[PATCH 1/1] UefiCpuPkg: Extend SMM CPU Service with rendezvous support.

["Li, Zhihao" <zhihao.li@intel.com>]

From: "Li, Zhihao" <zhihao.li@intel.com>

REF? https://bugzilla.tianocore.org/show_bug.cgi?id=3815

This patch define a new Protocol with the new services
SmmWaitForAllProcessor(), which can be used by SMI handler
to optionally wait for other APs to complete SMM rendezvous in
relaxed AP mode.

A new library SmmCpuRendezvousLib is provided to abstract the service
into library API to simple SMI handler code.

Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Siyuan Fu <siyuan.fu@intel.com>
Cc: Zhihao Li <zhihao.li@intel.com>

Signed-off-by: Zhihao Li <zhihao.li@intel.com>
---
 .../SmmCpuRendezvousLib/SmmCpuRendezvousLib.c | 103 ++++++++++++++++++
 UefiCpuPkg/PiSmmCpuDxeSmm/CpuService.c        |  69 +++++++++++-
 UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c         |  20 +++-
 .../Include/Library/SmmCpuRendezvousLib.h     |  27 +++++
 UefiCpuPkg/Include/Protocol/SmmCpuService.h   |  36 +++++-
 .../SmmCpuRendezvousLib.inf                   |  35 ++++++
 UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h    |  29 ++++-
 UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf  |   5 +-
 UefiCpuPkg/UefiCpuPkg.dec                     |   8 +-
 UefiCpuPkg/UefiCpuPkg.dsc                     |   2 +
 10 files changed, 322 insertions(+), 12 deletions(-)
 create mode 100644 UefiCpuPkg/Library/SmmCpuRendezvousLib/SmmCpuRendezvousLib.c
 create mode 100644 UefiCpuPkg/Include/Library/SmmCpuRendezvousLib.h
 create mode 100644 UefiCpuPkg/Library/SmmCpuRendezvousLib/SmmCpuRendezvousLib.inf

diff --git a/UefiCpuPkg/Library/SmmCpuRendezvousLib/SmmCpuRendezvousLib.c b/UefiCpuPkg/Library/SmmCpuRendezvousLib/SmmCpuRendezvousLib.c
new file mode 100644
index 000000000000..e573c2ecfb51
--- /dev/null
+++ b/UefiCpuPkg/Library/SmmCpuRendezvousLib/SmmCpuRendezvousLib.c
@@ -0,0 +1,103 @@
+/** @file
+  SMM CPU Rendezvous sevice implement.
+
+  Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Base.h>
+#include <Uefi.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MmServicesTableLib.h>
+#include <Protocol/SmmCpuService.h>
+#include <Library/SmmCpuRendezvousLib.h>
+
+STATIC EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL  *mSmmCpuRendezvous = NULL;
+STATIC VOID                               *mRegistration     = NULL;
+
+/**
+  Callback function to wait Smm cpu rendezvous service located.
+
+  SmmCpuRendezvousLib need to support MM_STANDALONE and DXE_SMM_DRIVER driver.
+  So do not use library constructor to locate the protocol.
+
+  @param[in] Protocol   Points to the protocol's unique identifier.
+  @param[in] Interface  Points to the interface instance.
+  @param[in] Handle     The handle on which the interface was installed.
+
+  @retval EFI_SUCCESS  Notification runs successfully.
+
+**/
+EFI_STATUS
+EFIAPI
+SmmCpuRendezvousProtocolNotify (
+  IN CONST EFI_GUID    *Protocol,
+  IN       VOID        *Interface,
+  IN       EFI_HANDLE  Handle
+  )
+{
+  EFI_STATUS  Status;
+
+  Status = gMmst->MmLocateProtocol (
+                    &gEdkiiSmmCpuRendezvousProtocolGuid,
+                    NULL,
+                    (VOID **)&mSmmCpuRendezvous
+                    );
+  ASSERT_EFI_ERROR (Status);
+
+  return EFI_SUCCESS;
+}
+
+/**
+  This routine wait for all AP processors to arrive in SMM.
+
+  @param[in] BlockingMode  Blocking mode or non-blocking mode.
+
+  @retval EFI_SUCCESS  All avaiable APs arrived.
+  @retval EFI_TIMEOUT  Wait for all APs until timeout.
+  @retval OTHER        Fail to register SMM CPU Rendezvous service Protocol.
+**/
+EFI_STATUS
+EFIAPI
+SmmWaitForAllProcessor (
+  IN BOOLEAN  BlockingMode
+  )
+{
+  EFI_STATUS  Status;
+
+  if ((mRegistration == NULL) && (mSmmCpuRendezvous == NULL)) {
+    //
+    // Locate SMM cpu rendezvous protocol for the first time execute the function.
+    //
+    Status = gMmst->MmLocateProtocol (
+                      &gEdkiiSmmCpuRendezvousProtocolGuid,
+                      NULL,
+                      (VOID **)&mSmmCpuRendezvous
+                      );
+    if (EFI_ERROR (Status)) {
+      Status = gMmst->MmRegisterProtocolNotify (
+                        &gEdkiiSmmCpuRendezvousProtocolGuid,
+                        SmmCpuRendezvousProtocolNotify,
+                        &mRegistration
+                        );
+      if (EFI_ERROR (Status)) {
+        return Status;
+      }
+    }
+  }
+
+  //
+  // The platform have not set up. It doesn't need smm cpu rendezvous.
+  //
+  if (mSmmCpuRendezvous == NULL) {
+    return EFI_SUCCESS;
+  }
+
+  Status = mSmmCpuRendezvous->WaitForAllProcessor (
+                                mSmmCpuRendezvous,
+                                BlockingMode
+                                );
+  return Status;
+}
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/CpuService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/CpuService.c
index 5d624f8e9ed6..2ebf4543c3ed 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/CpuService.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/CpuService.c
@@ -1,7 +1,7 @@
 /** @file
 Implementation of SMM CPU Services Protocol.
 
-Copyright (c) 2011 - 2015, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2011 - 2022, Intel Corporation. All rights reserved.<BR>
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -20,6 +20,13 @@ EFI_SMM_CPU_SERVICE_PROTOCOL  mSmmCpuService = {
   SmmRegisterExceptionHandler
 };
 
+//
+// EDKII SMM CPU Rendezvous Service Protocol instance
+//
+EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL  mSmmCpuRendezvousService = {
+  SmmCpuRendezvous
+};
+
 /**
   Gets processor information on the requested processor at the instant this call is made.
 
@@ -350,6 +357,7 @@ SmmRegisterExceptionHandler (
   @param ImageHandle The firmware allocated handle for the EFI image.
 
   @retval EFI_SUCCESS    EFI SMM CPU Services Protocol was installed successfully.
+  @retval OTHER          Fail to install Protocol.
 **/
 EFI_STATUS
 InitializeSmmCpuServices (
@@ -365,5 +373,64 @@ InitializeSmmCpuServices (
                     &mSmmCpuService
                     );
   ASSERT_EFI_ERROR (Status);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  Status = gSmst->SmmInstallProtocolInterface (
+                    &Handle,
+                    &gEdkiiSmmCpuRendezvousProtocolGuid,
+                    EFI_NATIVE_INTERFACE,
+                    &mSmmCpuRendezvousService
+                    );
+  ASSERT_EFI_ERROR (Status);
+  return Status;
+}
+
+/**
+  Wait for all processors enterring SMM until all CPUs are already synchronized or not.
+
+  If BlockingMode is False, timeout value is zero.
+
+  @param This          A pointer to the EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL instance.
+  @param BlockingMode  Blocking mode or non-blocking mode.
+
+  @retval EFI_SUCCESS  All avaiable APs arrived.
+  @retval EFI_TIMEOUT  Wait for all APs until timeout.
+
+**/
+EFI_STATUS
+EFIAPI
+SmmCpuRendezvous (
+  IN EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL  *This,
+  IN BOOLEAN                            BlockingMode
+  )
+{
+  EFI_STATUS  Status;
+
+  //
+  // Return success immediately if all CPUs are already synchronized.
+  //
+  if (mSmmMpSyncData->AllApArrivedWithException) {
+    Status = EFI_SUCCESS;
+    goto ON_EXIT;
+  }
+
+  if (!BlockingMode) {
+    Status = EFI_TIMEOUT;
+    goto ON_EXIT;
+  }
+
+  //
+  // There are some APs outside SMM, Wait for all avaiable APs to arrive.
+  //
+  SmmWaitForApArrival ();
+  Status = mSmmMpSyncData->AllApArrivedWithException ? EFI_SUCCESS : EFI_TIMEOUT;
+
+ON_EXIT:
+  if (!mSmmMpSyncData->AllApArrivedWithException) {
+    DEBUG ((DEBUG_INFO, "EdkiiSmmWaitForAllApArrival: Timeout to wait all APs arrival\n"));
+  }
+
   return Status;
 }
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
index 882dee4fe246..13c2cb8da4c3 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
@@ -1,7 +1,7 @@
 /** @file
 SMM MP service implementation
 
-Copyright (c) 2009 - 2021, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2009 - 2022, Intel Corporation. All rights reserved.<BR>
 Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
 
 SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -293,10 +293,14 @@ SmmWaitForApArrival (
   // Sync with APs 1st timeout
   //
   for (Timer = StartSyncTimer ();
-       !IsSyncTimerTimeout (Timer) && !(LmceEn && LmceSignal) &&
-       !AllCpusInSmmWithExceptions (ARRIVAL_EXCEPTION_BLOCKED | ARRIVAL_EXCEPTION_SMI_DISABLED);
+       !IsSyncTimerTimeout (Timer) && !(LmceEn && LmceSignal);
        )
   {
+    mSmmMpSyncData->AllApArrivedWithException = AllCpusInSmmWithExceptions (ARRIVAL_EXCEPTION_BLOCKED | ARRIVAL_EXCEPTION_SMI_DISABLED);
+    if (mSmmMpSyncData->AllApArrivedWithException) {
+      break;
+    }
+
     CpuPause ();
   }
 
@@ -330,10 +334,14 @@ SmmWaitForApArrival (
     // Sync with APs 2nd timeout.
     //
     for (Timer = StartSyncTimer ();
-         !IsSyncTimerTimeout (Timer) &&
-         !AllCpusInSmmWithExceptions (ARRIVAL_EXCEPTION_BLOCKED | ARRIVAL_EXCEPTION_SMI_DISABLED);
+         !IsSyncTimerTimeout (Timer);
          )
     {
+      mSmmMpSyncData->AllApArrivedWithException = AllCpusInSmmWithExceptions (ARRIVAL_EXCEPTION_BLOCKED | ARRIVAL_EXCEPTION_SMI_DISABLED);
+      if (mSmmMpSyncData->AllApArrivedWithException) {
+        break;
+      }
+
       CpuPause ();
     }
   }
@@ -1887,6 +1895,8 @@ InitializeMpSyncData (
     *mSmmMpSyncData->InsideSmm     = FALSE;
     *mSmmMpSyncData->AllCpusInSync = FALSE;
 
+    mSmmMpSyncData->AllApArrivedWithException = FALSE;
+
     for (CpuIndex = 0; CpuIndex < gSmmCpuPrivate->SmmCoreEntryContext.NumberOfCpus; CpuIndex++) {
       mSmmMpSyncData->CpuData[CpuIndex].Busy =
         (SPIN_LOCK *)((UINTN)mSmmCpuSemaphores.SemaphoreCpu.Busy + mSemaphoreSize * CpuIndex);
diff --git a/UefiCpuPkg/Include/Library/SmmCpuRendezvousLib.h b/UefiCpuPkg/Include/Library/SmmCpuRendezvousLib.h
new file mode 100644
index 000000000000..82e459e9106e
--- /dev/null
+++ b/UefiCpuPkg/Include/Library/SmmCpuRendezvousLib.h
@@ -0,0 +1,27 @@
+/** @file
+  SMM CPU Rendezvous library header file.
+
+  Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef SMM_CPU_RENDEZVOUS_H_
+#define SMM_CPU_RENDEZVOUS_H_
+
+/**
+  This routine wait for all AP processors to arrive in SMM.
+
+  @param[in]  BlockingMode  Blocking mode or non-blocking mode.
+
+  @retval EFI_SUCCESS       All processors checked in to SMM.
+  @retval EFI_TIMEOUT       Wait for all APs until timeout.
+
+**/
+EFI_STATUS
+EFIAPI
+SmmWaitForAllProcessor (
+  IN  BOOLEAN  BlockingMode
+  );
+
+#endif
diff --git a/UefiCpuPkg/Include/Protocol/SmmCpuService.h b/UefiCpuPkg/Include/Protocol/SmmCpuService.h
index 952767afce75..3d93d243409c 100644
--- a/UefiCpuPkg/Include/Protocol/SmmCpuService.h
+++ b/UefiCpuPkg/Include/Protocol/SmmCpuService.h
@@ -1,7 +1,7 @@
 /** @file
 SMM CPU Service protocol definition.
 
-Copyright (c) 2013 - 2015, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2013 - 2022, Intel Corporation. All rights reserved.<BR>
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -200,4 +200,38 @@ struct _EFI_SMM_CPU_SERVICE_PROTOCOL {
 
 extern EFI_GUID  gEfiSmmCpuServiceProtocolGuid;
 
+//
+//  EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL provide SMM CPU
+//  rendezvous service support.
+//
+#define EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL_GUID \
+  { \
+    0xaa00d50b, 0x4911, 0x428f, { 0xb9, 0x1a, 0xa5, 0x9d, 0xdb, 0x13, 0xe2, 0x4c } \
+  }
+
+typedef struct _EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL;
+
+/**
+  Wait for all APs to arrive SMM mode in given timeout constraint.
+
+  @param[in]  This                  A pointer to the EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL instance.
+  @param[in]  BlockingMode          Block or non-block mode.
+
+  @retval EFI_SUCCESS               All APs have arrived SMM mode except SMI disabled APs.
+  @retval EFI_TIMEOUT               There are APs not in SMM mode in given timeout constraint.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *EDKII_WAIT_FOR_ALL_PROCESSOR)(
+  IN  EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL  *This,
+  IN  BOOLEAN                            BlockingMode
+  );
+
+struct _EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL {
+  EDKII_WAIT_FOR_ALL_PROCESSOR    WaitForAllProcessor;
+};
+
+extern EFI_GUID  gEdkiiSmmCpuRendezvousProtocolGuid;
+
 #endif
diff --git a/UefiCpuPkg/Library/SmmCpuRendezvousLib/SmmCpuRendezvousLib.inf b/UefiCpuPkg/Library/SmmCpuRendezvousLib/SmmCpuRendezvousLib.inf
new file mode 100644
index 000000000000..52374bf6e9b4
--- /dev/null
+++ b/UefiCpuPkg/Library/SmmCpuRendezvousLib/SmmCpuRendezvousLib.inf
@@ -0,0 +1,35 @@
+## @file
+# SMM CPU Rendezvous service lib.
+#
+# This is SMM CPU rendezvous service lib that wait for all
+# APs to enter SMM mode.
+#
+# Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = SmmCpuRendezvousLib
+  FILE_GUID                      = 1509Bb36-9Ba4-438B-B195-Ac5914Db14E2
+  MODULE_TYPE                    = DXE_SMM_DRIVER
+  LIBRARY_CLASS                  = SmmCpuRendezvousLib|MM_STANDALONE DXE_SMM_DRIVER
+
+[Sources]
+  SmmCpuRendezvousLib.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  UefiCpuPkg/UefiCpuPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  MmServicesTableLib
+
+[Pcd]
+  gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmApSyncTimeout                 ## CONSUMES
+
+[Protocols]
+  gEdkiiSmmCpuRendezvousProtocolGuid
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h
index 26d07c5b5ea0..aed872836c99 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h
@@ -1,7 +1,7 @@
 /** @file
 Agent Module to load other modules to deploy SMM Entry Vector for X86 CPU.
 
-Copyright (c) 2009 - 2020, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2009 - 2022, Intel Corporation. All rights reserved.<BR>
 Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
 
 SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -428,6 +428,7 @@ typedef struct {
   volatile SMM_CPU_SYNC_MODE    EffectiveSyncMode;
   volatile BOOLEAN              SwitchBsp;
   volatile BOOLEAN              *CandidateBsp;
+  volatile BOOLEAN              AllApArrivedWithException;
   EFI_AP_PROCEDURE              StartupProcedure;
   VOID                          *StartupProcArgs;
 } SMM_DISPATCHER_MP_SYNC_DATA;
@@ -1488,4 +1489,30 @@ IsRestrictedMemoryAccess (
   VOID
   );
 
+/**
+  Choose blocking or non-blocking mode to Wait for all APs.
+
+  @param[in]  This                  A pointer to the EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL instance.
+  @param[in]  BlockingMode          Blocking or non-blocking mode.
+
+  @retval EFI_SUCCESS               All APs have arrived SMM mode except SMI disabled APs.
+  @retval EFI_TIMEOUT               There are APs not in SMM mode in given timeout constraint.
+
+**/
+EFI_STATUS
+EFIAPI
+SmmCpuRendezvous (
+  IN  EDKII_SMM_CPU_RENDEZVOUS_PROTOCOL  *This,
+  IN  BOOLEAN                            BlockingMode
+  );
+
+/**
+  Insure when this function returns, no AP will execute normal mode code before entering SMM, except SMI disabled APs.
+
+**/
+VOID
+SmmWaitForApArrival (
+  VOID
+  );
+
 #endif
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
index 0e88071c7079..deef00f9c6e9 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
@@ -4,7 +4,7 @@
 # This SMM driver performs SMM initialization, deploy SMM Entry Vector,
 # provides CPU specific services in SMM.
 #
-# Copyright (c) 2009 - 2021, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2009 - 2022, Intel Corporation. All rights reserved.<BR>
 # Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
 #
 # SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -107,7 +107,8 @@ [Protocols]
   gEfiSmmReadyToLockProtocolGuid           ## NOTIFY
   gEfiSmmCpuServiceProtocolGuid            ## PRODUCES
   gEdkiiSmmMemoryAttributeProtocolGuid     ## PRODUCES
-  gEfiMmMpProtocolGuid                    ## PRODUCES
+  gEfiMmMpProtocolGuid                     ## PRODUCES
+  gEdkiiSmmCpuRendezvousProtocolGuid       ## PRODUCES
 
 [Guids]
   gEfiAcpiVariableGuid                     ## SOMETIMES_CONSUMES ## HOB # it is used for S3 boot.
diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec
index 7de66fde674c..525cde463435 100644
--- a/UefiCpuPkg/UefiCpuPkg.dec
+++ b/UefiCpuPkg/UefiCpuPkg.dec
@@ -1,7 +1,7 @@
 ## @file  UefiCpuPkg.dec
 # This Package provides UEFI compatible CPU modules and libraries.
 #
-# Copyright (c) 2007 - 2021, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2007 - 2022, Intel Corporation. All rights reserved.<BR>
 #
 # SPDX-License-Identifier: BSD-2-Clause-Patent
 #
@@ -62,6 +62,9 @@ [LibraryClasses.IA32, LibraryClasses.X64]
   ##  @libraryclass  Provides function for loading microcode.
   MicrocodeLib|Include/Library/MicrocodeLib.h
 
+  ## @libraryclass  Provides function for SMM CPU Rendezvous Library.
+  SmmCpuRendezvousLib|Include/Library/SmmCpuRendezvousLib.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 }}
@@ -77,7 +80,8 @@ [Guids]
 
 [Protocols]
   ## Include/Protocol/SmmCpuService.h
-  gEfiSmmCpuServiceProtocolGuid  = { 0x1d202cab, 0xc8ab, 0x4d5c, { 0x94, 0xf7, 0x3c, 0xfc, 0xc0, 0xd3, 0xd3, 0x35 }}
+  gEfiSmmCpuServiceProtocolGuid   = { 0x1d202cab, 0xc8ab, 0x4d5c, { 0x94, 0xf7, 0x3c, 0xfc, 0xc0, 0xd3, 0xd3, 0x35 }}
+  gEdkiiSmmCpuRendezvousProtocolGuid = { 0xaa00d50b, 0x4911, 0x428f, { 0xb9, 0x1a, 0xa5, 0x9d, 0xdb, 0x13, 0xe2, 0x4c }}
 
   ## Include/Protocol/SmMonitorInit.h
   gEfiSmMonitorInitProtocolGuid  = { 0x228f344d, 0xb3de, 0x43bb, { 0xa4, 0xd7, 0xea, 0x20, 0xb, 0x1b, 0x14, 0x82 }}
diff --git a/UefiCpuPkg/UefiCpuPkg.dsc b/UefiCpuPkg/UefiCpuPkg.dsc
index d1d61dd6a03b..a0bbde9985d3 100644
--- a/UefiCpuPkg/UefiCpuPkg.dsc
+++ b/UefiCpuPkg/UefiCpuPkg.dsc
@@ -61,6 +61,7 @@ [LibraryClasses]
   TpmMeasurementLib|MdeModulePkg/Library/TpmMeasurementLibNull/TpmMeasurementLibNull.inf
   VmgExitLib|UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.inf
   MicrocodeLib|UefiCpuPkg/Library/MicrocodeLib/MicrocodeLib.inf
+  SmmCpuRendezvousLib|UefiCpuPkg/Library/SmmCpuRendezvousLib/SmmCpuRendezvousLib.inf
 
 [LibraryClasses.common.SEC]
   PlatformSecLib|UefiCpuPkg/Library/PlatformSecLibNull/PlatformSecLibNull.inf
@@ -173,6 +174,7 @@ [Components.IA32, Components.X64]
   }
   UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf
   UefiCpuPkg/ResetVector/Vtf0/Bin/ResetVector.inf
+  UefiCpuPkg/Library/SmmCpuRendezvousLib/SmmCpuRendezvousLib.inf
 
 [BuildOptions]
   *_*_*_CC_FLAGS = -D DISABLE_NEW_DEPRECATED_INTERFACES
-- 
2.26.2.windows.1