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>

8 files changed, 42 insertions, 6 deletions

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