[PATCH 3/4] UefiCpuPkg/MpInitLib: fix register restore issue in AP wakeup

[Jian J Wang <jian.j.wang@intel.com>]

The conflict issues are introduced by Stack Guard feature enabled for
PEI.

The first is CR0 which should be restored after CR3 and CR4.
Another is TR which should not be passed from BSP to AP during init
phase.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: "Ware, Ryan R" <ryan.r.ware@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
---
 UefiCpuPkg/Library/MpInitLib/MpLib.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index 377876643f..709fbc1575 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -217,9 +217,9 @@ RestoreVolatileRegisters (
   CPUID_VERSION_INFO_EDX        VersionInfoEdx;
   IA32_TSS_DESCRIPTOR           *Tss;
 
-  AsmWriteCr0 (VolatileRegisters->Cr0);
   AsmWriteCr3 (VolatileRegisters->Cr3);
   AsmWriteCr4 (VolatileRegisters->Cr4);
+  AsmWriteCr0 (VolatileRegisters->Cr0);
 
   if (IsRestoreDr) {
     AsmCpuid (CPUID_VERSION_INFO, NULL, NULL, NULL, &VersionInfoEdx.Uint32);
@@ -1558,7 +1558,7 @@ MpInitLibInitialize (
   ApLoopMode  = GetApLoopMode (&MonitorFilterSize);
 
   //
-  // Save BSP's Control registers for APs
+  // Save BSP's Control registers for APs.
   //
   SaveVolatileRegisters (&VolatileRegisters);
 
@@ -1656,6 +1656,10 @@ MpInitLibInitialize (
   //
   CopyMem ((VOID *)ApIdtBase, (VOID *)VolatileRegisters.Idtr.Base, VolatileRegisters.Idtr.Limit + 1);
   VolatileRegisters.Idtr.Base = ApIdtBase;
+  //
+  // Don't pass BSP's TR to APs to avoid AP init failure.
+  //
+  VolatileRegisters.Tr = 0;
   CopyMem (&CpuMpData->CpuData[0].VolatileRegisters, &VolatileRegisters, sizeof (VolatileRegisters));
   //
   // Set BSP basic information
-- 
2.16.2.windows.1