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   BuildGuidDataHob (
 102     &gEfiXenInfoGuid,
 103     &mXenInfo,
 104     sizeof(mXenInfo)
 105     );
 106
 107   return EFI_SUCCESS;
 108 }
 109
 110 /**
 111   Figures out if we are running inside Xen HVM.
 112
 113   @retval TRUE   Xen was detected
 114   @retval FALSE  Xen was not detected
 115
 116 **/
 117 BOOLEAN
 118 XenDetect (
 119   VOID
 120   )
 121 {
 122   UINT8 Signature[13];
 123
 124   if (mXenLeaf != 0) {
 125     return TRUE;
 126   }
 127
 128   Signature[12] = '\0';
 129   for (mXenLeaf = 0x40000000; mXenLeaf < 0x40010000; mXenLeaf += 0x100) {
 130     AsmCpuid (mXenLeaf,
 131               NULL,
 132               (UINT32 *) &Signature[0],
 133               (UINT32 *) &Signature[4],
 134               (UINT32 *) &Signature[8]);
 135
 136     if (!AsciiStrCmp ((CHAR8 *) Signature, "XenVMMXenVMM")) {
 137       mXen = TRUE;
 138       return TRUE;
 139     }
 140   }
 141
 142   mXenLeaf = 0;
 143   return FALSE;
 144 }
 145
 146
 147 VOID
 148 XenPublishRamRegions (
 149   VOID
 150   )
 151 {
 152   EFI_E820_ENTRY64  *E820Map;
 153   UINT32            E820EntriesCount;
 154   EFI_STATUS        Status;
 155
 156   if (!mXen) {
 157     return;
 158   }
 159
 160   DEBUG ((EFI_D_INFO, "Using memory map provided by Xen\n"));
 161
 162   //
 163   // Parse RAM in E820 map
 164   //
 165   E820EntriesCount = 0;
 166   Status = XenGetE820Map (&E820Map, &E820EntriesCount);
 167
 168   ASSERT_EFI_ERROR (Status);
 169
 170   if (E820EntriesCount > 0) {
 171     EFI_E820_ENTRY64 *Entry;
 172     UINT32 Loop;
 173
 174     for (Loop = 0; Loop < E820EntriesCount; Loop++) {
 175       Entry = E820Map + Loop;
 176
 177       //
 178       // Only care about RAM
 179       //
 180       if (Entry->Type != EfiAcpiAddressRangeMemory) {
 181         continue;
 182       }
 183
 184       AddMemoryBaseSizeHob (Entry->BaseAddr, Entry->Length);
 185
 186       MtrrSetMemoryAttribute (Entry->BaseAddr, Entry->Length, CacheWriteBack);
 187     }
 188   }
 189 }
 190
 191
 192 /**
 193   Perform Xen PEI initialization.
 194
 195   @return EFI_SUCCESS     Xen initialized successfully
 196   @return EFI_NOT_FOUND   Not running under Xen
 197
 198 **/
 199 EFI_STATUS
 200 InitializeXen (
 201   VOID
 202   )
 203 {
 204   RETURN_STATUS PcdStatus;
 205
 206   if (mXenLeaf == 0) {
 207     return EFI_NOT_FOUND;
 208   }
 209
 210   XenConnect (mXenLeaf);
 211
 212   //
 213   // Reserve away HVMLOADER reserved memory [0xFC000000,0xFD000000).
 214   // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE.
 215   //
 216   AddReservedMemoryBaseSizeHob (0xFC000000, 0x1000000, FALSE);
 217
 218   PcdStatus = PcdSetBoolS (PcdPciDisableBusEnumeration, TRUE);
 219   ASSERT_RETURN_ERROR (PcdStatus);
 220
 221   return EFI_SUCCESS;
 222 }