OvmfPkg/XenPlatformPei/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   Copyright (c) 2019, Citrix Systems, Inc.
   7
   8   SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10 **/
  11
  12 //
  13 // The package level header files this module uses
  14 //
  15 #include <PiPei.h>
  16
  17 //
  18 // The Library classes this module consumes
  19 //
  20 #include <Library/DebugLib.h>
  21 #include <Library/HobLib.h>
  22 #include <Library/MemoryAllocationLib.h>
  23 #include <Library/PcdLib.h>
  24 #include <Guid/XenInfo.h>
  25 #include <IndustryStandard/E820.h>
  26 #include <Library/ResourcePublicationLib.h>
  27 #include <Library/MtrrLib.h>
  28
  29 #include "Platform.h"
  30 #include "Xen.h"
  31
  32 STATIC UINT32 mXenLeaf = 0;
  33
  34 EFI_XEN_INFO mXenInfo;
  35
  36 //
  37 // Location of the firmware info struct setup by hvmloader.
  38 // Only the E820 table is used by OVMF.
  39 //
  40 EFI_XEN_OVMF_INFO *mXenHvmloaderInfo;
  41
  42 /**
  43   Returns E820 map provided by Xen
  44
  45   @param Entries      Pointer to E820 map
  46   @param Count        Number of entries
  47
  48   @return EFI_STATUS
  49 **/
  50 EFI_STATUS
  51 XenGetE820Map (
  52   EFI_E820_ENTRY64 **Entries,
  53   UINT32 *Count
  54   )
  55 {
  56   EFI_XEN_OVMF_INFO *Info =
  57     (EFI_XEN_OVMF_INFO *)(UINTN) OVMF_INFO_PHYSICAL_ADDRESS;
  58
  59   if (AsciiStrCmp ((CHAR8 *) Info->Signature, "XenHVMOVMF")) {
  60     return EFI_NOT_FOUND;
  61   }
  62
  63   ASSERT (Info->E820 < MAX_ADDRESS);
  64   *Entries = (EFI_E820_ENTRY64 *)(UINTN) Info->E820;
  65   *Count = Info->E820EntriesCount;
  66
  67   return EFI_SUCCESS;
  68 }
  69
  70 /**
  71   Connects to the Hypervisor.
  72
  73   @param  XenLeaf     CPUID index used to connect.
  74
  75   @return EFI_STATUS
  76
  77 **/
  78 EFI_STATUS
  79 XenConnect (
  80   UINT32 XenLeaf
  81   )
  82 {
  83   UINT32 Index;
  84   UINT32 TransferReg;
  85   UINT32 TransferPages;
  86   UINT32 XenVersion;
  87   EFI_XEN_OVMF_INFO *Info;
  88   CHAR8 Sig[sizeof (Info->Signature) + 1];
  89
  90   AsmCpuid (XenLeaf + 2, &TransferPages, &TransferReg, NULL, NULL);
  91   mXenInfo.HyperPages = AllocatePages (TransferPages);
  92   if (!mXenInfo.HyperPages) {
  93     return EFI_OUT_OF_RESOURCES;
  94   }
  95
  96   for (Index = 0; Index < TransferPages; Index++) {
  97     AsmWriteMsr64 (TransferReg,
  98                    (UINTN) mXenInfo.HyperPages +
  99                    (Index << EFI_PAGE_SHIFT) + Index);
 100   }
 101
 102   AsmCpuid (XenLeaf + 1, &XenVersion, NULL, NULL, NULL);
 103   DEBUG ((DEBUG_ERROR, "Detected Xen version %d.%d\n",
 104           XenVersion >> 16, XenVersion & 0xFFFF));
 105   mXenInfo.VersionMajor = (UINT16)(XenVersion >> 16);
 106   mXenInfo.VersionMinor = (UINT16)(XenVersion & 0xFFFF);
 107
 108   //
 109   // Check if there are information left by hvmloader
 110   //
 111
 112   Info = (EFI_XEN_OVMF_INFO *)(UINTN) OVMF_INFO_PHYSICAL_ADDRESS;
 113   //
 114   // Copy the signature, and make it null-terminated.
 115   //
 116   AsciiStrnCpyS (Sig, sizeof (Sig), (CHAR8 *) &Info->Signature,
 117     sizeof (Info->Signature));
 118   if (AsciiStrCmp (Sig, "XenHVMOVMF") == 0) {
 119     mXenHvmloaderInfo = Info;
 120   } else {
 121     mXenHvmloaderInfo = NULL;
 122   }
 123
 124   BuildGuidDataHob (
 125     &gEfiXenInfoGuid,
 126     &mXenInfo,
 127     sizeof(mXenInfo)
 128     );
 129
 130   return EFI_SUCCESS;
 131 }
 132
 133 /**
 134   Figures out if we are running inside Xen HVM.
 135
 136   @retval TRUE   Xen was detected
 137   @retval FALSE  Xen was not detected
 138
 139 **/
 140 BOOLEAN
 141 XenDetect (
 142   VOID
 143   )
 144 {
 145   UINT8 Signature[13];
 146
 147   if (mXenLeaf != 0) {
 148     return TRUE;
 149   }
 150
 151   Signature[12] = '\0';
 152   for (mXenLeaf = 0x40000000; mXenLeaf < 0x40010000; mXenLeaf += 0x100) {
 153     AsmCpuid (mXenLeaf,
 154               NULL,
 155               (UINT32 *) &Signature[0],
 156               (UINT32 *) &Signature[4],
 157               (UINT32 *) &Signature[8]);
 158
 159     if (!AsciiStrCmp ((CHAR8 *) Signature, "XenVMMXenVMM")) {
 160       return TRUE;
 161     }
 162   }
 163
 164   mXenLeaf = 0;
 165   return FALSE;
 166 }
 167
 168
 169 VOID
 170 XenPublishRamRegions (
 171   VOID
 172   )
 173 {
 174   EFI_E820_ENTRY64  *E820Map;
 175   UINT32            E820EntriesCount;
 176   EFI_STATUS        Status;
 177
 178   DEBUG ((DEBUG_INFO, "Using memory map provided by Xen\n"));
 179
 180   //
 181   // Parse RAM in E820 map
 182   //
 183   E820EntriesCount = 0;
 184   Status = XenGetE820Map (&E820Map, &E820EntriesCount);
 185
 186   ASSERT_EFI_ERROR (Status);
 187
 188   if (E820EntriesCount > 0) {
 189     EFI_E820_ENTRY64 *Entry;
 190     UINT32 Loop;
 191
 192     for (Loop = 0; Loop < E820EntriesCount; Loop++) {
 193       Entry = E820Map + Loop;
 194
 195       //
 196       // Only care about RAM
 197       //
 198       if (Entry->Type != EfiAcpiAddressRangeMemory) {
 199         continue;
 200       }
 201
 202       AddMemoryBaseSizeHob (Entry->BaseAddr, Entry->Length);
 203
 204       MtrrSetMemoryAttribute (Entry->BaseAddr, Entry->Length, CacheWriteBack);
 205     }
 206   }
 207 }
 208
 209
 210 /**
 211   Perform Xen PEI initialization.
 212
 213   @return EFI_SUCCESS     Xen initialized successfully
 214   @return EFI_NOT_FOUND   Not running under Xen
 215
 216 **/
 217 EFI_STATUS
 218 InitializeXen (
 219   VOID
 220   )
 221 {
 222   RETURN_STATUS PcdStatus;
 223
 224   if (mXenLeaf == 0) {
 225     return EFI_NOT_FOUND;
 226   }
 227
 228   XenConnect (mXenLeaf);
 229
 230   //
 231   // Reserve away HVMLOADER reserved memory [0xFC000000,0xFD000000).
 232   // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE.
 233   //
 234   AddReservedMemoryBaseSizeHob (0xFC000000, 0x1000000, FALSE);
 235
 236   PcdStatus = PcdSetBoolS (PcdPciDisableBusEnumeration, TRUE);
 237   ASSERT_RETURN_ERROR (PcdStatus);
 238
 239   return EFI_SUCCESS;
 240 }