OvmfPkg/PlatformPei/Xen.c

   1 /**@file
   2   Xen Platform PEI support
   3
   4   Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
   5   Copyright (c) 2011, Andrei Warkentin <andreiw@motorola.com>
   6
   7   SPDX-License-Identifier: BSD-2-Clause-Patent
   8
   9 **/
  10
  11 //
  12 // The package level header files this module uses
  13 //
  14 #include <PiPei.h>
  15
  16 //
  17 // The Library classes this module consumes
  18 //
  19 #include <Library/DebugLib.h>
  20 #include <Library/HobLib.h>
  21 #include <Library/MemoryAllocationLib.h>
  22 #include <Library/PcdLib.h>
  23 #include <Guid/XenInfo.h>
  24 #include <IndustryStandard/E820.h>
  25 #include <Library/ResourcePublicationLib.h>
  26 #include <Library/MtrrLib.h>
  27
  28 #include "Platform.h"
  29 #include "Xen.h"
  30
  31 BOOLEAN mXen = FALSE;
  32
  33 STATIC UINT32 mXenLeaf = 0;
  34
  35 EFI_XEN_INFO mXenInfo;
  36
  37 /**
  38   Returns E820 map provided by Xen
  39
  40   @param Entries      Pointer to E820 map
  41   @param Count        Number of entries
  42
  43   @return EFI_STATUS
  44 **/
  45 EFI_STATUS
  46 XenGetE820Map (
  47   EFI_E820_ENTRY64 **Entries,
  48   UINT32 *Count
  49   )
  50 {
  51   EFI_XEN_OVMF_INFO *Info =
  52     (EFI_XEN_OVMF_INFO *)(UINTN) OVMF_INFO_PHYSICAL_ADDRESS;
  53
  54   if (AsciiStrCmp ((CHAR8 *) Info->Signature, "XenHVMOVMF")) {
  55     return EFI_NOT_FOUND;
  56   }
  57
  58   ASSERT (Info->E820 < MAX_ADDRESS);
  59   *Entries = (EFI_E820_ENTRY64 *)(UINTN) Info->E820;
  60   *Count = Info->E820EntriesCount;
  61
  62   return EFI_SUCCESS;
  63 }
  64
  65 /**
  66   Connects to the Hypervisor.
  67
  68   @param  XenLeaf     CPUID index used to connect.
  69
  70   @return EFI_STATUS
  71
  72 **/
  73 EFI_STATUS
  74 XenConnect (
  75   UINT32 XenLeaf
  76   )
  77 {
  78   UINT32 Index;
  79   UINT32 TransferReg;
  80   UINT32 TransferPages;
  81   UINT32 XenVersion;
  82
  83   AsmCpuid (XenLeaf + 2, &TransferPages, &TransferReg, NULL, NULL);
  84   mXenInfo.HyperPages = AllocatePages (TransferPages);
  85   if (!mXenInfo.HyperPages) {
  86     return EFI_OUT_OF_RESOURCES;
  87   }
  88
  89   for (Index = 0; Index < TransferPages; Index++) {
  90     AsmWriteMsr64 (TransferReg,
  91                    (UINTN) mXenInfo.HyperPages +
  92                    (Index << EFI_PAGE_SHIFT) + Index);
  93   }
  94
  95   AsmCpuid (XenLeaf + 1, &XenVersion, NULL, NULL, NULL);
  96   DEBUG ((EFI_D_ERROR, "Detected Xen version %d.%d\n",
  97           XenVersion >> 16, XenVersion & 0xFFFF));
  98   mXenInfo.VersionMajor = (UINT16)(XenVersion >> 16);
  99   mXenInfo.VersionMinor = (UINT16)(XenVersion & 0xFFFF);
 100
 101   /* TBD: Locate hvm_info and reserve it away. */
 102   mXenInfo.HvmInfo = NULL;
 103
 104   BuildGuidDataHob (
 105     &gEfiXenInfoGuid,
 106     &mXenInfo,
 107     sizeof(mXenInfo)
 108     );
 109
 110   return EFI_SUCCESS;
 111 }
 112
 113 /**
 114   Figures out if we are running inside Xen HVM.
 115
 116   @retval TRUE   Xen was detected
 117   @retval FALSE  Xen was not detected
 118
 119 **/
 120 BOOLEAN
 121 XenDetect (
 122   VOID
 123   )
 124 {
 125   UINT8 Signature[13];
 126
 127   if (mXenLeaf != 0) {
 128     return TRUE;
 129   }
 130
 131   Signature[12] = '\0';
 132   for (mXenLeaf = 0x40000000; mXenLeaf < 0x40010000; mXenLeaf += 0x100) {
 133     AsmCpuid (mXenLeaf,
 134               NULL,
 135               (UINT32 *) &Signature[0],
 136               (UINT32 *) &Signature[4],
 137               (UINT32 *) &Signature[8]);
 138
 139     if (!AsciiStrCmp ((CHAR8 *) Signature, "XenVMMXenVMM")) {
 140       mXen = TRUE;
 141       return TRUE;
 142     }
 143   }
 144
 145   mXenLeaf = 0;
 146   return FALSE;
 147 }
 148
 149
 150 VOID
 151 XenPublishRamRegions (
 152   VOID
 153   )
 154 {
 155   EFI_E820_ENTRY64  *E820Map;
 156   UINT32            E820EntriesCount;
 157   EFI_STATUS        Status;
 158
 159   if (!mXen) {
 160     return;
 161   }
 162
 163   DEBUG ((EFI_D_INFO, "Using memory map provided by Xen\n"));
 164
 165   //
 166   // Parse RAM in E820 map
 167   //
 168   E820EntriesCount = 0;
 169   Status = XenGetE820Map (&E820Map, &E820EntriesCount);
 170
 171   ASSERT_EFI_ERROR (Status);
 172
 173   if (E820EntriesCount > 0) {
 174     EFI_E820_ENTRY64 *Entry;
 175     UINT32 Loop;
 176
 177     for (Loop = 0; Loop < E820EntriesCount; Loop++) {
 178       Entry = E820Map + Loop;
 179
 180       //
 181       // Only care about RAM
 182       //
 183       if (Entry->Type != EfiAcpiAddressRangeMemory) {
 184         continue;
 185       }
 186
 187       AddMemoryBaseSizeHob (Entry->BaseAddr, Entry->Length);
 188
 189       MtrrSetMemoryAttribute (Entry->BaseAddr, Entry->Length, CacheWriteBack);
 190     }
 191   }
 192 }
 193
 194
 195 /**
 196   Perform Xen PEI initialization.
 197
 198   @return EFI_SUCCESS     Xen initialized successfully
 199   @return EFI_NOT_FOUND   Not running under Xen
 200
 201 **/
 202 EFI_STATUS
 203 InitializeXen (
 204   VOID
 205   )
 206 {
 207   RETURN_STATUS PcdStatus;
 208
 209   if (mXenLeaf == 0) {
 210     return EFI_NOT_FOUND;
 211   }
 212
 213   XenConnect (mXenLeaf);
 214
 215   //
 216   // Reserve away HVMLOADER reserved memory [0xFC000000,0xFD000000).
 217   // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE.
 218   //
 219   AddReservedMemoryBaseSizeHob (0xFC000000, 0x1000000, FALSE);
 220
 221   PcdStatus = PcdSetBoolS (PcdPciDisableBusEnumeration, TRUE);
 222   ASSERT_RETURN_ERROR (PcdStatus);
 223
 224   return EFI_SUCCESS;
 225 }