UefiCpuPkg: Implement library support for VMGEXIT

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>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>

6 files changed, 271 insertions, 0 deletions

diff --git a/UefiCpuPkg/Include/Library/VmgExitLib.h b/UefiCpuPkg/Include/Library/VmgExitLib.h
new file mode 100644
index 0000000000..45fc27d35e
--- /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.

+  @return                     Exception number to be propagated, VMGEXIT

+                              processing did not succeed.

+

+**/

+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 0000000000..bb265e1700
--- /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.

+  @return                     Exception number to be propagated, VMGEXIT

+                              processing did not succeed.

+

+**/

+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.inf b/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.inf
new file mode 100644
index 0000000000..d8770a21c3
--- /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/Library/VmgExitLibNull/VmgExitLibNull.uni b/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.uni
new file mode 100644
index 0000000000..8639bc0e8c
--- /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."

+

diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec
index d52912ddca..17228cb5a8 100644
--- a/UefiCpuPkg/UefiCpuPkg.dec
+++ b/UefiCpuPkg/UefiCpuPkg.dec
@@ -53,6 +53,9 @@
   ##

   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 964720048d..b2b6d78a71 100644
--- a/UefiCpuPkg/UefiCpuPkg.dsc
+++ b/UefiCpuPkg/UefiCpuPkg.dsc
@@ -56,6 +56,7 @@
   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 @@
   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