[PATCH v4 3/6] MdeModulePkg/Universal/CapsulePei: Add support for PCD PcdPteMemoryEncryptionAddressOrMask

[Leo Duran <leo.duran@amd.com>]

This PCD holds the address mask for page table entries when memory
encryption is enabled on AMD processors supporting the Secure Encrypted
Virtualization (SEV) feature.

The mask is applied when 4GB tables are created (UefiCapsule.c), and when
the tables are expanded on-demand by page-faults above 4GB's (X64Entry.c).

Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Leo Duran <leo.duran@amd.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
---
 MdeModulePkg/Universal/CapsulePei/CapsulePei.inf   |  2 ++
 .../Universal/CapsulePei/Common/CommonHeader.h     |  5 +++++
 MdeModulePkg/Universal/CapsulePei/UefiCapsule.c    | 17 +++++++++++----
 MdeModulePkg/Universal/CapsulePei/X64/X64Entry.c   | 24 +++++++++++++++-------
 4 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/MdeModulePkg/Universal/CapsulePei/CapsulePei.inf b/MdeModulePkg/Universal/CapsulePei/CapsulePei.inf
index d2ca0d0..c54bc21 100644
--- a/MdeModulePkg/Universal/CapsulePei/CapsulePei.inf
+++ b/MdeModulePkg/Universal/CapsulePei/CapsulePei.inf
@@ -7,6 +7,7 @@
 #  buffer overflow, integer overflow.
 #
 # Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
 #
 # This program and the accompanying materials
 # are licensed and made available under the terms and conditions
@@ -76,6 +77,7 @@
 [Pcd.IA32]
   gEfiMdeModulePkgTokenSpaceGuid.PcdCapsuleCoalesceFile     ## SOMETIMES_CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdUse1GPageTable          ## SOMETIMES_CONSUMES
+  gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrMask    ## CONSUMES
 
 [FeaturePcd.IA32]
   gEfiMdeModulePkgTokenSpaceGuid.PcdDxeIplSwitchToLongMode  ## CONSUMES
diff --git a/MdeModulePkg/Universal/CapsulePei/Common/CommonHeader.h b/MdeModulePkg/Universal/CapsulePei/Common/CommonHeader.h
index 7298874..cac4442 100644
--- a/MdeModulePkg/Universal/CapsulePei/Common/CommonHeader.h
+++ b/MdeModulePkg/Universal/CapsulePei/Common/CommonHeader.h
@@ -2,6 +2,8 @@
   Common header file.
 
 Copyright (c) 2011 - 2016, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
+
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -20,6 +22,8 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 //
 #define EXTRA_PAGE_TABLE_PAGES      8
 
+#define PAGING_1G_ADDRESS_MASK_64   0x000FFFFFC0000000ull
+
 //
 // This capsule PEIM puts its private data at the start of the
 // coalesced capsule. Here's the structure definition.
@@ -60,6 +64,7 @@ typedef struct {
   EFI_PHYSICAL_ADDRESS  MemoryBase64Ptr;
   EFI_PHYSICAL_ADDRESS  MemorySize64Ptr;
   BOOLEAN               Page1GSupport;
+  UINT64                AddressEncMask;
 } SWITCH_32_TO_64_CONTEXT;
 
 typedef struct {
diff --git a/MdeModulePkg/Universal/CapsulePei/UefiCapsule.c b/MdeModulePkg/Universal/CapsulePei/UefiCapsule.c
index 9ac9d22..34b095a 100644
--- a/MdeModulePkg/Universal/CapsulePei/UefiCapsule.c
+++ b/MdeModulePkg/Universal/CapsulePei/UefiCapsule.c
@@ -2,6 +2,7 @@
   Capsule update PEIM for UEFI2.0
 
 Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
 
 This program and the accompanying materials
 are licensed and made available under the terms and conditions
@@ -41,6 +42,7 @@ GLOBAL_REMOVE_IF_UNREFERENCED CONST IA32_DESCRIPTOR mGdt = {
   (UINTN) mGdtEntries
   };
 
+
 /**
   The function will check if 1G page is supported.
 
@@ -145,6 +147,12 @@ Create4GPageTables (
   PAGE_TABLE_ENTRY                              *PageDirectoryEntry;
   UINTN                                         BigPageAddress;
   PAGE_TABLE_1G_ENTRY                           *PageDirectory1GEntry;
+  UINT64                                        AddressEncMask;
+
+  //
+  // Make sure AddressEncMask is contained to smallest supported address field.
+  //
+  AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64;
 
   //
   // Create 4G page table by default,
@@ -187,7 +195,7 @@ Create4GPageTables (
     //
     // Make a PML4 Entry
     //
-    PageMapLevel4Entry->Uint64 = (UINT64)(UINTN)PageDirectoryPointerEntry;
+    PageMapLevel4Entry->Uint64 = (UINT64)(UINTN)PageDirectoryPointerEntry | AddressEncMask;
     PageMapLevel4Entry->Bits.ReadWrite = 1;
     PageMapLevel4Entry->Bits.Present = 1;
 
@@ -198,7 +206,7 @@ Create4GPageTables (
         //
         // Fill in the Page Directory entries
         //
-        PageDirectory1GEntry->Uint64 = (UINT64)PageAddress;
+        PageDirectory1GEntry->Uint64 = (UINT64)PageAddress | AddressEncMask;
         PageDirectory1GEntry->Bits.ReadWrite = 1;
         PageDirectory1GEntry->Bits.Present = 1;
         PageDirectory1GEntry->Bits.MustBe1 = 1;
@@ -215,7 +223,7 @@ Create4GPageTables (
         //
         // Fill in a Page Directory Pointer Entries
         //
-        PageDirectoryPointerEntry->Uint64 = (UINT64)(UINTN)PageDirectoryEntry;
+        PageDirectoryPointerEntry->Uint64 = (UINT64)(UINTN)PageDirectoryEntry | AddressEncMask;
         PageDirectoryPointerEntry->Bits.ReadWrite = 1;
         PageDirectoryPointerEntry->Bits.Present = 1;
 
@@ -223,7 +231,7 @@ Create4GPageTables (
           //
           // Fill in the Page Directory entries
           //
-          PageDirectoryEntry->Uint64 = (UINT64)PageAddress;
+          PageDirectoryEntry->Uint64 = (UINT64)PageAddress | AddressEncMask;
           PageDirectoryEntry->Bits.ReadWrite = 1;
           PageDirectoryEntry->Bits.Present = 1;
           PageDirectoryEntry->Bits.MustBe1 = 1;
@@ -443,6 +451,7 @@ ModeSwitch (
   Context.MemoryBase64Ptr       = (EFI_PHYSICAL_ADDRESS)(UINTN)&MemoryBase64;
   Context.MemorySize64Ptr       = (EFI_PHYSICAL_ADDRESS)(UINTN)&MemorySize64;
   Context.Page1GSupport         = Page1GSupport;
+  Context.AddressEncMask        = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64;
 
   //
   // Prepare data for return back
diff --git a/MdeModulePkg/Universal/CapsulePei/X64/X64Entry.c b/MdeModulePkg/Universal/CapsulePei/X64/X64Entry.c
index 5ad95d2..e1871c3 100644
--- a/MdeModulePkg/Universal/CapsulePei/X64/X64Entry.c
+++ b/MdeModulePkg/Universal/CapsulePei/X64/X64Entry.c
@@ -2,6 +2,8 @@
   The X64 entrypoint is used to process capsule in long mode.
 
 Copyright (c) 2011 - 2016, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
+
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -29,6 +31,7 @@ typedef struct _PAGE_FAULT_CONTEXT {
   UINT64                        PhyMask;
   UINTN                         PageFaultBuffer;
   UINTN                         PageFaultIndex;
+  UINT64                        AddressEncMask;
   //
   // Store the uplink information for each page being used.
   //
@@ -114,21 +117,25 @@ AcquirePage (
   )
 {
   UINTN             Address;
+  UINT64            AddressEncMask;
 
   Address = PageFaultContext->PageFaultBuffer + EFI_PAGES_TO_SIZE (PageFaultContext->PageFaultIndex);
   ZeroMem ((VOID *) Address, EFI_PAGES_TO_SIZE (1));
 
+  AddressEncMask = PageFaultContext->AddressEncMask;
+
   //
   // Cut the previous uplink if it exists and wasn't overwritten.
   //
-  if ((PageFaultContext->PageFaultUplink[PageFaultContext->PageFaultIndex] != NULL) && ((*PageFaultContext->PageFaultUplink[PageFaultContext->PageFaultIndex] & PageFaultContext->PhyMask) == Address)) {
+  if ((PageFaultContext->PageFaultUplink[PageFaultContext->PageFaultIndex] != NULL) &&
+     ((*PageFaultContext->PageFaultUplink[PageFaultContext->PageFaultIndex] & ~AddressEncMask & PageFaultContext->PhyMask) == Address)) {
     *PageFaultContext->PageFaultUplink[PageFaultContext->PageFaultIndex] = 0;
   }
 
   //
   // Link & Record the current uplink.
   //
-  *Uplink = Address | IA32_PG_P | IA32_PG_RW;
+  *Uplink = Address | AddressEncMask | IA32_PG_P | IA32_PG_RW;
   PageFaultContext->PageFaultUplink[PageFaultContext->PageFaultIndex] = Uplink;
 
   PageFaultContext->PageFaultIndex = (PageFaultContext->PageFaultIndex + 1) % EXTRA_PAGE_TABLE_PAGES;
@@ -153,6 +160,7 @@ PageFaultHandler (
   UINT64                    *PageTable;
   UINT64                    PFAddress;
   UINTN                     PTIndex;
+  UINT64                    AddressEncMask;
 
   //
   // Get the IDT Descriptor.
@@ -163,6 +171,7 @@ PageFaultHandler (
   //
   PageFaultContext = (PAGE_FAULT_CONTEXT *) (UINTN) (Idtr.Base - sizeof (PAGE_FAULT_CONTEXT));
   PhyMask = PageFaultContext->PhyMask;
+  AddressEncMask = PageFaultContext->AddressEncMask;
 
   PFAddress = AsmReadCr2 ();
   DEBUG ((EFI_D_ERROR, "CapsuleX64 - PageFaultHandler: Cr2 - %lx\n", PFAddress));
@@ -179,19 +188,19 @@ PageFaultHandler (
   if ((PageTable[PTIndex] & IA32_PG_P) == 0) {
     AcquirePage (PageFaultContext, &PageTable[PTIndex]);
   }
-  PageTable = (UINT64*)(UINTN)(PageTable[PTIndex] & PhyMask);
+  PageTable = (UINT64*)(UINTN)(PageTable[PTIndex] & ~AddressEncMask & PhyMask);
   PTIndex = BitFieldRead64 (PFAddress, 30, 38);
   // PDPTE
   if (PageFaultContext->Page1GSupport) {
-    PageTable[PTIndex] = (PFAddress & ~((1ull << 30) - 1)) | IA32_PG_P | IA32_PG_RW | IA32_PG_PS;
+    PageTable[PTIndex] = ((PFAddress | AddressEncMask) & ~((1ull << 30) - 1)) | IA32_PG_P | IA32_PG_RW | IA32_PG_PS;
   } else {
     if ((PageTable[PTIndex] & IA32_PG_P) == 0) {
       AcquirePage (PageFaultContext, &PageTable[PTIndex]);
     }
-    PageTable = (UINT64*)(UINTN)(PageTable[PTIndex] & PhyMask);
+    PageTable = (UINT64*)(UINTN)(PageTable[PTIndex] & ~AddressEncMask & PhyMask);
     PTIndex = BitFieldRead64 (PFAddress, 21, 29);
     // PD
-    PageTable[PTIndex] = (PFAddress & ~((1ull << 21) - 1)) | IA32_PG_P | IA32_PG_RW | IA32_PG_PS;
+    PageTable[PTIndex] = ((PFAddress | AddressEncMask) & ~((1ull << 21) - 1)) | IA32_PG_P | IA32_PG_RW | IA32_PG_PS;
   }
 
   return NULL;
@@ -244,6 +253,7 @@ _ModuleEntryPoint (
   // Hook page fault handler to handle >4G request.
   //
   PageFaultIdtTable.PageFaultContext.Page1GSupport = EntrypointContext->Page1GSupport;
+  PageFaultIdtTable.PageFaultContext.AddressEncMask = EntrypointContext->AddressEncMask;
   IdtEntry = (IA32_IDT_GATE_DESCRIPTOR *) (X64Idtr.Base + (14 * sizeof (IA32_IDT_GATE_DESCRIPTOR)));
   HookPageFaultHandler (IdtEntry, &(PageFaultIdtTable.PageFaultContext));
 
@@ -298,4 +308,4 @@ _ModuleEntryPoint (
   //
   ASSERT (FALSE);
   return EFI_SUCCESS;
-}
\ No newline at end of file
+}
-- 
2.7.4