1 files changed, 125 insertions, 0 deletions
diff --git a/UefiCpuPkg/Library/SmmRelocationLib/AmdSmramSaveStateConfig.c b/UefiCpuPkg/Library/SmmRelocationLib/AmdSmramSaveStateConfig.c
new file mode 100644
index 0000000000..068ae60887
--- /dev/null
+++ b/UefiCpuPkg/Library/SmmRelocationLib/AmdSmramSaveStateConfig.c
@@ -0,0 +1,125 @@
+/** @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;
+}