Re: [PATCH v3] StandaloneMmPkg/Library: Install Variable Arch Protocol

[Jagadeesh Ujja <jagadeesh.ujja@arm.com>]

On Tue, Mar 5, 2019 at 7:39 PM Jagadeesh Ujja <jagadeesh.ujja@arm.com> wrote:
>
Adding Achin, Jiewen
> hi Jiewen, Achin
>
> On Mon, Mar 4, 2019 at 4:16 PM Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
> >
> > (add StandaloneMmPkg maintainers)
> >
> Please let me know if you have any comments on this patch
>
> > On Mon, 4 Mar 2019 at 09:54, Jagadeesh Ujja <jagadeesh.ujja@arm.com> wrote:
> > >
> > > In a system implementing the variable store in MM, there are no variable
> > > arch protocol and variable write arch protocol installed into the
> > > DXE_SMM protocol database. On such systems, it is not required to
> > > locate these protocols by the DXE runtime variable drivers because
> > > it can be assumed that these protocols are already installed in the
> > > MM context. But then such an implementation will deviate from the
> > > existing traditional MM based variable driver implementation.
> > >
> > > So in order to maintain consistency with the traditional MM variable
> > > driver implementation, allow platforms to install these protocols into
> > > the DXE protocol database but these protocol will not be consumed
> > > by non-secure variable service runtime driver.
> > >
> > > The Platform which uses StandaloneMM based secure variable storage
> > > have to include this library
> > >
> > > Example
> > > In edk2-platforms/Platform/ARM/SgiPkg/SgiPlatform.dsc
> > >
> > >   ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.inf {
> > >     <LibraryClasses>
> > >       NULL|StandaloneMmPkg/Library/VariableMmDependency/VariableMmDependency.inf
> > >   }
> > >
> > > Contributed-under: TianoCore Contribution Agreement 1.1
> > > Signed-off-by: Jagadeesh Ujja <jagadeesh.ujja@arm.com>
> >
> > Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >
> > > ---
> > > Changes since v2:
> > > - Addressed the comments from Ard Biesheuvel and Zeng Star
> > >
> > > Changes since v1:
> > > - This is a next version of patch
> > >    “MdeModulePkg/VariableSmmRuntimeDxe: Refactor locating Variable Arch Protocol”.
> > >    [https://lists.01.org/pipermail/edk2-devel/2019-February/036885.html]
> > > - Addressed the comments from Ard Biesheuvel and Zeng Star
> > > - Can this library be placed in MdePkg rather then the StandaloneMmPkg?
> > >
> > >  StandaloneMmPkg/Library/VariableMmDependency/VariableMmDependency.c   | 54 ++++++++++++++++++++
> > >  StandaloneMmPkg/Library/VariableMmDependency/VariableMmDependency.inf | 46 +++++++++++++++++
> > >  2 files changed, 100 insertions(+)
> > >
> > > diff --git a/StandaloneMmPkg/Library/VariableMmDependency/VariableMmDependency.c b/StandaloneMmPkg/Library/VariableMmDependency/VariableMmDependency.c
> > > new file mode 100644
> > > index 0000000..7e0f31b
> > > --- /dev/null
> > > +++ b/StandaloneMmPkg/Library/VariableMmDependency/VariableMmDependency.c
> > > @@ -0,0 +1,54 @@
> > > +/** @file
> > > +  Runtime DXE part corresponding to StanaloneMM variable module.
> > > +
> > > +This module installs variable arch protocol and variable write arch protocol
> > > +to StandaloneMM runtime variable service.
> > > +
> > > +Copyright (c) 2019, ARM Ltd. All rights reserved.
> > > +
> > > +This program and the accompanying materials
> > > +are licensed and made available under the terms and conditions of the BSD License
> > > +which accompanies this distribution.  The full text of the license may be found at
> > > +http://opensource.org/licenses/bsd-license.php.
> > > +
> > > +THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
> > > +WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
> > > +
> > > +**/
> > > +
> > > +#include <Library/DebugLib.h>
> > > +#include <Library/UefiBootServicesTableLib.h>
> > > +
> > > +/**
> > > +  The constructor function installs variable arch protocol and variable
> > > +  write arch protocol to StandaloneMM runtime variable service
> > > +
> > > +  @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
> > > +VariableMmDependencyLibConstructor (
> > > +  IN EFI_HANDLE                           ImageHandle,
> > > +  IN EFI_SYSTEM_TABLE                     *SystemTable
> > > +  )
> > > +{
> > > +  EFI_STATUS            Status;
> > > +  EFI_HANDLE            Handle;
> > > +
> > > +  Handle = NULL;
> > > +  Status = gBS->InstallMultipleProtocolInterfaces (
> > > +                  &Handle,
> > > +                  &gEfiSmmVariableProtocolGuid,
> > > +                  NULL,
> > > +                  &gSmmVariableWriteGuid,
> > > +                  NULL,
> > > +                  NULL
> > > +                  );
> > > +  ASSERT_EFI_ERROR (Status);
> > > +  return EFI_SUCCESS;
> > > +}
> > > +
> > > diff --git a/StandaloneMmPkg/Library/VariableMmDependency/VariableMmDependency.inf b/StandaloneMmPkg/Library/VariableMmDependency/VariableMmDependency.inf
> > > new file mode 100644
> > > index 0000000..e71c44d
> > > --- /dev/null
> > > +++ b/StandaloneMmPkg/Library/VariableMmDependency/VariableMmDependency.inf
> > > @@ -0,0 +1,46 @@
> > > +## @file
> > > +#  Runtime DXE part corresponding to StanaloneMM variable module.
> > > +#
> > > +#  This module installs variable arch protocol and variable write arch protocol
> > > +#  to StandaloneMM runtime variable service.
> > > +#
> > > +# Copyright (c) 2019, ARM Ltd. All rights reserved.
> > > +# This program and the accompanying materials
> > > +# are licensed and made available under the terms and conditions of the BSD License
> > > +# which accompanies this distribution. The full text of the license may be found at
> > > +# http://opensource.org/licenses/bsd-license.php
> > > +# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
> > > +# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
> > > +#
> > > +##
> > > +
> > > +[Defines]
> > > +  INF_VERSION                    = 0x0001001A
> > > +  BASE_NAME                      = VariableMmDependency
> > > +  FILE_GUID                      = 64BC4129-778E-4867-BA07-13999A4DEC3F
> > > +  MODULE_TYPE                    = DXE_DRIVER
> > > +  LIBRARY_CLASS                  = NULL
> > > +  CONSTRUCTOR                    = VariableMmDependencyLibConstructor
> > > +
> > > +#
> > > +# The following information is for reference only and not required by the build tools.
> > > +#
> > > +#  VALID_ARCHITECTURES           = AARCH64
> > > +#
> > > +#
> > > +
> > > +[Sources]
> > > +  VariableMmDependency.c
> > > +
> > > +[Packages]
> > > +  MdePkg/MdePkg.dec
> > > +  MdeModulePkg/MdeModulePkg.dec
> > > +
> > > +[Protocols]
> > > +  gEfiSmmVariableProtocolGuid        ## PRODUCES
> > > +
> > > +[Guids]
> > > +  gSmmVariableWriteGuid              ## PRODUCES             ## GUID # Install protocol
> > > +
> > > +[Depex]
> > > +  TRUE
> > > --
> > > 2.7.4
> > >
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