[PATCH v8 08/46] UefiCpuPkg: Implement library support for VMGEXIT

["Lendacky, Thomas" <thomas.lendacky@amd.com>]

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

To support handling #VC exceptions and issuing VMGEXIT instructions,
create a library with functions that can be used to perform these
#VC/VMGEXIT related operations. This includes functions for:
  - Handling #VC 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
SEV-ES guest.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 UefiCpuPkg/UefiCpuPkg.dec                     |   3 +
 UefiCpuPkg/UefiCpuPkg.dsc                     |   2 +
 .../Library/VmgExitLibNull/VmgExitLibNull.inf |  27 ++++
 UefiCpuPkg/Include/Library/VmgExitLib.h       | 103 +++++++++++++++
 .../Library/VmgExitLibNull/VmgExitLibNull.c   | 121 ++++++++++++++++++
 .../Library/VmgExitLibNull/VmgExitLibNull.uni |  15 +++
 6 files changed, 271 insertions(+)
 create mode 100644 UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.inf
 create mode 100644 UefiCpuPkg/Include/Library/VmgExitLib.h
 create mode 100644 UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.c
 create mode 100644 UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.uni

diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec
index df5d02bae6b4..cb92f34b6f55 100644
--- a/UefiCpuPkg/UefiCpuPkg.dec
+++ b/UefiCpuPkg/UefiCpuPkg.dec
@@ -53,6 +53,9 @@ [LibraryClasses.IA32, LibraryClasses.X64]
   ##
   MpInitLib|Include/Library/MpInitLib.h
 
+  ##  @libraryclass  Provides function to support VMGEXIT processing.
+  VmgExitLib|Include/Library/VmgExitLib.h
+
 [Guids]
   gUefiCpuPkgTokenSpaceGuid      = { 0xac05bf33, 0x995a, 0x4ed4, { 0xaa, 0xb8, 0xef, 0x7a, 0xe8, 0xf, 0x5c, 0xb0 }}
   gMsegSmramGuid                 = { 0x5802bce4, 0xeeee, 0x4e33, { 0xa1, 0x30, 0xeb, 0xad, 0x27, 0xf0, 0xe4, 0x39 }}
diff --git a/UefiCpuPkg/UefiCpuPkg.dsc b/UefiCpuPkg/UefiCpuPkg.dsc
index afa304128221..f0e58b90ff0a 100644
--- a/UefiCpuPkg/UefiCpuPkg.dsc
+++ b/UefiCpuPkg/UefiCpuPkg.dsc
@@ -56,6 +56,7 @@ [LibraryClasses]
   PeCoffGetEntryPointLib|MdePkg/Library/BasePeCoffGetEntryPointLib/BasePeCoffGetEntryPointLib.inf
   PeCoffExtraActionLib|MdePkg/Library/BasePeCoffExtraActionLibNull/BasePeCoffExtraActionLibNull.inf
   TpmMeasurementLib|MdeModulePkg/Library/TpmMeasurementLibNull/TpmMeasurementLibNull.inf
+  VmgExitLib|UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.inf
 
 [LibraryClasses.common.SEC]
   PlatformSecLib|UefiCpuPkg/Library/PlatformSecLibNull/PlatformSecLibNull.inf
@@ -143,6 +144,7 @@ [Components.IA32, Components.X64]
   UefiCpuPkg/Library/SmmCpuPlatformHookLibNull/SmmCpuPlatformHookLibNull.inf
   UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf
   UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibStm.inf
+  UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.inf
   UefiCpuPkg/PiSmmCommunication/PiSmmCommunicationPei.inf
   UefiCpuPkg/PiSmmCommunication/PiSmmCommunicationSmm.inf
   UefiCpuPkg/SecCore/SecCore.inf
diff --git a/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.inf b/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.inf
new file mode 100644
index 000000000000..d8770a21c355
--- /dev/null
+++ b/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.inf
@@ -0,0 +1,27 @@
+## @file
+#  VMGEXIT Support Library.
+#
+#  Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = VmgExitLibNull
+  MODULE_UNI_FILE                = VmgExitLibNull.uni
+  FILE_GUID                      = 3cd7368f-ef9b-4a9b-9571-2ed93813677e
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = VmgExitLib
+
+[Sources.common]
+  VmgExitLibNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  UefiCpuPkg/UefiCpuPkg.dec
+
+[LibraryClasses]
+  BaseLib
+
diff --git a/UefiCpuPkg/Include/Library/VmgExitLib.h b/UefiCpuPkg/Include/Library/VmgExitLib.h
new file mode 100644
index 000000000000..e7282a7e225d
--- /dev/null
+++ b/UefiCpuPkg/Include/Library/VmgExitLib.h
@@ -0,0 +1,103 @@
+/** @file
+  Public header file for the VMGEXIT Support library class.
+
+  This library class defines some routines used when invoking the VMGEXIT
+  instruction in support of SEV-ES and to handle #VC exceptions.
+
+  Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef __VMG_EXIT_LIB_H__
+#define __VMG_EXIT_LIB_H__
+
+#include <Protocol/DebugSupport.h>
+#include <Register/Amd/Ghcb.h>
+
+
+/**
+  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.
+  @retval  Others             VMGEXIT processing did not succeed. Exception
+                              number to be propagated.
+
+**/
+UINT64
+EFIAPI
+VmgExit (
+  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
+
+**/
+VOID
+EFIAPI
+VmgInit (
+  IN OUT GHCB                *Ghcb
+  );
+
+/**
+  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
+
+**/
+VOID
+EFIAPI
+VmgDone (
+  IN OUT GHCB                *Ghcb
+  );
+
+/**
+  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
+VmgExitHandleVc (
+  IN OUT EFI_EXCEPTION_TYPE  *ExceptionType,
+  IN OUT EFI_SYSTEM_CONTEXT  SystemContext
+  );
+
+#endif
diff --git a/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.c b/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.c
new file mode 100644
index 000000000000..da680ced5b09
--- /dev/null
+++ b/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.c
@@ -0,0 +1,121 @@
+/** @file
+  VMGEXIT Base Support Library.
+
+  Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Base.h>
+#include <Uefi.h>
+#include <Library/VmgExitLib.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.
+  @retval  Others             VMGEXIT processing did not succeed. Exception
+                              event to be propagated.
+
+**/
+UINT64
+EFIAPI
+VmgExit (
+  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.
+
+  The base library function does nothing.
+
+  @param[in, out]  Ghcb       A pointer to the GHCB
+
+**/
+VOID
+EFIAPI
+VmgInit (
+  IN OUT GHCB                *Ghcb
+  )
+{
+}
+
+/**
+  Perform post-VMGEXIT cleanup.
+
+  Performs the necessary steps to cleanup after invoking VMGEXIT. Must be
+  called after obtaining needed fields within the GHCB.
+
+  The base library function does nothing.
+
+  @param[in, out]  Ghcb       A pointer to the GHCB
+
+**/
+VOID
+EFIAPI
+VmgDone (
+  IN OUT GHCB                *Ghcb
+  )
+{
+}
+
+/**
+  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
+VmgExitHandleVc (
+  IN OUT EFI_EXCEPTION_TYPE  *ExceptionType,
+  IN OUT EFI_SYSTEM_CONTEXT  SystemContext
+  )
+{
+  *ExceptionType = VC_EXCEPTION;
+
+  return EFI_UNSUPPORTED;
+}
diff --git a/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.uni b/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.uni
new file mode 100644
index 000000000000..8639bc0e8ce9
--- /dev/null
+++ b/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.uni
@@ -0,0 +1,15 @@
+// /** @file
+// VMGEXIT support library instance.
+//
+// VMGEXIT support library instance.
+//
+// Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+// **/
+
+
+#string STR_MODULE_ABSTRACT             #language en-US "VMGEXIT support NULL library instance"
+
+#string STR_MODULE_DESCRIPTION          #language en-US "VMGEXIT support NULL library instance."
+
-- 
2.17.1