[edk2-devel] [Patch V6 01/14] OvmfPkg:Remove code that apply AddressEncMask to non-leaf entry

[duntan]

Remove code that apply AddressEncMask to non-leaf entry when split
smm page table by MemEncryptSevLib. In FvbServicesSmm driver, it
calls MemEncryptSevClearMmioPageEncMask to clear AddressEncMask
bit in page table for a specific range. In AMD SEV feature, this
AddressEncMask bit in page table is used to indicate if the memory
is guest private memory or shared memory. But all memory used by
page table are treated as encrypted regardless of encryption bit.
So remove the EncMask bit for smm non-leaf page table entry
doesn't impact AMD SEV feature.
If page split happens in the AddressEncMask bit clear process,
there will be some new non-leaf entries with AddressEncMask
applied in smm page table. When ReadyToLock, code in PiSmmCpuDxe
module will use CpuPageTableLib to modify smm page table. So
remove code to apply AddressEncMask for new non-leaf entries
since CpuPageTableLib doesn't consume the EncMask PCD.

Signed-off-by: Dun Tan <dun.tan at intel.com>
Cc: Ard Biesheuvel <ardb+tianocore at kernel.org>
Cc: Jiewen Yao <jiewen.yao at intel.com>
Cc: Jordan Justen <jordan.l.justen at intel.com>
Cc: Gerd Hoffmann <kraxel at redhat.com>
Cc: Tom Lendacky <thomas.lendacky at amd.com>
Reviewed-by: Ray Ni <ray.ni at intel.com>
---
 OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
index cf2441b551..aba2e8c081 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
@@ -233,7 +233,7 @@ Split2MPageTo4K (
   // Fill in 2M page entry.
   //
   *PageEntry2M = ((UINT64)(UINTN)PageTableEntry1 |
-                  IA32_PG_P | IA32_PG_RW | AddressEncMask);
+                  IA32_PG_P | IA32_PG_RW);
 }
 
 /**
@@ -352,7 +352,7 @@ SetPageTablePoolReadOnly (
         PhysicalAddress += LevelSize[Level - 1];
       }
 
-      PageTable[Index] = (UINT64)(UINTN)NewPageTable | AddressEncMask |
+      PageTable[Index] = (UINT64)(UINTN)NewPageTable |
                          IA32_PG_P | IA32_PG_RW;
       PageTable = NewPageTable;
     }
@@ -440,7 +440,7 @@ Split1GPageTo2M (
   // Fill in 1G page entry.
   //
   *PageEntry1G = ((UINT64)(UINTN)PageDirectoryEntry |
-                  IA32_PG_P | IA32_PG_RW | AddressEncMask);
+                  IA32_PG_P | IA32_PG_RW);
 
   PhysicalAddress2M = PhysicalAddress;
   for (IndexOfPageDirectoryEntries = 0;
-- 
2.31.1.windows.1



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