1 files changed, 85 insertions, 0 deletions
diff --git a/src/VBox/Devices/EFI/Firmware/MdeModulePkg/Library/VariablePolicyLib/VariablePolicyExtraInitRuntimeDxe.c b/src/VBox/Devices/EFI/Firmware/MdeModulePkg/Library/VariablePolicyLib/VariablePolicyExtraInitRuntimeDxe.c
new file mode 100644
index 00000000..c69a776e
--- /dev/null
+++ b/src/VBox/Devices/EFI/Firmware/MdeModulePkg/Library/VariablePolicyLib/VariablePolicyExtraInitRuntimeDxe.c
@@ -0,0 +1,85 @@
+/** @file -- VariablePolicyExtraInitRuntimeDxe.c
+This file contains extra init and deinit routines that register and unregister
+VariableAddressChange callbacks.
+
+Copyright (c) Microsoft Corporation.
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+
+extern EFI_GET_VARIABLE   mGetVariableHelper;
+extern UINT8              *mPolicyTable;
+STATIC BOOLEAN            mIsVirtualAddrConverted;
+STATIC EFI_EVENT          mVariablePolicyLibVirtualAddressChangeEvent  = NULL;
+
+/**
+  For the RuntimeDxe version of this lib, convert internal pointer addresses to virtual addresses.
+
+  @param[in] Event      Event whose notification function is being invoked.
+  @param[in] Context    The pointer to the notification function's context, which
+                        is implementation-dependent.
+**/
+STATIC
+VOID
+EFIAPI
+VariablePolicyLibVirtualAddressCallback (
+  IN  EFI_EVENT   Event,
+  IN  VOID        *Context
+  )
+{
+  gRT->ConvertPointer (0, (VOID **)&mPolicyTable);
+  gRT->ConvertPointer (0, (VOID **)&mGetVariableHelper);
+  mIsVirtualAddrConverted = TRUE;
+}
+
+
+/**
+  An extra init hook that enables the RuntimeDxe library instance to
+  register VirtualAddress change callbacks. Among other things.
+
+  @retval     EFI_SUCCESS   Everything is good. Continue with init.
+  @retval     Others        Uh... don't continue.
+
+**/
+EFI_STATUS
+VariablePolicyExtraInit (
+  VOID
+  )
+{
+  return gBS->CreateEventEx (EVT_NOTIFY_SIGNAL,
+                              TPL_NOTIFY,
+                              VariablePolicyLibVirtualAddressCallback,
+                              NULL,
+                              &gEfiEventVirtualAddressChangeGuid,
+                              &mVariablePolicyLibVirtualAddressChangeEvent);
+}
+
+
+/**
+  An extra deinit hook that enables the RuntimeDxe library instance to
+  register VirtualAddress change callbacks. Among other things.
+
+  @retval     EFI_SUCCESS   Everything is good. Continue with deinit.
+  @retval     Others        Uh... don't continue.
+
+**/
+EFI_STATUS
+VariablePolicyExtraDeinit (
+  VOID
+  )
+{
+  EFI_STATUS  Status;
+
+  Status = EFI_SUCCESS;
+  if (mIsVirtualAddrConverted) {
+    Status = gBS->CloseEvent (mVariablePolicyLibVirtualAddressChangeEvent);
+  }
+  else {
+    Status = EFI_SUCCESS;
+  }
+
+  return Status;
+}