[PATCH v6 6/6] UefiCpuPkg: Implements SmmCpuFeaturesLib for AMD Family

["Abdul Lateef Attar" <abdattar@amd.com>]

From: Abdul Lateef Attar <AbdulLateef.Attar@amd.com>

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4182

Implements interfaces to read and write save state
registers of AMD's processor family.
Initializes processor SMMADDR and MASK depends
on PcdSmrrEnable flag.
Program or corrects the IP once control returns from SMM.

Cc: Paul Grimes <paul.grimes@amd.com>
Cc: Garrett Kirkendall <garrett.kirkendall@amd.com>
Cc: Abner Chang <abner.chang@amd.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Signed-off-by: Abdul Lateef Attar <abdattar@amd.com>
Reviewed-by: Abner Chang <abner.chang@amd.com>
---
 .../AmdSmmCpuFeaturesLib.inf                  |   6 +
 .../SmmCpuFeaturesLib/AmdSmmCpuFeaturesLib.c  | 106 +++++++++++++++++-
 2 files changed, 109 insertions(+), 3 deletions(-)

diff --git a/UefiCpuPkg/Library/SmmCpuFeaturesLib/AmdSmmCpuFeaturesLib.inf b/UefiCpuPkg/Library/SmmCpuFeaturesLib/AmdSmmCpuFeaturesLib.inf
index 4c77efc64462..9d5b8c2e972d 100644
--- a/UefiCpuPkg/Library/SmmCpuFeaturesLib/AmdSmmCpuFeaturesLib.inf
+++ b/UefiCpuPkg/Library/SmmCpuFeaturesLib/AmdSmmCpuFeaturesLib.inf
@@ -31,3 +31,9 @@ [LibraryClasses]
   PcdLib
   MemoryAllocationLib
   DebugLib
+  SmmSmramSaveStateLib
+
+[FeaturePcd]
+  gUefiCpuPkgTokenSpaceGuid.PcdSmrrEnable               ## CONSUMES
+  gUefiCpuPkgTokenSpaceGuid.PcdSmmFeatureControlEnable  ## CONSUMES
+
diff --git a/UefiCpuPkg/Library/SmmCpuFeaturesLib/AmdSmmCpuFeaturesLib.c b/UefiCpuPkg/Library/SmmCpuFeaturesLib/AmdSmmCpuFeaturesLib.c
index c74e1a0c0c5b..af45be3e265a 100644
--- a/UefiCpuPkg/Library/SmmCpuFeaturesLib/AmdSmmCpuFeaturesLib.c
+++ b/UefiCpuPkg/Library/SmmCpuFeaturesLib/AmdSmmCpuFeaturesLib.c
@@ -11,6 +11,21 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 
 #include <Library/SmmCpuFeaturesLib.h>
 #include <Uefi/UefiBaseType.h>
+#include <Register/Amd/SmramSaveStateMap.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/SmmSmramSaveStateLib.h>
+
+// EFER register LMA bit
+#define LMA  BIT10
+
+// Machine Specific Registers (MSRs)
+#define SMMADDR_ADDRESS  0xC0010112ul
+#define SMMMASK_ADDRESS  0xC0010113ul
+#define EFER_ADDRESS     0XC0000080ul
+
+// The mode of the CPU at the time an SMI occurs
+STATIC UINT8  mSmmSaveStateRegisterLma;
 
 /**
   Read an SMM Save State register on the target processor.  If this function
@@ -39,7 +54,7 @@ SmmCpuFeaturesReadSaveStateRegister (
   OUT VOID                         *Buffer
   )
 {
-  return EFI_SUCCESS;
+  return SmramSaveStateReadRegister (CpuIndex, Register, Width, Buffer);
 }
 
 /**
@@ -67,7 +82,7 @@ SmmCpuFeaturesWriteSaveStateRegister (
   IN CONST VOID                   *Buffer
   )
 {
-  return EFI_SUCCESS;
+  return SmramSaveStateWriteRegister (CpuIndex, Register, Width, Buffer);
 }
 
 /**
@@ -82,6 +97,13 @@ CpuFeaturesLibInitialization (
   VOID
   )
 {
+  UINT32  LMAValue;
+
+  LMAValue                 = (UINT32)AsmReadMsr64 (EFER_ADDRESS) & LMA;
+  mSmmSaveStateRegisterLma = EFI_SMM_SAVE_STATE_REGISTER_LMA_32BIT;
+  if (LMAValue) {
+    mSmmSaveStateRegisterLma = EFI_SMM_SAVE_STATE_REGISTER_LMA_64BIT;
+  }
 }
 
 /**
@@ -117,6 +139,52 @@ SmmCpuFeaturesInitializeProcessor (
   IN CPU_HOT_PLUG_DATA          *CpuHotPlugData
   )
 {
+  AMD_SMRAM_SAVE_STATE_MAP  *CpuState;
+  UINT32                    LMAValue;
+
+  //
+  // Configure SMBASE.
+  //
+  CpuState             = (AMD_SMRAM_SAVE_STATE_MAP *)(UINTN)(SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET);
+  CpuState->x64.SMBASE = (UINT32)CpuHotPlugData->SmBase[CpuIndex];
+
+  // Re-initialize the value of mSmmSaveStateRegisterLma flag which might have been changed in PiCpuSmmDxeSmm Driver
+  // Entry point, to make sure correct value on AMD platform is assigned to be used by SmmCpuFeaturesLib.
+  LMAValue                 = (UINT32)AsmReadMsr64 (EFER_ADDRESS) & LMA;
+  mSmmSaveStateRegisterLma = EFI_SMM_SAVE_STATE_REGISTER_LMA_32BIT;
+  if (LMAValue) {
+    mSmmSaveStateRegisterLma = EFI_SMM_SAVE_STATE_REGISTER_LMA_64BIT;
+  }
+
+  //
+  // If SMRR is supported, then program SMRR base/mask MSRs.
+  // The EFI_MSR_SMRR_PHYS_MASK_VALID bit is not set until the first normal SMI.
+  // The code that initializes SMM environment is running in normal mode
+  // from SMRAM region.  If SMRR is enabled here, then the SMRAM region
+  // is protected and the normal mode code execution will fail.
+  //
+  if (FeaturePcdGet (PcdSmrrEnable)) {
+    //
+    // SMRR size cannot be less than 4-KBytes
+    // SMRR size must be of length 2^n
+    // SMRR base alignment cannot be less than SMRR length
+    //
+    if ((CpuHotPlugData->SmrrSize < SIZE_4KB) ||
+        (CpuHotPlugData->SmrrSize != GetPowerOfTwo32 (CpuHotPlugData->SmrrSize)) ||
+        ((CpuHotPlugData->SmrrBase & ~(CpuHotPlugData->SmrrSize - 1)) != CpuHotPlugData->SmrrBase))
+    {
+      //
+      // Print message and halt if CPU is Monarch
+      //
+      if (IsMonarch) {
+        DEBUG ((DEBUG_ERROR, "SMM Base/Size does not meet alignment/size requirement!\n"));
+        CpuDeadLoop ();
+      }
+    } else {
+      AsmWriteMsr64 (SMMADDR_ADDRESS, CpuHotPlugData->SmrrBase);
+      AsmWriteMsr64 (SMMMASK_ADDRESS, ((~(UINT64)(CpuHotPlugData->SmrrSize - 1)) | 0x6600));
+    }
+  }
 }
 
 /**
@@ -159,7 +227,39 @@ SmmCpuFeaturesHookReturnFromSmm (
   IN UINT64                NewInstructionPointer
   )
 {
-  return 0;
+  UINT64                    OriginalInstructionPointer;
+  AMD_SMRAM_SAVE_STATE_MAP  *AmdCpuState;
+
+  AmdCpuState = (AMD_SMRAM_SAVE_STATE_MAP *)CpuState;
+
+  if (mSmmSaveStateRegisterLma == EFI_SMM_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;
 }
 
 /**
-- 
2.25.1