Re: [edk2-devel] [Patch V2 0/3] Move gMpInformationHobGuid from StandaloneMmPkg to UefiCpuPkg.

["duntan" <dun.tan@intel.com>]

Hi Ard, 

I'm working on moving gMpInformationHobGuid from StandaloneMmPkg to UefiCpuPkg in this patch series. Currently in Edk2, the HOB is only consumed by StandaloneMmCpu.inf.

As we know that this HOB is used to provide a lightweight static information of MP processor. However, there might be a concern that the maximum HOB size 64KB is not large enough when CPU number is 1~2000 or bigger.

May I know if you considered this situation or is there any solution to avoid this issue on Arm?

Thanks, 
Dun

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of duntan
Sent: Friday, November 17, 2023 5:40 PM
To: devel@edk2.groups.io
Subject: [edk2-devel] [Patch V2 0/3] Move gMpInformationHobGuid from StandaloneMmPkg to UefiCpuPkg.

In the V2 patch set: Added more comments in the new MpInformation.h to document that some fields in this HOB may be invalidated.

Move gMpInformationHobGuid from StandaloneMmPkg to UefiCpuPkg.

Previously, the HOB is defined, created and consumed only in StandaloneMmPkg. The HOB contains the number of processors and EFI_PROCESSOR_INFORMATION structure. This is the same as the information that PiSmmCpuDxeSmm uses EfiMpServiceProtocolGuid to get.

The incoming plan is to create gMpInformationHobGuid for both StandaloneMm and legacy DXE_SMM in early phase(for example in CpuMpPei). Then PiSmmCpuDxeSmm can consume the hob, which can simplify code logic in PiSmmCpuDxeSmm driver.

So move this HOB definition to UefiCpuPkg in this patch series.

Dun Tan (3):
  UefiCpuPkg: Create MpInformation.h in UefiCpuPkg
  StandaloneMmPkg:Add UefiCpuPkg.dec in DependencyCheck
  StandaloneMmPkg:Remove MpInformation.h

 StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.inf                       | 1 +
 StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/StandaloneMmCoreEntryPoint.inf | 1 +
 StandaloneMmPkg/StandaloneMmPkg.ci.yaml                                           | 3 ++-
 StandaloneMmPkg/StandaloneMmPkg.dec                                               | 1 -
 {StandaloneMmPkg => UefiCpuPkg}/Include/Guid/MpInformation.h                      | 6 +++++-
 UefiCpuPkg/UefiCpuPkg.dec                                                         | 3 +++
 6 files changed, 12 insertions(+), 3 deletions(-)  rename {StandaloneMmPkg => UefiCpuPkg}/Include/Guid/MpInformation.h (71%)

--
2.31.1.windows.1








-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#111352): https://edk2.groups.io/g/devel/message/111352
Mute This Topic: https://groups.io/mt/102644629/7686176
Group Owner: devel+owner@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io]
-=-=-=-=-=-=-=-=-=-=-=-