OvmfPkg/IntelTdx/Sec/SecMain.c

   1 /** @file
   2   Main SEC phase code.  Transitions to PEI.
   3
   4   Copyright (c) 2008 - 2015, Intel Corporation. All rights reserved.<BR>
   5   (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
   6   Copyright (c) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
   7
   8   SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10 **/
  11
  12 #include <PiPei.h>
  13
  14 #include <Library/PeimEntryPoint.h>
  15 #include <Library/BaseLib.h>
  16 #include <Library/DebugLib.h>
  17 #include <Library/BaseMemoryLib.h>
  18 #include <Library/PcdLib.h>
  19 #include <Library/UefiCpuLib.h>
  20 #include <Library/DebugAgentLib.h>
  21 #include <Library/IoLib.h>
  22 #include <Library/PeCoffLib.h>
  23 #include <Library/PeCoffGetEntryPointLib.h>
  24 #include <Library/LocalApicLib.h>
  25 #include <Library/CpuExceptionHandlerLib.h>
  26 #include <IndustryStandard/Tdx.h>
  27 #include <Library/PlatformInitLib.h>
  28 #include <Library/CcProbeLib.h>
  29 #include <Library/PeilessStartupLib.h>
  30
  31 #define SEC_IDT_ENTRY_COUNT  34
  32
  33 typedef struct _SEC_IDT_TABLE {
  34   EFI_PEI_SERVICES            *PeiService;
  35   IA32_IDT_GATE_DESCRIPTOR    IdtTable[SEC_IDT_ENTRY_COUNT];
  36 } SEC_IDT_TABLE;
  37
  38 //
  39 // Template of an IDT entry pointing to 10:FFFFFFE4h.
  40 //
  41 IA32_IDT_GATE_DESCRIPTOR  mIdtEntryTemplate = {
  42   {                                      // Bits
  43     0xffe4,                              // OffsetLow
  44     0x10,                                // Selector
  45     0x0,                                 // Reserved_0
  46     IA32_IDT_GATE_TYPE_INTERRUPT_32,     // GateType
  47     0xffff                               // OffsetHigh
  48   }
  49 };
  50
  51 VOID
  52 EFIAPI
  53 SecCoreStartupWithStack (
  54   IN EFI_FIRMWARE_VOLUME_HEADER  *BootFv,
  55   IN VOID                        *TopOfCurrentStack
  56   )
  57 {
  58   EFI_SEC_PEI_HAND_OFF  SecCoreData;
  59   SEC_IDT_TABLE         IdtTableInStack;
  60   IA32_DESCRIPTOR       IdtDescriptor;
  61   UINT32                Index;
  62   volatile UINT8        *Table;
  63
  64   if (CcProbe () == CcGuestTypeIntelTdx) {
  65     //
  66     // For Td guests, the memory map info is in TdHobLib. It should be processed
  67     // first so that the memory is accepted. Otherwise access to the unaccepted
  68     // memory will trigger tripple fault.
  69     //
  70     if (ProcessTdxHobList () != EFI_SUCCESS) {
  71       CpuDeadLoop ();
  72     }
  73   }
  74
  75   //
  76   // To ensure SMM can't be compromised on S3 resume, we must force re-init of
  77   // the BaseExtractGuidedSectionLib. Since this is before library contructors
  78   // are called, we must use a loop rather than SetMem.
  79   //
  80   Table = (UINT8 *)(UINTN)FixedPcdGet64 (PcdGuidedExtractHandlerTableAddress);
  81   for (Index = 0;
  82        Index < FixedPcdGet32 (PcdGuidedExtractHandlerTableSize);
  83        ++Index)
  84   {
  85     Table[Index] = 0;
  86   }
  87
  88   //
  89   // Initialize IDT - Since this is before library constructors are called,
  90   // we use a loop rather than CopyMem.
  91   //
  92   IdtTableInStack.PeiService = NULL;
  93
  94   for (Index = 0; Index < SEC_IDT_ENTRY_COUNT; Index++) {
  95     //
  96     // Declare the local variables that actually move the data elements as
  97     // volatile to prevent the optimizer from replacing this function with
  98     // the intrinsic memcpy()
  99     //
 100     CONST UINT8     *Src;
 101     volatile UINT8  *Dst;
 102     UINTN           Byte;
 103
 104     Src = (CONST UINT8 *)&mIdtEntryTemplate;
 105     Dst = (volatile UINT8 *)&IdtTableInStack.IdtTable[Index];
 106
 107     for (Byte = 0; Byte < sizeof (mIdtEntryTemplate); Byte++) {
 108       Dst[Byte] = Src[Byte];
 109     }
 110   }
 111
 112   IdtDescriptor.Base  = (UINTN)&IdtTableInStack.IdtTable;
 113   IdtDescriptor.Limit = (UINT16)(sizeof (IdtTableInStack.IdtTable) - 1);
 114
 115   ProcessLibraryConstructorList (NULL, NULL);
 116
 117   //
 118   // Load the IDTR.
 119   //
 120   AsmWriteIdtr (&IdtDescriptor);
 121
 122   if (CcProbe () == CcGuestTypeIntelTdx) {
 123     //
 124     // InitializeCpuExceptionHandlers () should be called in Td guests so that
 125     // #VE exceptions can be handled correctly.
 126     //
 127     InitializeCpuExceptionHandlers (NULL);
 128   }
 129
 130   DEBUG ((
 131     DEBUG_INFO,
 132     "SecCoreStartupWithStack(0x%x, 0x%x)\n",
 133     (UINT32)(UINTN)BootFv,
 134     (UINT32)(UINTN)TopOfCurrentStack
 135     ));
 136
 137   //
 138   // Initialize floating point operating environment
 139   // to be compliant with UEFI spec.
 140   //
 141   InitializeFloatingPointUnits ();
 142
 143   //
 144   // ASSERT that the Page Tables were set by the reset vector code to
 145   // the address we expect.
 146   //
 147   ASSERT (AsmReadCr3 () == (UINTN)PcdGet32 (PcdOvmfSecPageTablesBase));
 148
 149   //
 150   // |-------------|       <-- TopOfCurrentStack
 151   // |   Stack     | 32k
 152   // |-------------|
 153   // |    Heap     | 32k
 154   // |-------------|       <-- SecCoreData.TemporaryRamBase
 155   //
 156
 157   ASSERT (
 158     (UINTN)(PcdGet32 (PcdOvmfSecPeiTempRamBase) +
 159             PcdGet32 (PcdOvmfSecPeiTempRamSize)) ==
 160     (UINTN)TopOfCurrentStack
 161     );
 162
 163   //
 164   // Initialize SEC hand-off state
 165   //
 166   SecCoreData.DataSize = sizeof (EFI_SEC_PEI_HAND_OFF);
 167
 168   SecCoreData.TemporaryRamSize = (UINTN)PcdGet32 (PcdOvmfSecPeiTempRamSize);
 169   SecCoreData.TemporaryRamBase = (VOID *)((UINT8 *)TopOfCurrentStack - SecCoreData.TemporaryRamSize);
 170
 171   SecCoreData.PeiTemporaryRamBase = SecCoreData.TemporaryRamBase;
 172   SecCoreData.PeiTemporaryRamSize = SecCoreData.TemporaryRamSize >> 1;
 173
 174   SecCoreData.StackBase = (UINT8 *)SecCoreData.TemporaryRamBase + SecCoreData.PeiTemporaryRamSize;
 175   SecCoreData.StackSize = SecCoreData.TemporaryRamSize >> 1;
 176
 177   SecCoreData.BootFirmwareVolumeBase = BootFv;
 178   SecCoreData.BootFirmwareVolumeSize = (UINTN)BootFv->FvLength;
 179
 180   //
 181   // Make sure the 8259 is masked before initializing the Debug Agent and the debug timer is enabled
 182   //
 183   IoWrite8 (0x21, 0xff);
 184   IoWrite8 (0xA1, 0xff);
 185
 186   //
 187   // Initialize Local APIC Timer hardware and disable Local APIC Timer
 188   // interrupts before initializing the Debug Agent and the debug timer is
 189   // enabled.
 190   //
 191   InitializeApicTimer (0, MAX_UINT32, TRUE, 5);
 192   DisableApicTimerInterrupt ();
 193
 194   PeilessStartup (&SecCoreData);
 195
 196   ASSERT (FALSE);
 197   CpuDeadLoop ();
 198 }