From ebfe2d3eb5ac7fd92d74011edb31303a181920c7 Mon Sep 17 00:00:00 2001
From: Guo Dong <guo.dong@intel.com>
Date: Thu, 7 Jan 2021 11:10:45 +0800
Subject: [PATCH] UefiCpuPkg/CpuDxe: Fix boot error

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3084

When DXE drivers are dispatched above 4GB memory in 64bit
mode, the address setCodeSelectorLongJump in stack will
be override by parameter. Jump to Qword is not supported
by some processors. So use "o64 retf" instead.

Signed-off-by: Guo Dong <guo.dong@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Tested-by: James Bottomley <jejb@linux.ibm.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
---
 UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm b/UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm
index c3489bcc3e..66f8857fc0 100644
--- a/UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm
+++ b/UefiCpuPkg/CpuDxe/X64/CpuAsm.nasm
@@ -20,13 +20,11 @@
 ;------------------------------------------------------------------------------
 global ASM_PFX(SetCodeSelector)
 ASM_PFX(SetCodeSelector):
-    sub     rsp, 0x10
+    push    rcx
     lea     rax, [setCodeSelectorLongJump]
-    mov     [rsp], rax
-    mov     [rsp+4], cx
-    jmp     dword far [rsp]
+    push    rax
+    o64 retf
 setCodeSelectorLongJump:
-    add     rsp, 0x10
     ret
 
 ;------------------------------------------------------------------------------
-- 
2.39.2