[Patch v2] UefiCpuPkg/S3Resume2Pei: disable paging before creating new page table.

[Patch v2] UefiCpuPkg/S3Resume2Pei: disable paging before creating new page table.

[Eric Dong]

V2 changes:
Only disable paging in 32 bit mode, no matter it is enable or not.

V1 changes:
PEI Stack Guard needs to enable paging. This might cause #GP in the
transition from 32-bit PEI to 64-bit SMM due to the code trying to
write CR3 register with PML4 page table while the processor is enabled
with PAE paging.

Simply disabling paging before updating CR3 can solve this conflict.

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=1232

Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by:Eric Dong <eric.dong@intel.com>
Signed-off-by: Eric Dong <eric.dong@intel.com>
---
 UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume.c       | 8 ++++++++
 UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf | 1 +
 2 files changed, 9 insertions(+)

diff --git a/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume.c b/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume.c
index f164c1713b..53ed76c6e6 100644
--- a/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume.c
+++ b/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume.c
@@ -1105,6 +1105,14 @@ S3RestoreConfig2 (
       //
       SetInterruptState (InterruptStatus);
 
+      if (sizeof(UINTN) == sizeof(UINT32)) {
+        //
+        // Paging maybe enabled. If current mode is 32 bit mode and code try to
+        // enable 64 bit mode page table, it will cause GP fault.
+        // To avoid conflict configuration, disable paging first anyway.
+        //
+        AsmWriteCr0 (AsmReadCr0 () & (~BIT31));
+      }
       AsmWriteCr3 ((UINTN)SmmS3ResumeState->SmmS3Cr3);
 
       //
diff --git a/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf b/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf
index 6ce1bf944c..0f131d19df 100644
--- a/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf
+++ b/UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume2Pei.inf
@@ -90,6 +90,7 @@
 [Pcd]
   gEfiMdeModulePkgTokenSpaceGuid.PcdUse1GPageTable  ## SOMETIMES_CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrMask    ## CONSUMES
+  gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard                       ## CONSUMES
 
 [Depex]
   TRUE
-- 
2.15.0.windows.1