OvmfPkg/VmgExitLib: Add support for RDPMC NAE events

[mirror_edk2.git] / OvmfPkg / Library / VmgExitLib / VmgExitLib.c

/** @file\r
  VMGEXIT Support Library.\r
\r
  Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include <Base.h>\r
#include <Uefi.h>\r
#include <Library/BaseMemoryLib.h>\r
#include <Library/VmgExitLib.h>\r
#include <Register/Amd/Msr.h>\r
\r
/**\r
  Check for VMGEXIT error\r
\r
  Check if the hypervisor has returned an error after completion of the VMGEXIT\r
  by examining the SwExitInfo1 field of the GHCB.\r
\r
  @param[in]  Ghcb       A pointer to the GHCB\r
\r
  @retval  0             VMGEXIT succeeded.\r
  @return                Exception number to be propagated, VMGEXIT processing\r
                         did not succeed.\r
\r
**/\r
STATIC\r
UINT64\r
VmgExitErrorCheck (\r
  IN GHCB                *Ghcb\r
  )\r
{\r
  GHCB_EVENT_INJECTION  Event;\r
  GHCB_EXIT_INFO        ExitInfo;\r
  UINT64                Status;\r
\r
  ExitInfo.Uint64 = Ghcb->SaveArea.SwExitInfo1;\r
  ASSERT ((ExitInfo.Elements.Lower32Bits == 0) ||\r
          (ExitInfo.Elements.Lower32Bits == 1));\r
\r
  Status = 0;\r
  if (ExitInfo.Elements.Lower32Bits == 0) {\r
    return Status;\r
  }\r
\r
  if (ExitInfo.Elements.Lower32Bits == 1) {\r
    ASSERT (Ghcb->SaveArea.SwExitInfo2 != 0);\r
\r
    //\r
    // Check that the return event is valid\r
    //\r
    Event.Uint64 = Ghcb->SaveArea.SwExitInfo2;\r
    if (Event.Elements.Valid &&\r
        Event.Elements.Type == GHCB_EVENT_INJECTION_TYPE_EXCEPTION) {\r
      switch (Event.Elements.Vector) {\r
      case GP_EXCEPTION:\r
      case UD_EXCEPTION:\r
        //\r
        // Use returned event as return code\r
        //\r
        Status = Event.Uint64;\r
      }\r
    }\r
  }\r
\r
  if (Status == 0) {\r
    GHCB_EVENT_INJECTION  GpEvent;\r
\r
    GpEvent.Uint64 = 0;\r
    GpEvent.Elements.Vector = GP_EXCEPTION;\r
    GpEvent.Elements.Type   = GHCB_EVENT_INJECTION_TYPE_EXCEPTION;\r
    GpEvent.Elements.Valid  = 1;\r
\r
    Status = GpEvent.Uint64;\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
  Perform VMGEXIT.\r
\r
  Sets the necessary fields of the GHCB, invokes the VMGEXIT instruction and\r
  then handles the return actions.\r
\r
  @param[in, out]  Ghcb       A pointer to the GHCB\r
  @param[in]       ExitCode   VMGEXIT code to be assigned to the SwExitCode\r
                              field of the GHCB.\r
  @param[in]       ExitInfo1  VMGEXIT information to be assigned to the\r
                              SwExitInfo1 field of the GHCB.\r
  @param[in]       ExitInfo2  VMGEXIT information to be assigned to the\r
                              SwExitInfo2 field of the GHCB.\r
\r
  @retval  0                  VMGEXIT succeeded.\r
  @return                     Exception number to be propagated, VMGEXIT\r
                              processing did not succeed.\r
\r
**/\r
UINT64\r
EFIAPI\r
VmgExit (\r
  IN OUT GHCB                *Ghcb,\r
  IN     UINT64              ExitCode,\r
  IN     UINT64              ExitInfo1,\r
  IN     UINT64              ExitInfo2\r
  )\r
{\r
  Ghcb->SaveArea.SwExitCode = ExitCode;\r
  Ghcb->SaveArea.SwExitInfo1 = ExitInfo1;\r
  Ghcb->SaveArea.SwExitInfo2 = ExitInfo2;\r
\r
  //\r
  // Guest memory is used for the guest-hypervisor communication, so fence\r
  // the invocation of the VMGEXIT instruction to ensure GHCB accesses are\r
  // synchronized properly.\r
  //\r
  MemoryFence ();\r
  AsmVmgExit ();\r
  MemoryFence ();\r
\r
  return VmgExitErrorCheck (Ghcb);\r
}\r
\r
/**\r
  Perform pre-VMGEXIT initialization/preparation.\r
\r
  Performs the necessary steps in preparation for invoking VMGEXIT. Must be\r
  called before setting any fields within the GHCB.\r
\r
  @param[in, out]  Ghcb       A pointer to the GHCB\r
\r
**/\r
VOID\r
EFIAPI\r
VmgInit (\r
  IN OUT GHCB                *Ghcb\r
  )\r
{\r
  SetMem (&Ghcb->SaveArea, sizeof (Ghcb->SaveArea), 0);\r
}\r
\r
/**\r
  Perform post-VMGEXIT cleanup.\r
\r
  Performs the necessary steps to cleanup after invoking VMGEXIT. Must be\r
  called after obtaining needed fields within the GHCB.\r
\r
  @param[in, out]  Ghcb       A pointer to the GHCB\r
\r
**/\r
VOID\r
EFIAPI\r
VmgDone (\r
  IN OUT GHCB                *Ghcb\r
  )\r
{\r
}\r
\r