6 files changed, 34 insertions, 0 deletions
diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.c b/UefiCpuPkg/CpuMpPei/CpuMpPei.c
index 7b75d354dd..40e62e0405 100644
--- a/UefiCpuPkg/CpuMpPei/CpuMpPei.c
+++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.c
@@ -169,6 +169,7 @@ ApCFunction (
   //
   InterlockedIncrement ((UINT32 *)&PeiCpuMpData->FinishedCount);
 
+  AsmCliHltLoop ();
 }
 
 /**
diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.h b/UefiCpuPkg/CpuMpPei/CpuMpPei.h
index 97d52bf563..c241349a97 100644
--- a/UefiCpuPkg/CpuMpPei/CpuMpPei.h
+++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.h
@@ -166,6 +166,15 @@ AsmInitializeGdt (
   IN IA32_DESCRIPTOR  *Gdtr
   );
 
+/**
+  Assembly code to do CLI-HALT loop.
+
+**/
+VOID
+EFIAPI
+AsmCliHltLoop (
+  VOID
+  );
 
 /**
   This function will be called by BSP to wakeup AP.
diff --git a/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.asm b/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.asm
index 63c80489f4..060f4670e0 100644
--- a/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.asm
+++ b/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.asm
@@ -144,6 +144,12 @@ CProcedureInvoke:
 RendezvousFunnelProc   ENDP
 RendezvousFunnelProcEnd::
 
+AsmCliHltLoop PROC near C PUBLIC
+    cli
+    hlt
+    jmp        $-2
+AsmCliHltLoop ENDP
+
 ;-------------------------------------------------------------------------------------
 ;  AsmGetAddressMap (&AddressMap);
 ;-------------------------------------------------------------------------------------
diff --git a/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.nasm b/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.nasm
index fe45cf1f9f..3a8e91fe74 100644
--- a/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.nasm
+++ b/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.nasm
@@ -132,6 +132,12 @@ CProcedureInvoke:
     jmp        $                 ; never reach here
 RendezvousFunnelProcEnd:
 
+global ASM_PFX(AsmCliHltLoop)
+ASM_PFX(AsmCliHltLoop):
+    cli
+    hlt
+    jmp        $-2
+
 ;-------------------------------------------------------------------------------------
 ;  AsmGetAddressMap (&AddressMap);
 ;-------------------------------------------------------------------------------------
diff --git a/UefiCpuPkg/CpuMpPei/X64/MpFuncs.asm b/UefiCpuPkg/CpuMpPei/X64/MpFuncs.asm
index 6622c43fcf..18c8b72a34 100644
--- a/UefiCpuPkg/CpuMpPei/X64/MpFuncs.asm
+++ b/UefiCpuPkg/CpuMpPei/X64/MpFuncs.asm
@@ -181,6 +181,12 @@ CProcedureInvoke:
 RendezvousFunnelProc   ENDP
 RendezvousFunnelProcEnd::
 
+AsmCliHltLoop PROC
+    cli
+    hlt
+    jmp $-2
+AsmCliHltLoop ENDP
+
 ;-------------------------------------------------------------------------------------
 ;  AsmGetAddressMap (&AddressMap);
 ;-------------------------------------------------------------------------------------
diff --git a/UefiCpuPkg/CpuMpPei/X64/MpFuncs.nasm b/UefiCpuPkg/CpuMpPei/X64/MpFuncs.nasm
index 8b93c0d1f7..4683543e3c 100644
--- a/UefiCpuPkg/CpuMpPei/X64/MpFuncs.nasm
+++ b/UefiCpuPkg/CpuMpPei/X64/MpFuncs.nasm
@@ -175,6 +175,12 @@ CProcedureInvoke:
 
 RendezvousFunnelProcEnd:
 
+global ASM_PFX(AsmCliHltLoop)
+ASM_PFX(AsmCliHltLoop):
+    cli
+    hlt
+    jmp $-2
+
 ;-------------------------------------------------------------------------------------
 ;  AsmGetAddressMap (&AddressMap);
 ;-------------------------------------------------------------------------------------