[edk2,v2,07/17] MdeModulePkg/VariableRuntimeDxe: factor out boot service accesses

Message ID 20190114132758.24054-8-ard.biesheuvel@linaro.org
State New
Headers show
Series
  • implement standalone MM versions of the variable runtime drivers
Related show

Commit Message

Ard Biesheuvel Jan. 14, 2019, 1:27 p.m.
In preparation of providing a standalone MM based variable runtime
driver, move the existing SMM driver to the new MM services table,
and factor out some pieces that are specific to the traditional
driver, mainly related to the use of UEFI boot services, which are
not accessible to standalone MM drivers.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
---
 MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf         |   5 +-
 MdeModulePkg/Universal/Variable/RuntimeDxe/PrivilegePolymorphic.h  |  58 +++++++++
 MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c         |  18 +--
 MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c           |  59 +++------
 MdeModulePkg/Universal/Variable/RuntimeDxe/VariableTraditionalMm.c | 130 ++++++++++++++++++++
 5 files changed, 211 insertions(+), 59 deletions(-)

-- 
2.20.1

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Comments

Zeng, Star Jan. 16, 2019, 4:57 a.m. | #1
Some minor comments.

With them handled, Reviewed-by: Star Zeng <star.zeng@intel.com>

On 2019/1/14 21:27, Ard Biesheuvel wrote:
> In preparation of providing a standalone MM based variable runtime

> driver, move the existing SMM driver to the new MM services table,

> and factor out some pieces that are specific to the traditional

> driver, mainly related to the use of UEFI boot services, which are

> not accessible to standalone MM drivers.

> 

> Contributed-under: TianoCore Contribution Agreement 1.1

> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> Regression-tested-by: Laszlo Ersek <lersek@redhat.com>

> ---

>   MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf         |   5 +-

>   MdeModulePkg/Universal/Variable/RuntimeDxe/PrivilegePolymorphic.h  |  58 +++++++++

>   MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c         |  18 +--

>   MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c           |  59 +++------

>   MdeModulePkg/Universal/Variable/RuntimeDxe/VariableTraditionalMm.c | 130 ++++++++++++++++++++

>   5 files changed, 211 insertions(+), 59 deletions(-)

> 


[Trimmed]

> diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/PrivilegePolymorphic.h b/MdeModulePkg/Universal/Variable/RuntimeDxe/PrivilegePolymorphic.h

> index 7af22a4ad671..eb84589fc404 100644

> --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/PrivilegePolymorphic.h

> +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/PrivilegePolymorphic.h

> @@ -97,4 +97,62 @@ VariableSpeculationBarrier (

>     VOID

>     );

>   

> +/**

> +  Notify the system that the SMM variable driver is ready

> +**/

> +VOID

> +VariableNotifySmmReady (

> +  VOID

> +  );

> +

> +/**

> +  Notify the system that the SMM variable write driver is ready

> +**/

> +VOID

> +VariableNotifySmmWriteReady (

> +  VOID

> +  );

> +

> +/**

> +  Variable service MM driver entry point


The block should be matched with the MmVariableServiceInitialize 
implementation in VariableSmm.c. But not SmmVariableServiceInitialize 
implementation in VariableTraditionalMm.c

> +**/

> +EFI_STATUS

> +EFIAPI

> +MmVariableServiceInitialize (

> +  VOID

> +  );

> +

> +/**

> +  This function checks if the buffer is valid per processor architecture and

> +  does not overlap with SMRAM.

> +

> +  @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 does not

> +                overlap with SMRAM.

> +  @retval FALSE This buffer is not valid per processor architecture or overlaps

> +                with SMRAM.

> +**/

> +BOOLEAN

> +VariableSmmIsBufferOutsideSmmValid (

> +  IN EFI_PHYSICAL_ADDRESS  Buffer,

> +  IN UINT64                Length

> +  );

> +

> +/**

> +  Whether the TCG or TCG2 protocols are installed in the UEFI protocol database.

> +  This information is used by the MorLock code to infer whether an existing

> +  MOR variable is legitimate or not.

> +

> +  @retval TRUE  Either the TCG or TCG2 protocol is installed in the UEFI

> +                protocol database

> +  @retval FALSE Neither the TCG nor the TCG2 protocol is installed in the UEFI

> +                protocol database

> +**/

> +BOOLEAN

> +VariableHaveTcgProtocols (

> +  VOID

> +  );

> +

>   #endif


[Trimmed]

> @@ -928,18 +920,11 @@ SmmFtwNotificationEvent (

>     runtime services in the EFI System Table and installs arch protocols

>     for variable read and write services being available. It also registers

>     a notification function for an EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE event.

> -

> -  @param[in] ImageHandle    The firmware allocated handle for the EFI image.

> -  @param[in] SystemTable    A pointer to the EFI System Table.

> -

> -  @retval EFI_SUCCESS       Variable service successfully initialized.


This line needs to be kept.

> -

>   **/

>   EFI_STATUS

>   EFIAPI

> -VariableServiceInitialize (

> -  IN EFI_HANDLE                           ImageHandle,

> -  IN EFI_SYSTEM_TABLE                     *SystemTable

> +MmVariableServiceInitialize (

> +  VOID

>     )

>   {

>     EFI_STATUS                              Status;

> @@ -957,7 +942,7 @@ VariableServiceInitialize (

>     // Install the Smm Variable Protocol on a new handle.

>     //

>     VariableHandle = NULL;

> -  Status = gSmst->SmmInstallProtocolInterface (

> +  Status = gMmst->MmInstallProtocolInterface (

>                       &VariableHandle,

>                       &gEfiSmmVariableProtocolGuid,

>                       EFI_NATIVE_INTERFACE,

> @@ -965,7 +950,7 @@ VariableServiceInitialize (

>                       );

>     ASSERT_EFI_ERROR (Status);

>   

> -  Status = gSmst->SmmInstallProtocolInterface (

> +  Status = gMmst->MmInstallProtocolInterface (

>                       &VariableHandle,

>                       &gEdkiiSmmVarCheckProtocolGuid,

>                       EFI_NATIVE_INTERFACE,

> @@ -976,7 +961,7 @@ VariableServiceInitialize (

>     mVariableBufferPayloadSize = GetMaxVariableSize () +

>                                  OFFSET_OF (SMM_VARIABLE_COMMUNICATE_VAR_CHECK_VARIABLE_PROPERTY, Name) - GetVariableHeaderSize ();

>   

> -  Status = gSmst->SmmAllocatePool (

> +  Status = gMmst->MmAllocatePool (

>                       EfiRuntimeServicesData,

>                       mVariableBufferPayloadSize,

>                       (VOID **)&mVariableBufferPayload

> @@ -987,25 +972,19 @@ VariableServiceInitialize (

>     /// Register SMM variable SMI handler

>     ///

>     VariableHandle = NULL;

> -  Status = gSmst->SmiHandlerRegister (SmmVariableHandler, &gEfiSmmVariableProtocolGuid, &VariableHandle);

> +  Status = gMmst->MmiHandlerRegister (SmmVariableHandler, &gEfiSmmVariableProtocolGuid, &VariableHandle);

>     ASSERT_EFI_ERROR (Status);

>   

>     //

>     // Notify the variable wrapper driver the variable service is ready

>     //

> -  Status = SystemTable->BootServices->InstallProtocolInterface (

> -                                        &mVariableHandle,

> -                                        &gEfiSmmVariableProtocolGuid,

> -                                        EFI_NATIVE_INTERFACE,

> -                                        &gSmmVariable

> -                                        );

> -  ASSERT_EFI_ERROR (Status);

> +  VariableNotifySmmReady ();

>   

>     //

>     // Register EFI_SMM_END_OF_DXE_PROTOCOL_GUID notify function.

>     //

> -  Status = gSmst->SmmRegisterProtocolNotify (

> -                    &gEfiSmmEndOfDxeProtocolGuid,

> +  Status = gMmst->MmRegisterProtocolNotify (

> +                    &gEfiMmEndOfDxeProtocolGuid,

>                       SmmEndOfDxeCallback,

>                       &SmmEndOfDxeRegistration

>                       );

> @@ -1014,7 +993,7 @@ VariableServiceInitialize (

>     //

>     // Register FtwNotificationEvent () notify function.

>     //

> -  Status = gSmst->SmmRegisterProtocolNotify (

> +  Status = gMmst->MmRegisterProtocolNotify (

>                       &gEfiSmmFaultTolerantWriteProtocolGuid,

>                       SmmFtwNotificationEvent,

>                       &SmmFtwRegistration

> diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableTraditionalMm.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableTraditionalMm.c

> new file mode 100644

> index 000000000000..d702c8f8db67

> --- /dev/null

> +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableTraditionalMm.c

> @@ -0,0 +1,130 @@


[Trimmed]

> +

> +/**

> +  Variable service MM driver entry point


The comments block should have description for the two parameters.

Thanks,
Star

> +**/

> +EFI_STATUS

> +EFIAPI

> +VariableServiceInitialize (

> +  IN EFI_HANDLE                           ImageHandle,

> +  IN EFI_SYSTEM_TABLE                     *SystemTable

> +  )

> +{

> +  return MmVariableServiceInitialize ();

> +}

> +

> +/**

> +  Whether the TCG or TCG2 protocols are installed in the UEFI protocol database.

> +  This information is used by the MorLock code to infer whether an existing

> +  MOR variable is legitimate or not.

> +

> +  @retval TRUE  Either the TCG or TCG2 protocol is installed in the UEFI

> +                protocol database

> +  @retval FALSE Neither the TCG nor the TCG2 protocol is installed in the UEFI

> +                protocol database

> +**/

> +BOOLEAN

> +VariableHaveTcgProtocols (

> +  VOID

> +  )

> +{

> +  EFI_STATUS            Status;

> +  VOID                  *Interface;

> +

> +  Status = gBS->LocateProtocol (

> +                  &gEfiTcg2ProtocolGuid,

> +                  NULL,                     // Registration

> +                  &Interface

> +                  );

> +  if (!EFI_ERROR (Status)) {

> +    return TRUE;

> +  }

> +

> +  Status = gBS->LocateProtocol (

> +                  &gEfiTcgProtocolGuid,

> +                  NULL,                     // Registration

> +                  &Interface

> +                  );

> +  return !EFI_ERROR (Status);

> +}

> 


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Patch

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf
index db7d220e06df..ed7392cbcffc 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf
@@ -48,6 +48,7 @@  [Defines]
 [Sources]
   Reclaim.c
   Variable.c
+  VariableTraditionalMm.c
   VariableSmm.c
   VarCheck.c
   Variable.h
@@ -66,7 +67,7 @@  [LibraryClasses]
   BaseLib
   SynchronizationLib
   UefiLib
-  SmmServicesTableLib
+  MmServicesTableLib
   BaseMemoryLib
   DebugLib
   DxeServicesTableLib
@@ -85,7 +86,7 @@  [Protocols]
   ## PRODUCES
   ## UNDEFINED # SmiHandlerRegister
   gEfiSmmVariableProtocolGuid
-  gEfiSmmEndOfDxeProtocolGuid                   ## NOTIFY
+  gEfiMmEndOfDxeProtocolGuid                    ## NOTIFY
   gEdkiiSmmVarCheckProtocolGuid                 ## PRODUCES
   gEfiTcgProtocolGuid                           ## SOMETIMES_CONSUMES
   gEfiTcg2ProtocolGuid                          ## SOMETIMES_CONSUMES
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/PrivilegePolymorphic.h b/MdeModulePkg/Universal/Variable/RuntimeDxe/PrivilegePolymorphic.h
index 7af22a4ad671..eb84589fc404 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/PrivilegePolymorphic.h
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/PrivilegePolymorphic.h
@@ -97,4 +97,62 @@  VariableSpeculationBarrier (
   VOID
   );
 
+/**
+  Notify the system that the SMM variable driver is ready
+**/
+VOID
+VariableNotifySmmReady (
+  VOID
+  );
+
+/**
+  Notify the system that the SMM variable write driver is ready
+**/
+VOID
+VariableNotifySmmWriteReady (
+  VOID
+  );
+
+/**
+  Variable service MM driver entry point
+**/
+EFI_STATUS
+EFIAPI
+MmVariableServiceInitialize (
+  VOID
+  );
+
+/**
+  This function checks if the buffer is valid per processor architecture and
+  does not overlap with SMRAM.
+
+  @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 does not
+                overlap with SMRAM.
+  @retval FALSE This buffer is not valid per processor architecture or overlaps
+                with SMRAM.
+**/
+BOOLEAN
+VariableSmmIsBufferOutsideSmmValid (
+  IN EFI_PHYSICAL_ADDRESS  Buffer,
+  IN UINT64                Length
+  );
+
+/**
+  Whether the TCG or TCG2 protocols are installed in the UEFI protocol database.
+  This information is used by the MorLock code to infer whether an existing
+  MOR variable is legitimate or not.
+
+  @retval TRUE  Either the TCG or TCG2 protocol is installed in the UEFI
+                protocol database
+  @retval FALSE Neither the TCG nor the TCG2 protocol is installed in the UEFI
+                protocol database
+**/
+BOOLEAN
+VariableHaveTcgProtocols (
+  VOID
+  );
+
 #endif
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c
index 28aa2893c6f8..009d96c3a65e 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c
@@ -21,7 +21,6 @@  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include <Library/DebugLib.h>
 #include <Library/BaseLib.h>
 #include <Library/BaseMemoryLib.h>
-#include <Library/UefiBootServicesTableLib.h>
 #include "Variable.h"
 
 typedef struct {
@@ -419,8 +418,6 @@  MorLockInitAtEndOfDxe (
 {
   UINTN      MorSize;
   EFI_STATUS MorStatus;
-  EFI_STATUS TcgStatus;
-  VOID       *TcgInterface;
 
   if (!mMorLockInitializationRequired) {
     //
@@ -458,20 +455,7 @@  MorLockInitAtEndOfDxe (
     // can be deduced from the absence of the TCG / TCG2 protocols, as edk2's
     // MOR implementation depends on (one of) those protocols.
     //
-    TcgStatus = gBS->LocateProtocol (
-                       &gEfiTcg2ProtocolGuid,
-                       NULL,                     // Registration
-                       &TcgInterface
-                       );
-    if (EFI_ERROR (TcgStatus)) {
-      TcgStatus = gBS->LocateProtocol (
-                         &gEfiTcgProtocolGuid,
-                         NULL,                   // Registration
-                         &TcgInterface
-                         );
-    }
-
-    if (!EFI_ERROR (TcgStatus)) {
+    if (VariableHaveTcgProtocols ()) {
       //
       // The MOR variable originates from the platform firmware; set the MOR
       // Control Lock variable to report the locking capability to the OS.
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c
index 8c53f84ff6e8..7245587052df 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c
@@ -15,6 +15,7 @@ 
   SmmVariableGetStatistics() should also do validation based on its own knowledge.
 
 Copyright (c) 2010 - 2016, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2018, Linaro, Ltd. 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
@@ -28,18 +29,15 @@  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include <Protocol/SmmVariable.h>
 #include <Protocol/SmmFirmwareVolumeBlock.h>
 #include <Protocol/SmmFaultTolerantWrite.h>
-#include <Protocol/SmmEndOfDxe.h>
+#include <Protocol/MmEndOfDxe.h>
 #include <Protocol/SmmVarCheck.h>
 
-#include <Library/SmmServicesTableLib.h>
-#include <Library/SmmMemLib.h>
+#include <Library/MmServicesTableLib.h>
 
 #include <Guid/SmmVariableCommon.h>
 #include "Variable.h"
 
 extern VARIABLE_INFO_ENTRY                           *gVariableInfo;
-EFI_HANDLE                                           mSmmVariableHandle      = NULL;
-EFI_HANDLE                                           mVariableHandle         = NULL;
 BOOLEAN                                              mAtRuntime              = FALSE;
 UINT8                                                *mVariableBufferPayload = NULL;
 UINTN                                                mVariableBufferPayloadSize;
@@ -218,7 +216,7 @@  GetFtwProtocol (
   //
   // Locate Smm Fault Tolerent Write protocol
   //
-  Status = gSmst->SmmLocateProtocol (
+  Status = gMmst->MmLocateProtocol (
                     &gEfiSmmFaultTolerantWriteProtocolGuid,
                     NULL,
                     FtwProtocol
@@ -248,7 +246,7 @@  GetFvbByHandle (
   //
   // To get the SMM FVB protocol interface on the handle
   //
-  return gSmst->SmmHandleProtocol (
+  return gMmst->MmHandleProtocol (
                   FvBlockHandle,
                   &gEfiSmmFirmwareVolumeBlockProtocolGuid,
                   (VOID **) FvBlock
@@ -287,7 +285,7 @@  GetFvbCountAndBuffer (
   BufferSize     = 0;
   *NumberHandles = 0;
   *Buffer        = NULL;
-  Status = gSmst->SmmLocateHandle (
+  Status = gMmst->MmLocateHandle (
                     ByProtocol,
                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
                     NULL,
@@ -303,7 +301,7 @@  GetFvbCountAndBuffer (
     return EFI_OUT_OF_RESOURCES;
   }
 
-  Status = gSmst->SmmLocateHandle (
+  Status = gMmst->MmLocateHandle (
                     ByProtocol,
                     &gEfiSmmFirmwareVolumeBlockProtocolGuid,
                     NULL,
@@ -500,7 +498,7 @@  SmmVariableHandler (
     return EFI_SUCCESS;
   }
 
-  if (!SmmIsBufferOutsideSmmValid ((UINTN)CommBuffer, TempCommBufferSize)) {
+  if (!VariableSmmIsBufferOutsideSmmValid ((UINTN)CommBuffer, TempCommBufferSize)) {
     DEBUG ((EFI_D_ERROR, "SmmVariableHandler: SMM communication buffer in SMRAM or overflow!\n"));
     return EFI_SUCCESS;
   }
@@ -911,13 +909,7 @@  SmmFtwNotificationEvent (
   //
   // Notify the variable wrapper driver the variable write service is ready
   //
-  Status = gBS->InstallProtocolInterface (
-                  &mSmmVariableHandle,
-                  &gSmmVariableWriteGuid,
-                  EFI_NATIVE_INTERFACE,
-                  NULL
-                  );
-  ASSERT_EFI_ERROR (Status);
+  VariableNotifySmmWriteReady ();
 
   return EFI_SUCCESS;
 }
@@ -928,18 +920,11 @@  SmmFtwNotificationEvent (
   runtime services in the EFI System Table and installs arch protocols
   for variable read and write services being available. It also registers
   a notification function for an EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE event.
-
-  @param[in] ImageHandle    The firmware allocated handle for the EFI image.
-  @param[in] SystemTable    A pointer to the EFI System Table.
-
-  @retval EFI_SUCCESS       Variable service successfully initialized.
-
 **/
 EFI_STATUS
 EFIAPI
-VariableServiceInitialize (
-  IN EFI_HANDLE                           ImageHandle,
-  IN EFI_SYSTEM_TABLE                     *SystemTable
+MmVariableServiceInitialize (
+  VOID
   )
 {
   EFI_STATUS                              Status;
@@ -957,7 +942,7 @@  VariableServiceInitialize (
   // Install the Smm Variable Protocol on a new handle.
   //
   VariableHandle = NULL;
-  Status = gSmst->SmmInstallProtocolInterface (
+  Status = gMmst->MmInstallProtocolInterface (
                     &VariableHandle,
                     &gEfiSmmVariableProtocolGuid,
                     EFI_NATIVE_INTERFACE,
@@ -965,7 +950,7 @@  VariableServiceInitialize (
                     );
   ASSERT_EFI_ERROR (Status);
 
-  Status = gSmst->SmmInstallProtocolInterface (
+  Status = gMmst->MmInstallProtocolInterface (
                     &VariableHandle,
                     &gEdkiiSmmVarCheckProtocolGuid,
                     EFI_NATIVE_INTERFACE,
@@ -976,7 +961,7 @@  VariableServiceInitialize (
   mVariableBufferPayloadSize = GetMaxVariableSize () +
                                OFFSET_OF (SMM_VARIABLE_COMMUNICATE_VAR_CHECK_VARIABLE_PROPERTY, Name) - GetVariableHeaderSize ();
 
-  Status = gSmst->SmmAllocatePool (
+  Status = gMmst->MmAllocatePool (
                     EfiRuntimeServicesData,
                     mVariableBufferPayloadSize,
                     (VOID **)&mVariableBufferPayload
@@ -987,25 +972,19 @@  VariableServiceInitialize (
   /// Register SMM variable SMI handler
   ///
   VariableHandle = NULL;
-  Status = gSmst->SmiHandlerRegister (SmmVariableHandler, &gEfiSmmVariableProtocolGuid, &VariableHandle);
+  Status = gMmst->MmiHandlerRegister (SmmVariableHandler, &gEfiSmmVariableProtocolGuid, &VariableHandle);
   ASSERT_EFI_ERROR (Status);
 
   //
   // Notify the variable wrapper driver the variable service is ready
   //
-  Status = SystemTable->BootServices->InstallProtocolInterface (
-                                        &mVariableHandle,
-                                        &gEfiSmmVariableProtocolGuid,
-                                        EFI_NATIVE_INTERFACE,
-                                        &gSmmVariable
-                                        );
-  ASSERT_EFI_ERROR (Status);
+  VariableNotifySmmReady ();
 
   //
   // Register EFI_SMM_END_OF_DXE_PROTOCOL_GUID notify function.
   //
-  Status = gSmst->SmmRegisterProtocolNotify (
-                    &gEfiSmmEndOfDxeProtocolGuid,
+  Status = gMmst->MmRegisterProtocolNotify (
+                    &gEfiMmEndOfDxeProtocolGuid,
                     SmmEndOfDxeCallback,
                     &SmmEndOfDxeRegistration
                     );
@@ -1014,7 +993,7 @@  VariableServiceInitialize (
   //
   // Register FtwNotificationEvent () notify function.
   //
-  Status = gSmst->SmmRegisterProtocolNotify (
+  Status = gMmst->MmRegisterProtocolNotify (
                     &gEfiSmmFaultTolerantWriteProtocolGuid,
                     SmmFtwNotificationEvent,
                     &SmmFtwRegistration
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableTraditionalMm.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableTraditionalMm.c
new file mode 100644
index 000000000000..d702c8f8db67
--- /dev/null
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableTraditionalMm.c
@@ -0,0 +1,130 @@ 
+/** @file
+
+  Parts of the SMM/MM implementation that are specific to traditional MM
+
+Copyright (c) 2011 - 2018, Intel Corporation. All rights reserved. <BR>
+Copyright (c) 2018, Linaro, Ltd. 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
+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.
+
+**/
+
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/SmmMemLib.h>
+#include "Variable.h"
+
+/**
+  This function checks if the buffer is valid per processor architecture and
+  does not overlap with SMRAM.
+
+  @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 does not
+                overlap with SMRAM.
+  @retval FALSE This buffer is not valid per processor architecture or overlaps
+                with SMRAM.
+**/
+BOOLEAN
+VariableSmmIsBufferOutsideSmmValid (
+  IN EFI_PHYSICAL_ADDRESS  Buffer,
+  IN UINT64                Length
+  )
+{
+  return SmmIsBufferOutsideSmmValid (Buffer, Length);
+}
+
+/**
+  Notify the system that the SMM variable driver is ready
+**/
+VOID
+VariableNotifySmmReady (
+  VOID
+  )
+{
+  EFI_STATUS            Status;
+  EFI_HANDLE            Handle;
+
+  Handle = NULL;
+  Status = gBS->InstallProtocolInterface (
+                  &Handle,
+                  &gEfiSmmVariableProtocolGuid,
+                  EFI_NATIVE_INTERFACE,
+                  NULL
+                  );
+  ASSERT_EFI_ERROR (Status);
+}
+
+/**
+  Notify the system that the SMM variable write driver is ready
+**/
+VOID
+VariableNotifySmmWriteReady (
+  VOID
+  )
+{
+  EFI_STATUS            Status;
+  EFI_HANDLE            Handle;
+
+  Handle = NULL;
+  Status = gBS->InstallProtocolInterface (
+                  &Handle,
+                  &gSmmVariableWriteGuid,
+                  EFI_NATIVE_INTERFACE,
+                  NULL
+                  );
+  ASSERT_EFI_ERROR (Status);
+}
+
+/**
+  Variable service MM driver entry point
+**/
+EFI_STATUS
+EFIAPI
+VariableServiceInitialize (
+  IN EFI_HANDLE                           ImageHandle,
+  IN EFI_SYSTEM_TABLE                     *SystemTable
+  )
+{
+  return MmVariableServiceInitialize ();
+}
+
+/**
+  Whether the TCG or TCG2 protocols are installed in the UEFI protocol database.
+  This information is used by the MorLock code to infer whether an existing
+  MOR variable is legitimate or not.
+
+  @retval TRUE  Either the TCG or TCG2 protocol is installed in the UEFI
+                protocol database
+  @retval FALSE Neither the TCG nor the TCG2 protocol is installed in the UEFI
+                protocol database
+**/
+BOOLEAN
+VariableHaveTcgProtocols (
+  VOID
+  )
+{
+  EFI_STATUS            Status;
+  VOID                  *Interface;
+
+  Status = gBS->LocateProtocol (
+                  &gEfiTcg2ProtocolGuid,
+                  NULL,                     // Registration
+                  &Interface
+                  );
+  if (!EFI_ERROR (Status)) {
+    return TRUE;
+  }
+
+  Status = gBS->LocateProtocol (
+                  &gEfiTcgProtocolGuid,
+                  NULL,                     // Registration
+                  &Interface
+                  );
+  return !EFI_ERROR (Status);
+}