OvmfPkg/Library/PlatformInitLib/IntelTdx.c

   1 /** @file
   2   Initialize Intel TDX support.
   3
   4   Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
   5
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #include <Base.h>
  11 #include <PiPei.h>
  12 #include <Library/BaseLib.h>
  13 #include <Library/DebugLib.h>
  14 #include <Library/HobLib.h>
  15 #include <Library/BaseMemoryLib.h>
  16 #include <Library/MemoryAllocationLib.h>
  17 #include <IndustryStandard/Tdx.h>
  18 #include <IndustryStandard/IntelTdx.h>
  19 #include <Library/PeiServicesLib.h>
  20 #include <Pi/PrePiHob.h>
  21 #include <WorkArea.h>
  22 #include <ConfidentialComputingGuestAttr.h>
  23
  24 /**
  25  * Build ResourceDescriptorHob for the unaccepted memory region.
  26  * This memory region may be splitted into 2 parts because of lazy accept.
  27  *
  28  * @param Hob     Point to the EFI_HOB_RESOURCE_DESCRIPTOR
  29  * @return VOID
  30  */
  31 VOID
  32 BuildResourceDescriptorHobForUnacceptedMemory (
  33   IN EFI_HOB_RESOURCE_DESCRIPTOR  *Hob
  34   )
  35 {
  36   EFI_PHYSICAL_ADDRESS         PhysicalStart;
  37   EFI_PHYSICAL_ADDRESS         PhysicalEnd;
  38   UINT64                       ResourceLength;
  39   EFI_RESOURCE_TYPE            ResourceType;
  40   EFI_RESOURCE_ATTRIBUTE_TYPE  ResourceAttribute;
  41   UINT64                       MaxAcceptedMemoryAddress;
  42
  43   ASSERT (Hob->ResourceType == BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED);
  44
  45   ResourceType      = BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED;
  46   ResourceAttribute = Hob->ResourceAttribute;
  47   PhysicalStart     = Hob->PhysicalStart;
  48   ResourceLength    = Hob->ResourceLength;
  49   PhysicalEnd       = PhysicalStart + ResourceLength;
  50
  51   //
  52   // In the first stage of lazy-accept, all the memory under 4G will be accepted.
  53   // The memory above 4G will not be accepted.
  54   //
  55   MaxAcceptedMemoryAddress = BASE_4GB;
  56
  57   if (PhysicalEnd <= MaxAcceptedMemoryAddress) {
  58     //
  59     // This memory region has been accepted.
  60     //
  61     ResourceType       = EFI_RESOURCE_SYSTEM_MEMORY;
  62     ResourceAttribute |= (EFI_RESOURCE_ATTRIBUTE_PRESENT | EFI_RESOURCE_ATTRIBUTE_INITIALIZED | EFI_RESOURCE_ATTRIBUTE_TESTED);
  63   } else if (PhysicalStart >= MaxAcceptedMemoryAddress) {
  64     //
  65     // This memory region hasn't been accepted.
  66     // So keep the ResourceType and ResourceAttribute unchange.
  67     //
  68   }
  69
  70   BuildResourceDescriptorHob (
  71     ResourceType,
  72     ResourceAttribute,
  73     PhysicalStart,
  74     ResourceLength
  75     );
  76 }
  77
  78 /**
  79   Transfer the incoming HobList for the TD to the final HobList for Dxe.
  80   The Hobs transferred in this function are ResourceDescriptor hob and
  81   MemoryAllocation hob.
  82
  83   @param[in] VmmHobList    The Hoblist pass the firmware
  84
  85 **/
  86 VOID
  87 EFIAPI
  88 TransferTdxHobList (
  89   VOID
  90   )
  91 {
  92   EFI_PEI_HOB_POINTERS         Hob;
  93   EFI_RESOURCE_TYPE            ResourceType;
  94   EFI_RESOURCE_ATTRIBUTE_TYPE  ResourceAttribute;
  95   VOID                         *GuidedData;
  96
  97   //
  98   // PcdOvmfSecGhcbBase is used as the TD_HOB in Tdx guest.
  99   //
 100   Hob.Raw = (UINT8 *)(UINTN)FixedPcdGet32 (PcdOvmfSecGhcbBase);
 101   while (!END_OF_HOB_LIST (Hob)) {
 102     switch (Hob.Header->HobType) {
 103       case EFI_HOB_TYPE_RESOURCE_DESCRIPTOR:
 104         ResourceType      = Hob.ResourceDescriptor->ResourceType;
 105         ResourceAttribute = Hob.ResourceDescriptor->ResourceAttribute;
 106
 107         if (ResourceType == BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED) {
 108           BuildResourceDescriptorHobForUnacceptedMemory (Hob.ResourceDescriptor);
 109         } else {
 110           BuildResourceDescriptorHob (
 111             ResourceType,
 112             ResourceAttribute,
 113             Hob.ResourceDescriptor->PhysicalStart,
 114             Hob.ResourceDescriptor->ResourceLength
 115             );
 116         }
 117
 118         break;
 119       case EFI_HOB_TYPE_MEMORY_ALLOCATION:
 120         BuildMemoryAllocationHob (
 121           Hob.MemoryAllocation->AllocDescriptor.MemoryBaseAddress,
 122           Hob.MemoryAllocation->AllocDescriptor.MemoryLength,
 123           Hob.MemoryAllocation->AllocDescriptor.MemoryType
 124           );
 125         break;
 126       case EFI_HOB_TYPE_GUID_EXTENSION:
 127         GuidedData = (VOID *)(&Hob.Guid->Name + 1);
 128         BuildGuidDataHob (&Hob.Guid->Name, GuidedData, Hob.Guid->Header.HobLength - sizeof (EFI_HOB_GUID_TYPE));
 129         break;
 130     }
 131
 132     Hob.Raw = GET_NEXT_HOB (Hob);
 133   }
 134 }
 135
 136 /**
 137   In Tdx guest, the system memory is passed in TdHob by host VMM. So
 138   the major task of PlatformTdxPublishRamRegions is to walk thru the
 139   TdHob list and transfer the ResourceDescriptorHob and MemoryAllocationHob
 140   to the hobs in DXE phase.
 141
 142   MemoryAllocationHob should also be created for Mailbox and Ovmf work area.
 143 **/
 144 VOID
 145 EFIAPI
 146 PlatformTdxPublishRamRegions (
 147   VOID
 148   )
 149 {
 150   if (!TdIsEnabled ()) {
 151     return;
 152   }
 153
 154   TransferTdxHobList ();
 155
 156   //
 157   // The memory region defined by PcdOvmfSecGhcbBackupBase is pre-allocated by
 158   // host VMM and used as the td mailbox at the beginning of system boot.
 159   //
 160   BuildMemoryAllocationHob (
 161     FixedPcdGet32 (PcdOvmfSecGhcbBackupBase),
 162     FixedPcdGet32 (PcdOvmfSecGhcbBackupSize),
 163     EfiACPIMemoryNVS
 164     );
 165
 166   if (FixedPcdGet32 (PcdOvmfWorkAreaSize) != 0) {
 167     //
 168     // Reserve the work area.
 169     //
 170     // Since this memory range will be used by the Reset Vector on S3
 171     // resume, it must be reserved as ACPI NVS.
 172     //
 173     // If S3 is unsupported, then various drivers might still write to the
 174     // work area. We ought to prevent DXE from serving allocation requests
 175     // such that they would overlap the work area.
 176     //
 177     BuildMemoryAllocationHob (
 178       (EFI_PHYSICAL_ADDRESS)(UINTN)FixedPcdGet32 (PcdOvmfWorkAreaBase),
 179       (UINT64)(UINTN)FixedPcdGet32 (PcdOvmfWorkAreaSize),
 180       EfiBootServicesData
 181       );
 182   }
 183 }