audk/OvmfPkg/XenPlatformPei/AmdSev.c

65 lines
1.6 KiB
C

/**@file
Initialize Secure Encrypted Virtualization (SEV) support
Copyright (c) 2017, Advanced Micro Devices. All rights reserved.<BR>
Copyright (c) 2019, Citrix Systems, Inc.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
//
// The package level header files this module uses
//
#include <Library/DebugLib.h>
#include <Library/MemEncryptSevLib.h>
#include <Library/PcdLib.h>
#include <PiPei.h>
#include <Register/Amd/Cpuid.h>
#include <Register/Cpuid.h>
#include "Platform.h"
/**
Function checks if SEV support is available, if present then it sets
the dynamic PcdPteMemoryEncryptionAddressOrMask with memory encryption mask.
**/
VOID
AmdSevInitialize (
VOID
)
{
CPUID_MEMORY_ENCRYPTION_INFO_EBX Ebx;
UINT64 EncryptionMask;
RETURN_STATUS PcdStatus;
//
// Check if SEV is enabled
//
if (!MemEncryptSevIsEnabled ()) {
return;
}
//
// CPUID Fn8000_001F[EBX] Bit 0:5 (memory encryption bit position)
//
AsmCpuid (CPUID_MEMORY_ENCRYPTION_INFO, NULL, &Ebx.Uint32, NULL, NULL);
EncryptionMask = LShiftU64 (1, Ebx.Bits.PtePosBits);
//
// Set Memory Encryption Mask PCD
//
PcdStatus = PcdSet64S (PcdPteMemoryEncryptionAddressOrMask, EncryptionMask);
ASSERT_RETURN_ERROR (PcdStatus);
DEBUG ((DEBUG_INFO, "SEV is enabled (mask 0x%lx)\n", EncryptionMask));
//
// Set Pcd to Deny the execution of option ROM when security
// violation.
//
PcdStatus = PcdSet32S (PcdOptionRomImageVerificationPolicy, 0x4);
ASSERT_RETURN_ERROR (PcdStatus);
}