OvmfPkg: Create a calling area used to communicate with the SVSM

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654

An SVSM requires a calling area page whose address (CAA) is used by the
SVSM to communicate and process the SVSM request.

Add a pre-defined page area to the OvmfPkg and AmdSev packages and define
corresponding PCDs used to communicate the location and size of the area.
Keep the AmdSev package in sync with the OvmfPkg and adjust the AmdSev
launch and hash area memory locations.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Min Xu <min.m.xu@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/OvmfPkg/PlatformPei/PlatformPei.inf b/OvmfPkg/PlatformPei/PlatformPei.inf
index 2206316fec..20b1b98292 100644
--- a/OvmfPkg/PlatformPei/PlatformPei.inf
+++ b/OvmfPkg/PlatformPei/PlatformPei.inf
@@ -128,6 +128,8 @@
   gEmbeddedTokenSpaceGuid.PcdMemoryTypeEfiRuntimeServicesData

   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBackupBase

   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBackupSize

+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecSvsmCaaBase

+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecSvsmCaaSize

   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfWorkAreaBase

   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfWorkAreaSize

   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase