OvmfPkg/TdxDxe/TdxDxe.c - edk2 - Git at Google

 /** @file

   TDX Dxe driver. This driver is dispatched early in DXE, due to being list
   in APRIORI.

   This module is responsible for:
     - Sets max logical cpus based on TDINFO
     - Sets PCI PCDs based on resource hobs
     - Alter MATD table to record address of Mailbox

   Copyright (c) 2020 - 2021, Intel Corporation. All rights reserved.<BR>

   SPDX-License-Identifier: BSD-2-Clause-Patent

 **/

 #include <Library/BaseLib.h>
 #include <Library/BaseMemoryLib.h>
 #include <Library/DebugLib.h>
 #include <Library/DxeServicesTableLib.h>
 #include <Library/MemoryAllocationLib.h>
 #include <Library/PcdLib.h>
 #include <Library/UefiLib.h>
 #include <Library/HobLib.h>
 #include <Protocol/Cpu.h>
 #include <Protocol/MpInitLibDepProtocols.h>
 #include <Protocol/MemoryAccept.h>
 #include <Library/UefiBootServicesTableLib.h>
 #include <ConfidentialComputingGuestAttr.h>
 #include <IndustryStandard/Tdx.h>
 #include <Library/PlatformInitLib.h>
 #include <Library/TdxLib.h>
 #include <TdxAcpiTable.h>
 #include <Library/MemEncryptTdxLib.h>

 #define ALIGNED_2MB_MASK  0x1fffff
 EFI_HANDLE  mTdxDxeHandle = NULL;

 EFI_STATUS
 EFIAPI
 TdxMemoryAccept (
   IN EDKII_MEMORY_ACCEPT_PROTOCOL  *This,
   IN EFI_PHYSICAL_ADDRESS          StartAddress,
   IN UINTN                         Size
   )
 {
   EFI_STATUS  Status;
   UINT32      AcceptPageSize;
   UINT64      StartAddress1;
   UINT64      StartAddress2;
   UINT64      StartAddress3;
   UINT64      Length1;
   UINT64      Length2;
   UINT64      Length3;
   UINT64      Pages;

   AcceptPageSize = FixedPcdGet32 (PcdTdxAcceptPageSize);
   StartAddress1  = 0;
   StartAddress2  = 0;
   StartAddress3  = 0;
   Length1        = 0;
   Length2        = 0;
   Length3        = 0;

   if (Size == 0) {
     return EFI_SUCCESS;
   }

   if (ALIGN_VALUE (StartAddress, SIZE_2MB) != StartAddress) {
     StartAddress1 = StartAddress;
     Length1       = ALIGN_VALUE (StartAddress, SIZE_2MB) - StartAddress;
     if (Length1 >= Size) {
       Length1 = Size;
     }

     StartAddress += Length1;
     Size         -= Length1;
   }

   if (Size > SIZE_2MB) {
     StartAddress2 = StartAddress;
     Length2       = Size & ~(UINT64)ALIGNED_2MB_MASK;
     StartAddress += Length2;
     Size         -= Length2;
   }

   if (Size) {
     StartAddress3 = StartAddress;
     Length3       = Size;
   }

   Status = EFI_SUCCESS;
   if (Length1 > 0) {
     Pages  = Length1 / SIZE_4KB;
     Status = TdAcceptPages (StartAddress1, Pages, SIZE_4KB);
     if (EFI_ERROR (Status)) {
       return Status;
     }
   }

   if (Length2 > 0) {
     Pages  = Length2 / AcceptPageSize;
     Status = TdAcceptPages (StartAddress2, Pages, AcceptPageSize);
     if (EFI_ERROR (Status)) {
       return Status;
     }
   }

   if (Length3 > 0) {
     Pages  = Length3 / SIZE_4KB;
     Status = TdAcceptPages (StartAddress3, Pages, SIZE_4KB);
     ASSERT (!EFI_ERROR (Status));
     if (EFI_ERROR (Status)) {
       return Status;
     }
   }

   return Status;
 }

 EDKII_MEMORY_ACCEPT_PROTOCOL  mMemoryAcceptProtocol = {
   TdxMemoryAccept
 };

 VOID
 SetPcdSettings (
   EFI_HOB_PLATFORM_INFO  *PlatformInfoHob
   )
 {
   RETURN_STATUS  PcdStatus;

   PcdStatus = PcdSet64S (PcdConfidentialComputingGuestAttr, PlatformInfoHob->PcdConfidentialComputingGuestAttr);
   ASSERT_RETURN_ERROR (PcdStatus);
   PcdStatus = PcdSetBoolS (PcdSetNxForStack, PlatformInfoHob->PcdSetNxForStack);
   ASSERT_RETURN_ERROR (PcdStatus);

   DEBUG ((
     DEBUG_INFO,
     "HostBridgeDevId=0x%x, CCAttr=0x%x, SetNxForStack=%x\n",
     PlatformInfoHob->HostBridgeDevId,
     PlatformInfoHob->PcdConfidentialComputingGuestAttr,
     PlatformInfoHob->PcdSetNxForStack
     ));

   PcdStatus = PcdSet32S (PcdCpuBootLogicalProcessorNumber, PlatformInfoHob->PcdCpuBootLogicalProcessorNumber);
   ASSERT_RETURN_ERROR (PcdStatus);
   PcdStatus = PcdSet32S (PcdCpuMaxLogicalProcessorNumber, PlatformInfoHob->PcdCpuMaxLogicalProcessorNumber);
   ASSERT_RETURN_ERROR (PcdStatus);

   DEBUG ((
     DEBUG_INFO,
     "MaxCpuCount=0x%x, BootCpuCount=0x%x\n",
     PlatformInfoHob->PcdCpuMaxLogicalProcessorNumber,
     PlatformInfoHob->PcdCpuBootLogicalProcessorNumber
     ));

   PcdSet64S (PcdEmuVariableNvStoreReserved, PlatformInfoHob->PcdEmuVariableNvStoreReserved);

   if (TdIsEnabled ()) {
     PcdStatus = PcdSet64S (PcdTdxSharedBitMask, TdSharedPageMask ());
     ASSERT_RETURN_ERROR (PcdStatus);
     DEBUG ((DEBUG_INFO, "TdxSharedBitMask=0x%llx\n", PcdGet64 (PcdTdxSharedBitMask)));
   }

   PcdStatus = PcdSet64S (PcdPciMmio64Base, PlatformInfoHob->PcdPciMmio64Base);
   ASSERT_RETURN_ERROR (PcdStatus);
   PcdStatus = PcdSet64S (PcdPciMmio64Size, PlatformInfoHob->PcdPciMmio64Size);
   ASSERT_RETURN_ERROR (PcdStatus);
   PcdStatus = PcdSet64S (PcdPciMmio32Base, PlatformInfoHob->PcdPciMmio32Base);
   ASSERT_RETURN_ERROR (PcdStatus);
   PcdStatus = PcdSet64S (PcdPciMmio32Size, PlatformInfoHob->PcdPciMmio32Size);
   ASSERT_RETURN_ERROR (PcdStatus);
   PcdStatus = PcdSet64S (PcdPciIoBase, PlatformInfoHob->PcdPciIoBase);
   ASSERT_RETURN_ERROR (PcdStatus);
   PcdStatus = PcdSet64S (PcdPciIoSize, PlatformInfoHob->PcdPciIoSize);
   ASSERT_RETURN_ERROR (PcdStatus);
 }

 /**
   Location of resource hob matching type and starting address

   @param[in]  Type             The type of resource hob to locate.

   @param[in]  Start            The resource hob must at least begin at address.

   @retval pointer to resource  Return pointer to a resource hob that matches or NULL.
 **/
 STATIC
 EFI_HOB_RESOURCE_DESCRIPTOR *
 GetResourceDescriptor (
   EFI_RESOURCE_TYPE     Type,
   EFI_PHYSICAL_ADDRESS  Start,
   EFI_PHYSICAL_ADDRESS  End
   )
 {
   EFI_PEI_HOB_POINTERS         Hob;
   EFI_HOB_RESOURCE_DESCRIPTOR  *ResourceDescriptor = NULL;

   Hob.Raw = GetFirstHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR);
   while (Hob.Raw != NULL) {
     DEBUG ((
       DEBUG_INFO,
       "%a:%d: resource type 0x%x %llx %llx\n",
       __func__,
       __LINE__,
       Hob.ResourceDescriptor->ResourceType,
       Hob.ResourceDescriptor->PhysicalStart,
       Hob.ResourceDescriptor->ResourceLength
       ));

     if ((Hob.ResourceDescriptor->ResourceType == Type) &&
         (Hob.ResourceDescriptor->PhysicalStart >= Start) &&
         ((Hob.ResourceDescriptor->PhysicalStart + Hob.ResourceDescriptor->ResourceLength) < End))
     {
       ResourceDescriptor = Hob.ResourceDescriptor;
       break;
     }

     Hob.Raw = GET_NEXT_HOB (Hob);
     Hob.Raw = GetNextHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR, Hob.Raw);
   }

   return ResourceDescriptor;
 }

 /**
   Location of resource hob matching type and highest address below end

   @param[in]  Type             The type of resource hob to locate.

   @param[in]  End              The resource hob return is the closest to the End address

   @retval pointer to resource  Return pointer to a resource hob that matches or NULL.
 **/
 STATIC
 EFI_HOB_RESOURCE_DESCRIPTOR *
 GetHighestResourceDescriptor (
   EFI_RESOURCE_TYPE     Type,
   EFI_PHYSICAL_ADDRESS  End
   )
 {
   EFI_PEI_HOB_POINTERS         Hob;
   EFI_HOB_RESOURCE_DESCRIPTOR  *ResourceDescriptor = NULL;

   Hob.Raw = GetFirstHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR);
   while (Hob.Raw != NULL) {
     if ((Hob.ResourceDescriptor->ResourceType == Type) &&
         (Hob.ResourceDescriptor->PhysicalStart < End))
     {
       if (!ResourceDescriptor ||
           (ResourceDescriptor->PhysicalStart < Hob.ResourceDescriptor->PhysicalStart))
       {
         ResourceDescriptor = Hob.ResourceDescriptor;
       }
     }

     Hob.Raw = GET_NEXT_HOB (Hob);
     Hob.Raw = GetNextHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR, Hob.Raw);
   }

   return ResourceDescriptor;
 }

 /**
   Set the shared bit for mmio region in Tdx guest.

   In Tdx guest there are 2 ways to access mmio, TdVmcall or direct access.
   For direct access, the shared bit of the PageTableEntry should be set.
   The mmio region information is retrieved from hob list.

   @retval EFI_SUCCESS                 The shared bit is set successfully.
   @retval EFI_UNSUPPORTED             Setting the shared bit of memory region
                                       is not supported
 **/
 EFI_STATUS
 SetMmioSharedBit (
   VOID
   )
 {
   EFI_PEI_HOB_POINTERS  Hob;

   Hob.Raw = (UINT8 *)GetHobList ();

   //
   // Parse the HOB list until end of list or matching type is found.
   //
   while (!END_OF_HOB_LIST (Hob)) {
     if (  (Hob.Header->HobType == EFI_HOB_TYPE_RESOURCE_DESCRIPTOR)
        && (Hob.ResourceDescriptor->ResourceType == EFI_RESOURCE_MEMORY_MAPPED_IO))
     {
       MemEncryptTdxSetPageSharedBit (
         0,
         Hob.ResourceDescriptor->PhysicalStart,
         EFI_SIZE_TO_PAGES (Hob.ResourceDescriptor->ResourceLength)
         );
     }

     Hob.Raw = GET_NEXT_HOB (Hob);
   }

   return EFI_SUCCESS;
 }

 EFI_STATUS
 EFIAPI
 TdxDxeEntryPoint (
   IN EFI_HANDLE        ImageHandle,
   IN EFI_SYSTEM_TABLE  *SystemTable
   )
 {
   EFI_STATUS                   Status;
   RETURN_STATUS                PcdStatus;
   EFI_HOB_RESOURCE_DESCRIPTOR  *Res          = NULL;
   EFI_HOB_RESOURCE_DESCRIPTOR  *MemRes       = NULL;
   EFI_HOB_PLATFORM_INFO        *PlatformInfo = NULL;
   EFI_HOB_GUID_TYPE            *GuidHob;
   UINT32                       CpuMaxLogicalProcessorNumber;
   TD_RETURN_DATA               TdReturnData;
   EFI_EVENT                    QemuAcpiTableEvent;
   void                         *Registration;

   GuidHob = GetFirstGuidHob (&gUefiOvmfPkgPlatformInfoGuid);

   if (GuidHob == NULL) {
     return EFI_UNSUPPORTED;
   }

   //
   // Both Td and Non-Td guest have PlatformInfoHob which contains the HostBridgePciDevId
   //
   PlatformInfo = (EFI_HOB_PLATFORM_INFO *)GET_GUID_HOB_DATA (GuidHob);
   ASSERT (PlatformInfo->HostBridgeDevId != 0);
   PcdStatus = PcdSet16S (PcdOvmfHostBridgePciDevId, PlatformInfo->HostBridgeDevId);
   ASSERT_RETURN_ERROR (PcdStatus);

  #ifdef TDX_PEI_LESS_BOOT
   //
   // For Pei-less boot, PlatformInfo contains more information and
   // need to set PCDs based on these information.
   //
   SetPcdSettings (PlatformInfo);
  #endif

   if (!TdIsEnabled ()) {
     //
     // If it is Non-Td guest, we install gEfiMpInitLibMpDepProtocolGuid so that
     // MpInitLib will be used in CpuDxe driver.
     //
     gBS->InstallProtocolInterface (
            &ImageHandle,
            &gEfiMpInitLibMpDepProtocolGuid,
            EFI_NATIVE_INTERFACE,
            NULL
            );

     return EFI_SUCCESS;
   }

   SetMmioSharedBit ();

   //
   // It is Td guest, we install gEfiMpInitLibUpDepProtocolGuid so that
   // MpInitLibUp will be used in CpuDxe driver.
   //
   gBS->InstallProtocolInterface (
          &ImageHandle,
          &gEfiMpInitLibUpDepProtocolGuid,
          EFI_NATIVE_INTERFACE,
          NULL
          );

   //
   // Install MemoryAccept protocol for TDX
   //
   Status = gBS->InstallProtocolInterface (
                   &mTdxDxeHandle,
                   &gEdkiiMemoryAcceptProtocolGuid,
                   EFI_NATIVE_INTERFACE,
                   &mMemoryAcceptProtocol
                   );
   if (EFI_ERROR (Status)) {
     DEBUG ((DEBUG_ERROR, "Install EdkiiMemoryAcceptProtocol failed.\n"));
   }

   //
   // Call TDINFO to get actual number of cpus in domain
   //
   Status = TdCall (TDCALL_TDINFO, 0, 0, 0, &TdReturnData);
   ASSERT (Status == EFI_SUCCESS);

   CpuMaxLogicalProcessorNumber = PcdGet32 (PcdCpuMaxLogicalProcessorNumber);

   //
   // Adjust PcdCpuMaxLogicalProcessorNumber, if needed. If firmware is configured for
   // more than number of reported cpus, update.
   //
   if (CpuMaxLogicalProcessorNumber > TdReturnData.TdInfo.NumVcpus) {
     PcdStatus = PcdSet32S (PcdCpuMaxLogicalProcessorNumber, TdReturnData.TdInfo.NumVcpus);
     ASSERT_RETURN_ERROR (PcdStatus);
   }

   //
   // Register for protocol notifications to call the AlterAcpiTable(),
   // the protocol will be installed in AcpiPlatformDxe when the ACPI
   // table provided by Qemu is ready.
   //
   Status = gBS->CreateEvent (
                   EVT_NOTIFY_SIGNAL,
                   TPL_CALLBACK,
                   AlterAcpiTable,
                   NULL,
                   &QemuAcpiTableEvent
                   );

   Status = gBS->RegisterProtocolNotify (
                   &gQemuAcpiTableNotifyProtocolGuid,
                   QemuAcpiTableEvent,
                   &Registration
                   );

   #define INIT_PCDSET(NAME, RES)  do {\
   PcdStatus = PcdSet64S (NAME##Base, (RES)->PhysicalStart); \
   ASSERT_RETURN_ERROR (PcdStatus); \
   PcdStatus = PcdSet64S (NAME##Size, (RES)->ResourceLength); \
   ASSERT_RETURN_ERROR (PcdStatus); \
 } while(0)

   if (PlatformInfo) {
     PcdSet16S (PcdOvmfHostBridgePciDevId, PlatformInfo->HostBridgeDevId);

     if ((Res = GetResourceDescriptor (EFI_RESOURCE_MEMORY_MAPPED_IO, (EFI_PHYSICAL_ADDRESS)0x100000000, (EFI_PHYSICAL_ADDRESS)-1)) != NULL) {
       INIT_PCDSET (PcdPciMmio64, Res);
     }

     if ((Res = GetResourceDescriptor (EFI_RESOURCE_IO, 0, 0x10001)) != NULL) {
       INIT_PCDSET (PcdPciIo, Res);
     }

     //
     // To find low mmio, first find top of low memory, and then search for io space.
     //
     if ((MemRes = GetHighestResourceDescriptor (EFI_RESOURCE_SYSTEM_MEMORY, 0xffc00000)) != NULL) {
       if ((Res = GetResourceDescriptor (EFI_RESOURCE_MEMORY_MAPPED_IO, MemRes->PhysicalStart, 0x100000000)) != NULL) {
         INIT_PCDSET (PcdPciMmio32, Res);
       }
     }
   }

   return EFI_SUCCESS;
 }
	/** @file

	TDX Dxe driver. This driver is dispatched early in DXE, due to being list
	in APRIORI.

	This module is responsible for:
	- Sets max logical cpus based on TDINFO
	- Sets PCI PCDs based on resource hobs
	- Alter MATD table to record address of Mailbox

	Copyright (c) 2020 - 2021, Intel Corporation. All rights reserved.<BR>

	SPDX-License-Identifier: BSD-2-Clause-Patent

	**/

	#include <Library/BaseLib.h>
	#include <Library/BaseMemoryLib.h>
	#include <Library/DebugLib.h>
	#include <Library/DxeServicesTableLib.h>
	#include <Library/MemoryAllocationLib.h>
	#include <Library/PcdLib.h>
	#include <Library/UefiLib.h>
	#include <Library/HobLib.h>
	#include <Protocol/Cpu.h>
	#include <Protocol/MpInitLibDepProtocols.h>
	#include <Protocol/MemoryAccept.h>
	#include <Library/UefiBootServicesTableLib.h>
	#include <ConfidentialComputingGuestAttr.h>
	#include <IndustryStandard/Tdx.h>
	#include <Library/PlatformInitLib.h>
	#include <Library/TdxLib.h>
	#include <TdxAcpiTable.h>
	#include <Library/MemEncryptTdxLib.h>

	#define ALIGNED_2MB_MASK 0x1fffff
	EFI_HANDLE mTdxDxeHandle = NULL;

	EFI_STATUS
	EFIAPI
	TdxMemoryAccept (
	IN EDKII_MEMORY_ACCEPT_PROTOCOL *This,
	IN EFI_PHYSICAL_ADDRESS StartAddress,
	IN UINTN Size
	)
	{
	EFI_STATUS Status;
	UINT32 AcceptPageSize;
	UINT64 StartAddress1;
	UINT64 StartAddress2;
	UINT64 StartAddress3;
	UINT64 Length1;
	UINT64 Length2;
	UINT64 Length3;
	UINT64 Pages;

	AcceptPageSize = FixedPcdGet32 (PcdTdxAcceptPageSize);
	StartAddress1 = 0;
	StartAddress2 = 0;
	StartAddress3 = 0;
	Length1 = 0;
	Length2 = 0;
	Length3 = 0;

	if (Size == 0) {
	return EFI_SUCCESS;
	}

	if (ALIGN_VALUE (StartAddress, SIZE_2MB) != StartAddress) {
	StartAddress1 = StartAddress;
	Length1 = ALIGN_VALUE (StartAddress, SIZE_2MB) - StartAddress;
	if (Length1 >= Size) {
	Length1 = Size;
	}

	StartAddress += Length1;
	Size -= Length1;
	}

	if (Size > SIZE_2MB) {
	StartAddress2 = StartAddress;
	Length2 = Size & ~(UINT64)ALIGNED_2MB_MASK;
	StartAddress += Length2;
	Size -= Length2;
	}

	if (Size) {
	StartAddress3 = StartAddress;
	Length3 = Size;
	}

	Status = EFI_SUCCESS;
	if (Length1 > 0) {
	Pages = Length1 / SIZE_4KB;
	Status = TdAcceptPages (StartAddress1, Pages, SIZE_4KB);
	if (EFI_ERROR (Status)) {
	return Status;
	}
	}

	if (Length2 > 0) {
	Pages = Length2 / AcceptPageSize;
	Status = TdAcceptPages (StartAddress2, Pages, AcceptPageSize);
	if (EFI_ERROR (Status)) {
	return Status;
	}
	}

	if (Length3 > 0) {
	Pages = Length3 / SIZE_4KB;
	Status = TdAcceptPages (StartAddress3, Pages, SIZE_4KB);
	ASSERT (!EFI_ERROR (Status));
	if (EFI_ERROR (Status)) {
	return Status;
	}
	}

	return Status;
	}

	EDKII_MEMORY_ACCEPT_PROTOCOL mMemoryAcceptProtocol = {
	TdxMemoryAccept
	};

	VOID
	SetPcdSettings (
	EFI_HOB_PLATFORM_INFO *PlatformInfoHob
	)
	{
	RETURN_STATUS PcdStatus;

	PcdStatus = PcdSet64S (PcdConfidentialComputingGuestAttr, PlatformInfoHob->PcdConfidentialComputingGuestAttr);
	ASSERT_RETURN_ERROR (PcdStatus);
	PcdStatus = PcdSetBoolS (PcdSetNxForStack, PlatformInfoHob->PcdSetNxForStack);
	ASSERT_RETURN_ERROR (PcdStatus);

	DEBUG ((
	DEBUG_INFO,
	"HostBridgeDevId=0x%x, CCAttr=0x%x, SetNxForStack=%x\n",
	PlatformInfoHob->HostBridgeDevId,
	PlatformInfoHob->PcdConfidentialComputingGuestAttr,
	PlatformInfoHob->PcdSetNxForStack
	));

	PcdStatus = PcdSet32S (PcdCpuBootLogicalProcessorNumber, PlatformInfoHob->PcdCpuBootLogicalProcessorNumber);
	ASSERT_RETURN_ERROR (PcdStatus);
	PcdStatus = PcdSet32S (PcdCpuMaxLogicalProcessorNumber, PlatformInfoHob->PcdCpuMaxLogicalProcessorNumber);
	ASSERT_RETURN_ERROR (PcdStatus);

	DEBUG ((
	DEBUG_INFO,
	"MaxCpuCount=0x%x, BootCpuCount=0x%x\n",
	PlatformInfoHob->PcdCpuMaxLogicalProcessorNumber,
	PlatformInfoHob->PcdCpuBootLogicalProcessorNumber
	));

	PcdSet64S (PcdEmuVariableNvStoreReserved, PlatformInfoHob->PcdEmuVariableNvStoreReserved);

	if (TdIsEnabled ()) {
	PcdStatus = PcdSet64S (PcdTdxSharedBitMask, TdSharedPageMask ());
	ASSERT_RETURN_ERROR (PcdStatus);
	DEBUG ((DEBUG_INFO, "TdxSharedBitMask=0x%llx\n", PcdGet64 (PcdTdxSharedBitMask)));
	}

	PcdStatus = PcdSet64S (PcdPciMmio64Base, PlatformInfoHob->PcdPciMmio64Base);
	ASSERT_RETURN_ERROR (PcdStatus);
	PcdStatus = PcdSet64S (PcdPciMmio64Size, PlatformInfoHob->PcdPciMmio64Size);
	ASSERT_RETURN_ERROR (PcdStatus);
	PcdStatus = PcdSet64S (PcdPciMmio32Base, PlatformInfoHob->PcdPciMmio32Base);
	ASSERT_RETURN_ERROR (PcdStatus);
	PcdStatus = PcdSet64S (PcdPciMmio32Size, PlatformInfoHob->PcdPciMmio32Size);
	ASSERT_RETURN_ERROR (PcdStatus);
	PcdStatus = PcdSet64S (PcdPciIoBase, PlatformInfoHob->PcdPciIoBase);
	ASSERT_RETURN_ERROR (PcdStatus);
	PcdStatus = PcdSet64S (PcdPciIoSize, PlatformInfoHob->PcdPciIoSize);
	ASSERT_RETURN_ERROR (PcdStatus);
	}

	/**
	Location of resource hob matching type and starting address

	@param[in] Type The type of resource hob to locate.

	@param[in] Start The resource hob must at least begin at address.

	@retval pointer to resource Return pointer to a resource hob that matches or NULL.
	**/
	STATIC
	EFI_HOB_RESOURCE_DESCRIPTOR *
	GetResourceDescriptor (
	EFI_RESOURCE_TYPE Type,
	EFI_PHYSICAL_ADDRESS Start,
	EFI_PHYSICAL_ADDRESS End
	)
	{
	EFI_PEI_HOB_POINTERS Hob;
	EFI_HOB_RESOURCE_DESCRIPTOR *ResourceDescriptor = NULL;

	Hob.Raw = GetFirstHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR);
	while (Hob.Raw != NULL) {
	DEBUG ((
	DEBUG_INFO,
	"%a:%d: resource type 0x%x %llx %llx\n",
	__func__,
	__LINE__,
	Hob.ResourceDescriptor->ResourceType,
	Hob.ResourceDescriptor->PhysicalStart,
	Hob.ResourceDescriptor->ResourceLength
	));

	if ((Hob.ResourceDescriptor->ResourceType == Type) &&
	(Hob.ResourceDescriptor->PhysicalStart >= Start) &&
	((Hob.ResourceDescriptor->PhysicalStart + Hob.ResourceDescriptor->ResourceLength) < End))
	{
	ResourceDescriptor = Hob.ResourceDescriptor;
	break;
	}

	Hob.Raw = GET_NEXT_HOB (Hob);
	Hob.Raw = GetNextHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR, Hob.Raw);
	}

	return ResourceDescriptor;
	}

	/**
	Location of resource hob matching type and highest address below end

	@param[in] Type The type of resource hob to locate.

	@param[in] End The resource hob return is the closest to the End address

	@retval pointer to resource Return pointer to a resource hob that matches or NULL.
	**/
	STATIC
	EFI_HOB_RESOURCE_DESCRIPTOR *
	GetHighestResourceDescriptor (
	EFI_RESOURCE_TYPE Type,
	EFI_PHYSICAL_ADDRESS End
	)
	{
	EFI_PEI_HOB_POINTERS Hob;
	EFI_HOB_RESOURCE_DESCRIPTOR *ResourceDescriptor = NULL;

	Hob.Raw = GetFirstHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR);
	while (Hob.Raw != NULL) {
	if ((Hob.ResourceDescriptor->ResourceType == Type) &&
	(Hob.ResourceDescriptor->PhysicalStart < End))
	{
	if (!ResourceDescriptor \|\|
	(ResourceDescriptor->PhysicalStart < Hob.ResourceDescriptor->PhysicalStart))
	{
	ResourceDescriptor = Hob.ResourceDescriptor;
	}
	}

	Hob.Raw = GET_NEXT_HOB (Hob);
	Hob.Raw = GetNextHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR, Hob.Raw);
	}

	return ResourceDescriptor;
	}

	/**
	Set the shared bit for mmio region in Tdx guest.

	In Tdx guest there are 2 ways to access mmio, TdVmcall or direct access.
	For direct access, the shared bit of the PageTableEntry should be set.
	The mmio region information is retrieved from hob list.

	@retval EFI_SUCCESS The shared bit is set successfully.
	@retval EFI_UNSUPPORTED Setting the shared bit of memory region
	is not supported
	**/
	EFI_STATUS
	SetMmioSharedBit (
	VOID
	)
	{
	EFI_PEI_HOB_POINTERS Hob;

	Hob.Raw = (UINT8 *)GetHobList ();

	//
	// Parse the HOB list until end of list or matching type is found.
	//
	while (!END_OF_HOB_LIST (Hob)) {
	if ( (Hob.Header->HobType == EFI_HOB_TYPE_RESOURCE_DESCRIPTOR)
	&& (Hob.ResourceDescriptor->ResourceType == EFI_RESOURCE_MEMORY_MAPPED_IO))
	{
	MemEncryptTdxSetPageSharedBit (
	0,
	Hob.ResourceDescriptor->PhysicalStart,
	EFI_SIZE_TO_PAGES (Hob.ResourceDescriptor->ResourceLength)
	);
	}

	Hob.Raw = GET_NEXT_HOB (Hob);
	}

	return EFI_SUCCESS;
	}

	EFI_STATUS
	EFIAPI
	TdxDxeEntryPoint (
	IN EFI_HANDLE ImageHandle,
	IN EFI_SYSTEM_TABLE *SystemTable
	)
	{
	EFI_STATUS Status;
	RETURN_STATUS PcdStatus;
	EFI_HOB_RESOURCE_DESCRIPTOR *Res = NULL;
	EFI_HOB_RESOURCE_DESCRIPTOR *MemRes = NULL;
	EFI_HOB_PLATFORM_INFO *PlatformInfo = NULL;
	EFI_HOB_GUID_TYPE *GuidHob;
	UINT32 CpuMaxLogicalProcessorNumber;
	TD_RETURN_DATA TdReturnData;
	EFI_EVENT QemuAcpiTableEvent;
	void *Registration;

	GuidHob = GetFirstGuidHob (&gUefiOvmfPkgPlatformInfoGuid);

	if (GuidHob == NULL) {
	return EFI_UNSUPPORTED;
	}

	//
	// Both Td and Non-Td guest have PlatformInfoHob which contains the HostBridgePciDevId
	//
	PlatformInfo = (EFI_HOB_PLATFORM_INFO *)GET_GUID_HOB_DATA (GuidHob);
	ASSERT (PlatformInfo->HostBridgeDevId != 0);
	PcdStatus = PcdSet16S (PcdOvmfHostBridgePciDevId, PlatformInfo->HostBridgeDevId);
	ASSERT_RETURN_ERROR (PcdStatus);

	#ifdef TDX_PEI_LESS_BOOT
	//
	// For Pei-less boot, PlatformInfo contains more information and
	// need to set PCDs based on these information.
	//
	SetPcdSettings (PlatformInfo);
	#endif

	if (!TdIsEnabled ()) {
	//
	// If it is Non-Td guest, we install gEfiMpInitLibMpDepProtocolGuid so that
	// MpInitLib will be used in CpuDxe driver.
	//
	gBS->InstallProtocolInterface (
	&ImageHandle,
	&gEfiMpInitLibMpDepProtocolGuid,
	EFI_NATIVE_INTERFACE,
	NULL
	);

	return EFI_SUCCESS;
	}

	SetMmioSharedBit ();

	//
	// It is Td guest, we install gEfiMpInitLibUpDepProtocolGuid so that
	// MpInitLibUp will be used in CpuDxe driver.
	//
	gBS->InstallProtocolInterface (
	&ImageHandle,
	&gEfiMpInitLibUpDepProtocolGuid,
	EFI_NATIVE_INTERFACE,
	NULL
	);

	//
	// Install MemoryAccept protocol for TDX
	//
	Status = gBS->InstallProtocolInterface (
	&mTdxDxeHandle,
	&gEdkiiMemoryAcceptProtocolGuid,
	EFI_NATIVE_INTERFACE,
	&mMemoryAcceptProtocol
	);
	if (EFI_ERROR (Status)) {
	DEBUG ((DEBUG_ERROR, "Install EdkiiMemoryAcceptProtocol failed.\n"));
	}

	//
	// Call TDINFO to get actual number of cpus in domain
	//
	Status = TdCall (TDCALL_TDINFO, 0, 0, 0, &TdReturnData);
	ASSERT (Status == EFI_SUCCESS);

	CpuMaxLogicalProcessorNumber = PcdGet32 (PcdCpuMaxLogicalProcessorNumber);

	//
	// Adjust PcdCpuMaxLogicalProcessorNumber, if needed. If firmware is configured for
	// more than number of reported cpus, update.
	//
	if (CpuMaxLogicalProcessorNumber > TdReturnData.TdInfo.NumVcpus) {
	PcdStatus = PcdSet32S (PcdCpuMaxLogicalProcessorNumber, TdReturnData.TdInfo.NumVcpus);
	ASSERT_RETURN_ERROR (PcdStatus);
	}

	//
	// Register for protocol notifications to call the AlterAcpiTable(),
	// the protocol will be installed in AcpiPlatformDxe when the ACPI
	// table provided by Qemu is ready.
	//
	Status = gBS->CreateEvent (
	EVT_NOTIFY_SIGNAL,
	TPL_CALLBACK,
	AlterAcpiTable,
	NULL,
	&QemuAcpiTableEvent
	);

	Status = gBS->RegisterProtocolNotify (
	&gQemuAcpiTableNotifyProtocolGuid,
	QemuAcpiTableEvent,
	&Registration
	);

	#define INIT_PCDSET(NAME, RES) do {\
	PcdStatus = PcdSet64S (NAME##Base, (RES)->PhysicalStart); \
	ASSERT_RETURN_ERROR (PcdStatus); \
	PcdStatus = PcdSet64S (NAME##Size, (RES)->ResourceLength); \
	ASSERT_RETURN_ERROR (PcdStatus); \
	} while(0)

	if (PlatformInfo) {
	PcdSet16S (PcdOvmfHostBridgePciDevId, PlatformInfo->HostBridgeDevId);

	if ((Res = GetResourceDescriptor (EFI_RESOURCE_MEMORY_MAPPED_IO, (EFI_PHYSICAL_ADDRESS)0x100000000, (EFI_PHYSICAL_ADDRESS)-1)) != NULL) {
	INIT_PCDSET (PcdPciMmio64, Res);
	}

	if ((Res = GetResourceDescriptor (EFI_RESOURCE_IO, 0, 0x10001)) != NULL) {
	INIT_PCDSET (PcdPciIo, Res);
	}

	//
	// To find low mmio, first find top of low memory, and then search for io space.
	//
	if ((MemRes = GetHighestResourceDescriptor (EFI_RESOURCE_SYSTEM_MEMORY, 0xffc00000)) != NULL) {
	if ((Res = GetResourceDescriptor (EFI_RESOURCE_MEMORY_MAPPED_IO, MemRes->PhysicalStart, 0x100000000)) != NULL) {
	INIT_PCDSET (PcdPciMmio32, Res);
	}
	}
	}

	return EFI_SUCCESS;
	}