Re: [PATCH V2 04/10] OvmfPkg/IntelTdx: Implement other helper functions in SecTdxHelperLib

["Min Xu" <min.m.xu@intel.com>]

On January 19, 2023 5:54 PM, Gerd Hoffmann wrote:
> 
> > +#pragma pack(1)
> > +
> > +#define HANDOFF_TABLE_DESC  "TdxTable"
> > +typedef struct {
> > +  UINT8                      TableDescriptionSize;
> > +  UINT8                      TableDescription[sizeof (HANDOFF_TABLE_DESC)];
> > +  UINT64                     NumberOfTables;
> > +  EFI_CONFIGURATION_TABLE    TableEntry[1];
> > +} TDX_HANDOFF_TABLE_POINTERS2;
> > +
> > +#define FV_HANDOFF_TABLE_DESC  "Fv(XXXXXXXX-XXXX-XXXX-XXXX-
> XXXXXXXXXXXX)"
> > +typedef struct {
> > +  UINT8                   BlobDescriptionSize;
> > +  UINT8                   BlobDescription[sizeof (FV_HANDOFF_TABLE_DESC)];
> > +  EFI_PHYSICAL_ADDRESS    BlobBase;
> > +  UINT64                  BlobLength;
> > +} FV_HANDOFF_TABLE_POINTERS2;
> > +
> > +#pragma pack()
> 
> Why do you need this?  For standard event types we should have those
> structs already defined somewhere in edk2 I think ...
> 
FV_HANDOFF_TABLE_POINTERS2 is related to standard event type (EV_EFI_PLATFORM_FIRMWARE_BLOB2).
According to comment (https://github.com/tianocore/edk2/blob/master/MdePkg/Include/IndustryStandard/UefiTcgPlatform.h#L145-L156) we can see this event type uses the structure of UEFI_PLATFORM_FIRMWARE_BLOB2. It is not a data struct with fixed size. Instead its size depends on BlobDescriptionSize. 
Tcg2Pei measures the FV image with the event type (EV_EFI_PLATFORM_FIRMWARE_BLOB2) and data struct (FV_HANDOFF_TABLE_POINTERS2). 
Tdx measurement does the same measurement to the Configuration FV image. 
@Yao, Jiewen Can we define FV_HANDOFF_TABLE_POINTERS2 and FV_HANDOFF_TABLE_POINTERS2 in MdePkg/Include/IndustryStandard/UefiTcgPlatform.h?

Thanks
Min