1 files changed, 67 insertions, 0 deletions
diff --git a/src/VBox/Devices/EFI/Firmware/MdePkg/Library/BaseLib/Ia32/ReadMsr64.c b/src/VBox/Devices/EFI/Firmware/MdePkg/Library/BaseLib/Ia32/ReadMsr64.c
new file mode 100644
index 00000000..f3f6b0f3
--- /dev/null
+++ b/src/VBox/Devices/EFI/Firmware/MdePkg/Library/BaseLib/Ia32/ReadMsr64.c
@@ -0,0 +1,67 @@
+/** @file
+  AsmReadMsr64 function
+
+  Copyright (c) 2006 - 2021, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+
+#include <Library/RegisterFilterLib.h>
+
+/**
+  Returns a 64-bit Machine Specific Register(MSR).
+
+  Reads and returns the 64-bit MSR specified by Index. No parameter checking is
+  performed on Index, and some Index values may cause CPU exceptions. The
+  caller must either guarantee that Index is valid, or the caller must set up
+  exception handlers to catch the exceptions. This function is only available
+  on IA-32 and x64.
+
+  @param  Index The 32-bit MSR index to read.
+
+  @return The value of the MSR identified by Index.
+
+**/
+UINT64
+AsmReadMsr64Internal (
+  IN UINT32  Index
+  )
+{
+  _asm {
+    mov     ecx, Index
+    rdmsr
+  }
+}
+
+/**
+  Returns a 64-bit Machine Specific Register(MSR).
+
+  Reads and returns the 64-bit MSR specified by Index. No parameter checking is
+  performed on Index, and some Index values may cause CPU exceptions. The
+  caller must either guarantee that Index is valid, or the caller must set up
+  exception handlers to catch the exceptions. This function is only available
+  on IA-32 and x64.
+
+  @param  Index The 32-bit MSR index to read.
+
+  @return The value of the MSR identified by Index.
+
+**/
+UINT64
+EFIAPI
+AsmReadMsr64 (
+  IN UINT32  Index
+  )
+{
+  UINT64                            Value;
+  BOOLEAN                           Flag;
+
+  Flag = FilterBeforeMsrRead (Index, &Value);
+  if (Flag) {
+    Value = AsmReadMsr64Internal (Index);
+  }
+  FilterAfterMsrRead (Index, &Value);
+
+  return Value;
+}