OvmfPkg/BaseMemEncryptSevLib: introduce MemEncryptSevClearMmioPageEncMask()

[mirror_edk2.git] / OvmfPkg / Library / BaseMemEncryptSevLib / Ia32 / MemEncryptSevLib.c

diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c b/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c
index 12a5bf495bd73cf06edecf4c18136e7a33c39541..169d3118e44f8a1c82103a38b417c0f0920f9ea1 100644 (file)
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c
@@ -111,3 +111,34 @@ MemEncryptSevGetAddressRangeState (
   //\r
   return MemEncryptSevAddressRangeEncrypted;\r
 }\r
+\r
+/**\r
+  This function clears memory encryption bit for the MMIO region specified by\r
+  BaseAddress and NumPages.\r
+\r
+  @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use\r
+                                      current CR3)\r
+  @param[in]  BaseAddress             The physical address that is the start\r
+                                      address of a MMIO region.\r
+  @param[in]  NumPages                The number of pages from start memory\r
+                                      region.\r
+\r
+  @retval RETURN_SUCCESS              The attributes were cleared for the\r
+                                      memory region.\r
+  @retval RETURN_INVALID_PARAMETER    Number of pages is zero.\r
+  @retval RETURN_UNSUPPORTED          Clearing the memory encryption attribute\r
+                                      is not supported\r
+**/\r
+RETURN_STATUS\r
+EFIAPI\r
+MemEncryptSevClearMmioPageEncMask (\r
+  IN PHYSICAL_ADDRESS         Cr3BaseAddress,\r
+  IN PHYSICAL_ADDRESS         BaseAddress,\r
+  IN UINTN                    NumPages\r
+  )\r
+{\r
+  //\r
+  // Memory encryption bit is not accessible in 32-bit mode\r
+  //\r
+  return RETURN_UNSUPPORTED;\r
+}\r