Re: [PATCH 0/6] implement standalone MM versions of the variable runtime drivers

["Gao, Liming" <liming.gao@intel.com>]

Ard:
  I agree this design is good. But, I need some time to evaluate its impact on our X86 platform. Could you wait for several days?

Thanks
Liming
> -----Original Message-----
> From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org]
> Sent: Friday, January 4, 2019 2:28 AM
> To: edk2-devel@lists.01.org
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>; Laszlo Ersek <lersek@redhat.com>; Leif Lindholm <leif.lindholm@linaro.org>; Kinney,
> Michael D <michael.d.kinney@intel.com>; Gao, Liming <liming.gao@intel.com>; Wang, Jian J <jian.j.wang@intel.com>; Wu, Hao A
> <hao.a.wu@intel.com>; Jagadeesh Ujja <jagadeesh.ujja@arm.com>; Achin Gupta <Achin.Gupta@arm.com>; Thomas Panakamattam
> Abraham <thomas.abraham@arm.com>; Sami Mujawar <Sami.Mujawar@arm.com>
> Subject: [PATCH 0/6] implement standalone MM versions of the variable runtime drivers
> 
> This series proposed an alternative approach to the series sent out by
> Jagadeesh [0]. In particular, it gets rid of the InMm() calls and the
> special PCD, as well as some other if() conditionals.
> 
> The primary difference is that this series defines and implements
> MmServicesTableLib in such a way that the traditional SMM drivers
> can use it as well. This is appropriate, considering that the PI
> spec has rebranded traditional SMM as one implementation of the generic
> MM framework.
> 
> Patch #1 is based on Jagadeesh's patch, and introduces the MmServicesTableLib
> library class, but for all SMM flavours, not only for standalone MM.
> 
> Patch #2 implements MmServicesTableLib for traditional SMM implementations.
> 
> Patch #3 refactors FaultTolerantWriteDxe so that the parts of the SMM
> driver that invoke boot services are separated from the core SMM pieces.
> 
> Patch #4 implements FaultTolerantWriteSmm for the standalone MM environment.
> 
> Patches #5 and #6 do the same, respectively, for the variable runtime driver.
> 
> This approach minimizes the delta, and thus the maintenance burden, between
> the traditional SMM and standalone MM drivers, while not resorting to runtime
> checks or other conditionals in the code to implement logic that should be
> decided at build time.
> 
> Note that this series only covers part of the work contributed by Jagadeesh.
> This series focuses on the MdePkg and MdeModulePkg changes that affect shared
> code.
> 
> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Leif Lindholm <leif.lindholm@linaro.org>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Hao Wu <hao.a.wu@intel.com>
> Cc: Jagadeesh Ujja <jagadeesh.ujja@arm.com>
> Cc: Achin Gupta <Achin.Gupta@arm.com>
> Cc: Thomas Panakamattam Abraham <thomas.abraham@arm.com>
> Cc: Sami Mujawar <Sami.Mujawar@arm.com>
> 
> Ard Biesheuvel (5):
>   MdePkg: implement MmServicesTableLib based on traditional SMM
>   MdeModulePkg/FaultTolerantWriteDxe: factor out boot service accesses
>   MdeModulePkg/FaultTolerantWriteDxe: implement standalone MM version
>   MdeModulePkg/VariableRuntimeDxe: factor out boot service accesses
>   MdeModulePkg/VariableRuntimeDxe: implement standalone MM version
> 
> Jagadeesh Ujja (1):
>   MdePkg/Include: add MmServicesTableLib header file
> 
>  MdeModulePkg/MdeModulePkg.dsc                 |   1 +
>  .../FaultTolerantWrite.h                      |  22 ++-
>  .../FaultTolerantWriteDxe.c                   |  31 ++++
>  .../FaultTolerantWriteSmm.c                   |  54 +++----
>  .../FaultTolerantWriteSmm.inf                 |   5 +-
>  .../FaultTolerantWriteSmmCommon.h             |  31 ++++
>  .../FaultTolerantWriteSmmDxe.c                |   1 +
>  .../FaultTolerantWriteStandaloneMm.c          |  70 +++++++++
>  .../FaultTolerantWriteStandaloneMm.inf        |  90 ++++++++++++
>  .../FaultTolerantWriteTraditionalMm.c         |  94 ++++++++++++
>  .../UpdateWorkingBlock.c                      |  10 +-
>  .../Variable/RuntimeDxe/TcgMorLockSmm.c       |  18 +--
>  .../Universal/Variable/RuntimeDxe/Variable.h  |  50 +++++++
>  .../Variable/RuntimeDxe/VariableSmm.c         |  59 +++-----
>  .../Variable/RuntimeDxe/VariableSmm.inf       |   5 +-
>  .../RuntimeDxe/VariableStandaloneMm.c         |  69 +++++++++
>  .../RuntimeDxe/VariableStandaloneMm.inf       | 135 ++++++++++++++++++
>  .../RuntimeDxe/VariableTraditionalMm.c        | 114 +++++++++++++++
>  MdePkg/Include/Library/MmServicesTableLib.h   |  25 ++++
>  .../MmServicesTableLib/MmServicesTableLib.c   |  63 ++++++++
>  .../MmServicesTableLib/MmServicesTableLib.inf |  45 ++++++
>  .../MmServicesTableLib/MmServicesTableLib.uni |  22 +++
>  MdePkg/MdePkg.dec                             |   4 +
>  MdePkg/MdePkg.dsc                             |   1 +
>  24 files changed, 916 insertions(+), 103 deletions(-)
>  create mode 100644 MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteStandaloneMm.c
>  create mode 100644 MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteStandaloneMm.inf
>  create mode 100644 MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteTraditionalMm.c
>  create mode 100644 MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.c
>  create mode 100644 MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf
>  create mode 100644 MdeModulePkg/Universal/Variable/RuntimeDxe/VariableTraditionalMm.c
>  create mode 100644 MdePkg/Include/Library/MmServicesTableLib.h
>  create mode 100644 MdePkg/Library/MmServicesTableLib/MmServicesTableLib.c
>  create mode 100644 MdePkg/Library/MmServicesTableLib/MmServicesTableLib.inf
>  create mode 100644 MdePkg/Library/MmServicesTableLib/MmServicesTableLib.uni
> 
> --
> 2.17.1