Re: [edk2-devel] [PATCH v4 0/8] Add Variable Flash Info HOB

["Michael Kubacki" <mikuback@linux.microsoft.com>]

A friendly reminder to those on the CC line to help review your 
respective packages in this patch series.

Some of the patches are just minor changes to DSC files and others do 
not have a significant number of changes.

Thanks,
Michael

On 4/12/2022 12:29 PM, Michael Kubacki wrote:
> From: Michael Kubacki <michael.kubacki@microsoft.com>
> 
> REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3479
> 
> The UEFI variable drivers such as VariableRuntimeDxe, VariableSmm,
> VariableStandaloneMm, etc. (and their dependent protocol/library
> stack), typically acquire UEFI variable store flash information
> with PCDs declared in MdeModulePkg.
> 
> For example:
> [Pcd]
>    gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase
>    gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase64
>    gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableSize
> 
> These PCDs work as-is in the StandaloneMm driver if they are not
> dynamic such as Dynamic or DynamicEx because PCD services are not
> readily available in the Standalone MM environment. Platforms that
> use Standalone MM today, must define these PCDs as FixedAtBuild in
> their platform build. However, the PCDs do allow platforms to treat
> the PCDs as Dynamic/DynamicEx and being able to support that is
> currently a gap for Standalone MM.
> 
> This patch series introduces a HOB that can be produced by the
> platform to provide the same information. The HOB list is
> available to Standalone MM.
> 
> The PCD declarations are left as-is in MdeModulePkg for backward
> compatibility. This means unless a platform wants to use the HOB,
> their code will continue to work with no change (they do not need
> to produce the HOB). Only if the HOB is found, is its value used
> instead of the PCDs.
> 
> Due to the large number of consumers of this information, access
> to the base address and size values is abstracted in a new library
> class (as requested in the v1 series) called VariableFlashInfoLib.
> 
> The API of VariableFlashInfoLib does not bind the underlying data
> structure to the information returned to library users to allow
> flexibility in the library implementation in the future.
> 
> V4 changes:
> 1. Add a UINT32 "Reserved" field to VARIABLE_FLASH_INFO.
> 2. Add a descriptive comment to VariableFlashInfo.h to explain
>     HOB usage.
> 
> V3 changes:
> 1. To better clarify usage, renamed the members
>     "NvStorageBaseAddress" and "NvStorageLength" in
>     "VARIABLE_FLASH_INFO" to "NvVariableBaseAddress" and
>     "NvVariableLength".
> 2. Added description comments to the fields in "VARIABLE_FLASH_INFO".
> 
> V2 changes:
> 1. Abstracted flash info data access with VariableFlashInfoLib.
> 2. Updated package builds in the repo that build the variable and
>     FTW drivers to include VariableFlashInfoLib.
> 3. Removed a redundant variable assignment in VariableSmm.c.
> 4. Updated comments in FtwMisc.c and FaultTolerantWritePei.c to
>     indicate driver assumption is UINTN (not UINT32)
> 5. Added a version field to the VARIABLE_FLASH_INFO structure.
> 
> Cc: Abner Chang <abner.chang@hpe.com>
> Cc: Andrew Fish <afish@apple.com>
> Cc: Anthony Perard <anthony.perard@citrix.com>
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Benjamin You <benjamin.you@intel.com>
> Cc: Brijesh Singh <brijesh.singh@amd.com>
> Cc: Erdem Aktas <erdemaktas@google.com>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: Guo Dong <guo.dong@intel.com>
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Julien Grall <julien@xen.org>
> Cc: Leif Lindholm <quic_llindhol@quicinc.com>
> Cc: Liming Gao <gaoliming@byosoft.com.cn>
> Cc: Maurice Ma <maurice.ma@intel.com>
> Cc: Min Xu <min.m.xu@intel.com>
> Cc: Nickle Wang <nickle.wang@hpe.com>
> Cc: Peter Grehan <grehan@freebsd.org>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Rebecca Cran <rebecca@bsdio.com>
> Cc: Sami Mujawar <sami.mujawar@arm.com>
> Cc: Sean Rhodes <sean@starlabs.systems>
> Cc: Sebastien Boeuf <sebastien.boeuf@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
> 
> Michael Kubacki (8):
>    MdeModulePkg: Add Variable Flash Info HOB
>    MdeModulePkg/VariableFlashInfoLib: Add initial library
>    MdeModulePkg/Variable: Consume Variable Flash Info
>    MdeModulePkg/FaultTolerantWrite: Consume Variable Flash Info
>    ArmVirtPkg/ArmVirt.dsc.inc: Add VariableFlashInfoLib
>    EmulatorPkg: Add VariableFlashInfoLib
>    OvmfPkg: Add VariableFlashInfoLib
>    UefiPayloadPkg: Add VariableFlashInfoLib
> 
>   MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.c        | 178 ++++++++++++++++++++
>   MdeModulePkg/Universal/FaultTolerantWriteDxe/FtwMisc.c                          |  41 +++--
>   MdeModulePkg/Universal/FaultTolerantWriteDxe/UpdateWorkingBlock.c               |   7 +-
>   MdeModulePkg/Universal/FaultTolerantWritePei/FaultTolerantWritePei.c            |  28 +--
>   MdeModulePkg/Universal/Variable/Pei/Variable.c                                  |  14 +-
>   MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c                        |  16 +-
>   MdeModulePkg/Universal/Variable/RuntimeDxe/VariableNonVolatile.c                |  14 +-
>   MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.c                        |  17 +-
>   ArmVirtPkg/ArmVirt.dsc.inc                                                      |   1 +
>   EmulatorPkg/EmulatorPkg.dsc                                                     |   1 +
>   MdeModulePkg/Include/Guid/VariableFlashInfo.h                                   | 111 ++++++++++++
>   MdeModulePkg/Include/Library/VariableFlashInfoLib.h                             |  68 ++++++++
>   MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf      |  48 ++++++
>   MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.uni      |  12 ++
>   MdeModulePkg/MdeModulePkg.dec                                                   |   8 +
>   MdeModulePkg/MdeModulePkg.dsc                                                   |   2 +
>   MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWrite.h               |   7 +-
>   MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.inf          |  10 +-
>   MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.inf          |  10 +-
>   MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteStandaloneMm.inf |  10 +-
>   MdeModulePkg/Universal/FaultTolerantWritePei/FaultTolerantWritePei.inf          |  10 +-
>   MdeModulePkg/Universal/Variable/Pei/Variable.h                                  |   2 +
>   MdeModulePkg/Universal/Variable/Pei/VariablePei.inf                             |   5 +-
>   MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.h                           |   7 +-
>   MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf               |   5 +-
>   MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf                      |   5 +-
>   MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf             |   5 +-
>   OvmfPkg/AmdSev/AmdSevX64.dsc                                                    |   1 +
>   OvmfPkg/Bhyve/BhyveX64.dsc                                                      |   1 +
>   OvmfPkg/CloudHv/CloudHvX64.dsc                                                  |   1 +
>   OvmfPkg/IntelTdx/IntelTdxX64.dsc                                                |   1 +
>   OvmfPkg/Microvm/MicrovmX64.dsc                                                  |   1 +
>   OvmfPkg/OvmfPkgIa32.dsc                                                         |   1 +
>   OvmfPkg/OvmfPkgIa32X64.dsc                                                      |   1 +
>   OvmfPkg/OvmfPkgX64.dsc                                                          |   1 +
>   OvmfPkg/OvmfXen.dsc                                                             |   1 +
>   UefiPayloadPkg/UefiPayloadPkg.dsc                                               |   1 +
>   37 files changed, 558 insertions(+), 94 deletions(-)
>   create mode 100644 MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.c
>   create mode 100644 MdeModulePkg/Include/Guid/VariableFlashInfo.h
>   create mode 100644 MdeModulePkg/Include/Library/VariableFlashInfoLib.h
>   create mode 100644 MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf
>   create mode 100644 MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.uni
>