1 files changed, 108 insertions, 0 deletions
diff --git a/UefiCpuPkg/Library/AmdSvsmLibNull/AmdSvsmLibNull.c b/UefiCpuPkg/Library/AmdSvsmLibNull/AmdSvsmLibNull.c
new file mode 100644
index 0000000000..a83fcbd6ce
--- /dev/null
+++ b/UefiCpuPkg/Library/AmdSvsmLibNull/AmdSvsmLibNull.c
@@ -0,0 +1,108 @@
+/** @file
+  AmdSvsm Base 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/AmdSvsmLib.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
+AmdSvsmIsSvsmPresent (
+  VOID
+  )
+{
+  return FALSE;
+}
+
+/**
+  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
+AmdSvsmSnpGetVmpl (
+  VOID
+  )
+{
+  return 0;
+}
+
+/**
+  Report the Calling Area address (CAA) for the BSP of the SEV-SNP guest.
+
+  If an SVSM is present, the CAA for the BSP is returned.
+
+  @return                         The CAA
+
+**/
+UINT64
+EFIAPI
+AmdSvsmSnpGetCaa (
+  VOID
+  )
+{
+  return 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
+AmdSvsmSnpPvalidate (
+  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
+AmdSvsmSnpVmsaRmpAdjust (
+  IN SEV_ES_SAVE_AREA  *Vmsa,
+  IN UINT32            ApicId,
+  IN BOOLEAN           SetVmsa
+  )
+{
+  return EFI_UNSUPPORTED;
+}