MdePkg/Baseib: Filter/trace MSR access for IA32/X64

[mirror_edk2.git] / MdePkg / Library / BaseLib / Ia32 / ReadMsr64.c

/** @file\r
  AsmReadMsr64 function\r
\r
  Copyright (c) 2006 - 2021, Intel Corporation. All rights reserved.<BR>\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
\r
#include <Library/RegisterFilterLib.h>\r
\r
/**\r
  Returns a 64-bit Machine Specific Register(MSR).\r
\r
  Reads and returns the 64-bit MSR specified by Index. No parameter checking is\r
  performed on Index, and some Index values may cause CPU exceptions. The\r
  caller must either guarantee that Index is valid, or the caller must set up\r
  exception handlers to catch the exceptions. This function is only available\r
  on IA-32 and x64.\r
\r
  @param  Index The 32-bit MSR index to read.\r
\r
  @return The value of the MSR identified by Index.\r
\r
**/\r
UINT64\r
AsmReadMsr64Internal (\r
  IN UINT32  Index\r
  )\r
{\r
  _asm {\r
    mov     ecx, Index\r
    rdmsr\r
  }\r
}\r
\r
/**\r
  Returns a 64-bit Machine Specific Register(MSR).\r
\r
  Reads and returns the 64-bit MSR specified by Index. No parameter checking is\r
  performed on Index, and some Index values may cause CPU exceptions. The\r
  caller must either guarantee that Index is valid, or the caller must set up\r
  exception handlers to catch the exceptions. This function is only available\r
  on IA-32 and x64.\r
\r
  @param  Index The 32-bit MSR index to read.\r
\r
  @return The value of the MSR identified by Index.\r
\r
**/\r
UINT64\r
EFIAPI\r
AsmReadMsr64 (\r
  IN UINT32  Index\r
  )\r
{\r
  UINT64                            Value;\r
  BOOLEAN                           Flag;\r
\r
  Flag = FilterBeforeMsrRead (Index, &Value);\r
  if (Flag) {\r
    Value = AsmReadMsr64Internal (Index);\r
  }\r
  FilterAfterMsrRead (Index, &Value);\r
\r
  return Value;\r
}\r