Re: [edk2-devel] [edk2-platforms: PATCH v3] IntelSiliconPkg/SpiFvbServiceSmm: Rewrite VariableStore header.

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

Hi Chasel,

I agree with the high-level problem. Here's some observations.

1. I'm not a big fan of implicitly associating index zero of the 
mPlatformFvBaseAddress array as the variable FV entry. It could be easy 
for that to silently get out of sync in the future.

Perhaps you could check if the base address at a given index equals the 
variable store address since it is retrieved via 
GetVariableFlashNvStorageInfo() at the beginning of FvbInitialize().

2. VariableFlashInfoLib is meant to abstract var store info with 
GetVariableFlashNvStorageInfo().

Please use that instead of directly getting it with PcdGet32 
(PcdFlashNvStorageVariableSize).

3. Suggest a blank link before the following text for readability.

             //
             // Write buffer to flash
             //

4. Usually there's a few default variables in the var store FV that form 
a foundation that the variable HOB gets written upon when the HOB gets 
flushed. Does the original var store FV still contain some of those 
entries? If so, this just restores an empty store, so those are known to 
be lost, right?

If that's true, please call it out in the patch description.

Thanks,
Michael

On 2/7/2023 2:42 PM, Chiu, Chasel wrote:
> When invalid VariableStore FV header detected, current SpiFvbService
> will erase both FV and VariableStore headers from flash, however,
> it will only rewrite FV header back and cause invalid VariableStore
> header.
> 
> This patch adding the support for rewriting both FV header and
> VariableStore header when VariableStore corruption happened.
> 
> Platform has to set PcdFlashVariableStoreType to inform SpiFvbService
> which VariableStoreType should be rewritten.
> 
> Cc: Ashraf Ali S <ashraf.ali.s@intel.com>
> Cc: Isaac Oram <isaac.w.oram@intel.com>
> Cc: Rangasai V Chaganty <rangasai.v.chaganty@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Michael Kubacki <michael.kubacki@microsoft.com>
> Signed-off-by: Chasel Chiu <chasel.chiu@intel.com>
> ---
>   Silicon/Intel/IntelSiliconPkg/Feature/Flash/SpiFvbService/SpiFvbServiceMm.c    | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
>   Silicon/Intel/IntelSiliconPkg/Feature/Flash/SpiFvbService/SpiFvbServiceSmm.inf |  4 ++++
>   Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dec                              |  8 ++++++++
>   3 files changed, 71 insertions(+), 5 deletions(-)
> 
> diff --git a/Silicon/Intel/IntelSiliconPkg/Feature/Flash/SpiFvbService/SpiFvbServiceMm.c b/Silicon/Intel/IntelSiliconPkg/Feature/Flash/SpiFvbService/SpiFvbServiceMm.c
> index 6b4bcdcfe3..6338442e1a 100644
> --- a/Silicon/Intel/IntelSiliconPkg/Feature/Flash/SpiFvbService/SpiFvbServiceMm.c
> +++ b/Silicon/Intel/IntelSiliconPkg/Feature/Flash/SpiFvbService/SpiFvbServiceMm.c
> @@ -12,6 +12,7 @@
>   #include <Library/MmServicesTableLib.h>
> 
>   #include <Library/UefiDriverEntryPoint.h>
> 
>   #include <Protocol/SmmFirmwareVolumeBlock.h>
> 
> +#include <Guid/VariableFormat.h>
> 
>   
> 
>   /**
> 
>     The function installs EFI_FIRMWARE_VOLUME_BLOCK protocol
> 
> @@ -114,6 +115,10 @@ FvbInitialize (
>     UINT32                                BytesWritten;
> 
>     UINTN                                 BytesErased;
> 
>     UINT64                                NvStorageFvSize;
> 
> +  UINT32                                ExpectedBytesWritten;
> 
> +  VARIABLE_STORE_HEADER                 *VariableStoreHeader;
> 
> +  UINT8                                 VariableStoreType;
> 
> +  UINT8                                 *NvStoreBuffer;
> 
>   
> 
>     Status = GetVariableFlashNvStorageInfo (&BaseAddress, &NvStorageFvSize);
> 
>     if (EFI_ERROR (Status)) {
> 
> @@ -186,8 +191,57 @@ FvbInitialize (
>             }
> 
>             continue;
> 
>           }
> 
> -        BytesWritten = FvHeader->HeaderLength;
> 
> -        Status = SpiFlashWrite ((UINTN)BaseAddress, &BytesWritten, (UINT8*)FvHeader);
> 
> +
> 
> +        BytesWritten         = FvHeader->HeaderLength;
> 
> +        ExpectedBytesWritten = BytesWritten;
> 
> +        if (Idx != 0) {
> 
> +          Status = SpiFlashWrite ((UINTN)BaseAddress, &BytesWritten, (UINT8 *)FvHeader);
> 
> +        } else {
> 
> +          //
> 
> +          // This is Variable Store, rewrite both EFI_FIRMWARE_VOLUME_HEADER and VARIABLE_STORE_HEADER
> 
> +          //
> 
> +          NvStoreBuffer = NULL;
> 
> +          NvStoreBuffer = AllocateZeroPool (sizeof (VARIABLE_STORE_HEADER) + FvHeader->HeaderLength);
> 
> +          if (NvStoreBuffer != NULL) {
> 
> +            //
> 
> +            // Combine FV header and VariableStore header into the buffer.
> 
> +            //
> 
> +            CopyMem (NvStoreBuffer, FvHeader, FvHeader->HeaderLength);
> 
> +            VariableStoreHeader = (VARIABLE_STORE_HEADER *)(NvStoreBuffer + FvHeader->HeaderLength);
> 
> +            VariableStoreType   = PcdGet8 (PcdFlashVariableStoreType);
> 
> +            switch (VariableStoreType) {
> 
> +              case 0:
> 
> +                DEBUG ((DEBUG_ERROR, "Type: gEfiVariableGuid\n"));
> 
> +                CopyGuid (&VariableStoreHeader->Signature, &gEfiVariableGuid);
> 
> +                break;
> 
> +              case 1:
> 
> +                DEBUG ((DEBUG_ERROR, "Type: gEfiAuthenticatedVariableGuid\n"));
> 
> +                CopyGuid (&VariableStoreHeader->Signature, &gEfiAuthenticatedVariableGuid);
> 
> +                break;
> 
> +              default:
> 
> +                break;
> 
> +            }
> 
> +
> 
> +            //
> 
> +            // Initialize common VariableStore header fields
> 
> +            //
> 
> +            VariableStoreHeader->Size      = PcdGet32 (PcdFlashNvStorageVariableSize) - FvHeader->HeaderLength;
> 
> +            VariableStoreHeader->Format    = VARIABLE_STORE_FORMATTED;
> 
> +            VariableStoreHeader->State     = VARIABLE_STORE_HEALTHY;
> 
> +            VariableStoreHeader->Reserved  = 0;
> 
> +            VariableStoreHeader->Reserved1 = 0;
> 
> +            //
> 
> +            // Write buffer to flash
> 
> +            //
> 
> +            BytesWritten         = FvHeader->HeaderLength + sizeof (VARIABLE_STORE_HEADER);
> 
> +            ExpectedBytesWritten = BytesWritten;
> 
> +            Status               = SpiFlashWrite ((UINTN)BaseAddress, &BytesWritten, NvStoreBuffer);
> 
> +            FreePool (NvStoreBuffer);
> 
> +          } else {
> 
> +            Status = EFI_OUT_OF_RESOURCES;
> 
> +          }
> 
> +        }
> 
> +
> 
>           if (EFI_ERROR (Status)) {
> 
>             DEBUG ((DEBUG_WARN, "ERROR - SpiFlashWrite Error  %r\n", Status));
> 
>             if (FvHeader != NULL) {
> 
> @@ -195,9 +249,9 @@ FvbInitialize (
>             }
> 
>             continue;
> 
>           }
> 
> -        if (BytesWritten != FvHeader->HeaderLength) {
> 
> -          DEBUG ((DEBUG_WARN, "ERROR - BytesWritten != HeaderLength\n"));
> 
> -          DEBUG ((DEBUG_INFO, " BytesWritten = 0x%X\n HeaderLength = 0x%X\n", BytesWritten, FvHeader->HeaderLength));
> 
> +        if (BytesWritten != ExpectedBytesWritten) {
> 
> +          DEBUG ((DEBUG_WARN, "ERROR - BytesWritten != ExpectedBytesWritten\n"));
> 
> +          DEBUG ((DEBUG_INFO, " BytesWritten = 0x%X\n ExpectedBytesWritten = 0x%X\n", BytesWritten, ExpectedBytesWritten));
> 
>             if (FvHeader != NULL) {
> 
>               FreePool (FvHeader);
> 
>             }
> 
> diff --git a/Silicon/Intel/IntelSiliconPkg/Feature/Flash/SpiFvbService/SpiFvbServiceSmm.inf b/Silicon/Intel/IntelSiliconPkg/Feature/Flash/SpiFvbService/SpiFvbServiceSmm.inf
> index 0cfa3f909b..0485b73679 100644
> --- a/Silicon/Intel/IntelSiliconPkg/Feature/Flash/SpiFvbService/SpiFvbServiceSmm.inf
> +++ b/Silicon/Intel/IntelSiliconPkg/Feature/Flash/SpiFvbService/SpiFvbServiceSmm.inf
> @@ -45,6 +45,8 @@
>   [Pcd]
> 
>     gIntelSiliconPkgTokenSpaceGuid.PcdFlashMicrocodeFvBase         ## CONSUMES
> 
>     gIntelSiliconPkgTokenSpaceGuid.PcdFlashMicrocodeFvSize         ## CONSUMES
> 
> +  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableSize   ## SOMETIMES_CONSUMES
> 
> +  gIntelSiliconPkgTokenSpaceGuid.PcdFlashVariableStoreType       ## SOMETIMES_CONSUMES
> 
>   
> 
>   [Sources]
> 
>     FvbInfo.c
> 
> @@ -61,6 +63,8 @@
>   [Guids]
> 
>     gEfiFirmwareFileSystem2Guid                   ## CONSUMES
> 
>     gEfiSystemNvDataFvGuid                        ## CONSUMES
> 
> +  gEfiVariableGuid                              ## SOMETIMES_CONSUMES
> 
> +  gEfiAuthenticatedVariableGuid                 ## SOMETIMES_CONSUMES
> 
>   
> 
>   [Depex]
> 
>     TRUE
> 
> diff --git a/Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dec b/Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dec
> index 485cb3e80a..63dae756ad 100644
> --- a/Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dec
> +++ b/Silicon/Intel/IntelSiliconPkg/IntelSiliconPkg.dec
> @@ -186,3 +186,11 @@
>     # @Prompt VTd abort DMA mode support.
> 
>     gIntelSiliconPkgTokenSpaceGuid.PcdVTdSupportAbortDmaMode|FALSE|BOOLEAN|0x0000000C
> 
>   
> 
> +  ## Define Flash Variable Store type.<BR><BR>
> 
> +  #  When Flash Variable Store corruption happened, the SpiFvbService will recreate Variable Store
> 
> +  #  with valid header information provided by this PCD value.<BR>
> 
> +  #  0: Variable Store is gEfiVariableGuid type.<BR>
> 
> +  #  1: Variable Store is gEfiAuthenticatedVariableGuid type.<BR>
> 
> +  #  Other value: reserved for future use.<BR>
> 
> +  # @Prompt Flash Variable Store type.
> 
> +  gIntelSiliconPkgTokenSpaceGuid.PcdFlashVariableStoreType|0x00|UINT8|0x0000000E
>