UefiCpuPkg/MpInitLib: move SEV specific routines in AmdSev.c

[mirror_edk2.git] / UefiCpuPkg / Library / MpInitLib / AmdSev.c

/** @file\r
  CPU MP Initialize helper function for AMD SEV.\r
\r
  Copyright (c) 2021, AMD Inc. All rights reserved.<BR>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "MpLib.h"\r
#include <Library/VmgExitLib.h>\r
\r
/**\r
  Get Protected mode code segment with 16-bit default addressing\r
  from current GDT table.\r
\r
  @return  Protected mode 16-bit code segment value.\r
**/\r
STATIC\r
UINT16\r
GetProtectedMode16CS (\r
  VOID\r
  )\r
{\r
  IA32_DESCRIPTOR          GdtrDesc;\r
  IA32_SEGMENT_DESCRIPTOR  *GdtEntry;\r
  UINTN                    GdtEntryCount;\r
  UINT16                   Index;\r
\r
  Index = (UINT16)-1;\r
  AsmReadGdtr (&GdtrDesc);\r
  GdtEntryCount = (GdtrDesc.Limit + 1) / sizeof (IA32_SEGMENT_DESCRIPTOR);\r
  GdtEntry      = (IA32_SEGMENT_DESCRIPTOR *)GdtrDesc.Base;\r
  for (Index = 0; Index < GdtEntryCount; Index++) {\r
    if ((GdtEntry->Bits.L == 0) &&\r
        (GdtEntry->Bits.DB == 0) &&\r
        (GdtEntry->Bits.Type > 8))\r
    {\r
      break;\r
    }\r
\r
    GdtEntry++;\r
  }\r
\r
  ASSERT (Index != GdtEntryCount);\r
  return Index * 8;\r
}\r
\r
/**\r
  Get Protected mode code segment with 32-bit default addressing\r
  from current GDT table.\r
\r
  @return  Protected mode 32-bit code segment value.\r
**/\r
STATIC\r
UINT16\r
GetProtectedMode32CS (\r
  VOID\r
  )\r
{\r
  IA32_DESCRIPTOR          GdtrDesc;\r
  IA32_SEGMENT_DESCRIPTOR  *GdtEntry;\r
  UINTN                    GdtEntryCount;\r
  UINT16                   Index;\r
\r
  Index = (UINT16)-1;\r
  AsmReadGdtr (&GdtrDesc);\r
  GdtEntryCount = (GdtrDesc.Limit + 1) / sizeof (IA32_SEGMENT_DESCRIPTOR);\r
  GdtEntry      = (IA32_SEGMENT_DESCRIPTOR *)GdtrDesc.Base;\r
  for (Index = 0; Index < GdtEntryCount; Index++) {\r
    if ((GdtEntry->Bits.L == 0) &&\r
        (GdtEntry->Bits.DB == 1) &&\r
        (GdtEntry->Bits.Type > 8))\r
    {\r
      break;\r
    }\r
\r
    GdtEntry++;\r
  }\r
\r
  ASSERT (Index != GdtEntryCount);\r
  return Index * 8;\r
}\r
\r
/**\r
  Reset an AP when in SEV-ES mode.\r
\r
  If successful, this function never returns.\r
\r
  @param[in] Ghcb                 Pointer to the GHCB\r
  @param[in] CpuMpData            Pointer to CPU MP Data\r
\r
**/\r
VOID\r
MpInitLibSevEsAPReset (\r
  IN GHCB         *Ghcb,\r
  IN CPU_MP_DATA  *CpuMpData\r
  )\r
{\r
  EFI_STATUS  Status;\r
  UINTN       ProcessorNumber;\r
  UINT16      Code16, Code32;\r
  AP_RESET    *APResetFn;\r
  UINTN       BufferStart;\r
  UINTN       StackStart;\r
\r
  Status = GetProcessorNumber (CpuMpData, &ProcessorNumber);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  Code16 = GetProtectedMode16CS ();\r
  Code32 = GetProtectedMode32CS ();\r
\r
  if (CpuMpData->WakeupBufferHigh != 0) {\r
    APResetFn = (AP_RESET *)(CpuMpData->WakeupBufferHigh + CpuMpData->AddressMap.SwitchToRealNoNxOffset);\r
  } else {\r
    APResetFn = (AP_RESET *)(CpuMpData->MpCpuExchangeInfo->BufferStart + CpuMpData->AddressMap.SwitchToRealOffset);\r
  }\r
\r
  BufferStart = CpuMpData->MpCpuExchangeInfo->BufferStart;\r
  StackStart  = CpuMpData->SevEsAPResetStackStart -\r
                (AP_RESET_STACK_SIZE * ProcessorNumber);\r
\r
  //\r
  // This call never returns.\r
  //\r
  APResetFn (BufferStart, Code16, Code32, StackStart);\r
}\r
\r
/**\r
  Allocate the SEV-ES AP jump table buffer.\r
\r
  @param[in, out]  CpuMpData  The pointer to CPU MP Data structure.\r
**/\r
VOID\r
AllocateSevEsAPMemory (\r
  IN OUT CPU_MP_DATA  *CpuMpData\r
  )\r
{\r
  if (CpuMpData->SevEsAPBuffer == (UINTN)-1) {\r
    CpuMpData->SevEsAPBuffer =\r
      CpuMpData->SevEsIsEnabled ? GetSevEsAPMemory () : 0;\r
  }\r
}\r
\r
/**\r
  Program the SEV-ES AP jump table buffer.\r
\r
  @param[in]  SipiVector  The SIPI vector used for the AP Reset\r
**/\r
VOID\r
SetSevEsJumpTable (\r
  IN UINTN  SipiVector\r
  )\r
{\r
  SEV_ES_AP_JMP_FAR  *JmpFar;\r
  UINT32             Offset, InsnByte;\r
  UINT8              LoNib, HiNib;\r
\r
  JmpFar = (SEV_ES_AP_JMP_FAR *)(UINTN)FixedPcdGet32 (PcdSevEsWorkAreaBase);\r
  ASSERT (JmpFar != NULL);\r
\r
  //\r
  // Obtain the address of the Segment/Rip location in the workarea.\r
  // This will be set to a value derived from the SIPI vector and will\r
  // be the memory address used for the far jump below.\r
  //\r
  Offset  = FixedPcdGet32 (PcdSevEsWorkAreaBase);\r
  Offset += sizeof (JmpFar->InsnBuffer);\r
  LoNib   = (UINT8)Offset;\r
  HiNib   = (UINT8)(Offset >> 8);\r
\r
  //\r
  // Program the workarea (which is the initial AP boot address) with\r
  // far jump to the SIPI vector (where XX and YY represent the\r
  // address of where the SIPI vector is stored.\r
  //\r
  //   JMP FAR [CS:XXYY] => 2E FF 2E YY XX\r
  //\r
  InsnByte                       = 0;\r
  JmpFar->InsnBuffer[InsnByte++] = 0x2E;  // CS override prefix\r
  JmpFar->InsnBuffer[InsnByte++] = 0xFF;  // JMP (FAR)\r
  JmpFar->InsnBuffer[InsnByte++] = 0x2E;  // ModRM (JMP memory location)\r
  JmpFar->InsnBuffer[InsnByte++] = LoNib; // YY offset ...\r
  JmpFar->InsnBuffer[InsnByte++] = HiNib; // XX offset ...\r
\r
  //\r
  // Program the Segment/Rip based on the SIPI vector (always at least\r
  // 16-byte aligned, so Rip is set to 0).\r
  //\r
  JmpFar->Rip     = 0;\r
  JmpFar->Segment = (UINT16)(SipiVector >> 4);\r
}\r
\r
/**\r
  The function puts the AP in halt loop.\r
\r
  @param[in]  CpuMpData  The pointer to CPU MP Data structure.\r
**/\r
VOID\r
SevEsPlaceApHlt (\r
  CPU_MP_DATA  *CpuMpData\r
  )\r
{\r
  MSR_SEV_ES_GHCB_REGISTER  Msr;\r
  GHCB                      *Ghcb;\r
  UINT64                    Status;\r
  BOOLEAN                   DoDecrement;\r
  BOOLEAN                   InterruptState;\r
\r
  DoDecrement = (BOOLEAN)(CpuMpData->InitFlag == ApInitConfig);\r
\r
  while (TRUE) {\r
    Msr.GhcbPhysicalAddress = AsmReadMsr64 (MSR_SEV_ES_GHCB);\r
    Ghcb                    = Msr.Ghcb;\r
\r
    VmgInit (Ghcb, &InterruptState);\r
\r
    if (DoDecrement) {\r
      DoDecrement = FALSE;\r
\r
      //\r
      // Perform the delayed decrement just before issuing the first\r
      // VMGEXIT with AP_RESET_HOLD.\r
      //\r
      InterlockedDecrement ((UINT32 *)&CpuMpData->MpCpuExchangeInfo->NumApsExecuting);\r
    }\r
\r
    Status = VmgExit (Ghcb, SVM_EXIT_AP_RESET_HOLD, 0, 0);\r
    if ((Status == 0) && (Ghcb->SaveArea.SwExitInfo2 != 0)) {\r
      VmgDone (Ghcb, InterruptState);\r
      break;\r
    }\r
\r
    VmgDone (Ghcb, InterruptState);\r
  }\r
\r
  //\r
  // Awakened in a new phase? Use the new CpuMpData\r
  //\r
  if (CpuMpData->NewCpuMpData != NULL) {\r
    CpuMpData = CpuMpData->NewCpuMpData;\r
  }\r
\r
  MpInitLibSevEsAPReset (Ghcb, CpuMpData);\r
}\r