MdePkg/Library/BaseLib/X64/ReadMsr64.c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44

/** @file
  CpuBreakpoint function.

  Copyright (c) 2006 - 2021, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

/**
  Microsoft Visual Studio 7.1 Function Prototypes for I/O Intrinsics.
**/

#include <Library/RegisterFilterLib.h>

unsigned __int64 __readmsr (int register);

#pragma intrinsic(__readmsr)

/**
  Read data to MSR.

  @param  Index                Register index of MSR.

  @return Value read from MSR.

**/
UINT64
EFIAPI
AsmReadMsr64 (
  IN UINT32  Index
  )
{
  UINT64                            Value;
  BOOLEAN                           Flag;

  Flag = FilterBeforeMsrRead (Index, &Value);
  if (Flag) {
    Value = __readmsr (Index);
  }
  FilterAfterMsrRead (Index, &Value);

  return Value;
}