[edk2-devel] [PATCH 2/4] UefiCpuPkg/CpuDxe: Support parsing 5-level page table

[Ni, Ray]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2008

Signed-off-by: Ray Ni <ray.ni at intel.com>
Cc: Eric Dong <eric.dong at intel.com>
Cc: Laszlo Ersek <lersek at redhat.com>
---
 UefiCpuPkg/CpuDxe/CpuPageTable.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/UefiCpuPkg/CpuDxe/CpuPageTable.c b/UefiCpuPkg/CpuDxe/CpuPageTable.c
index c369b44f12..8e959eb2b7 100644
--- a/UefiCpuPkg/CpuDxe/CpuPageTable.c
+++ b/UefiCpuPkg/CpuDxe/CpuPageTable.c
@@ -1,7 +1,7 @@
 /** @file
   Page table management support.
 
-  Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2017 - 2019, Intel Corporation. All rights reserved.<BR>
   Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -276,25 +276,43 @@ GetPageTableEntry (
   UINTN                 Index2;
   UINTN                 Index3;
   UINTN                 Index4;
+  UINTN                 Index5;
   UINT64                *L1PageTable;
   UINT64                *L2PageTable;
   UINT64                *L3PageTable;
   UINT64                *L4PageTable;
+  UINT64                *L5PageTable;
   UINT64                AddressEncMask;
+  IA32_CR4              Cr4;
+  BOOLEAN               Enable5LevelPaging;
 
   ASSERT (PagingContext != NULL);
 
+  Index5 = ((UINTN)RShiftU64 (Address, 48)) & PAGING_PAE_INDEX_MASK;
   Index4 = ((UINTN)RShiftU64 (Address, 39)) & PAGING_PAE_INDEX_MASK;
   Index3 = ((UINTN)Address >> 30) & PAGING_PAE_INDEX_MASK;
   Index2 = ((UINTN)Address >> 21) & PAGING_PAE_INDEX_MASK;
   Index1 = ((UINTN)Address >> 12) & PAGING_PAE_INDEX_MASK;
 
+  Cr4.UintN = AsmReadCr4 ();
+  Enable5LevelPaging = (BOOLEAN) (Cr4.Bits.LA57 == 1);
+
   // Make sure AddressEncMask is contained to smallest supported address field.
   //
   AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64;
 
   if (PagingContext->MachineType == IMAGE_FILE_MACHINE_X64) {
-    L4PageTable = (UINT64 *)(UINTN)PagingContext->ContextData.X64.PageTableBase;
+    if (Enable5LevelPaging) {
+      L5PageTable = (UINT64 *)(UINTN)PagingContext->ContextData.X64.PageTableBase;
+      if (L5PageTable[Index5] == 0) {
+        *PageAttribute = PageNone;
+        return NULL;
+      }
+
+      L4PageTable = (UINT64 *)(UINTN)(L5PageTable[Index5] & ~AddressEncMask & PAGING_4K_ADDRESS_MASK_64);
+    } else {
+      L4PageTable = (UINT64 *)(UINTN)PagingContext->ContextData.X64.PageTableBase;
+    }
     if (L4PageTable[Index4] == 0) {
       *PageAttribute = PageNone;
       return NULL;
-- 
2.21.0.windows.1


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