Hi Jiewen,

This is essentially following the example of VariableStandaloneMm model here:

StandaloneMmPkg/Library: Install Variable Arch Protocol · tianocore/edk2@326598e (github.com)

The intended usage for this library, in the context of Standalone MM, is to link this library to the MM IPL driver (or any other drivers that has a dependency on gEfiMmCommunication2ProtocolGuid), which will make sure MM communicate is ready to use (and all MM drivers dispatched) before DXE core dispatch Tcg2Acpi driver. I could add an example like below in the commit message if you think that will help on the intended usage:

```

MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmDxe.inf {

NULL| SecurityPkg/Library/Tcg2MmDependencyLib/Tcg2MmDependencyLib.inf

}

```

Or if you have any other ideas on making sure of the loading order, please let me know as well.

Thanks,

Kun

From: Yao, Jiewen
Sent: Tuesday, February 23, 2021 17:26
To: Kun Qin; devel@edk2.groups.io
Cc: Wang, Jian J; Zhang, Qi1; Kumar, Rahul1
Subject: Re: [edk2-devel] [PATCH v2 5/6] SecurityPkg: Tcg2Smm: Added support for Standalone Mm

I am not sure if Tcg2MmDependencyLib is the best solution.

It seems NULL lib instance. But I am not sure how it is used.

Can we have an example in SecurityPkg.dsc?

> -----Original Message-----
> From: Kun Qin <kun.q@outlook.com>
> Sent: Wednesday, February 10, 2021 9:25 AM
> To: devel@edk2.groups.io
> Cc: Yao, Jiewen <jiewen.yao@intel.com>; Wang, Jian J <jian.j.wang@intel.com>;
> Zhang, Qi1 <qi1.zhang@intel.com>; Kumar, Rahul1 <rahul1.kumar@intel.com>
> Subject: [PATCH v2 5/6] SecurityPkg: Tcg2Smm: Added support for Standalone
> Mm
>
> https://bugzilla.tianocore.org/show_bug.cgi?id=3169
>
> This change added Standalone MM instance of Tcg2. The notify function for
> Standalone MM instance is left empty.
>
> A designated dependency library was created for DXE drivers to link as an
> anonymous library.
>
> Lastly, the support of CI build for Tcg2 Standalone MM module is added.
>
> 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>
> ---
>
> Notes:
> v2:
> - Newly added.
>
> SecurityPkg/Library/Tcg2MmDependencyLib/Tcg2MmDependencyLib.c | 48
> ++++++++++++
> SecurityPkg/Tcg/Tcg2Smm/Tcg2StandaloneMm.c | 71
> ++++++++++++++++++
> SecurityPkg/Library/Tcg2MmDependencyLib/Tcg2MmDependencyLib.inf | 39
> ++++++++++
> SecurityPkg/SecurityPkg.ci.yaml | 1 +
> SecurityPkg/SecurityPkg.dec | 1 +
> SecurityPkg/SecurityPkg.dsc | 10 +++
> SecurityPkg/Tcg/Tcg2Smm/Tcg2StandaloneMm.inf | 77
> ++++++++++++++++++++
> 7 files changed, 247 insertions(+)
>
> diff --git
> a/SecurityPkg/Library/Tcg2MmDependencyLib/Tcg2MmDependencyLib.c
> b/SecurityPkg/Library/Tcg2MmDependencyLib/Tcg2MmDependencyLib.c
> new file mode 100644
> index 000000000000..12b23813dce1
> --- /dev/null
> +++ b/SecurityPkg/Library/Tcg2MmDependencyLib/Tcg2MmDependencyLib.c
> @@ -0,0 +1,48 @@
> +/** @file
> + Runtime DXE part corresponding to StandaloneMM Tcg2 module.
> +
> +This module installs gTcg2MmSwSmiRegisteredGuid to notify readiness of
> +StandaloneMM Tcg2 module.
> +
> +Copyright (c) 2019 - 2021, Arm Ltd. All rights reserved.
> +Copyright (c) Microsoft Corporation.
> +
> +SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#include <PiDxe.h>
> +
> +#include <Library/DebugLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +
> +/**
> + The constructor function installs gTcg2MmSwSmiRegisteredGuid to notify
> + readiness of StandaloneMM Tcg2 module.
> +
> + @param ImageHandle The firmware allocated handle for the EFI image.
> + @param SystemTable A pointer to the Management mode System Table.
> +
> + @retval EFI_SUCCESS The constructor always returns EFI_SUCCESS.
> +
> +**/
> +EFI_STATUS
> +EFIAPI
> +Tcg2MmDependencyLibConstructor (
> + IN EFI_HANDLE ImageHandle,
> + IN EFI_SYSTEM_TABLE *SystemTable
> + )
> +{
> + EFI_STATUS Status;
> + EFI_HANDLE Handle;
> +
> + Handle = NULL;
> + Status = gBS->InstallProtocolInterface (
> + &Handle,
> + &gTcg2MmSwSmiRegisteredGuid,
> + EFI_NATIVE_INTERFACE,
> + NULL
> + );
> + ASSERT_EFI_ERROR (Status);
> + return EFI_SUCCESS;
> +}
> diff --git a/SecurityPkg/Tcg/Tcg2Smm/Tcg2StandaloneMm.c
> b/SecurityPkg/Tcg/Tcg2Smm/Tcg2StandaloneMm.c
> new file mode 100644
> index 000000000000..9e0095efbc5e
> --- /dev/null
> +++ b/SecurityPkg/Tcg/Tcg2Smm/Tcg2StandaloneMm.c
> @@ -0,0 +1,71 @@
> +/** @file
> + TCG2 Standalone MM 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. 
> +Copyright (c) Microsoft Corporation.
> +SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#include "Tcg2Smm.h"
> +#include <Library/StandaloneMmMemLib.h>
> +
> +/**
> + Notify the system that the SMM variable driver is ready.
> +**/
> +VOID
> +Tcg2NotifyMmReady (
> + VOID
> + )
> +{
> + // Do nothing
> +}
> +
> +/**
> + 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 MmIsBufferOutsideMmValid (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
> +InitializeTcgStandaloneMm (
> + IN EFI_HANDLE ImageHandle,
> + IN EFI_MM_SYSTEM_TABLE *SystemTable
> + )
> +{
> + return InitializeTcgCommon ();
> +}
> diff --git
> a/SecurityPkg/Library/Tcg2MmDependencyLib/Tcg2MmDependencyLib.inf
> b/SecurityPkg/Library/Tcg2MmDependencyLib/Tcg2MmDependencyLib.inf
> new file mode 100644
> index 000000000000..5533ce2b6e6e
> --- /dev/null
> +++ b/SecurityPkg/Library/Tcg2MmDependencyLib/Tcg2MmDependencyLib.inf
> @@ -0,0 +1,39 @@
> +## @file
> +# Runtime DXE part corresponding to StandaloneMM Tcg2 module.
> +#
> +# This module installs gTcg2MmSwSmiRegisteredGuid to notify readiness of
> +# StandaloneMM Tcg2 module.
> +#
> +# Copyright (c) Microsoft Corporation.
> +# SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> + INF_VERSION = 0x0001001A
> + BASE_NAME = Tcg2MmDependencyLib
> + FILE_GUID = 94C210EA-3113-4563-ADEB-76FE759C2F46
> + MODULE_TYPE = DXE_DRIVER
> + LIBRARY_CLASS = NULL
> + CONSTRUCTOR = Tcg2MmDependencyLibConstructor
> +
> +#
> +# The following information is for reference only and not required by the build
> tools.
> +#
> +# VALID_ARCHITECTURES = IA32 X64
> +#
> +#
> +
> +[Sources]
> + Tcg2MmDependencyLib.c
> +
> +[Packages]
> + MdePkg/MdePkg.dec
> + MdeModulePkg/MdeModulePkg.dec
> + SecurityPkg/SecurityPkg.dec
> +
> +[Guids]
> + gTcg2MmSwSmiRegisteredGuid ## PRODUCES ## GUID # Install
> protocol
> +
> +[Depex]
> + TRUE
> diff --git a/SecurityPkg/SecurityPkg.ci.yaml b/SecurityPkg/SecurityPkg.ci.yaml
> index 03be2e94ca97..d7b9e1f4e239 100644
> --- a/SecurityPkg/SecurityPkg.ci.yaml
> +++ b/SecurityPkg/SecurityPkg.ci.yaml
> @@ -31,6 +31,7 @@
> "MdePkg/MdePkg.dec",
> "MdeModulePkg/MdeModulePkg.dec",
> "SecurityPkg/SecurityPkg.dec",
> + "StandaloneMmPkg/StandaloneMmPkg.dec",
> "CryptoPkg/CryptoPkg.dec"
> ],
> # For host based unit tests
> diff --git a/SecurityPkg/SecurityPkg.dec b/SecurityPkg/SecurityPkg.dec
> index 0970cae5c75e..dfbbb0365a2b 100644
> --- a/SecurityPkg/SecurityPkg.dec
> +++ b/SecurityPkg/SecurityPkg.dec
> @@ -383,6 +383,7 @@ [PcdsFixedAtBuild, PcdsPatchableInModule,
> PcdsDynamic, PcdsDynamicEx]
> gEfiSecurityPkgTokenSpaceGuid.PcdTpmScrtmPolicy|1|UINT8|0x0001000E
>
> ## Guid name to identify TPM instance. 
> + # NOTE: This Pcd must be FixedAtBuild if Standalone MM is used
> # TPM_DEVICE_INTERFACE_NONE means disable. 
> # TPM_DEVICE_INTERFACE_TPM12 means TPM 1.2 DTPM. 
> # TPM_DEVICE_INTERFACE_DTPM2 means TPM 2.0 DTPM. 
> diff --git a/SecurityPkg/SecurityPkg.dsc b/SecurityPkg/SecurityPkg.dsc
> index 928bff72baa3..37242da93f3d 100644
> --- a/SecurityPkg/SecurityPkg.dsc
> +++ b/SecurityPkg/SecurityPkg.dsc
> @@ -166,6 +166,14 @@ [LibraryClasses.common.DXE_SMM_DRIVER]
>
> Tcg2PhysicalPresenceLib|SecurityPkg/Library/SmmTcg2PhysicalPresenceLib/Sm
> mTcg2PhysicalPresenceLib.inf
> SmmIoLib|MdePkg/Library/SmmIoLib/SmmIoLib.inf
>
> +[LibraryClasses.common.MM_STANDALONE]
> +
> StandaloneMmDriverEntryPoint|MdePkg/Library/StandaloneMmDriverEntryPoin
> t/StandaloneMmDriverEntryPoint.inf
> +
> MmServicesTableLib|MdePkg/Library/StandaloneMmServicesTableLib/Standalo
> neMmServicesTableLib.inf
> +
> Tcg2PhysicalPresenceLib|SecurityPkg/Library/SmmTcg2PhysicalPresenceLib/Sta
> ndaloneMmTcg2PhysicalPresenceLib.inf
> +
> MemLib|StandaloneMmPkg/Library/StandaloneMmMemLib/StandaloneMmMe
> mLib.inf
> +
> HobLib|StandaloneMmPkg/Library/StandaloneMmHobLib/StandaloneMmHobLi
> b.inf
> +
> MemoryAllocationLib|StandaloneMmPkg/Library/StandaloneMmMemoryAlloca
> tionLib/StandaloneMmMemoryAllocationLib.inf
> +
> [PcdsDynamicDefault.common.DEFAULT]
> gEfiSecurityPkgTokenSpaceGuid.PcdTpmInstanceGuid|{0xb6, 0xe5, 0x01, 0x8b,
> 0x19, 0x4f, 0xe8, 0x46, 0xab, 0x93, 0x1c, 0x53, 0x67, 0x1b, 0x90, 0xcc}
> gEfiSecurityPkgTokenSpaceGuid.PcdTpm2InitializationPolicy|1
> @@ -183,6 +191,7 @@ [PcdsDynamicHii.common.DEFAULT]
> [Components]
> SecurityPkg/Library/DxeImageVerificationLib/DxeImageVerificationLib.inf
>
> SecurityPkg/Library/DxeImageAuthenticationStatusLib/DxeImageAuthentication
> StatusLib.inf
> + SecurityPkg/Library/Tcg2MmDependencyLib/Tcg2MmDependencyLib.inf
>
> #
> # TPM
> @@ -317,6 +326,7 @@ [Components.IA32, Components.X64]
> SecurityPkg/Tcg/MemoryOverwriteRequestControlLock/TcgMorLockSmm.inf
> SecurityPkg/Tcg/TcgSmm/TcgSmm.inf
> SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.inf
> + SecurityPkg/Tcg/Tcg2Smm/Tcg2StandaloneMm.inf
> SecurityPkg/Tcg/Tcg2Acpi/Tcg2Acpi.inf
>
> SecurityPkg/Library/SmmTcg2PhysicalPresenceLib/SmmTcg2PhysicalPresenceLib
> .inf
>
> SecurityPkg/Library/SmmTcg2PhysicalPresenceLib/StandaloneMmTcg2PhysicalP
> resenceLib.inf
> diff --git a/SecurityPkg/Tcg/Tcg2Smm/Tcg2StandaloneMm.inf
> b/SecurityPkg/Tcg/Tcg2Smm/Tcg2StandaloneMm.inf
> new file mode 100644
> index 000000000000..746eda3e9fed
> --- /dev/null
> +++ b/SecurityPkg/Tcg/Tcg2Smm/Tcg2StandaloneMm.inf
> @@ -0,0 +1,77 @@
> +## @file
> +# Provides ACPI methods for TPM 2.0 support
> +#
> +# Spec Compliance Info:
> +# "TCG ACPI Specification Version 1.2 Revision 8"
> +# "Physical Presence Interface Specification Version 1.30 Revision 00.52"
> +# along with
> +# "Errata Version 0.4 for TCG PC Client Platform Physical Presence Interface
> Specification"
> +# "Platform Reset Attack Mitigation Specification Version 1.00"
> +# TPM2.0 ACPI device object
> +# "TCG PC Client Platform Firmware Profile Specification for TPM Family 2.0
> Level 00 Revision 1.03 v51"
> +# along with
> +# "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.
> +#
> +# 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.
> +#
> +# Copyright (c) 2015 - 2019, Intel Corporation. All rights reserved. 
> +# Copyright (c) Microsoft Corporation. 
> +# SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> + INF_VERSION = 0x00010005
> + BASE_NAME = Tcg2StandaloneMm
> + FILE_GUID = D40F321F-5349-4724-B667-131670587861
> + MODULE_TYPE = MM_STANDALONE
> + PI_SPECIFICATION_VERSION = 0x00010032
> + VERSION_STRING = 1.0
> + ENTRY_POINT = InitializeTcgStandaloneMm
> +
> +[Sources]
> + Tcg2Smm.h
> + Tcg2Smm.c
> + Tcg2StandaloneMm.c
> +
> +[Packages]
> + MdePkg/MdePkg.dec
> + MdeModulePkg/MdeModulePkg.dec
> + SecurityPkg/SecurityPkg.dec
> + StandaloneMmPkg/StandaloneMmPkg.dec
> +
> +[LibraryClasses]
> + BaseLib
> + BaseMemoryLib
> + StandaloneMmDriverEntryPoint
> + MmServicesTableLib
> + DebugLib
> + Tcg2PhysicalPresenceLib
> + PcdLib
> + MemLib
> +
> +[Guids]
> + ## SOMETIMES_PRODUCES ## Variable:L"MemoryOverwriteRequestControl"
> + ## SOMETIMES_CONSUMES ## Variable:L"MemoryOverwriteRequestControl"
> + gEfiMemoryOverwriteControlDataGuid
> +
> + gEfiTpmDeviceInstanceTpm20DtpmGuid ## PRODUCES ##
> GUID # TPM device identifier
> + gTpmNvsMmGuid ## CONSUMES
> +
> +[Protocols]
> + gEfiSmmSwDispatch2ProtocolGuid ## CONSUMES
> + gEfiSmmVariableProtocolGuid ## CONSUMES
> + gEfiMmReadyToLockProtocolGuid ## CONSUMES
> +
> +[Pcd]
> + gEfiSecurityPkgTokenSpaceGuid.PcdTpmInstanceGuid ## CONSUMES
> +
> +[Depex]
> + gEfiSmmSwDispatch2ProtocolGuid AND
> + gEfiSmmVariableProtocolGuid
> --
> 2.30.0.windows.1