[PATCH 1/8] UefiCpuPkg: Add CcExitLib

["Min Xu" <min.m.xu@intel.com>]

From: Min M Xu <min.m.xu@intel.com>

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4123

CcExitLib is designed to support handling #VC/#VE exceptions and issuing
VMGEXIT instructions. It can be used to perform these:
  - Handling #VC exceptions
  - Handling #VE exceptions
  - Preparing for and issuing a VMGEXIT
  - Performing MMIO-related write operations to support flash emulation
  - Performing AP related boot opeations

The base functions in this driver will not do anything and will return
an error if a return value is required. It is expected that other packages
(like OvmfPkg) will create a version of the library to fully support an
CC gueste (such as SEV-ES and TDX).

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
---
 UefiCpuPkg/Include/Library/CcExitLib.h        | 176 ++++++++++++++++
 .../Library/CcExitLibNull/CcExitLibNull.c     | 194 ++++++++++++++++++
 .../Library/CcExitLibNull/CcExitLibNull.inf   |  28 +++
 .../Library/CcExitLibNull/CcExitLibNull.uni   |  14 ++
 UefiCpuPkg/UefiCpuPkg.dec                     |   3 +
 5 files changed, 415 insertions(+)
 create mode 100644 UefiCpuPkg/Include/Library/CcExitLib.h
 create mode 100644 UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.c
 create mode 100644 UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.inf
 create mode 100644 UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.uni

diff --git a/UefiCpuPkg/Include/Library/CcExitLib.h b/UefiCpuPkg/Include/Library/CcExitLib.h
new file mode 100644
index 000000000000..40372e10b39e
--- /dev/null
+++ b/UefiCpuPkg/Include/Library/CcExitLib.h
@@ -0,0 +1,176 @@
+/** @file
+  Public header file for the CcExitLib.
+
+  This library class defines some routines used for below CcExit handler.
+   - Invoking the VMGEXIT instruction in support of SEV-ES and to handle
+     #VC exceptions.
+   - Handle #VE exception in TDX.
+
+  Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+  Copyright (c) 2020 - 2022, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef CC_EXIT_LIB_H_
+#define CC_EXIT_LIB_H_
+
+#include <Protocol/DebugSupport.h>
+#include <Register/Amd/Ghcb.h>
+
+#define VE_EXCEPTION  20
+
+/**
+  Perform VMGEXIT.
+
+  Sets the necessary fields of the GHCB, invokes the VMGEXIT instruction and
+  then handles the return actions.
+
+  @param[in, out]  Ghcb       A pointer to the GHCB
+  @param[in]       ExitCode   VMGEXIT code to be assigned to the SwExitCode
+                              field of the GHCB.
+  @param[in]       ExitInfo1  VMGEXIT information to be assigned to the
+                              SwExitInfo1 field of the GHCB.
+  @param[in]       ExitInfo2  VMGEXIT information to be assigned to the
+                              SwExitInfo2 field of the GHCB.
+
+  @retval  0                  VMGEXIT succeeded.
+  @return                     Exception number to be propagated, VMGEXIT
+                              processing did not succeed.
+
+**/
+UINT64
+EFIAPI
+CcExitLibVmgExit (
+  IN OUT GHCB    *Ghcb,
+  IN     UINT64  ExitCode,
+  IN     UINT64  ExitInfo1,
+  IN     UINT64  ExitInfo2
+  );
+
+/**
+  Perform pre-VMGEXIT initialization/preparation.
+
+  Performs the necessary steps in preparation for invoking VMGEXIT. Must be
+  called before setting any fields within the GHCB.
+
+  @param[in, out]  Ghcb            A pointer to the GHCB
+  @param[in, out]  InterruptState  A pointer to hold the current interrupt
+                                   state, used for restoring in CcExitLibVmgDone ()
+
+**/
+VOID
+EFIAPI
+CcExitLibVmgInit (
+  IN OUT GHCB     *Ghcb,
+  IN OUT BOOLEAN  *InterruptState
+  );
+
+/**
+  Perform post-VMGEXIT cleanup.
+
+  Performs the necessary steps to cleanup after invoking VMGEXIT. Must be
+  called after obtaining needed fields within the GHCB.
+
+  @param[in, out]  Ghcb            A pointer to the GHCB
+  @param[in]       InterruptState  An indicator to conditionally (re)enable
+                                   interrupts
+
+**/
+VOID
+EFIAPI
+CcExitLibVmgDone (
+  IN OUT GHCB     *Ghcb,
+  IN     BOOLEAN  InterruptState
+  );
+
+/**
+  Marks a specified offset as valid in the GHCB.
+
+  The ValidBitmap area represents the areas of the GHCB that have been marked
+  valid. Set the bit in ValidBitmap for the input offset.
+
+  @param[in, out]  Ghcb       A pointer to the GHCB
+  @param[in]       Offset     Qword offset in the GHCB to mark valid
+
+**/
+VOID
+EFIAPI
+CcExitLibVmgSetOffsetValid (
+  IN OUT GHCB           *Ghcb,
+  IN     GHCB_REGISTER  Offset
+  );
+
+/**
+  Checks if a specified offset is valid in the GHCB.
+
+  The ValidBitmap area represents the areas of the GHCB that have been marked
+  valid. Return whether the bit in the ValidBitmap is set for the input offset.
+
+  @param[in]  Ghcb            A pointer to the GHCB
+  @param[in]  Offset          Qword offset in the GHCB to mark valid
+
+  @retval TRUE                Offset is marked valid in the GHCB
+  @retval FALSE               Offset is not marked valid in the GHCB
+
+**/
+BOOLEAN
+EFIAPI
+CcExitLibVmgIsOffsetValid (
+  IN GHCB           *Ghcb,
+  IN GHCB_REGISTER  Offset
+  );
+
+/**
+  Handle a #VC exception.
+
+  Performs the necessary processing to handle a #VC exception.
+
+  The base library function returns an error equal to VC_EXCEPTION,
+  to be propagated to the standard exception handling stack.
+
+  @param[in, out]  ExceptionType  Pointer to an EFI_EXCEPTION_TYPE to be set
+                                  as value to use on error.
+  @param[in, out]  SystemContext  Pointer to EFI_SYSTEM_CONTEXT
+
+  @retval  EFI_SUCCESS            Exception handled
+  @retval  EFI_UNSUPPORTED        #VC not supported, (new) exception value to
+                                  propagate provided
+  @retval  EFI_PROTOCOL_ERROR     #VC handling failed, (new) exception value to
+                                  propagate provided
+
+**/
+EFI_STATUS
+EFIAPI
+CcExitHandleVc (
+  IN OUT EFI_EXCEPTION_TYPE  *ExceptionType,
+  IN OUT EFI_SYSTEM_CONTEXT  SystemContext
+  );
+
+/**
+  Handle a #VE exception.
+
+  Performs the necessary processing to handle a #VE exception.
+
+  The base library function returns an error equal to VE_EXCEPTION,
+  to be propagated to the standard exception handling stack.
+
+  @param[in, out]  ExceptionType  Pointer to an EFI_EXCEPTION_TYPE to be set
+                                  as value to use on error.
+  @param[in, out]  SystemContext  Pointer to EFI_SYSTEM_CONTEXT
+
+  @retval  EFI_SUCCESS            Exception handled
+  @retval  EFI_UNSUPPORTED        #VE not supported, (new) exception value to
+                                  propagate provided
+  @retval  EFI_PROTOCOL_ERROR     #VE handling failed, (new) exception value to
+                                  propagate provided
+
+**/
+EFI_STATUS
+EFIAPI
+CcExitHandleVe (
+  IN OUT EFI_EXCEPTION_TYPE  *ExceptionType,
+  IN OUT EFI_SYSTEM_CONTEXT  SystemContext
+  );
+
+#endif
diff --git a/UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.c b/UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.c
new file mode 100644
index 000000000000..bd23793f1e04
--- /dev/null
+++ b/UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.c
@@ -0,0 +1,194 @@
+/** @file
+  CcExit Base Support Library.
+
+  Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+  Copyright (c) 2020 - 2022, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Base.h>
+#include <Uefi.h>
+#include <Library/CcExitLib.h>
+
+/**
+  Perform VMGEXIT.
+
+  Sets the necessary fields of the GHCB, invokes the VMGEXIT instruction and
+  then handles the return actions.
+
+  The base library function returns an error in the form of a
+  GHCB_EVENT_INJECTION representing a GP_EXCEPTION.
+
+  @param[in, out]  Ghcb       A pointer to the GHCB
+  @param[in]       ExitCode   VMGEXIT code to be assigned to the SwExitCode
+                              field of the GHCB.
+  @param[in]       ExitInfo1  VMGEXIT information to be assigned to the
+                              SwExitInfo1 field of the GHCB.
+  @param[in]       ExitInfo2  VMGEXIT information to be assigned to the
+                              SwExitInfo2 field of the GHCB.
+
+  @retval  0                  VMGEXIT succeeded.
+  @return                     Exception number to be propagated, VMGEXIT
+                              processing did not succeed.
+
+**/
+UINT64
+EFIAPI
+CcExitLibVmgExit (
+  IN OUT GHCB    *Ghcb,
+  IN     UINT64  ExitCode,
+  IN     UINT64  ExitInfo1,
+  IN     UINT64  ExitInfo2
+  )
+{
+  GHCB_EVENT_INJECTION  Event;
+
+  Event.Uint64          = 0;
+  Event.Elements.Vector = GP_EXCEPTION;
+  Event.Elements.Type   = GHCB_EVENT_INJECTION_TYPE_EXCEPTION;
+  Event.Elements.Valid  = 1;
+
+  return Event.Uint64;
+}
+
+/**
+  Perform pre-VMGEXIT initialization/preparation.
+
+  Performs the necessary steps in preparation for invoking VMGEXIT. Must be
+  called before setting any fields within the GHCB.
+
+  @param[in, out]  Ghcb            A pointer to the GHCB
+  @param[in, out]  InterruptState  A pointer to hold the current interrupt
+                                   state, used for restoring in CcExitLibVmgDone ()
+
+**/
+VOID
+EFIAPI
+CcExitLibVmgInit (
+  IN OUT GHCB     *Ghcb,
+  IN OUT BOOLEAN  *InterruptState
+  )
+{
+}
+
+/**
+  Perform post-VMGEXIT cleanup.
+
+  Performs the necessary steps to cleanup after invoking VMGEXIT. Must be
+  called after obtaining needed fields within the GHCB.
+
+  @param[in, out]  Ghcb            A pointer to the GHCB
+  @param[in]       InterruptState  An indicator to conditionally (re)enable
+                                   interrupts
+
+**/
+VOID
+EFIAPI
+CcExitLibVmgDone (
+  IN OUT GHCB     *Ghcb,
+  IN     BOOLEAN  InterruptState
+  )
+{
+}
+
+/**
+  Marks a field at the specified offset as valid in the GHCB.
+
+  The ValidBitmap area represents the areas of the GHCB that have been marked
+  valid. Set the bit in ValidBitmap for the input offset.
+
+  @param[in, out] Ghcb    Pointer to the Guest-Hypervisor Communication Block
+  @param[in]      Offset  Qword offset in the GHCB to mark valid
+
+**/
+VOID
+EFIAPI
+CcExitLibVmgSetOffsetValid (
+  IN OUT GHCB           *Ghcb,
+  IN     GHCB_REGISTER  Offset
+  )
+{
+}
+
+/**
+  Checks if a specified offset is valid in the GHCB.
+
+  The ValidBitmap area represents the areas of the GHCB that have been marked
+  valid. Return whether the bit in the ValidBitmap is set for the input offset.
+
+  @param[in]  Ghcb            A pointer to the GHCB
+  @param[in]  Offset          Qword offset in the GHCB to mark valid
+
+  @retval TRUE                Offset is marked valid in the GHCB
+  @retval FALSE               Offset is not marked valid in the GHCB
+
+**/
+BOOLEAN
+EFIAPI
+CcExitLibVmgIsOffsetValid (
+  IN GHCB           *Ghcb,
+  IN GHCB_REGISTER  Offset
+  )
+{
+  return FALSE;
+}
+
+/**
+  Handle a #VC exception.
+
+  Performs the necessary processing to handle a #VC exception.
+
+  The base library function returns an error equal to VC_EXCEPTION,
+  to be propagated to the standard exception handling stack.
+
+  @param[in, out]  ExceptionType  Pointer to an EFI_EXCEPTION_TYPE to be set
+                                  as value to use on error.
+  @param[in, out]  SystemContext  Pointer to EFI_SYSTEM_CONTEXT
+
+  @retval  EFI_SUCCESS            Exception handled
+  @retval  EFI_UNSUPPORTED        #VC not supported, (new) exception value to
+                                  propagate provided
+  @retval  EFI_PROTOCOL_ERROR     #VC handling failed, (new) exception value to
+                                  propagate provided
+
+**/
+EFI_STATUS
+EFIAPI
+CcExitHandleVc (
+  IN OUT EFI_EXCEPTION_TYPE  *ExceptionType,
+  IN OUT EFI_SYSTEM_CONTEXT  SystemContext
+  )
+{
+  *ExceptionType = VC_EXCEPTION;
+
+  return EFI_UNSUPPORTED;
+}
+
+/**
+  Handle a #VE exception.
+
+  Performs the necessary processing to handle a #VE exception.
+
+  @param[in, out]  ExceptionType  Pointer to an EFI_EXCEPTION_TYPE to be set
+                                  as value to use on error.
+  @param[in, out]  SystemContext  Pointer to EFI_SYSTEM_CONTEXT
+
+  @retval  EFI_SUCCESS            Exception handled
+  @retval  EFI_UNSUPPORTED        #VE not supported, (new) exception value to
+                                  propagate provided
+  @retval  EFI_PROTOCOL_ERROR     #VE handling failed, (new) exception value to
+                                  propagate provided
+
+**/
+EFI_STATUS
+EFIAPI
+CcExitHandleVe (
+  IN OUT EFI_EXCEPTION_TYPE  *ExceptionType,
+  IN OUT EFI_SYSTEM_CONTEXT  SystemContext
+  )
+{
+  *ExceptionType = VE_EXCEPTION;
+
+  return EFI_UNSUPPORTED;
+}
diff --git a/UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.inf b/UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.inf
new file mode 100644
index 000000000000..c1f53e42dbe4
--- /dev/null
+++ b/UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.inf
@@ -0,0 +1,28 @@
+## @file
+#  CcExit Base Support Library.
+#
+#  Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+#  Copyright (c) 2020 - 2022, Intel Corporation. All rights reserved.<BR>
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = CcExitLibNull
+  MODULE_UNI_FILE                = CcExitLibNull.uni
+  FILE_GUID                      = 4029bbf2-ed6c-4cf6-ac17-a0213684ae41
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = CcExitLib
+
+[Sources.common]
+  CcExitLibNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  UefiCpuPkg/UefiCpuPkg.dec
+
+[LibraryClasses]
+  BaseLib
+
diff --git a/UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.uni b/UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.uni
new file mode 100644
index 000000000000..b18ae8792ed7
--- /dev/null
+++ b/UefiCpuPkg/Library/CcExitLibNull/CcExitLibNull.uni
@@ -0,0 +1,14 @@
+// /** @file
+// CcExitLib instance.
+//
+// Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+// Copyright (c) 2020 - 2022, Intel Corporation. All rights reserved.<BR>
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+// **/
+
+
+#string STR_MODULE_ABSTRACT             #language en-US "CcExitLib NULL instance"
+
+#string STR_MODULE_DESCRIPTION          #language en-US "CcExitLib NULL instance."
+
diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec
index 718323d9042c..8058b679412f 100644
--- a/UefiCpuPkg/UefiCpuPkg.dec
+++ b/UefiCpuPkg/UefiCpuPkg.dec
@@ -56,6 +56,9 @@
   ##  @libraryclass  Provides function to support VMGEXIT processing.
   VmgExitLib|Include/Library/VmgExitLib.h
 
+  ##  @libraryclass  Provides function to support CcExit processing.
+  CcExitLib|Include/Library/CcExitLib.h
+
   ##  @libraryclass  Provides function to get CPU cache information.
   CpuCacheInfoLib|Include/Library/CpuCacheInfoLib.h
 
-- 
2.29.2.windows.2