Re: [PATCH 5/5] CpuException: Add InitializeSeparateExceptionStacks

["Dong, Eric" <eric.dong@intel.com>]

Acked-by: Eric Dong <eric.dong@intel.com>

-----Original Message-----
From: Ni, Ray <ray.ni@intel.com> 
Sent: Friday, May 20, 2022 10:16 PM
To: devel@edk2.groups.io
Cc: Dong, Eric <eric.dong@intel.com>; Wang, Jian J <jian.j.wang@intel.com>
Subject: [PATCH 5/5] CpuException: Add InitializeSeparateExceptionStacks

Today InitializeCpuExceptionHandlersEx is called from three modules:
1. DxeCore (links to DxeCpuExceptionHandlerLib)
    DxeCore expects it initializes the IDT entries as well as
    assigning separate stacks for #DF and #PF.
2. CpuMpPei (links to PeiCpuExceptionHandlerLib)
   and CpuDxe (links to DxeCpuExceptionHandlerLib)
    It's called for each thread for only assigning separate stacks for
    #DF and #PF. The IDT entries initialization is skipped because
    caller sets InitData->X64.InitDefaultHandlers to FALSE.

Additionally, SecPeiCpuExceptionHandlerLib, SmmCpuExceptionHandlerLib also implement such API and the behavior of the API is simply to initialize IDT entries only.

Because it mixes the IDT entries initialization and separate stacks assignment for certain exception handlers together, in order to know whether the function call only initializes IDT entries, or assigns stacks, we need to check:
1. value of InitData->X64.InitDefaultHandlers 2. library instance

This patch cleans up the code to separate the stack assignment to a new API:
InitializeSeparateExceptionStacks().

Only when caller calls the new API, the separate stacks are assigned.
With this change, the SecPei and Smm instance can return unsupported which gives caller a very clear status.

The old API InitializeCpuExceptionHandlersEx() is removed in this patch.
Because no platform module is consuming the old API, the impact is none.

Signed-off-by: Ray Ni <ray.ni@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
---
 MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c       |  2 +-
 .../Include/Library/CpuExceptionHandlerLib.h  | 24 ++---
 .../CpuExceptionHandlerLibNull.c              | 26 ++----
 UefiCpuPkg/CpuDxe/CpuMp.c                     |  6 +-
 UefiCpuPkg/CpuMpPei/CpuMpPei.c                |  4 +-
 .../CpuExceptionHandlerLib/DxeException.c     | 91 ++++++-------------
 .../CpuExceptionHandlerLib/PeiCpuException.c  | 51 ++---------
 .../SecPeiCpuException.c                      | 27 ++----
 .../CpuExceptionHandlerLib/SmmException.c     | 27 ++----
 9 files changed, 74 insertions(+), 184 deletions(-)

diff --git a/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c b/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
index 2c27fc0695..83f49d7c00 100644
--- a/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
+++ b/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c
@@ -253,7 +253,7 @@ DxeMain (
     VectorInfoList = (EFI_VECTOR_HANDOFF_INFO *)(GET_GUID_HOB_DATA (GuidHob));   } -  Status = InitializeCpuExceptionHandlersEx (VectorInfoList, NULL);+  Status = InitializeCpuExceptionHandlers (VectorInfoList);   ASSERT_EFI_ERROR (Status);    //diff --git a/MdeModulePkg/Include/Library/CpuExceptionHandlerLib.h b/MdeModulePkg/Include/Library/CpuExceptionHandlerLib.h
index d4649bebe1..9a495081f7 100644
--- a/MdeModulePkg/Include/Library/CpuExceptionHandlerLib.h
+++ b/MdeModulePkg/Include/Library/CpuExceptionHandlerLib.h
@@ -103,32 +103,20 @@ InitializeCpuExceptionHandlers (
   );  /**-  Initializes all CPU exceptions entries with optional extra initializations.+  Setup separate stacks for certain exception handlers. -  By default, this method should include all functionalities implemented by-  InitializeCpuExceptionHandlers(), plus extra initialization works, if any.-  This could be done by calling InitializeCpuExceptionHandlers() directly-  in this method besides the extra works.+  InitData is optional and processor arch dependent. -  InitData is optional and its use and content are processor arch dependent.-  The typical usage of it is to convey resources which have to be reserved-  elsewhere and are necessary for the extra initializations of exception.+  @param[in]  InitData      Pointer to data optional for information about how+                            to assign stacks for certain exception handlers. -  @param[in]  VectorInfo    Pointer to reserved vector list.-  @param[in]  InitData      Pointer to data optional for extra initializations-                            of exception.--  @retval EFI_SUCCESS             The exceptions have been successfully-                                  initialized.-  @retval EFI_INVALID_PARAMETER   VectorInfo or InitData contains invalid-                                  content.+  @retval EFI_SUCCESS             The stacks are assigned successfully.   @retval EFI_UNSUPPORTED         This function is not supported.  **/ EFI_STATUS EFIAPI-InitializeCpuExceptionHandlersEx (-  IN EFI_VECTOR_HANDOFF_INFO  *VectorInfo OPTIONAL,+InitializeSeparateExceptionStacks (   IN CPU_EXCEPTION_INIT_DATA  *InitData OPTIONAL   ); diff --git a/MdeModulePkg/Library/CpuExceptionHandlerLibNull/CpuExceptionHandlerLibNull.c b/MdeModulePkg/Library/CpuExceptionHandlerLibNull/CpuExceptionHandlerLibNull.c
index 54f38788fe..8aeedcb4d1 100644
--- a/MdeModulePkg/Library/CpuExceptionHandlerLibNull/CpuExceptionHandlerLibNull.c
+++ b/MdeModulePkg/Library/CpuExceptionHandlerLibNull/CpuExceptionHandle
+++ rLibNull.c
@@ -82,34 +82,22 @@ DumpCpuContext (
 }  /**-  Initializes all CPU exceptions entries with optional extra initializations.+  Setup separate stacks for certain exception handlers. -  By default, this method should include all functionalities implemented by-  InitializeCpuExceptionHandlers(), plus extra initialization works, if any.-  This could be done by calling InitializeCpuExceptionHandlers() directly-  in this method besides the extra works.+  InitData is optional and processor arch dependent. -  InitData is optional and its use and content are processor arch dependent.-  The typical usage of it is to convey resources which have to be reserved-  elsewhere and are necessary for the extra initializations of exception.+  @param[in]  InitData      Pointer to data optional for information about how+                            to assign stacks for certain exception handlers. -  @param[in]  VectorInfo    Pointer to reserved vector list.-  @param[in]  InitData      Pointer to data optional for extra initializations-                            of exception.--  @retval EFI_SUCCESS             The exceptions have been successfully-                                  initialized.-  @retval EFI_INVALID_PARAMETER   VectorInfo or InitData contains invalid-                                  content.+  @retval EFI_SUCCESS             The stacks are assigned successfully.   @retval EFI_UNSUPPORTED         This function is not supported.  **/ EFI_STATUS EFIAPI-InitializeCpuExceptionHandlersEx (-  IN EFI_VECTOR_HANDOFF_INFO  *VectorInfo OPTIONAL,+InitializeSeparateExceptionStacks (   IN CPU_EXCEPTION_INIT_DATA  *InitData OPTIONAL   ) {-  return InitializeCpuExceptionHandlers (VectorInfo);+  return EFI_UNSUPPORTED; }diff --git a/UefiCpuPkg/CpuDxe/CpuMp.c b/UefiCpuPkg/CpuDxe/CpuMp.c
index 1f218367b3..e385f585c7 100644
--- a/UefiCpuPkg/CpuDxe/CpuMp.c
+++ b/UefiCpuPkg/CpuDxe/CpuMp.c
@@ -1,7 +1,7 @@
 /** @file   CPU DXE Module to produce CPU MP Protocol. -  Copyright (c) 2008 - 2017, Intel Corporation. All rights reserved.<BR>+  Copyright (c) 2008 - 2022, Intel Corporation. All rights reserved.<BR>   SPDX-License-Identifier: BSD-2-Clause-Patent  **/@@ -617,7 +617,7 @@ GetGdtr (
 /**   Initializes CPU exceptions handlers for the sake of stack switch requirement. -  This function is a wrapper of InitializeCpuExceptionHandlersEx. It's mainly+  This function is a wrapper of InitializeSeparateExceptionStacks. It's mainly   for the sake of AP's init because of EFI_AP_PROCEDURE API requirement.    @param[in,out] Buffer  The pointer to private data buffer.@@ -641,7 +641,7 @@ InitializeExceptionStackSwitchHandlers (
   AsmReadIdtr (&Idtr);   EssData->Ia32.IdtTable     = (VOID *)Idtr.Base;   EssData->Ia32.IdtTableSize = Idtr.Limit + 1;-  Status                     = InitializeCpuExceptionHandlersEx (NULL, EssData);+  Status                     = InitializeSeparateExceptionStacks (EssData);   ASSERT_EFI_ERROR (Status); } diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.c b/UefiCpuPkg/CpuMpPei/CpuMpPei.c
index 1e68c91d95..d4786979fa 100644
--- a/UefiCpuPkg/CpuMpPei/CpuMpPei.c
+++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.c
@@ -432,7 +432,7 @@ GetGdtr (
 /**   Initializes CPU exceptions handlers for the sake of stack switch requirement. -  This function is a wrapper of InitializeCpuExceptionHandlersEx. It's mainly+  This function is a wrapper of InitializeSeparateExceptionStacks. It's mainly   for the sake of AP's init because of EFI_AP_PROCEDURE API requirement.    @param[in,out] Buffer  The pointer to private data buffer.@@ -456,7 +456,7 @@ InitializeExceptionStackSwitchHandlers (
   AsmReadIdtr (&Idtr);   EssData->Ia32.IdtTable     = (VOID *)Idtr.Base;   EssData->Ia32.IdtTableSize = Idtr.Limit + 1;-  Status                     = InitializeCpuExceptionHandlersEx (NULL, EssData);+  Status                     = InitializeSeparateExceptionStacks (EssData);   ASSERT_EFI_ERROR (Status); } diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c
index c7c1fe31d2..e62bb5e6c0 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c
@@ -103,82 +103,49 @@ RegisterCpuInterruptHandler (
 }  /**-  Initializes CPU exceptions entries and setup stack switch for given exceptions.+  Setup separate stacks for certain exception handlers. -  This method will call InitializeCpuExceptionHandlers() to setup default-  exception handlers unless indicated not to do it explicitly.+  InitData is optional and processor arch dependent. -  If InitData is passed with NULL, this method will use the resource reserved-  by global variables to initialize it; Otherwise it will use data in InitData-  to setup stack switch. This is for the different use cases in DxeCore and-  Cpu MP exception initialization.+  @param[in]  InitData      Pointer to data optional for information about how+                            to assign stacks for certain exception handlers. -  @param[in]  VectorInfo    Pointer to reserved vector list.-  @param[in]  InitData      Pointer to data required to setup stack switch for-                            given exceptions.--  @retval EFI_SUCCESS             The exceptions have been successfully-                                  initialized.-  @retval EFI_INVALID_PARAMETER   VectorInfo or InitData contains invalid-                                  content.+  @retval EFI_SUCCESS             The stacks are assigned successfully.+  @retval EFI_UNSUPPORTED         This function is not supported.  **/ EFI_STATUS EFIAPI-InitializeCpuExceptionHandlersEx (-  IN EFI_VECTOR_HANDOFF_INFO  *VectorInfo OPTIONAL,+InitializeSeparateExceptionStacks (   IN CPU_EXCEPTION_INIT_DATA  *InitData OPTIONAL   ) {-  EFI_STATUS               Status;   CPU_EXCEPTION_INIT_DATA  EssData;   IA32_DESCRIPTOR          Idtr;   IA32_DESCRIPTOR          Gdtr; -  //-  // To avoid repeat initialization of default handlers, the caller should pass-  // an extended init data with InitDefaultHandlers set to FALSE. There's no-  // need to call this method to just initialize default handlers. Call non-ex-  // version instead; or this method must be implemented as a simple wrapper of-  // non-ex version of it, if this version has to be called.-  //-  if ((InitData == NULL) || InitData->X64.InitDefaultHandlers) {-    Status = InitializeCpuExceptionHandlers (VectorInfo);-  } else {-    Status = EFI_SUCCESS;-  }--  if (!EFI_ERROR (Status)) {-    //-    // Initializing stack switch is only necessary for Stack Guard functionality.-    //-    if (PcdGetBool (PcdCpuStackGuard)) {-      if (InitData == NULL) {-        SetMem (mNewGdt, sizeof (mNewGdt), 0);--        AsmReadIdtr (&Idtr);-        AsmReadGdtr (&Gdtr);--        EssData.X64.Revision                   = CPU_EXCEPTION_INIT_DATA_REV;-        EssData.X64.KnownGoodStackTop          = (UINTN)mNewStack + sizeof (mNewStack);-        EssData.X64.KnownGoodStackSize         = CPU_KNOWN_GOOD_STACK_SIZE;-        EssData.X64.StackSwitchExceptions      = CPU_STACK_SWITCH_EXCEPTION_LIST;-        EssData.X64.StackSwitchExceptionNumber = CPU_STACK_SWITCH_EXCEPTION_NUMBER;-        EssData.X64.IdtTable                   = (VOID *)Idtr.Base;-        EssData.X64.IdtTableSize               = Idtr.Limit + 1;-        EssData.X64.GdtTable                   = mNewGdt;-        EssData.X64.GdtTableSize               = sizeof (mNewGdt);-        EssData.X64.ExceptionTssDesc           = mNewGdt + Gdtr.Limit + 1;-        EssData.X64.ExceptionTssDescSize       = CPU_TSS_DESC_SIZE;-        EssData.X64.ExceptionTss               = mNewGdt + Gdtr.Limit + 1 + CPU_TSS_DESC_SIZE;-        EssData.X64.ExceptionTssSize           = CPU_TSS_SIZE;--        InitData = &EssData;-      }--      Status = ArchSetupExceptionStack (InitData);-    }+  if (InitData == NULL) {+    SetMem (mNewGdt, sizeof (mNewGdt), 0);++    AsmReadIdtr (&Idtr);+    AsmReadGdtr (&Gdtr);++    EssData.X64.Revision                   = CPU_EXCEPTION_INIT_DATA_REV;+    EssData.X64.KnownGoodStackTop          = (UINTN)mNewStack + sizeof (mNewStack);+    EssData.X64.KnownGoodStackSize         = CPU_KNOWN_GOOD_STACK_SIZE;+    EssData.X64.StackSwitchExceptions      = CPU_STACK_SWITCH_EXCEPTION_LIST;+    EssData.X64.StackSwitchExceptionNumber = CPU_STACK_SWITCH_EXCEPTION_NUMBER;+    EssData.X64.IdtTable                   = (VOID *)Idtr.Base;+    EssData.X64.IdtTableSize               = Idtr.Limit + 1;+    EssData.X64.GdtTable                   = mNewGdt;+    EssData.X64.GdtTableSize               = sizeof (mNewGdt);+    EssData.X64.ExceptionTssDesc           = mNewGdt + Gdtr.Limit + 1;+    EssData.X64.ExceptionTssDescSize       = CPU_TSS_DESC_SIZE;+    EssData.X64.ExceptionTss               = mNewGdt + Gdtr.Limit + 1 + CPU_TSS_DESC_SIZE;+    EssData.X64.ExceptionTssSize           = CPU_TSS_SIZE;++    InitData = &EssData;   } -  return Status;+  return ArchSetupExceptionStack (InitData); }diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuException.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuException.c
index 1ae611c75e..494c2ab433 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuException.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiCpuException.c
@@ -150,57 +150,26 @@ InitializeCpuExceptionHandlers (
 }  /**-  Initializes all CPU exceptions entries with optional extra initializations.+  Setup separate stacks for certain exception handlers. -  By default, this method should include all functionalities implemented by-  InitializeCpuExceptionHandlers(), plus extra initialization works, if any.-  This could be done by calling InitializeCpuExceptionHandlers() directly-  in this method besides the extra works.+  InitData is optional and processor arch dependent. -  InitData is optional and its use and content are processor arch dependent.-  The typical usage of it is to convey resources which have to be reserved-  elsewhere and are necessary for the extra initializations of exception.+  @param[in]  InitData      Pointer to data optional for information about how+                            to assign stacks for certain exception handlers. -  @param[in]  VectorInfo    Pointer to reserved vector list.-  @param[in]  InitData      Pointer to data optional for extra initializations-                            of exception.--  @retval EFI_SUCCESS             The exceptions have been successfully-                                  initialized.-  @retval EFI_INVALID_PARAMETER   VectorInfo or InitData contains invalid-                                  content.+  @retval EFI_SUCCESS             The stacks are assigned successfully.+  @retval EFI_UNSUPPORTED         This function is not supported.  **/ EFI_STATUS EFIAPI-InitializeCpuExceptionHandlersEx (-  IN EFI_VECTOR_HANDOFF_INFO  *VectorInfo OPTIONAL,+InitializeSeparateExceptionStacks (   IN CPU_EXCEPTION_INIT_DATA  *InitData OPTIONAL   ) {-  EFI_STATUS  Status;--  //-  // To avoid repeat initialization of default handlers, the caller should pass-  // an extended init data with InitDefaultHandlers set to FALSE. There's no-  // need to call this method to just initialize default handlers. Call non-ex-  // version instead; or this method must be implemented as a simple wrapper of-  // non-ex version of it, if this version has to be called.-  //-  if ((InitData == NULL) || InitData->Ia32.InitDefaultHandlers) {-    Status = InitializeCpuExceptionHandlers (VectorInfo);-  } else {-    Status = EFI_SUCCESS;-  }--  if (!EFI_ERROR (Status)) {-    //-    // Initializing stack switch is only necessary for Stack Guard functionality.-    //-    if (PcdGetBool (PcdCpuStackGuard) && (InitData != NULL)) {-      Status = ArchSetupExceptionStack (InitData);-    }+  if (InitData == NULL) {+    return EFI_UNSUPPORTED;   } -  return Status;+  return ArchSetupExceptionStack (InitData); }diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c
index e894ead612..4313cc5582 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c
@@ -200,33 +200,22 @@ RegisterCpuInterruptHandler (
 }  /**-  Initializes all CPU exceptions entries with optional extra initializations.+  Setup separate stacks for certain exception handlers. -  By default, this method should include all functionalities implemented by-  InitializeCpuExceptionHandlers(), plus extra initialization works, if any.-  This could be done by calling InitializeCpuExceptionHandlers() directly-  in this method besides the extra works.+  InitData is optional and processor arch dependent. -  InitData is optional and its use and content are processor arch dependent.-  The typical usage of it is to convey resources which have to be reserved-  elsewhere and are necessary for the extra initializations of exception.+  @param[in]  InitData      Pointer to data optional for information about how+                            to assign stacks for certain exception handlers. -  @param[in]  VectorInfo    Pointer to reserved vector list.-  @param[in]  InitData      Pointer to data optional for extra initializations-                            of exception.--  @retval EFI_SUCCESS             The exceptions have been successfully-                                  initialized.-  @retval EFI_INVALID_PARAMETER   VectorInfo or InitData contains invalid-                                  content.+  @retval EFI_SUCCESS             The stacks are assigned successfully.+  @retval EFI_UNSUPPORTED         This function is not supported.  **/ EFI_STATUS EFIAPI-InitializeCpuExceptionHandlersEx (-  IN EFI_VECTOR_HANDOFF_INFO  *VectorInfo OPTIONAL,+InitializeSeparateExceptionStacks (   IN CPU_EXCEPTION_INIT_DATA  *InitData OPTIONAL   ) {-  return InitializeCpuExceptionHandlers (VectorInfo);+  return EFI_UNSUPPORTED; }diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmException.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmException.c
index ec643556c7..1c97dab926 100644
--- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmException.c
+++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SmmException.c
@@ -96,33 +96,22 @@ RegisterCpuInterruptHandler (
 }  /**-  Initializes all CPU exceptions entries with optional extra initializations.+  Setup separate stacks for certain exception handlers. -  By default, this method should include all functionalities implemented by-  InitializeCpuExceptionHandlers(), plus extra initialization works, if any.-  This could be done by calling InitializeCpuExceptionHandlers() directly-  in this method besides the extra works.+  InitData is optional and processor arch dependent. -  InitData is optional and its use and content are processor arch dependent.-  The typical usage of it is to convey resources which have to be reserved-  elsewhere and are necessary for the extra initializations of exception.+  @param[in]  InitData      Pointer to data optional for information about how+                            to assign stacks for certain exception handlers. -  @param[in]  VectorInfo    Pointer to reserved vector list.-  @param[in]  InitData      Pointer to data optional for extra initializations-                            of exception.--  @retval EFI_SUCCESS             The exceptions have been successfully-                                  initialized.-  @retval EFI_INVALID_PARAMETER   VectorInfo or InitData contains invalid-                                  content.+  @retval EFI_SUCCESS             The stacks are assigned successfully.+  @retval EFI_UNSUPPORTED         This function is not supported.  **/ EFI_STATUS EFIAPI-InitializeCpuExceptionHandlersEx (-  IN EFI_VECTOR_HANDOFF_INFO  *VectorInfo OPTIONAL,+InitializeSeparateExceptionStacks (   IN CPU_EXCEPTION_INIT_DATA  *InitData OPTIONAL   ) {-  return InitializeCpuExceptionHandlers (VectorInfo);+  return EFI_UNSUPPORTED; }-- 
2.35.1.windows.2