diff --git a/OvmfPkg/AmdSev/AmdSevX64.fdf b/OvmfPkg/AmdSev/AmdSevX64.fdf
index b84981e7ba..d49555c6c8 100644
--- a/OvmfPkg/AmdSev/AmdSevX64.fdf
+++ b/OvmfPkg/AmdSev/AmdSevX64.fdf
@@ -68,13 +68,16 @@ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase|gUefiOvmfPkgTokenSpaceGuid.PcdO
 0x00E000|0x001000
 gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidSize
 
-0x00F000|0x000C00
+0x00F000|0x001000
+gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecSvsmCaaBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecSvsmCaaSize
+
+0x010000|0x000C00
 gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretBase|gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretSize
 
-0x00FC00|0x000400
+0x010C00|0x000400
 gUefiOvmfPkgTokenSpaceGuid.PcdQemuHashTableBase|gUefiOvmfPkgTokenSpaceGuid.PcdQemuHashTableSize
 
-0x010000|0x010000
+0x011000|0x00F000
 gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamSize
 
 0x020000|0x0E0000
diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index fbc81e4c80..2f7bded926 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -338,6 +338,10 @@
   ## Restrict boot to EFI applications in firmware volumes.
   gUefiOvmfPkgTokenSpaceGuid.PcdBootRestrictToFirmware|FALSE|BOOLEAN|0x6c
 
+  ## The base address and size of the initial SVSM Calling Area.
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecSvsmCaaBase|0|UINT32|0x70
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecSvsmCaaSize|0|UINT32|0x71
+
 [PcdsDynamic, PcdsDynamicEx]
   gUefiOvmfPkgTokenSpaceGuid.PcdEmuVariableEvent|0|UINT64|2
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashVariablesEnable|FALSE|BOOLEAN|0x10
diff --git a/OvmfPkg/OvmfPkgX64.fdf b/OvmfPkg/OvmfPkgX64.fdf
index c3b18b638f..fecb1fcfda 100644
--- a/OvmfPkg/OvmfPkgX64.fdf
+++ b/OvmfPkg/OvmfPkgX64.fdf
@@ -94,6 +94,9 @@ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase|gUefiOvmfPkgTokenSpaceGuid.PcdO
 0x00E000|0x001000
 gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidSize
 
+0x00F000|0x001000
+gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecSvsmCaaBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecSvsmCaaSize
+
 0x010000|0x010000
 gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamSize
 
diff --git a/OvmfPkg/PlatformPei/AmdSev.c b/OvmfPkg/PlatformPei/AmdSev.c
index a9de33074a..e6724cf493 100644
--- a/OvmfPkg/PlatformPei/AmdSev.c
+++ b/OvmfPkg/PlatformPei/AmdSev.c
@@ -555,5 +555,16 @@ SevInitializeRam (
       (UINT64)(UINTN)PcdGet32 (PcdOvmfCpuidSize),
       EfiReservedMemoryType
       );
+
+    //
+    // The calling area memory needs to be protected until the OS can create
+    // its own calling area. Mark it as EfiReservedMemoryType so that the
+    // guest firmware and OS do not use it as a system memory.
+    //
+    BuildMemoryAllocationHob (
+      (EFI_PHYSICAL_ADDRESS)(UINTN)PcdGet32 (PcdOvmfSecSvsmCaaBase),
+      (UINT64)(UINTN)PcdGet32 (PcdOvmfSecSvsmCaaSize),
+      EfiReservedMemoryType
+      );
   }
 }
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
diff --git a/OvmfPkg/ResetVector/ResetVector.inf b/OvmfPkg/ResetVector/ResetVector.inf
index 65f71b05a0..7bd517e63a 100644
--- a/OvmfPkg/ResetVector/ResetVector.inf
+++ b/OvmfPkg/ResetVector/ResetVector.inf
@@ -62,6 +62,8 @@
   gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretSize
   gUefiOvmfPkgTokenSpaceGuid.PcdQemuHashTableBase
   gUefiOvmfPkgTokenSpaceGuid.PcdQemuHashTableSize
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecSvsmCaaBase
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecSvsmCaaSize
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsSize
   gEfiMdeModulePkgTokenSpaceGuid.PcdUse5LevelPageTable
diff --git a/OvmfPkg/ResetVector/ResetVector.nasmb b/OvmfPkg/ResetVector/ResetVector.nasmb
index 2bd80149e5..7279ac64b1 100644
--- a/OvmfPkg/ResetVector/ResetVector.nasmb
+++ b/OvmfPkg/ResetVector/ResetVector.nasmb
@@ -3,7 +3,7 @@
 ; This file includes all other code files to assemble the reset vector code
 ;
 ; Copyright (c) 2008 - 2013, Intel Corporation. All rights reserved.<BR>
-; Copyright (c) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+; Copyright (c) 2020 - 2024, Advanced Micro Devices, Inc. All rights reserved.<BR>
 ; SPDX-License-Identifier: BSD-2-Clause-Patent
 ;
 ;------------------------------------------------------------------------------
@@ -69,6 +69,8 @@
 %define SEV_SNP_SECRETS_SIZE          (FixedPcdGet32 (PcdOvmfSnpSecretsSize))
 %define CPUID_BASE                    (FixedPcdGet32 (PcdOvmfCpuidBase))
 %define CPUID_SIZE                    (FixedPcdGet32 (PcdOvmfCpuidSize))
+%define SVSM_CAA_BASE                 (FixedPcdGet32 (PcdOvmfSecSvsmCaaBase))
+%define SVSM_CAA_SIZE                 (FixedPcdGet32 (PcdOvmfSecSvsmCaaSize))
 %if (FixedPcdGet32 (PcdSevLaunchSecretBase) > 0)
   ; There's a reserved page for SEV secrets and hashes; the VMM will fill and
   ; validate the page, or mark it as a zero page.
@@ -89,7 +91,7 @@
 ;
 %define SNP_SEC_MEM_BASE_DESC_2       (GHCB_BASE + 0x1000)
 %define SNP_SEC_MEM_SIZE_DESC_2       (SEV_SNP_SECRETS_BASE - SNP_SEC_MEM_BASE_DESC_2)
-%define SNP_SEC_MEM_BASE_DESC_3       (CPUID_BASE + CPUID_SIZE + SEV_SNP_KERNEL_HASHES_SIZE)
+%define SNP_SEC_MEM_BASE_DESC_3       (SVSM_CAA_BASE + SVSM_CAA_SIZE + SEV_SNP_KERNEL_HASHES_SIZE)
 %define SNP_SEC_MEM_SIZE_DESC_3       (FixedPcdGet32 (PcdOvmfPeiMemFvBase) - SNP_SEC_MEM_BASE_DESC_3)
 
 %ifdef ARCH_X64
diff --git a/OvmfPkg/ResetVector/X64/OvmfSevMetadata.asm b/OvmfPkg/ResetVector/X64/OvmfSevMetadata.asm
index 8aa77d8701..2511073a46 100644
--- a/OvmfPkg/ResetVector/X64/OvmfSevMetadata.asm
+++ b/OvmfPkg/ResetVector/X64/OvmfSevMetadata.asm
@@ -2,7 +2,7 @@
 ; @file
 ; OVMF metadata for the AMD SEV confidential computing guests
 ;
-; Copyright (c) 2021, AMD Inc. All rights reserved.<BR>
+; Copyright (c) 2021 - 2024, AMD Inc. All rights reserved.<BR>
 ;
 ; SPDX-License-Identifier: BSD-2-Clause-Patent
 ;-----------------------------------------------------------------------------
@@ -26,6 +26,9 @@ BITS  64
 ;
 %define OVMF_SECTION_TYPE_CPUID           0x3
 
+; The SVSM Calling Area Address (CAA)
+%define OVMF_SECTION_TYPE_SVSM_CAA        0x4
+
 ; Kernel hashes section for measured direct boot
 %define OVMF_SECTION_TYPE_KERNEL_HASHES   0x10
 
@@ -67,6 +70,12 @@ CpuidSec:
   DD  CPUID_SIZE
   DD  OVMF_SECTION_TYPE_CPUID
 
+; SVSM CAA page
+SvsmCaa:
+  DD  SVSM_CAA_BASE
+  DD  SVSM_CAA_SIZE
+  DD  OVMF_SECTION_TYPE_SVSM_CAA
+
 %if (SEV_SNP_KERNEL_HASHES_BASE > 0)
 ; Kernel hashes for measured direct boot, or zero page if
 ; there are no kernel hashes / SEV secrets