000000000..64c0f5c346fa
--- /dev/null
+++ b/SecurityPkg/Include/Guid/TpmNvsMm.h
@@ -0,0 +1,68 @@
+/** @file
+  TPM NVS MM guid, used for exchanging information, including SWI value and NVS region
+  information, for patching TPM ACPI table.
+
+Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) Microsoft Corporation.
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef TCG2_NVS_MM_H_
+#define TCG2_NVS_MM_H_
+
+#define MM_TPM_NVS_HOB_GUID \
+  { 0xc96c76eb, 0xbc78, 0x429c, { 0x9f, 0x4b, 0xda, 0x51, 0x78, 0xc2, 0x84, 0x57 }}
+
+extern EFI_GUID gTpmNvsMmGuid;
+
+#pragma pack(1)
+typedef struct {
+  UINT8                  SoftwareSmi;
+  UINT32                 Parameter;
+  UINT32                 Response;
+  UINT32                 Request;
+  UINT32                 RequestParameter;
+  UINT32                 LastRequest;
+  UINT32                 ReturnCode;
+} PHYSICAL_PRESENCE_NVS;
+
+typedef struct {
+  UINT8                  SoftwareSmi;
+  UINT32                 Parameter;
+  UINT32                 Request;
+  UINT32                 ReturnCode;
+} MEMORY_CLEAR_NVS;
+
+typedef struct {
+  PHYSICAL_PRESENCE_NVS  PhysicalPresence;
+  MEMORY_CLEAR_NVS       MemoryClear;
+  UINT32                 PPRequestUserConfirm;
+  UINT32                 TpmIrqNum;
+  BOOLEAN                IsShortFormPkgLength;
+} TCG_NVS;
+
+typedef struct {
+  UINT8                  OpRegionOp;
+  UINT32                 NameString;
+  UINT8                  RegionSpace;
+  UINT8                  DWordPrefix;
+  UINT32                 RegionOffset;
+  UINT8                  BytePrefix;
+  UINT8                  RegionLen;
+} AML_OP_REGION_32_8;
+
+typedef struct {
+  UINT64                Function;
+  UINT64                ReturnStatus;
+  EFI_PHYSICAL_ADDRESS  TargetAddress;
+  UINT64                RegisteredPpSwiValue;
+  UINT64                RegisteredMcSwiValue;
+} TPM_NVS_MM_COMM_BUFFER;
+#pragma pack()
+
+typedef enum {
+  TpmNvsMmExchangeInfo,
+} TPM_NVS_MM_FUNCTION;
+
+#endif  // TCG2_NVS_MM_H_
diff --git a/SecurityPkg/SecurityPkg.dec b/SecurityPkg/SecurityPkg.dec
index 1b7d62e802b3..0970cae5c75e 100644
--- a/SecurityPkg/SecurityPkg.dec
+++ b/SecurityPkg/SecurityPkg.dec
@@ -183,6 +183,13 @@ [Guids]
   ## Include/OpalPasswordExtraInfoVariable.h
   gOpalExtraInfoVariableGuid =  {0x44a2ad5d, 0x612c, 0x47b3, {0xb0, 0x6e, 0xc8, 0xf5, 0x0b, 0xfb, 0xf0, 0x7d}}
 
+  ## GUID used to exchange registered SWI value and NVS region between Tcg2Acpi and Tcg2Smm.
+  ## Include/Guid/TpmNvsMm.h
+  gTpmNvsMmGuid                      = { 0xc96c76eb, 0xbc78, 0x429c, { 0x9f, 0x4b, 0xda, 0x51, 0x78, 0xc2, 0x84, 0x57 }}
+
+  ## GUID used to enforce loading order between Tcg2Acpi and Tcg2Smm
+  gTcg2MmSwSmiRegisteredGuid         = { 0x9d4548b9, 0xa48d, 0x4db4, { 0x9a, 0x68, 0x32, 0xc5, 0x13, 0x9e, 0x20, 0x18 } }
+
 
 [Ppis]
   ## The PPI GUID for that TPM physical presence should be locked.
diff --git a/SecurityPkg/SecurityPkg.dsc b/SecurityPkg/SecurityPkg.dsc
index 618420a56c33..928bff72baa3 100644
--- a/SecurityPkg/SecurityPkg.dsc
+++ b/SecurityPkg/SecurityPkg.dsc
@@ -317,6 +317,7 @@ [Components.IA32, Components.X64]
   SecurityPkg/Tcg/MemoryOverwriteRequestControlLock/TcgMorLockSmm.inf
   SecurityPkg/Tcg/TcgSmm/TcgSmm.inf
   SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.inf
+  SecurityPkg/Tcg/Tcg2Acpi/Tcg2Acpi.inf
   SecurityPkg/Library/SmmTcg2PhysicalPresenceLib/SmmTcg2PhysicalPresenceLib.inf
   SecurityPkg/Library/SmmTcg2PhysicalPresenceLib/StandaloneMmTcg2PhysicalPresenceLib.inf
 
diff --git a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.inf b/SecurityPkg/Tcg/Tcg2Acpi/Tcg2Acpi.inf
similarity index 76%
copy from SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.inf
copy to SecurityPkg/Tcg/Tcg2Acpi/Tcg2Acpi.inf
index 872ed27cbe71..42ddb4bd1f39 100644
--- a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.inf
+++ b/SecurityPkg/Tcg/Tcg2Acpi/Tcg2Acpi.inf
@@ -13,8 +13,10 @@
 #     "Errata for PC Client Specific Platform Firmware Profile Specification Version 1.0 Revision 1.03"
 #
 #  This driver implements TPM 2.0 definition block in ACPI table and
-#  registers SMI callback functions for Tcg2 physical presence and
-#  MemoryClear to handle the requests from ACPI method.
+#  populates registered SMI callback functions for Tcg2 physical presence
+#  and MemoryClear to handle the requests for ACPI method. It needs to be
+#  used together with Tcg2 MM drivers to exchange information on registered
+#  SwSmiValue and allocated NVS region address.
 #
 #  Caution: This module requires additional review when modified.
 #  This driver will have external input - variable and ACPINvs data in SMM mode.
@@ -28,17 +30,15 @@
 
 [Defines]
   INF_VERSION                    = 0x00010005
-  BASE_NAME                      = Tcg2Smm
-  MODULE_UNI_FILE                = Tcg2Smm.uni
-  FILE_GUID                      = 44A20657-10B8-4049-A148-ACD8812AF257
-  MODULE_TYPE                    = DXE_SMM_DRIVER
+  BASE_NAME                      = Tcg2Acpi
+  FILE_GUID                      = 0D4BBF18-C2CC-4C23-BD63-BFDAD4C710D0
+  MODULE_TYPE                    = DXE_DRIVER
   PI_SPECIFICATION_VERSION       = 0x0001000A
   VERSION_STRING                 = 1.0
-  ENTRY_POINT                    = InitializeTcgSmm
+  ENTRY_POINT                    = InitializeTcgAcpi
 
 [Sources]
-  Tcg2Smm.h
-  Tcg2Smm.c
+  Tcg2Acpi.c
   Tpm.asl
 
 [Packages]
@@ -50,7 +50,6 @@ [LibraryClasses]
   BaseLib
   BaseMemoryLib
   UefiDriverEntryPoint
-  MmServicesTableLib
   UefiBootServicesTableLib
   DebugLib
   DxeServicesLib
@@ -60,16 +59,13 @@ [LibraryClasses]
   PcdLib
 
 [Guids]
-  ## SOMETIMES_PRODUCES ## Variable:L"MemoryOverwriteRequestControl"
-  ## SOMETIMES_CONSUMES ## Variable:L"MemoryOverwriteRequestControl"
-  gEfiMemoryOverwriteControlDataGuid
-
   gEfiTpmDeviceInstanceTpm20DtpmGuid                            ## PRODUCES           ## GUID       # TPM device identifier
+  gTpmNvsMmGuid                                                 ## CONSUMES
+  gEdkiiPiSmmCommunicationRegionTableGuid                       ## CONSUMES
 
 [Protocols]
-  gEfiSmmSwDispatch2ProtocolGuid                                ## CONSUMES
-  gEfiSmmVariableProtocolGuid                                   ## CONSUMES
   gEfiAcpiTableProtocolGuid                                     ## CONSUMES
+  gEfiMmCommunicationProtocolGuid                               ## CONSUMES
 
 [FixedPcd]
   gEfiSecurityPkgTokenSpaceGuid.PcdSmiCommandIoPort             ## CONSUMES
@@ -93,9 +89,5 @@ [Pcd]
 
 [Depex]
   gEfiAcpiTableProtocolGuid AND
-  gEfiSmmSwDispatch2ProtocolGuid AND
-  gEfiSmmVariableProtocolGuid AND
+  gTcg2MmSwSmiRegisteredGuid AND
   gEfiTcg2ProtocolGuid
-
-[UserExtensions.TianoCore."ExtraFiles"]
-  Tcg2SmmExtra.uni
diff --git a/SecurityPkg/Tcg/Tcg2Smm/Tpm.asl b/SecurityPkg/Tcg/Tcg2Acpi/Tpm.asl
similarity index 100%
rename from SecurityPkg/Tcg/Tcg2Smm/Tpm.asl
rename to SecurityPkg/Tcg/Tcg2Acpi/Tpm.asl
diff --git a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.h b/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.h
index d7328c8f2ac9..d7f78aa43275 100644
--- a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.h
+++ b/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.h
@@ -2,6 +2,7 @@
   The header file for Tcg2 SMM driver.
 
 Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) Microsoft Corporation.
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -9,13 +10,13 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #ifndef __TCG2_SMM_H__
 #define __TCG2_SMM_H__
 
-#include <PiDxe.h>
-#include <IndustryStandard/Acpi.h>
-#include <IndustryStandard/Tpm2Acpi.h>
+#include <PiMm.h>
 
 #include <Guid/MemoryOverwriteControl.h>
 #include <Guid/TpmInstance.h>
+#include <Guid/TpmNvsMm.h>
 
+#include <Protocol/MmReadyToLock.h>
 #include <Protocol/SmmSwDispatch2.h>
 #include <Protocol/AcpiTable.h>
 #include <Protocol/SmmVariable.h>
@@ -25,56 +26,14 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #include <Library/BaseMemoryLib.h>
 #include <Library/DebugLib.h>
 #include <Library/MmServicesTableLib.h>
-#include <Library/UefiDriverEntryPoint.h>
-#include <Library/UefiBootServicesTableLib.h>
-#include <Library/DxeServicesLib.h>
-#include <Library/TpmMeasurementLib.h>
 #include <Library/Tpm2CommandLib.h>
 #include <Library/Tcg2PhysicalPresenceLib.h>
 #include <Library/IoLib.h>
-#include <Library/PrintLib.h>
 #include <Library/PcdLib.h>
 #include <Library/Tpm2DeviceLib.h>
 
 #include <IndustryStandard/TpmPtp.h>
 
-#pragma pack(1)
-typedef struct {
-  UINT8                  SoftwareSmi;
-  UINT32                 Parameter;
-  UINT32                 Response;
-  UINT32                 Request;
-  UINT32                 RequestParameter;
-  UINT32                 LastRequest;
-  UINT32                 ReturnCode;
-} PHYSICAL_PRESENCE_NVS;
-
-typedef struct {
-  UINT8                  SoftwareSmi;
-  UINT32                 Parameter;
-  UINT32                 Request;
-  UINT32                 ReturnCode;
-} MEMORY_CLEAR_NVS;
-
-typedef struct {
-  PHYSICAL_PRESENCE_NVS  PhysicalPresence;
-  MEMORY_CLEAR_NVS       MemoryClear;
-  UINT32                 PPRequestUserConfirm;
-  UINT32                 TpmIrqNum;
-  BOOLEAN                IsShortFormPkgLength;
-} TCG_NVS;
-
-typedef struct {
-  UINT8                  OpRegionOp;
-  UINT32                 NameString;
-  UINT8                  RegionSpace;
-  UINT8                  DWordPrefix;
-  UINT32                 RegionOffset;
-  UINT8                  BytePrefix;
-  UINT8                  RegionLen;
-} AML_OP_REGION_32_8;
-#pragma pack()
-
 //
 // The definition for TCG MOR
 //
@@ -87,36 +46,42 @@ typedef struct {
 #define MOR_REQUEST_SUCCESS                                        0
 #define MOR_REQUEST_GENERAL_FAILURE                                1
 
-//
-// Physical Presence Interface Version supported by Platform
-//
-#define PHYSICAL_PRESENCE_VERSION_TAG                              "$PV"
-#define PHYSICAL_PRESENCE_VERSION_SIZE                             4
-
-//
-// PNP _HID for TPM2 device
-//
-#define TPM_HID_TAG                                                "NNNN0000"
-#define TPM_HID_PNP_SIZE                                           8
-#define TPM_HID_ACPI_SIZE                                          9
-
-#define TPM_PRS_RESL                                               "RESL"
-#define TPM_PRS_RESS                                               "RESS"
-#define TPM_PRS_RES_NAME_SIZE                                      4
-//
-// Minimum PRS resource template size
-//  1 byte    for  BufferOp
-//  1 byte    for  PkgLength
-//  2 bytes   for  BufferSize
-//  12 bytes  for  Memory32Fixed descriptor
-//  5 bytes   for  Interrupt descriptor
-//  2 bytes   for  END Tag
-//
-#define TPM_POS_RES_TEMPLATE_MIN_SIZE                              (1 + 1 + 2 + 12 + 5 + 2)
-
-//
-// Max Interrupt buffer size for PRS interrupt resource
-// Now support 15 interrupts in maxmum
-//
-#define MAX_PRS_INT_BUF_SIZE                                       (15*4)
+/**
+  Notify the system that the SMM variable driver is ready.
+**/
+VOID
+Tcg2NotifyMmReady (
+  VOID
+  );
+
+/**
+  This function is an abstraction layer for implementation specific Mm buffer validation routine.
+
+  @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
+IsBufferOutsideMmValid (
+  IN EFI_PHYSICAL_ADDRESS  Buffer,
+  IN UINT64                Length
+  );
+
+/**
+  The driver's common initialization routine.
+
+  It install callbacks for TPM physical presence and MemoryClear, and locate
+  SMM variable to be used in the callback function.
+
+  @retval EFI_SUCCESS     The entry point is executed successfully.
+  @retval Others          Some error occurs when executing this entry point.
+
+**/
+EFI_STATUS
+InitializeTcgCommon (
+  VOID
+  );
+
 #endif  // __TCG_SMM_H__
diff --git a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.inf b/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.inf
index 872ed27cbe71..096338d0ef47 100644
--- a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.inf
+++ b/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.inf
@@ -39,7 +39,7 @@ [Defines]
 [Sources]
   Tcg2Smm.h
   Tcg2Smm.c
-  Tpm.asl
+  Tcg2TraditionalMm.c
 
 [Packages]
   MdePkg/MdePkg.dec
@@ -58,6 +58,7 @@ [LibraryClasses]
   Tpm2CommandLib
   Tcg2PhysicalPresenceLib
   PcdLib
+  SmmMemLib
 
 [Guids]
   ## SOMETIMES_PRODUCES ## Variable:L"MemoryOverwriteRequestControl"
@@ -65,34 +66,18 @@ [Guids]
   gEfiMemoryOverwriteControlDataGuid
 
   gEfiTpmDeviceInstanceTpm20DtpmGuid                            ## PRODUCES           ## GUID       # TPM device identifier
+  gTcg2MmSwSmiRegisteredGuid                                    ## PRODUCES
+  gTpmNvsMmGuid                                                 ## CONSUMES
 
 [Protocols]
   gEfiSmmSwDispatch2ProtocolGuid                                ## CONSUMES
   gEfiSmmVariableProtocolGuid                                   ## CONSUMES
-  gEfiAcpiTableProtocolGuid                                     ## CONSUMES
-
-[FixedPcd]
-  gEfiSecurityPkgTokenSpaceGuid.PcdSmiCommandIoPort             ## CONSUMES
+  gEfiMmReadyToLockProtocolGuid                                 ## CONSUMES
 
 [Pcd]
   gEfiSecurityPkgTokenSpaceGuid.PcdTpmInstanceGuid              ## CONSUMES
-  gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiDefaultOemId            ## SOMETIMES_CONSUMES
-  gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiDefaultOemTableId       ## SOMETIMES_CONSUMES
-  gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiDefaultOemRevision      ## SOMETIMES_CONSUMES
-  gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiDefaultCreatorId        ## SOMETIMES_CONSUMES
-  gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiDefaultCreatorRevision  ## SOMETIMES_CONSUMES
-  gEfiSecurityPkgTokenSpaceGuid.PcdTpmBaseAddress               ## CONSUMES
-  gEfiSecurityPkgTokenSpaceGuid.PcdTcgPhysicalPresenceInterfaceVer  ## CONSUMES
-  gEfiSecurityPkgTokenSpaceGuid.PcdTpm2AcpiTableRev                 ## CONSUMES
-  gEfiSecurityPkgTokenSpaceGuid.PcdTpmPlatformClass                 ## SOMETIMES_CONSUMES
-  gEfiSecurityPkgTokenSpaceGuid.PcdTpm2CurrentIrqNum            ## CONSUMES
-  gEfiSecurityPkgTokenSpaceGuid.PcdTpm2PossibleIrqNumBuf        ## CONSUMES
-  gEfiSecurityPkgTokenSpaceGuid.PcdActiveTpmInterfaceType       ## CONSUMES
-  gEfiSecurityPkgTokenSpaceGuid.PcdTpm2AcpiTableLaml            ## CONSUMES
-  gEfiSecurityPkgTokenSpaceGuid.PcdTpm2AcpiTableLasa            ## CONSUMES
 
 [Depex]
-  gEfiAcpiTableProtocolGuid AND
   gEfiSmmSwDispatch2ProtocolGuid AND
   gEfiSmmVariableProtocolGuid AND
   gEfiTcg2ProtocolGuid
-- 
2.30.0.windows.1