BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654
Add initial support for the new CcExitLib interfaces to the OvmfPkg
version of the library. The initial implementation will fully implement
the SVSM presence check API and the SVSM VMPL API, with later patches
fully implementing the other interfaces.
The SVSM presence check, CcExitSnpSvsmPresent(), determines the presence
of an SVSM by checking if an SVSM has been advertised in the SEV-SNP
Secrets Page. The SVSM VMPL API, CcExitSnpGetVmpl(), returns the VMPL
level at which the OVMF is currently running.
Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
---
OvmfPkg/Library/CcExitLib/CcExitLib.inf | 5 +-
OvmfPkg/Library/CcExitLib/SecCcExitLib.inf | 5 +-
OvmfPkg/Library/CcExitLib/CcExitSvsm.c | 102 ++++++++++++++++++++
3 files changed, 110 insertions(+), 2 deletions(-)
diff --git a/OvmfPkg/Library/CcExitLib/CcExitLib.inf
b/OvmfPkg/Library/CcExitLib/CcExitLib.inf
index bc75cd5f5a04..2e68b12bb4e2 100644
--- a/OvmfPkg/Library/CcExitLib/CcExitLib.inf
+++ b/OvmfPkg/Library/CcExitLib/CcExitLib.inf
@@ -1,7 +1,7 @@
## @file
# CcExitLib Library.
#
-# Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+# Copyright (C) 2020 - 2024, Advanced Micro Devices, Inc. All rights
reserved.<BR>
# Copyright (C) 2020 - 2022, Intel Corporation. All rights reserved.<BR>
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
@@ -23,6 +23,7 @@ [Defines]
[Sources.common]
CcExitLib.c
+ CcExitSvsm.c
CcExitVcHandler.c
CcExitVcHandler.h
CcInstruction.c
@@ -45,3 +46,5 @@ [LibraryClasses]
[Pcd]
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidSize
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsSize
diff --git a/OvmfPkg/Library/CcExitLib/SecCcExitLib.inf
b/OvmfPkg/Library/CcExitLib/SecCcExitLib.inf
index 811269dd2c06..7b81900a11d4 100644
--- a/OvmfPkg/Library/CcExitLib/SecCcExitLib.inf
+++ b/OvmfPkg/Library/CcExitLib/SecCcExitLib.inf
@@ -1,7 +1,7 @@
## @file
# VMGEXIT Support Library.
#
-# 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
#
##
@@ -22,6 +22,7 @@ [Defines]
[Sources.common]
CcExitLib.c
+ CcExitSvsm.c
CcExitVcHandler.c
CcExitVcHandler.h
CcInstruction.c
@@ -45,5 +46,7 @@ [LibraryClasses]
[FixedPcd]
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBackupBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBackupSize
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsBase
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSnpSecretsSize
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidSize
diff --git a/OvmfPkg/Library/CcExitLib/CcExitSvsm.c
b/OvmfPkg/Library/CcExitLib/CcExitSvsm.c
new file mode 100644
index 000000000000..fb8b762caadc
--- /dev/null
+++ b/OvmfPkg/Library/CcExitLib/CcExitSvsm.c
@@ -0,0 +1,102 @@
+/** @file
+ SVSM Support Library.
+
+ Copyright (C) 2024, Advanced Micro Devices, Inc. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Base.h>
+#include <Uefi.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/CcExitLib.h>
+#include <Register/Amd/Msr.h>
+#include <Register/Amd/Svsm.h>
+
+/**
+ Report the presence of an Secure Virtual Services Module (SVSM).
+
+ Determines the presence of an SVSM.
+
+ @retval TRUE An SVSM is present
+ @retval FALSE An SVSM is not present
+
+**/
+BOOLEAN
+EFIAPI
+CcExitSnpSvsmPresent (
+ VOID
+ )
+{
+ SVSM_INFORMATION *SvsmInfo;
+
+ SvsmInfo = (SVSM_INFORMATION *)(UINTN)PcdGet32 (PcdOvmfSnpSecretsBase);
+
+ return (SvsmInfo != NULL && SvsmInfo->SvsmSize != 0);
+}
+
+/**
+ Report the VMPL level at which the SEV-SNP guest is running.
+
+ Determines the VMPL level at which the guest is running. If an SVSM is
+ not present, then it must be VMPL0, otherwise return what is reported
+ by the SVSM.
+
+ @return The VMPL level
+
+**/
+UINT8
+EFIAPI
+CcExitSnpGetVmpl (
+ VOID
+ )
+{
+ SVSM_INFORMATION *SvsmInfo;
+
+ SvsmInfo = (SVSM_INFORMATION *)(UINTN)PcdGet32 (PcdOvmfSnpSecretsBase);
+
+ return CcExitSnpSvsmPresent () ? SvsmInfo->SvsmGuestVmpl : 0;
+}
+
+/**
+ Perform a PVALIDATE operation for the page ranges specified.
+
+ Validate or rescind the validation of the specified pages.
+
+ @param[in] Info Pointer to a page state change structure
+
+**/
+VOID
+EFIAPI
+CcExitSnpPvalidate (
+ IN SNP_PAGE_STATE_CHANGE_INFO *Info
+ )
+{
+}
+
+/**
+ Perform an RMPADJUST operation to alter the VMSA setting of a page.
+
+ Add or remove the VMSA attribute for a page.
+
+ @param[in] Vmsa Pointer to an SEV-ES save area page
+ @param[in] ApicId APIC ID associated with the VMSA
+ @param[in] SetVmsa Boolean indicator as to whether to set or
+ or clear the VMSA setting for the page
+
+ @retval EFI_SUCCESS RMPADJUST operation successful
+ @retval EFI_UNSUPPORTED Operation is not supported
+ @retval EFI_INVALID_PARAMETER RMPADJUST operation failed, an invalid
+ parameter was supplied
+
+**/
+EFI_STATUS
+EFIAPI
+CcExitSnpVmsaRmpAdjust (
+ IN SEV_ES_SAVE_AREA *Vmsa,
+ IN UINT32 ApicId,
+ IN BOOLEAN SetVmsa
+ )
+{
+ return EFI_UNSUPPORTED;
+}
--
2.42.0
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