UefiCpuPkg/PiSmmCpuDxeSmm: Enable MM MP Protocol

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1937

Add MM Mp Protocol in PiSmmCpuDxeSmm driver.

Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>

UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c

@@ -34,6 +34,8 @@ SMM_CPU_PRIVATE_DATA  mSmmCpuPrivateData = {
     mSmmCpuPrivateData.SmmReservedSmramRegion,  // SmmConfiguration.SmramReservedRegions
     RegisterSmmEntry                            // SmmConfiguration.RegisterSmmEntry
   },
+  NULL,                                         // pointer to Ap Wrapper Func array
+  {NULL, NULL},                                 // List_Entry for Tokens.
 };
 
 CPU_HOT_PLUG_DATA mCpuHotPlugData = {
@@ -996,6 +998,22 @@ PiCpuSmmEntry (
                     );
   ASSERT_EFI_ERROR (Status);
 
+  //
+  // Initialize global buffer for MM MP.
+  //
+  InitializeDataForMmMp ();
+
+  //
+  // Install the SMM Mp Protocol into SMM protocol database
+  //
+  Status = gSmst->SmmInstallProtocolInterface (
+                    &mSmmCpuHandle,
+                    &gEfiMmMpProtocolGuid,
+                    EFI_NATIVE_INTERFACE,
+                    &mSmmMp
+                    );
+  ASSERT_EFI_ERROR (Status);
+
   //
   // Expose address of CPU Hot Plug Data structure if CPU hot plug is supported.
   //