[PATCH v4 0/4] Fix AP Jump Table Handling for SEV-SNP

["Roth, Michael" <Michael.Roth@amd.com>]

A full-featured SEV-SNP guest will not rely on the AP jump table, and
will instead use the AP Creation interface defined by the GHCB. However,
a guest is still allowed to use the AP jump table if desired.

However, unlike with SEV-ES guests, SEV-SNP guests should not
store/retrieve the jump table address via GHCB requests to the
hypervisor, they should instead store/retrieve it via the SEV-SNP
secrets page.

This series implements the store side of this for OVMF by introducing a
PCD that can be used to pass the SEV-SNP secrets page address to
UefiCpuPkg, where the jump table address is allocated. It also
introduces a struct that defines the SEV-SNP secrets page format
according to the GHCB v2.01 and SEV-SNP FW ABI specifications.

v4:
 - Move storing of jump table address after relevant comment rather
   than before it. (Tom)

v3:
 - Break up single patch into a set of patches containing the specific
   changes for each package. (Ray)

v2:
 - Update Secrets OS area to match latest GHCB 2.01 spec (Tom)
 - Move Secrets header file into ./Register/AMD subdirectory (Tom)
 - Fix CI EccCheck due to assignment in variable declaration

----------------------------------------------------------------
Michael Roth (4):
      MdePkg: Add header for SEV-SNP secrets page struct
      MdePkg: Add PcdSevSnpSecretsAddress to export SEV-SNP secrets page
      OvmfPkg: Initialize the PcdSevSnpSecretsAddress PCD during PEI phase
      UefiCpuPkg: Store SEV-SNP AP jump table in the secrets page

 MdePkg/Include/Register/Amd/SnpSecretsPage.h  | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 MdePkg/MdePkg.dec                             |  4 ++++
 OvmfPkg/AmdSev/AmdSevX64.dsc                  |  3 +++
 OvmfPkg/CloudHv/CloudHvX64.dsc                |  3 +++
 OvmfPkg/IntelTdx/IntelTdxX64.dsc              |  3 +++
 OvmfPkg/Microvm/MicrovmX64.dsc                |  3 +++
 OvmfPkg/OvmfPkgIa32.dsc                       |  3 +++
 OvmfPkg/OvmfPkgIa32X64.dsc                    |  3 +++
 OvmfPkg/OvmfPkgX64.dsc                        |  3 +++
 OvmfPkg/PlatformPei/AmdSev.c                  |  5 +++++
 OvmfPkg/PlatformPei/PlatformPei.inf           |  1 +
 UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf |  1 +
 UefiCpuPkg/Library/MpInitLib/DxeMpLib.c       | 10 ++++++++++
 13 files changed, 98 insertions(+)
 create mode 100644 MdePkg/Include/Register/Amd/SnpSecretsPage.h