diff options
| -rw-r--r-- | OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c index f1485722f7..814f814035 100644 --- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c +++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c @@ -17,6 +17,7 @@ #include <Register/Cpuid.h>
#include "VirtualMemory.h"
+#include "SnpPageStateChange.h"
STATIC BOOLEAN mAddressEncMaskChecked = FALSE;
STATIC UINT64 mAddressEncMask;
@@ -693,10 +694,12 @@ SetMemoryEncDec ( PAGE_MAP_AND_DIRECTORY_POINTER *PageDirectoryPointerEntry;
PAGE_TABLE_1G_ENTRY *PageDirectory1GEntry;
PAGE_TABLE_ENTRY *PageDirectory2MEntry;
+ PHYSICAL_ADDRESS OrigPhysicalAddress;
PAGE_TABLE_4K_ENTRY *PageTableEntry;
UINT64 PgTableMask;
UINT64 AddressEncMask;
BOOLEAN IsWpEnabled;
+ UINTN OrigLength;
RETURN_STATUS Status;
//
@@ -749,6 +752,22 @@ SetMemoryEncDec ( Status = EFI_SUCCESS;
+ //
+ // To maintain the security gurantees we must set the page to shared in the RMP
+ // table before clearing the memory encryption mask from the current page table.
+ //
+ // The InternalSetPageState() is used for setting the page state in the RMP table.
+ //
+ if ((Mode == ClearCBit) && MemEncryptSevSnpIsEnabled ()) {
+ InternalSetPageState (PhysicalAddress, EFI_SIZE_TO_PAGES (Length), SevSnpPageShared, FALSE);
+ }
+
+ //
+ // Save the specified length and physical address (we need it later).
+ //
+ OrigLength = Length;
+ OrigPhysicalAddress = PhysicalAddress;
+
while (Length != 0) {
//
// If Cr3BaseAddress is not specified then read the current CR3
@@ -922,6 +941,21 @@ SetMemoryEncDec ( //
CpuFlushTlb ();
+ //
+ // SEV-SNP requires that all the private pages (i.e pages mapped encrypted) must be
+ // added in the RMP table before the access.
+ //
+ // The InternalSetPageState() is used for setting the page state in the RMP table.
+ //
+ if ((Mode == SetCBit) && MemEncryptSevSnpIsEnabled ()) {
+ InternalSetPageState (
+ OrigPhysicalAddress,
+ EFI_SIZE_TO_PAGES (OrigLength),
+ SevSnpPagePrivate,
+ FALSE
+ );
+ }
+
Done:
//
// Restore page table write protection, if any.
|