Re: [edk2-devel] [PATCH v1 1/1] StandaloneMmPkg/StandaloneMmHobLib: Remove HOB creation

["Oliver Smith-Denny" <osde@linux.microsoft.com>]

Hi folks, returning to this thread because I noticed that HOB
creation still exists in StandaloneMmCore for ARM:

https://github.com/tianocore/edk2/blob/5d4c5253e8bbc0baa8837fcd868925212df85201/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/Arm/CreateHobList.c

As far as I can tell, there is only this one file that creates 6
HOBs from StandaloneMmCore. Per our earlier discussion that led to
disabling HOB creation in StandaloneMm, I think that this falls into
the case where StandaloneMm is a HOB consumer phase, not a producer
phase and so it should not be creating these HOBs. On the x64 side,
all of the StandaloneMm HOB creation functions ASSERT with the
comment that StandaloneMm is a HOB consumer phase and should not
be creating HOBs.

On ARM this is more complicated, as all of this information would
seem to originate from TF-A and so we would need TF-A to produce
these HOBs to tell StandaloneMm the information it needs to
operate. Today TF-A already has to communicate this information, the
HOBs are just created in StandaloneMmCore instead of in TF-A.

Curious to get other folks thoughts here on this paradigm.

Thanks,
Oliver

On 12/5/2023 5:47 AM, Nhi Pham wrote:
> According to the discussion in "StandaloneMmPkg: Fix HOB space and
> heap space conflicted issue" [1], Standalone MM modules should be HOB
> consumers where HOB is read-only. Therefore, this patch removes the
> supported functions for HOB creation in the StandaloneMmHobLib.
> 
> [1] https://edk2.groups.io/g/devel/message/108333
> 
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Sami Mujawar <sami.mujawar@arm.com>
> Cc: Oliver Smith-Denny <osde@linux.microsoft.com>
> Signed-off-by: Nhi Pham <nhiphambka@gmail.com>
> ---
>   StandaloneMmPkg/Library/StandaloneMmHobLib/StandaloneMmHobLib.c | 171 ++++++--------------
>   1 file changed, 51 insertions(+), 120 deletions(-)
> 
> diff --git a/StandaloneMmPkg/Library/StandaloneMmHobLib/StandaloneMmHobLib.c b/StandaloneMmPkg/Library/StandaloneMmHobLib/StandaloneMmHobLib.c
> index ee61bdd227d0..bef66d167494 100644
> --- a/StandaloneMmPkg/Library/StandaloneMmHobLib/StandaloneMmHobLib.c
> +++ b/StandaloneMmPkg/Library/StandaloneMmHobLib/StandaloneMmHobLib.c
> @@ -1,5 +1,5 @@
>   /** @file
> 
> -  HOB Library implementation for Standalone MM Core.
> 
> +  HOB Library implementation for Standalone MM modules.
> 
>   
> 
>   Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
> 
>   Copyright (c) 2017 - 2018, ARM Limited. All rights reserved.<BR>
> 
> @@ -250,48 +250,13 @@ GetBootModeHob (
>     return HandOffHob->BootMode;
> 
>   }
> 
>   
> 
> -VOID *
> 
> -CreateHob (
> 
> -  IN  UINT16  HobType,
> 
> -  IN  UINT16  HobLength
> 
> -  )
> 
> -{
> 
> -  EFI_HOB_HANDOFF_INFO_TABLE  *HandOffHob;
> 
> -  EFI_HOB_GENERIC_HEADER      *HobEnd;
> 
> -  EFI_PHYSICAL_ADDRESS        FreeMemory;
> 
> -  VOID                        *Hob;
> 
> -
> 
> -  HandOffHob = GetHobList ();
> 
> -
> 
> -  HobLength = (UINT16)((HobLength + 0x7) & (~0x7));
> 
> -
> 
> -  FreeMemory = HandOffHob->EfiFreeMemoryTop - HandOffHob->EfiFreeMemoryBottom;
> 
> -
> 
> -  if (FreeMemory < HobLength) {
> 
> -    return NULL;
> 
> -  }
> 
> -
> 
> -  Hob                                        = (VOID *)(UINTN)HandOffHob->EfiEndOfHobList;
> 
> -  ((EFI_HOB_GENERIC_HEADER *)Hob)->HobType   = HobType;
> 
> -  ((EFI_HOB_GENERIC_HEADER *)Hob)->HobLength = HobLength;
> 
> -  ((EFI_HOB_GENERIC_HEADER *)Hob)->Reserved  = 0;
> 
> -
> 
> -  HobEnd                      = (EFI_HOB_GENERIC_HEADER *)((UINTN)Hob + HobLength);
> 
> -  HandOffHob->EfiEndOfHobList = (EFI_PHYSICAL_ADDRESS)(UINTN)HobEnd;
> 
> -
> 
> -  HobEnd->HobType   = EFI_HOB_TYPE_END_OF_HOB_LIST;
> 
> -  HobEnd->HobLength = sizeof (EFI_HOB_GENERIC_HEADER);
> 
> -  HobEnd->Reserved  = 0;
> 
> -  HobEnd++;
> 
> -  HandOffHob->EfiFreeMemoryBottom = (EFI_PHYSICAL_ADDRESS)(UINTN)HobEnd;
> 
> -
> 
> -  return Hob;
> 
> -}
> 
> -
> 
>   /**
> 
>     Builds a HOB for a loaded PE32 module.
> 
>   
> 
>     This function builds a HOB for a loaded PE32 module.
> 
> +  It can only be invoked by Standalone MM Core.
> 
> +  For Standalone MM drivers, it will ASSERT() since HOB is read only for Standalone MM drivers.
> 
> +
> 
>     If ModuleName is NULL, then ASSERT().
> 
>     If there is no additional space for HOB creation, then ASSERT().
> 
>   
> 
> @@ -310,33 +275,19 @@ BuildModuleHob (
>     IN EFI_PHYSICAL_ADDRESS  EntryPoint
> 
>     )
> 
>   {
> 
> -  EFI_HOB_MEMORY_ALLOCATION_MODULE  *Hob;
> 
> -
> 
> -  ASSERT (
> 
> -    ((MemoryAllocationModule & (EFI_PAGE_SIZE - 1)) == 0) &&
> 
> -    ((ModuleLength & (EFI_PAGE_SIZE - 1)) == 0)
> 
> -    );
> 
> -
> 
> -  Hob = CreateHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, sizeof (EFI_HOB_MEMORY_ALLOCATION_MODULE));
> 
> -
> 
> -  CopyGuid (&(Hob->MemoryAllocationHeader.Name), &gEfiHobMemoryAllocModuleGuid);
> 
> -  Hob->MemoryAllocationHeader.MemoryBaseAddress = MemoryAllocationModule;
> 
> -  Hob->MemoryAllocationHeader.MemoryLength      = ModuleLength;
> 
> -  Hob->MemoryAllocationHeader.MemoryType        = EfiBootServicesCode;
> 
> -
> 
>     //
> 
> -  // Zero the reserved space to match HOB spec
> 
> +  // HOB is read only for Standalone MM drivers
> 
>     //
> 
> -  ZeroMem (Hob->MemoryAllocationHeader.Reserved, sizeof (Hob->MemoryAllocationHeader.Reserved));
> 
> -
> 
> -  CopyGuid (&Hob->ModuleName, ModuleName);
> 
> -  Hob->EntryPoint = EntryPoint;
> 
> +  ASSERT (FALSE);
> 
>   }
> 
>   
> 
>   /**
> 
>     Builds a HOB that describes a chunk of system memory.
> 
>   
> 
>     This function builds a HOB that describes a chunk of system memory.
> 
> +  It can only be invoked by Standalone MM Core.
> 
> +  For Standalone MM drivers, it will ASSERT() since HOB is read only for Standalone MM drivers.
> 
> +
> 
>     If there is no additional space for HOB creation, then ASSERT().
> 
>   
> 
>     @param  ResourceType        The type of resource described by this HOB.
> 
> @@ -354,15 +305,10 @@ BuildResourceDescriptorHob (
>     IN UINT64                       NumberOfBytes
> 
>     )
> 
>   {
> 
> -  EFI_HOB_RESOURCE_DESCRIPTOR  *Hob;
> 
> -
> 
> -  Hob = CreateHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR, sizeof (EFI_HOB_RESOURCE_DESCRIPTOR));
> 
> -  ASSERT (Hob != NULL);
> 
> -
> 
> -  Hob->ResourceType      = ResourceType;
> 
> -  Hob->ResourceAttribute = ResourceAttribute;
> 
> -  Hob->PhysicalStart     = PhysicalStart;
> 
> -  Hob->ResourceLength    = NumberOfBytes;
> 
> +  //
> 
> +  // HOB is read only for Standalone MM drivers
> 
> +  //
> 
> +  ASSERT (FALSE);
> 
>   }
> 
>   
> 
>   /**
> 
> @@ -371,6 +317,9 @@ BuildResourceDescriptorHob (
>     This function builds a customized HOB tagged with a GUID for identification
> 
>     and returns the start address of GUID HOB data so that caller can fill the customized data.
> 
>     The HOB Header and Name field is already stripped.
> 
> +  It can only be invoked by Standalone MM Core.
> 
> +  For Standalone MM drivers, it will ASSERT() since HOB is read only for Standalone MM drivers.
> 
> +
> 
>     If Guid is NULL, then ASSERT().
> 
>     If there is no additional space for HOB creation, then ASSERT().
> 
>     If DataLength >= (0x10000 - sizeof (EFI_HOB_GUID_TYPE)), then ASSERT().
> 
> @@ -388,16 +337,11 @@ BuildGuidHob (
>     IN UINTN           DataLength
> 
>     )
> 
>   {
> 
> -  EFI_HOB_GUID_TYPE  *Hob;
> 
> -
> 
>     //
> 
> -  // Make sure that data length is not too long.
> 
> +  // HOB is read only for Standalone MM drivers
> 
>     //
> 
> -  ASSERT (DataLength <= (0xffff - sizeof (EFI_HOB_GUID_TYPE)));
> 
> -
> 
> -  Hob = CreateHob (EFI_HOB_TYPE_GUID_EXTENSION, (UINT16)(sizeof (EFI_HOB_GUID_TYPE) + DataLength));
> 
> -  CopyGuid (&Hob->Name, Guid);
> 
> -  return Hob + 1;
> 
> +  ASSERT (FALSE);
> 
> +  return NULL;
> 
>   }
> 
>   
> 
>   /**
> 
> @@ -406,6 +350,9 @@ BuildGuidHob (
>     This function builds a customized HOB tagged with a GUID for identification,
> 
>     copies the input data to the HOB data field and returns the start address of the GUID HOB data.
> 
>     The HOB Header and Name field is already stripped.
> 
> +  It can only be invoked by Standalone MM Core.
> 
> +  For Standalone MM drivers, it will ASSERT() since HOB is read only for Standalone MM drivers.
> 
> +
> 
>     If Guid is NULL, then ASSERT().
> 
>     If Data is NULL and DataLength > 0, then ASSERT().
> 
>     If there is no additional space for HOB creation, then ASSERT().
> 
> @@ -426,19 +373,20 @@ BuildGuidDataHob (
>     IN UINTN           DataLength
> 
>     )
> 
>   {
> 
> -  VOID  *HobData;
> 
> -
> 
> -  ASSERT (Data != NULL || DataLength == 0);
> 
> -
> 
> -  HobData = BuildGuidHob (Guid, DataLength);
> 
> -
> 
> -  return CopyMem (HobData, Data, DataLength);
> 
> +  //
> 
> +  // HOB is read only for Standalone MM drivers
> 
> +  //
> 
> +  ASSERT (FALSE);
> 
> +  return NULL;
> 
>   }
> 
>   
> 
>   /**
> 
>     Builds a Firmware Volume HOB.
> 
>   
> 
>     This function builds a Firmware Volume HOB.
> 
> +  It can only be invoked by Standalone MM Core.
> 
> +  For Standalone MM drivers, it will ASSERT() since HOB is read only for Standalone MM drivers.
> 
> +
> 
>     If there is no additional space for HOB creation, then ASSERT().
> 
>   
> 
>     @param  BaseAddress   The base address of the Firmware Volume.
> 
> @@ -452,18 +400,19 @@ BuildFvHob (
>     IN UINT64                Length
> 
>     )
> 
>   {
> 
> -  EFI_HOB_FIRMWARE_VOLUME  *Hob;
> 
> -
> 
> -  Hob = CreateHob (EFI_HOB_TYPE_FV, sizeof (EFI_HOB_FIRMWARE_VOLUME));
> 
> -
> 
> -  Hob->BaseAddress = BaseAddress;
> 
> -  Hob->Length      = Length;
> 
> +  //
> 
> +  // HOB is read only for Standalone MM drivers
> 
> +  //
> 
> +  ASSERT (FALSE);
> 
>   }
> 
>   
> 
>   /**
> 
>     Builds a EFI_HOB_TYPE_FV2 HOB.
> 
>   
> 
>     This function builds a EFI_HOB_TYPE_FV2 HOB.
> 
> +  It can only be invoked by Standalone MM Core.
> 
> +  For Standalone MM drivers, it will ASSERT() since HOB is read only for Standalone MM drivers.
> 
> +
> 
>     If there is no additional space for HOB creation, then ASSERT().
> 
>   
> 
>     @param  BaseAddress   The base address of the Firmware Volume.
> 
> @@ -481,20 +430,19 @@ BuildFv2Hob (
>     IN CONST    EFI_GUID              *FileName
> 
>     )
> 
>   {
> 
> -  EFI_HOB_FIRMWARE_VOLUME2  *Hob;
> 
> -
> 
> -  Hob = CreateHob (EFI_HOB_TYPE_FV2, sizeof (EFI_HOB_FIRMWARE_VOLUME2));
> 
> -
> 
> -  Hob->BaseAddress = BaseAddress;
> 
> -  Hob->Length      = Length;
> 
> -  CopyGuid (&Hob->FvName, FvName);
> 
> -  CopyGuid (&Hob->FileName, FileName);
> 
> +  //
> 
> +  // HOB is read only for Standalone MM drivers
> 
> +  //
> 
> +  ASSERT (FALSE);
> 
>   }
> 
>   
> 
>   /**
> 
>     Builds a HOB for the CPU.
> 
>   
> 
>     This function builds a HOB for the CPU.
> 
> +  It can only be invoked by Standalone MM Core.
> 
> +  For Standalone MM drivers, it will ASSERT() since HOB is read only for Standalone MM drivers.
> 
> +
> 
>     If there is no additional space for HOB creation, then ASSERT().
> 
>   
> 
>     @param  SizeOfMemorySpace   The maximum physical memory addressability of the processor.
> 
> @@ -508,23 +456,19 @@ BuildCpuHob (
>     IN UINT8  SizeOfIoSpace
> 
>     )
> 
>   {
> 
> -  EFI_HOB_CPU  *Hob;
> 
> -
> 
> -  Hob = CreateHob (EFI_HOB_TYPE_CPU, sizeof (EFI_HOB_CPU));
> 
> -
> 
> -  Hob->SizeOfMemorySpace = SizeOfMemorySpace;
> 
> -  Hob->SizeOfIoSpace     = SizeOfIoSpace;
> 
> -
> 
>     //
> 
> -  // Zero the reserved space to match HOB spec
> 
> +  // HOB is read only for Standalone MM drivers
> 
>     //
> 
> -  ZeroMem (Hob->Reserved, sizeof (Hob->Reserved));
> 
> +  ASSERT (FALSE);
> 
>   }
> 
>   
> 
>   /**
> 
>     Builds a HOB for the memory allocation.
> 
>   
> 
>     This function builds a HOB for the memory allocation.
> 
> +  It can only be invoked by Standalone MM Core.
> 
> +  For Standalone MM drivers, it will ASSERT() since HOB is read only for Standalone MM drivers.
> 
> +
> 
>     If there is no additional space for HOB creation, then ASSERT().
> 
>   
> 
>     @param  BaseAddress   The 64 bit physical address of the memory.
> 
> @@ -540,23 +484,10 @@ BuildMemoryAllocationHob (
>     IN EFI_MEMORY_TYPE       MemoryType
> 
>     )
> 
>   {
> 
> -  EFI_HOB_MEMORY_ALLOCATION  *Hob;
> 
> -
> 
> -  ASSERT (
> 
> -    ((BaseAddress & (EFI_PAGE_SIZE - 1)) == 0) &&
> 
> -    ((Length & (EFI_PAGE_SIZE - 1)) == 0)
> 
> -    );
> 
> -
> 
> -  Hob = CreateHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, sizeof (EFI_HOB_MEMORY_ALLOCATION));
> 
> -
> 
> -  ZeroMem (&(Hob->AllocDescriptor.Name), sizeof (EFI_GUID));
> 
> -  Hob->AllocDescriptor.MemoryBaseAddress = BaseAddress;
> 
> -  Hob->AllocDescriptor.MemoryLength      = Length;
> 
> -  Hob->AllocDescriptor.MemoryType        = MemoryType;
> 
>     //
> 
> -  // Zero the reserved space to match HOB spec
> 
> +  // HOB is read only for Standalone MM drivers
> 
>     //
> 
> -  ZeroMem (Hob->AllocDescriptor.Reserved, sizeof (Hob->AllocDescriptor.Reserved));
> 
> +  ASSERT (FALSE);
> 
>   }
> 
>   
> 
>   /**
> 


-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#118482): https://edk2.groups.io/g/devel/message/118482
Mute This Topic: https://groups.io/mt/103018869/7686176
Group Owner: devel+owner@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io]
-=-=-=-=-=-=-=-=-=-=-=-