[mirror_edk2.git] / OvmfPkg / PlatformPei / Platform.c

/**@file\r
  Platform PEI driver\r
\r
  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>\r
  Copyright (c) 2011, Andrei Warkentin <andreiw@motorola.com>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
//\r
// The package level header files this module uses\r
//\r
#include <PiPei.h>\r
\r
//\r
// The Library classes this module consumes\r
//\r
#include <Library/BaseLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/HobLib.h>\r
#include <Library/IoLib.h>\r
#include <Library/MemoryAllocationLib.h>\r
#include <Library/PcdLib.h>\r
#include <Library/PciLib.h>\r
#include <Library/PeimEntryPoint.h>\r
#include <Library/PeiServicesLib.h>\r
#include <Library/QemuFwCfgLib.h>\r
#include <Library/QemuFwCfgS3Lib.h>\r
#include <Library/QemuFwCfgSimpleParserLib.h>\r
#include <Library/ResourcePublicationLib.h>\r
#include <Ppi/MasterBootMode.h>\r
#include <IndustryStandard/I440FxPiix4.h>\r
#include <IndustryStandard/Microvm.h>\r
#include <IndustryStandard/Pci22.h>\r
#include <IndustryStandard/Q35MchIch9.h>\r
#include <IndustryStandard/QemuCpuHotplug.h>\r
#include <OvmfPlatforms.h>\r
\r
#include "Platform.h"\r
#include "Cmos.h"\r
\r
EFI_PEI_PPI_DESCRIPTOR   mPpiBootMode[] = {\r
  {\r
    EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST,\r
    &gEfiPeiMasterBootModePpiGuid,\r
    NULL\r
  }\r
};\r
\r
\r
UINT16 mHostBridgeDevId;\r
\r
EFI_BOOT_MODE mBootMode = BOOT_WITH_FULL_CONFIGURATION;\r
\r
BOOLEAN mS3Supported = FALSE;\r
\r
UINT32 mMaxCpuCount;\r
\r
VOID\r
AddIoMemoryBaseSizeHob (\r
  EFI_PHYSICAL_ADDRESS        MemoryBase,\r
  UINT64                      MemorySize\r
  )\r
{\r
  BuildResourceDescriptorHob (\r
    EFI_RESOURCE_MEMORY_MAPPED_IO,\r
      EFI_RESOURCE_ATTRIBUTE_PRESENT     |\r
      EFI_RESOURCE_ATTRIBUTE_INITIALIZED |\r
      EFI_RESOURCE_ATTRIBUTE_UNCACHEABLE |\r
      EFI_RESOURCE_ATTRIBUTE_TESTED,\r
    MemoryBase,\r
    MemorySize\r
    );\r
}\r
\r
VOID\r
AddReservedMemoryBaseSizeHob (\r
  EFI_PHYSICAL_ADDRESS        MemoryBase,\r
  UINT64                      MemorySize,\r
  BOOLEAN                     Cacheable\r
  )\r
{\r
  BuildResourceDescriptorHob (\r
    EFI_RESOURCE_MEMORY_RESERVED,\r
      EFI_RESOURCE_ATTRIBUTE_PRESENT     |\r
      EFI_RESOURCE_ATTRIBUTE_INITIALIZED |\r
      EFI_RESOURCE_ATTRIBUTE_UNCACHEABLE |\r
      (Cacheable ?\r
       EFI_RESOURCE_ATTRIBUTE_WRITE_COMBINEABLE |\r
       EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |\r
       EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE :\r
       0\r
       ) |\r
      EFI_RESOURCE_ATTRIBUTE_TESTED,\r
    MemoryBase,\r
    MemorySize\r
    );\r
}\r
\r
VOID\r
AddIoMemoryRangeHob (\r
  EFI_PHYSICAL_ADDRESS        MemoryBase,\r
  EFI_PHYSICAL_ADDRESS        MemoryLimit\r
  )\r
{\r
  AddIoMemoryBaseSizeHob (MemoryBase, (UINT64)(MemoryLimit - MemoryBase));\r
}\r
\r
\r
VOID\r
AddMemoryBaseSizeHob (\r
  EFI_PHYSICAL_ADDRESS        MemoryBase,\r
  UINT64                      MemorySize\r
  )\r
{\r
  BuildResourceDescriptorHob (\r
    EFI_RESOURCE_SYSTEM_MEMORY,\r
      EFI_RESOURCE_ATTRIBUTE_PRESENT |\r
      EFI_RESOURCE_ATTRIBUTE_INITIALIZED |\r
      EFI_RESOURCE_ATTRIBUTE_UNCACHEABLE |\r
      EFI_RESOURCE_ATTRIBUTE_WRITE_COMBINEABLE |\r
      EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |\r
      EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE |\r
      EFI_RESOURCE_ATTRIBUTE_TESTED,\r
    MemoryBase,\r
    MemorySize\r
    );\r
}\r
\r
\r
VOID\r
AddMemoryRangeHob (\r
  EFI_PHYSICAL_ADDRESS        MemoryBase,\r
  EFI_PHYSICAL_ADDRESS        MemoryLimit\r
  )\r
{\r
  AddMemoryBaseSizeHob (MemoryBase, (UINT64)(MemoryLimit - MemoryBase));\r
}\r
\r
\r
VOID\r
MemMapInitialization (\r
  VOID\r
  )\r
{\r
  UINT64        PciIoBase;\r
  UINT64        PciIoSize;\r
  RETURN_STATUS PcdStatus;\r
  UINT32        TopOfLowRam;\r
  UINT64        PciExBarBase;\r
  UINT32        PciBase;\r
  UINT32        PciSize;\r
\r
  PciIoBase = 0xC000;\r
  PciIoSize = 0x4000;\r
\r
  //\r
  // Video memory + Legacy BIOS region\r
  //\r
  AddIoMemoryRangeHob (0x0A0000, BASE_1MB);\r
\r
  if (mHostBridgeDevId == 0xffff /* microvm */) {\r
    AddIoMemoryBaseSizeHob (0xFEC00000, SIZE_4KB); /* ioapic #1 */\r
    AddIoMemoryBaseSizeHob (0xFEC10000, SIZE_4KB); /* ioapic #2 */\r
    return;\r
  }\r
\r
  TopOfLowRam = GetSystemMemorySizeBelow4gb ();\r
  PciExBarBase = 0;\r
  if (mHostBridgeDevId == INTEL_Q35_MCH_DEVICE_ID) {\r
    //\r
    // The MMCONFIG area is expected to fall between the top of low RAM and\r
    // the base of the 32-bit PCI host aperture.\r
    //\r
    PciExBarBase = FixedPcdGet64 (PcdPciExpressBaseAddress);\r
    ASSERT (TopOfLowRam <= PciExBarBase);\r
    ASSERT (PciExBarBase <= MAX_UINT32 - SIZE_256MB);\r
    PciBase = (UINT32)(PciExBarBase + SIZE_256MB);\r
  } else {\r
    ASSERT (TopOfLowRam <= mQemuUc32Base);\r
    PciBase = mQemuUc32Base;\r
  }\r
\r
  //\r
  // address       purpose   size\r
  // ------------  --------  -------------------------\r
  // max(top, 2g)  PCI MMIO  0xFC000000 - max(top, 2g)\r
  // 0xFC000000    gap                           44 MB\r
  // 0xFEC00000    IO-APIC                        4 KB\r
  // 0xFEC01000    gap                         1020 KB\r
  // 0xFED00000    HPET                           1 KB\r
  // 0xFED00400    gap                          111 KB\r
  // 0xFED1C000    gap (PIIX4) / RCRB (ICH9)     16 KB\r
  // 0xFED20000    gap                          896 KB\r
  // 0xFEE00000    LAPIC                          1 MB\r
  //\r
  PciSize = 0xFC000000 - PciBase;\r
  AddIoMemoryBaseSizeHob (PciBase, PciSize);\r
  PcdStatus = PcdSet64S (PcdPciMmio32Base, PciBase);\r
  ASSERT_RETURN_ERROR (PcdStatus);\r
  PcdStatus = PcdSet64S (PcdPciMmio32Size, PciSize);\r
  ASSERT_RETURN_ERROR (PcdStatus);\r
\r
  AddIoMemoryBaseSizeHob (0xFEC00000, SIZE_4KB);\r
  AddIoMemoryBaseSizeHob (0xFED00000, SIZE_1KB);\r
  if (mHostBridgeDevId == INTEL_Q35_MCH_DEVICE_ID) {\r
    AddIoMemoryBaseSizeHob (ICH9_ROOT_COMPLEX_BASE, SIZE_16KB);\r
    //\r
    // Note: there should be an\r
    //\r
    //   AddIoMemoryBaseSizeHob (PciExBarBase, SIZE_256MB);\r
    //\r
    // call below, just like the one above for RCBA. However, Linux insists\r
    // that the MMCONFIG area be marked in the E820 or UEFI memory map as\r
    // "reserved memory" -- Linux does not content itself with a simple gap\r
    // in the memory map wherever the MCFG ACPI table points to.\r
    //\r
    // This appears to be a safety measure. The PCI Firmware Specification\r
    // (rev 3.1) says in 4.1.2. "MCFG Table Description": "The resources can\r
    // *optionally* be returned in [...] EFIGetMemoryMap as reserved memory\r
    // [...]". (Emphasis added here.)\r
    //\r
    // Normally we add memory resource descriptor HOBs in\r
    // QemuInitializeRam(), and pre-allocate from those with memory\r
    // allocation HOBs in InitializeRamRegions(). However, the MMCONFIG area\r
    // is most definitely not RAM; so, as an exception, cover it with\r
    // uncacheable reserved memory right here.\r
    //\r
    AddReservedMemoryBaseSizeHob (PciExBarBase, SIZE_256MB, FALSE);\r
    BuildMemoryAllocationHob (PciExBarBase, SIZE_256MB,\r
      EfiReservedMemoryType);\r
  }\r
  AddIoMemoryBaseSizeHob (PcdGet32(PcdCpuLocalApicBaseAddress), SIZE_1MB);\r
\r
  //\r
  // On Q35, the IO Port space is available for PCI resource allocations from\r
  // 0x6000 up.\r
  //\r
  if (mHostBridgeDevId == INTEL_Q35_MCH_DEVICE_ID) {\r
    PciIoBase = 0x6000;\r
    PciIoSize = 0xA000;\r
    ASSERT ((ICH9_PMBASE_VALUE & 0xF000) < PciIoBase);\r
  }\r
\r
  //\r
  // Add PCI IO Port space available for PCI resource allocations.\r
  //\r
  BuildResourceDescriptorHob (\r
    EFI_RESOURCE_IO,\r
    EFI_RESOURCE_ATTRIBUTE_PRESENT     |\r
    EFI_RESOURCE_ATTRIBUTE_INITIALIZED,\r
    PciIoBase,\r
    PciIoSize\r
    );\r
  PcdStatus = PcdSet64S (PcdPciIoBase, PciIoBase);\r
  ASSERT_RETURN_ERROR (PcdStatus);\r
  PcdStatus = PcdSet64S (PcdPciIoSize, PciIoSize);\r
  ASSERT_RETURN_ERROR (PcdStatus);\r
}\r
\r
#define UPDATE_BOOLEAN_PCD_FROM_FW_CFG(TokenName)                   \\r
          do {                                                      \\r
            BOOLEAN       Setting;                                  \\r
            RETURN_STATUS PcdStatus;                                \\r
                                                                    \\r
            if (!RETURN_ERROR (QemuFwCfgParseBool (                 \\r
                              "opt/ovmf/" #TokenName, &Setting))) { \\r
              PcdStatus = PcdSetBoolS (TokenName, Setting);         \\r
              ASSERT_RETURN_ERROR (PcdStatus);                      \\r
            }                                                       \\r
          } while (0)\r
\r
VOID\r
NoexecDxeInitialization (\r
  VOID\r
  )\r
{\r
  UPDATE_BOOLEAN_PCD_FROM_FW_CFG (PcdSetNxForStack);\r
}\r
\r
VOID\r
PciExBarInitialization (\r
  VOID\r
  )\r
{\r
  union {\r
    UINT64 Uint64;\r
    UINT32 Uint32[2];\r
  } PciExBarBase;\r
\r
  //\r
  // We only support the 256MB size for the MMCONFIG area:\r
  // 256 buses * 32 devices * 8 functions * 4096 bytes config space.\r
  //\r
  // The masks used below enforce the Q35 requirements that the MMCONFIG area\r
  // be (a) correctly aligned -- here at 256 MB --, (b) located under 64 GB.\r
  //\r
  // Note that (b) also ensures that the minimum address width we have\r
  // determined in AddressWidthInitialization(), i.e., 36 bits, will suffice\r
  // for DXE's page tables to cover the MMCONFIG area.\r
  //\r
  PciExBarBase.Uint64 = FixedPcdGet64 (PcdPciExpressBaseAddress);\r
  ASSERT ((PciExBarBase.Uint32[1] & MCH_PCIEXBAR_HIGHMASK) == 0);\r
  ASSERT ((PciExBarBase.Uint32[0] & MCH_PCIEXBAR_LOWMASK) == 0);\r
\r
  //\r
  // Clear the PCIEXBAREN bit first, before programming the high register.\r
  //\r
  PciWrite32 (DRAMC_REGISTER_Q35 (MCH_PCIEXBAR_LOW), 0);\r
\r
  //\r
  // Program the high register. Then program the low register, setting the\r
  // MMCONFIG area size and enabling decoding at once.\r
  //\r
  PciWrite32 (DRAMC_REGISTER_Q35 (MCH_PCIEXBAR_HIGH), PciExBarBase.Uint32[1]);\r
  PciWrite32 (\r
    DRAMC_REGISTER_Q35 (MCH_PCIEXBAR_LOW),\r
    PciExBarBase.Uint32[0] | MCH_PCIEXBAR_BUS_FF | MCH_PCIEXBAR_EN\r
    );\r
}\r
\r
VOID\r
MiscInitialization (\r
  VOID\r
  )\r
{\r
  UINTN         PmCmd;\r
  UINTN         Pmba;\r
  UINT32        PmbaAndVal;\r
  UINT32        PmbaOrVal;\r
  UINTN         AcpiCtlReg;\r
  UINT8         AcpiEnBit;\r
  RETURN_STATUS PcdStatus;\r
\r
  //\r
  // Disable A20 Mask\r
  //\r
  IoOr8 (0x92, BIT1);\r
\r
  //\r
  // Build the CPU HOB with guest RAM size dependent address width and 16-bits\r
  // of IO space. (Side note: unlike other HOBs, the CPU HOB is needed during\r
  // S3 resume as well, so we build it unconditionally.)\r
  //\r
  BuildCpuHob (mPhysMemAddressWidth, 16);\r
\r
  //\r
  // Determine platform type and save Host Bridge DID to PCD\r
  //\r
  switch (mHostBridgeDevId) {\r
    case INTEL_82441_DEVICE_ID:\r
      PmCmd      = POWER_MGMT_REGISTER_PIIX4 (PCI_COMMAND_OFFSET);\r
      Pmba       = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMBA);\r
      PmbaAndVal = ~(UINT32)PIIX4_PMBA_MASK;\r
      PmbaOrVal  = PIIX4_PMBA_VALUE;\r
      AcpiCtlReg = POWER_MGMT_REGISTER_PIIX4 (PIIX4_PMREGMISC);\r
      AcpiEnBit  = PIIX4_PMREGMISC_PMIOSE;\r
      break;\r
    case INTEL_Q35_MCH_DEVICE_ID:\r
      PmCmd      = POWER_MGMT_REGISTER_Q35 (PCI_COMMAND_OFFSET);\r
      Pmba       = POWER_MGMT_REGISTER_Q35 (ICH9_PMBASE);\r
      PmbaAndVal = ~(UINT32)ICH9_PMBASE_MASK;\r
      PmbaOrVal  = ICH9_PMBASE_VALUE;\r
      AcpiCtlReg = POWER_MGMT_REGISTER_Q35 (ICH9_ACPI_CNTL);\r
      AcpiEnBit  = ICH9_ACPI_CNTL_ACPI_EN;\r
      break;\r
    case 0xffff: /* microvm */\r
      DEBUG ((DEBUG_INFO, "%a: microvm\n", __FUNCTION__));\r
      PcdStatus = PcdSet16S (PcdOvmfHostBridgePciDevId,\r
                             MICROVM_PSEUDO_DEVICE_ID);\r
      ASSERT_RETURN_ERROR (PcdStatus);\r
      return;\r
    default:\r
      DEBUG ((DEBUG_ERROR, "%a: Unknown Host Bridge Device ID: 0x%04x\n",\r
        __FUNCTION__, mHostBridgeDevId));\r
      ASSERT (FALSE);\r
      return;\r
  }\r
  PcdStatus = PcdSet16S (PcdOvmfHostBridgePciDevId, mHostBridgeDevId);\r
  ASSERT_RETURN_ERROR (PcdStatus);\r
\r
  //\r
  // If the appropriate IOspace enable bit is set, assume the ACPI PMBA has\r
  // been configured and skip the setup here. This matches the logic in\r
  // AcpiTimerLibConstructor ().\r
  //\r
  if ((PciRead8 (AcpiCtlReg) & AcpiEnBit) == 0) {\r
    //\r
    // The PEI phase should be exited with fully accessibe ACPI PM IO space:\r
    // 1. set PMBA\r
    //\r
    PciAndThenOr32 (Pmba, PmbaAndVal, PmbaOrVal);\r
\r
    //\r
    // 2. set PCICMD/IOSE\r
    //\r
    PciOr8 (PmCmd, EFI_PCI_COMMAND_IO_SPACE);\r
\r
    //\r
    // 3. set ACPI PM IO enable bit (PMREGMISC:PMIOSE or ACPI_CNTL:ACPI_EN)\r
    //\r
    PciOr8 (AcpiCtlReg, AcpiEnBit);\r
  }\r
\r
  if (mHostBridgeDevId == INTEL_Q35_MCH_DEVICE_ID) {\r
    //\r
    // Set Root Complex Register Block BAR\r
    //\r
    PciWrite32 (\r
      POWER_MGMT_REGISTER_Q35 (ICH9_RCBA),\r
      ICH9_ROOT_COMPLEX_BASE | ICH9_RCBA_EN\r
      );\r
\r
    //\r
    // Set PCI Express Register Range Base Address\r
    //\r
    PciExBarInitialization ();\r
  }\r
}\r
\r
\r
VOID\r
BootModeInitialization (\r
  VOID\r
  )\r
{\r
  EFI_STATUS    Status;\r
\r
  if (CmosRead8 (0xF) == 0xFE) {\r
    mBootMode = BOOT_ON_S3_RESUME;\r
  }\r
  CmosWrite8 (0xF, 0x00);\r
\r
  Status = PeiServicesSetBootMode (mBootMode);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  Status = PeiServicesInstallPpi (mPpiBootMode);\r
  ASSERT_EFI_ERROR (Status);\r
}\r
\r
\r
VOID\r
ReserveEmuVariableNvStore (\r
  )\r
{\r
  EFI_PHYSICAL_ADDRESS VariableStore;\r
  RETURN_STATUS        PcdStatus;\r
\r
  //\r
  // Allocate storage for NV variables early on so it will be\r
  // at a consistent address.  Since VM memory is preserved\r
  // across reboots, this allows the NV variable storage to survive\r
  // a VM reboot.\r
  //\r
  VariableStore =\r
    (EFI_PHYSICAL_ADDRESS)(UINTN)\r
      AllocateRuntimePages (\r
        EFI_SIZE_TO_PAGES (2 * PcdGet32 (PcdFlashNvStorageFtwSpareSize))\r
        );\r
  DEBUG ((DEBUG_INFO,\r
          "Reserved variable store memory: 0x%lX; size: %dkb\n",\r
          VariableStore,\r
          (2 * PcdGet32 (PcdFlashNvStorageFtwSpareSize)) / 1024\r
        ));\r
  PcdStatus = PcdSet64S (PcdEmuVariableNvStoreReserved, VariableStore);\r
  ASSERT_RETURN_ERROR (PcdStatus);\r
}\r
\r
\r
VOID\r
DebugDumpCmos (\r
  VOID\r
  )\r
{\r
  UINT32 Loop;\r
\r
  DEBUG ((DEBUG_INFO, "CMOS:\n"));\r
\r
  for (Loop = 0; Loop < 0x80; Loop++) {\r
    if ((Loop % 0x10) == 0) {\r
      DEBUG ((DEBUG_INFO, "%02x:", Loop));\r
    }\r
    DEBUG ((DEBUG_INFO, " %02x", CmosRead8 (Loop)));\r
    if ((Loop % 0x10) == 0xf) {\r
      DEBUG ((DEBUG_INFO, "\n"));\r
    }\r
  }\r
}\r
\r
\r
VOID\r
S3Verification (\r
  VOID\r
  )\r
{\r
#if defined (MDE_CPU_X64)\r
  if (FeaturePcdGet (PcdSmmSmramRequire) && mS3Supported) {\r
    DEBUG ((DEBUG_ERROR,\r
      "%a: S3Resume2Pei doesn't support X64 PEI + SMM yet.\n", __FUNCTION__));\r
    DEBUG ((DEBUG_ERROR,\r
      "%a: Please disable S3 on the QEMU command line (see the README),\n",\r
      __FUNCTION__));\r
    DEBUG ((DEBUG_ERROR,\r
      "%a: or build OVMF with \"OvmfPkgIa32X64.dsc\".\n", __FUNCTION__));\r
    ASSERT (FALSE);\r
    CpuDeadLoop ();\r
  }\r
#endif\r
}\r
\r
\r
VOID\r
Q35BoardVerification (\r
  VOID\r
  )\r
{\r
  if (mHostBridgeDevId == INTEL_Q35_MCH_DEVICE_ID) {\r
    return;\r
  }\r
\r
  DEBUG ((\r
    DEBUG_ERROR,\r
    "%a: no TSEG (SMRAM) on host bridge DID=0x%04x; "\r
    "only DID=0x%04x (Q35) is supported\n",\r
    __FUNCTION__,\r
    mHostBridgeDevId,\r
    INTEL_Q35_MCH_DEVICE_ID\r
    ));\r
  ASSERT (FALSE);\r
  CpuDeadLoop ();\r
}\r
\r
\r
/**\r
  Fetch the boot CPU count and the possible CPU count from QEMU, and expose\r
  them to UefiCpuPkg modules. Set the mMaxCpuCount variable.\r
**/\r
VOID\r
MaxCpuCountInitialization (\r
  VOID\r
  )\r
{\r
  UINT16        BootCpuCount;\r
  RETURN_STATUS PcdStatus;\r
\r
  //\r
  // Try to fetch the boot CPU count.\r
  //\r
  QemuFwCfgSelectItem (QemuFwCfgItemSmpCpuCount);\r
  BootCpuCount = QemuFwCfgRead16 ();\r
  if (BootCpuCount == 0) {\r
    //\r
    // QEMU doesn't report the boot CPU count. (BootCpuCount == 0) will let\r
    // MpInitLib count APs up to (PcdCpuMaxLogicalProcessorNumber - 1), or\r
    // until PcdCpuApInitTimeOutInMicroSeconds elapses (whichever is reached\r
    // first).\r
    //\r
    DEBUG ((DEBUG_WARN, "%a: boot CPU count unavailable\n", __FUNCTION__));\r
    mMaxCpuCount = PcdGet32 (PcdCpuMaxLogicalProcessorNumber);\r
  } else {\r
    //\r
    // We will expose BootCpuCount to MpInitLib. MpInitLib will count APs up to\r
    // (BootCpuCount - 1) precisely, regardless of timeout.\r
    //\r
    // Now try to fetch the possible CPU count.\r
    //\r
    UINTN CpuHpBase;\r
    UINT32 CmdData2;\r
\r
    CpuHpBase = ((mHostBridgeDevId == INTEL_Q35_MCH_DEVICE_ID) ?\r
                 ICH9_CPU_HOTPLUG_BASE : PIIX4_CPU_HOTPLUG_BASE);\r
\r
    //\r
    // If only legacy mode is available in the CPU hotplug register block, or\r
    // the register block is completely missing, then the writes below are\r
    // no-ops.\r
    //\r
    // 1. Switch the hotplug register block to modern mode.\r
    //\r
    IoWrite32 (CpuHpBase + QEMU_CPUHP_W_CPU_SEL, 0);\r
    //\r
    // 2. Select a valid CPU for deterministic reading of\r
    //    QEMU_CPUHP_R_CMD_DATA2.\r
    //\r
    //    CPU#0 is always valid; it is the always present and non-removable\r
    //    BSP.\r
    //\r
    IoWrite32 (CpuHpBase + QEMU_CPUHP_W_CPU_SEL, 0);\r
    //\r
    // 3. Send a command after which QEMU_CPUHP_R_CMD_DATA2 is specified to\r
    //    read as zero, and which does not invalidate the selector. (The\r
    //    selector may change, but it must not become invalid.)\r
    //\r
    //    Send QEMU_CPUHP_CMD_GET_PENDING, as it will prove useful later.\r
    //\r
    IoWrite8 (CpuHpBase + QEMU_CPUHP_W_CMD, QEMU_CPUHP_CMD_GET_PENDING);\r
    //\r
    // 4. Read QEMU_CPUHP_R_CMD_DATA2.\r
    //\r
    //    If the register block is entirely missing, then this is an unassigned\r
    //    IO read, returning all-bits-one.\r
    //\r
    //    If only legacy mode is available, then bit#0 stands for CPU#0 in the\r
    //    "CPU present bitmap". CPU#0 is always present.\r
    //\r
    //    Otherwise, QEMU_CPUHP_R_CMD_DATA2 is either still reserved (returning\r
    //    all-bits-zero), or it is specified to read as zero after the above\r
    //    steps. Both cases confirm modern mode.\r
    //\r
    CmdData2 = IoRead32 (CpuHpBase + QEMU_CPUHP_R_CMD_DATA2);\r
    DEBUG ((DEBUG_VERBOSE, "%a: CmdData2=0x%x\n", __FUNCTION__, CmdData2));\r
    if (CmdData2 != 0) {\r
      //\r
      // QEMU doesn't support the modern CPU hotplug interface. Assume that the\r
      // possible CPU count equals the boot CPU count (precluding hotplug).\r
      //\r
      DEBUG ((DEBUG_WARN, "%a: modern CPU hotplug interface unavailable\n",\r
        __FUNCTION__));\r
      mMaxCpuCount = BootCpuCount;\r
    } else {\r
      //\r
      // Grab the possible CPU count from the modern CPU hotplug interface.\r
      //\r
      UINT32 Present, Possible, Selected;\r
\r
      Present = 0;\r
      Possible = 0;\r
\r
      //\r
      // We've sent QEMU_CPUHP_CMD_GET_PENDING last; this ensures\r
      // QEMU_CPUHP_RW_CMD_DATA can now be read usefully. However,\r
      // QEMU_CPUHP_CMD_GET_PENDING may have selected a CPU with actual pending\r
      // hotplug events; therefore, select CPU#0 forcibly.\r
      //\r
      IoWrite32 (CpuHpBase + QEMU_CPUHP_W_CPU_SEL, Possible);\r
\r
      do {\r
        UINT8 CpuStatus;\r
\r
        //\r
        // Read the status of the currently selected CPU. This will help with a\r
        // sanity check against "BootCpuCount".\r
        //\r
        CpuStatus = IoRead8 (CpuHpBase + QEMU_CPUHP_R_CPU_STAT);\r
        if ((CpuStatus & QEMU_CPUHP_STAT_ENABLED) != 0) {\r
          ++Present;\r
        }\r
        //\r
        // Attempt to select the next CPU.\r
        //\r
        ++Possible;\r
        IoWrite32 (CpuHpBase + QEMU_CPUHP_W_CPU_SEL, Possible);\r
        //\r
        // If the selection is successful, then the following read will return\r
        // the selector (which we know is positive at this point). Otherwise,\r
        // the read will return 0.\r
        //\r
        Selected = IoRead32 (CpuHpBase + QEMU_CPUHP_RW_CMD_DATA);\r
        ASSERT (Selected == Possible || Selected == 0);\r
      } while (Selected > 0);\r
\r
      //\r
      // Sanity check: fw_cfg and the modern CPU hotplug interface should\r
      // return the same boot CPU count.\r
      //\r
      if (BootCpuCount != Present) {\r
        DEBUG ((DEBUG_WARN, "%a: QEMU v2.7 reset bug: BootCpuCount=%d "\r
          "Present=%u\n", __FUNCTION__, BootCpuCount, Present));\r
        //\r
        // The handling of QemuFwCfgItemSmpCpuCount, across CPU hotplug plus\r
        // platform reset (including S3), was corrected in QEMU commit\r
        // e3cadac073a9 ("pc: fix FW_CFG_NB_CPUS to account for -device added\r
        // CPUs", 2016-11-16), part of release v2.8.0.\r
        //\r
        BootCpuCount = (UINT16)Present;\r
      }\r
\r
      mMaxCpuCount = Possible;\r
    }\r
  }\r
\r
  DEBUG ((DEBUG_INFO, "%a: BootCpuCount=%d mMaxCpuCount=%u\n", __FUNCTION__,\r
    BootCpuCount, mMaxCpuCount));\r
  ASSERT (BootCpuCount <= mMaxCpuCount);\r
\r
  PcdStatus = PcdSet32S (PcdCpuBootLogicalProcessorNumber, BootCpuCount);\r
  ASSERT_RETURN_ERROR (PcdStatus);\r
  PcdStatus = PcdSet32S (PcdCpuMaxLogicalProcessorNumber, mMaxCpuCount);\r
  ASSERT_RETURN_ERROR (PcdStatus);\r
}\r
\r
\r
/**\r
  Perform Platform PEI initialization.\r
\r
  @param  FileHandle      Handle of the file being invoked.\r
  @param  PeiServices     Describes the list of possible PEI Services.\r
\r
  @return EFI_SUCCESS     The PEIM initialized successfully.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
InitializePlatform (\r
  IN       EFI_PEI_FILE_HANDLE  FileHandle,\r
  IN CONST EFI_PEI_SERVICES     **PeiServices\r
  )\r
{\r
  EFI_STATUS    Status;\r
\r
  DEBUG ((DEBUG_INFO, "Platform PEIM Loaded\n"));\r
\r
  DebugDumpCmos ();\r
\r
  if (QemuFwCfgS3Enabled ()) {\r
    DEBUG ((DEBUG_INFO, "S3 support was detected on QEMU\n"));\r
    mS3Supported = TRUE;\r
    Status = PcdSetBoolS (PcdAcpiS3Enable, TRUE);\r
    ASSERT_EFI_ERROR (Status);\r
  }\r
\r
  S3Verification ();\r
  BootModeInitialization ();\r
  AddressWidthInitialization ();\r
\r
  //\r
  // Query Host Bridge DID\r
  //\r
  mHostBridgeDevId = PciRead16 (OVMF_HOSTBRIDGE_DID);\r
\r
  MaxCpuCountInitialization ();\r
\r
  if (FeaturePcdGet (PcdSmmSmramRequire)) {\r
    Q35BoardVerification ();\r
    Q35TsegMbytesInitialization ();\r
    Q35SmramAtDefaultSmbaseInitialization ();\r
  }\r
\r
  PublishPeiMemory ();\r
\r
  QemuUc32BaseInitialization ();\r
\r
  InitializeRamRegions ();\r
\r
  if (mBootMode != BOOT_ON_S3_RESUME) {\r
    if (!FeaturePcdGet (PcdSmmSmramRequire)) {\r
      ReserveEmuVariableNvStore ();\r
    }\r
    PeiFvInitialization ();\r
    MemTypeInfoInitialization ();\r
    MemMapInitialization ();\r
    NoexecDxeInitialization ();\r
  }\r
\r
  InstallClearCacheCallback ();\r
  AmdSevInitialize ();\r
  MiscInitialization ();\r
  InstallFeatureControlCallback ();\r
\r
  return EFI_SUCCESS;\r
}\r