/** @file | |
Config SMRAM Save State for SmmBases Relocation. | |
Copyright (C) 2023 Advanced Micro Devices, Inc. All rights reserved.<BR> | |
Copyright (c) 2024, Intel Corporation. All rights reserved.<BR> | |
SPDX-License-Identifier: BSD-2-Clause-Patent | |
**/ | |
#include "InternalSmmRelocationLib.h" | |
#include <Register/Amd/SmramSaveStateMap.h> | |
#define EFER_ADDRESS 0XC0000080ul | |
/** | |
Get the mode of the CPU at the time an SMI occurs | |
@retval EFI_MM_SAVE_STATE_REGISTER_LMA_32BIT 32 bit. | |
@retval EFI_MM_SAVE_STATE_REGISTER_LMA_64BIT 64 bit. | |
**/ | |
UINT8 | |
GetMmSaveStateRegisterLma ( | |
VOID | |
) | |
{ | |
UINT8 SmmSaveStateRegisterLma; | |
UINT32 LMAValue; | |
SmmSaveStateRegisterLma = (UINT8)EFI_MM_SAVE_STATE_REGISTER_LMA_32BIT; | |
LMAValue = (UINT32)AsmReadMsr64 (EFER_ADDRESS) & LMA; | |
if (LMAValue) { | |
SmmSaveStateRegisterLma = (UINT8)EFI_MM_SAVE_STATE_REGISTER_LMA_64BIT; | |
} | |
return SmmSaveStateRegisterLma; | |
} | |
/** | |
This function configures the SmBase on the currently executing CPU. | |
@param[in] SmBase The SmBase on the currently executing CPU. | |
**/ | |
VOID | |
EFIAPI | |
ConfigureSmBase ( | |
IN UINT64 SmBase | |
) | |
{ | |
AMD_SMRAM_SAVE_STATE_MAP *AmdCpuState; | |
AmdCpuState = (AMD_SMRAM_SAVE_STATE_MAP *)(UINTN)(SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET); | |
AmdCpuState->x64.SMBASE = (UINT32)SmBase; | |
} | |
/** | |
This function updates the SMRAM save state on the currently executing CPU | |
to resume execution at a specific address after an RSM instruction. This | |
function must evaluate the SMRAM save state to determine the execution mode | |
the RSM instruction resumes and update the resume execution address with | |
either NewInstructionPointer32 or NewInstructionPoint. The auto HALT restart | |
flag in the SMRAM save state must always be cleared. This function returns | |
the value of the instruction pointer from the SMRAM save state that was | |
replaced. If this function returns 0, then the SMRAM save state was not | |
modified. | |
This function is called during the very first SMI on each CPU after | |
SmmCpuFeaturesInitializeProcessor() to set a flag in normal execution mode | |
to signal that the SMBASE of each CPU has been updated before the default | |
SMBASE address is used for the first SMI to the next CPU. | |
@param[in,out] CpuState Pointer to SMRAM Save State Map for the | |
currently executing CPU. | |
@param[in] NewInstructionPointer32 Instruction pointer to use if resuming to | |
32-bit mode from 64-bit SMM. | |
@param[in] NewInstructionPointer Instruction pointer to use if resuming to | |
same mode as SMM. | |
@retval The value of the original instruction pointer before it was hooked. | |
**/ | |
UINT64 | |
EFIAPI | |
HookReturnFromSmm ( | |
IN OUT SMRAM_SAVE_STATE_MAP *CpuState, | |
IN UINT64 NewInstructionPointer32, | |
IN UINT64 NewInstructionPointer | |
) | |
{ | |
UINT64 OriginalInstructionPointer; | |
AMD_SMRAM_SAVE_STATE_MAP *AmdCpuState; | |
AmdCpuState = (AMD_SMRAM_SAVE_STATE_MAP *)CpuState; | |
if (GetMmSaveStateRegisterLma () == EFI_MM_SAVE_STATE_REGISTER_LMA_32BIT) { | |
OriginalInstructionPointer = (UINT64)AmdCpuState->x86._EIP; | |
AmdCpuState->x86._EIP = (UINT32)NewInstructionPointer; | |
// | |
// Clear the auto HALT restart flag so the RSM instruction returns | |
// program control to the instruction following the HLT instruction. | |
// | |
if ((AmdCpuState->x86.AutoHALTRestart & BIT0) != 0) { | |
AmdCpuState->x86.AutoHALTRestart &= ~BIT0; | |
} | |
} else { | |
OriginalInstructionPointer = AmdCpuState->x64._RIP; | |
if ((AmdCpuState->x64.EFER & LMA) == 0) { | |
AmdCpuState->x64._RIP = (UINT32)NewInstructionPointer32; | |
} else { | |
AmdCpuState->x64._RIP = (UINT32)NewInstructionPointer; | |
} | |
// | |
// Clear the auto HALT restart flag so the RSM instruction returns | |
// program control to the instruction following the HLT instruction. | |
// | |
if ((AmdCpuState->x64.AutoHALTRestart & BIT0) != 0) { | |
AmdCpuState->x64.AutoHALTRestart &= ~BIT0; | |
} | |
} | |
return OriginalInstructionPointer; | |
} |