OvmfPkg/Library/PeilessStartupLib/Hob.c

   1 /** @file
   2   Main SEC phase code. Handles initial TDX Hob List Processing
   3
   4   Copyright (c) 2008, Intel Corporation. All rights reserved.<BR>
   5   (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
   6
   7   SPDX-License-Identifier: BSD-2-Clause-Patent
   8
   9 **/
  10
  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/PciLib.h>
  17 #include <Library/PrePiLib.h>
  18 #include <Library/QemuFwCfgLib.h>
  19 #include <IndustryStandard/Tdx.h>
  20 #include <IndustryStandard/UefiTcgPlatform.h>
  21 #include <Library/PlatformInitLib.h>
  22 #include <OvmfPlatforms.h>
  23 #include "PeilessStartupInternal.h"
  24
  25 #define EFI_RESOURCE_MEMORY_UNACCEPTED  7
  26
  27 /**
  28  * Construct the HobList in SEC phase.
  29  *
  30  * @return EFI_SUCCESS      Successfully construct the firmware hoblist.
  31  * @return EFI_NOT_FOUND    Cannot find a memory region to be the fw hoblist.
  32  */
  33 EFI_STATUS
  34 EFIAPI
  35 ConstructSecHobList (
  36   )
  37 {
  38   UINT32  LowMemorySize;
  39   UINT32  LowMemoryStart;
  40
  41   EFI_HOB_HANDOFF_INFO_TABLE  *HobList;
  42   EFI_HOB_PLATFORM_INFO       PlatformInfoHob;
  43
  44   ZeroMem (&PlatformInfoHob, sizeof (PlatformInfoHob));
  45   PlatformInfoHob.HostBridgeDevId = PciRead16 (OVMF_HOSTBRIDGE_DID);
  46   LowMemorySize                   = PlatformGetSystemMemorySizeBelow4gb (&PlatformInfoHob);
  47   ASSERT (LowMemorySize != 0);
  48   LowMemoryStart = FixedPcdGet32 (PcdOvmfDxeMemFvBase) + FixedPcdGet32 (PcdOvmfDxeMemFvSize);
  49   LowMemorySize -= LowMemoryStart;
  50
  51   DEBUG ((DEBUG_INFO, "LowMemory Start and End: %x, %x\n", LowMemoryStart, LowMemoryStart + LowMemorySize));
  52   HobList = HobConstructor (
  53               (VOID *)(UINTN)LowMemoryStart,
  54               LowMemorySize,
  55               (VOID *)(UINTN)LowMemoryStart,
  56               (VOID *)(UINTN)(LowMemoryStart + LowMemorySize)
  57               );
  58
  59   SetHobList ((VOID *)(UINT64)HobList);
  60
  61   return EFI_SUCCESS;
  62 }
  63
  64 /**
  65  * This function is to find a memory region which is the largest one below 4GB.
  66  * It will be used as the firmware hoblist.
  67  *
  68  * @param VmmHobList    Vmm passed hoblist which constains the memory information.
  69  * @return EFI_SUCCESS  Successfully construct the firmware hoblist.
  70  */
  71 EFI_STATUS
  72 EFIAPI
  73 ConstructFwHobList (
  74   IN CONST VOID  *VmmHobList
  75   )
  76 {
  77   EFI_PEI_HOB_POINTERS  Hob;
  78   EFI_PHYSICAL_ADDRESS  PhysicalEnd;
  79   UINT64                ResourceLength;
  80   EFI_PHYSICAL_ADDRESS  LowMemoryStart;
  81   UINT64                LowMemoryLength;
  82
  83   ASSERT (VmmHobList != NULL);
  84
  85   Hob.Raw = (UINT8 *)VmmHobList;
  86
  87   LowMemoryLength = 0;
  88   LowMemoryStart  = 0;
  89
  90   //
  91   // Parse the HOB list until end of list or matching type is found.
  92   //
  93   while (!END_OF_HOB_LIST (Hob)) {
  94     if (Hob.Header->HobType == EFI_HOB_TYPE_RESOURCE_DESCRIPTOR) {
  95       if (Hob.ResourceDescriptor->ResourceType == EFI_RESOURCE_MEMORY_UNACCEPTED) {
  96         PhysicalEnd    = Hob.ResourceDescriptor->PhysicalStart + Hob.ResourceDescriptor->ResourceLength;
  97         ResourceLength = Hob.ResourceDescriptor->ResourceLength;
  98
  99         if (PhysicalEnd <= BASE_4GB) {
 100           if (ResourceLength > LowMemoryLength) {
 101             LowMemoryStart  = Hob.ResourceDescriptor->PhysicalStart;
 102             LowMemoryLength = ResourceLength;
 103           }
 104         } else {
 105           break;
 106         }
 107       }
 108     }
 109
 110     Hob.Raw = GET_NEXT_HOB (Hob);
 111   }
 112
 113   if (LowMemoryLength == 0) {
 114     DEBUG ((DEBUG_ERROR, "Cannot find a memory region under 4GB for Fw hoblist.\n"));
 115     return EFI_NOT_FOUND;
 116   }
 117
 118   //
 119   // HobLib doesn't like HobStart at address 0 so adjust is needed
 120   //
 121   if (LowMemoryStart == 0) {
 122     LowMemoryStart  += EFI_PAGE_SIZE;
 123     LowMemoryLength -= EFI_PAGE_SIZE;
 124   }
 125
 126   DEBUG ((DEBUG_INFO, "LowMemory Start and End: %x, %x\n", LowMemoryStart, LowMemoryStart + LowMemoryLength));
 127   HobConstructor (
 128     (VOID *)LowMemoryStart,
 129     LowMemoryLength,
 130     (VOID *)LowMemoryStart,
 131     (VOID *)(LowMemoryStart + LowMemoryLength)
 132     );
 133
 134   SetHobList ((VOID *)(UINT64)LowMemoryStart);
 135
 136   return EFI_SUCCESS;
 137 }