Re: [PATCH v5 0/2] Enhanced SMM support for AMD-based x86 systems.

[Paolo Bonzini <pbonzini@redhat.com>]

On 13/10/2017 03:52, Yao, Jiewen wrote:
> I recommend we move AMD_SMRAM_SAVE_STATE_MAP_OFFSET to UefiCpuPkg\Include\Register\Amd\SmramSaveStateMap.h, because it is standard.
> +//
> +// Definitions for AMD systems are based on contents of the
> +// AMD64 Architecture Programmer's Manual
> +// Volume 2: System Programming, Section 10 System-Management Mode
> +//
> +#define AMD_SMRAM_SAVE_STATE_MAP_OFFSET  0xfe00

If I understand correctly, I think AMD can keep on using 0xfc00 and just 
adjust the offsets up by 0x200 bytes.  For example, QEMU_SMRAM_SAVE_STATE_MAP
in OvmfPkg/Include/Register/QemuSmramStateSaveMap.h is essentially the AMD
format and it starts with:

  UINT8   Reserved0[0x200]; // 7c00h
  UINT8   Reserved1[0xf8];  // 7e00h

See also the comment in SMRAM_SAVE_STATE_MAP32:

  UINT8   Reserved[0x200];  // 7c00h
                            // Padded an extra 0x200 bytes so 32-bit and 64-bit
                            // SMRAM Save State Maps are the same size
  UINT8   Reserved1[0xf8];  // 7e00h

Thanks,

Paolo