OvmfPkg/PlatformPei/Xen.c

   1 /**@file
   2   Xen Platform PEI support
   3
   4   Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
   5   Copyright (c) 2011, Andrei Warkentin <andreiw@motorola.com>
   6
   7   This program and the accompanying materials
   8   are licensed and made available under the terms and conditions of the BSD License
   9   which accompanies this distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17 //
  18 // The package level header files this module uses
  19 //
  20 #include <PiPei.h>
  21
  22 //
  23 // The Library classes this module consumes
  24 //
  25 #include <Library/DebugLib.h>
  26 #include <Library/HobLib.h>
  27 #include <Library/MemoryAllocationLib.h>
  28 #include <Library/PcdLib.h>
  29 #include <Guid/XenInfo.h>
  30
  31 #include "Platform.h"
  32 #include "Xen.h"
  33
  34 BOOLEAN mXen = FALSE;
  35
  36 STATIC UINT32 mXenLeaf = 0;
  37
  38 EFI_XEN_INFO mXenInfo;
  39
  40 /**
  41   Returns E820 map provided by Xen
  42
  43   @param Entries      Pointer to E820 map
  44   @param Count        Number of entries
  45
  46   @return EFI_STATUS
  47 **/
  48 EFI_STATUS
  49 XenGetE820Map (
  50   EFI_E820_ENTRY64 **Entries,
  51   UINT32 *Count
  52   )
  53 {
  54   EFI_XEN_OVMF_INFO *Info =
  55     (EFI_XEN_OVMF_INFO *)(UINTN) OVMF_INFO_PHYSICAL_ADDRESS;
  56
  57   if (AsciiStrCmp ((CHAR8 *) Info->Signature, "XenHVMOVMF")) {
  58     return EFI_NOT_FOUND;
  59   }
  60
  61   ASSERT (Info->E820 < MAX_ADDRESS);
  62   *Entries = (EFI_E820_ENTRY64 *)(UINTN) Info->E820;
  63   *Count = Info->E820EntriesCount;
  64
  65   return EFI_SUCCESS;
  66 }
  67
  68 /**
  69   Connects to the Hypervisor.
  70
  71   @param  XenLeaf     CPUID index used to connect.
  72
  73   @return EFI_STATUS
  74
  75 **/
  76 EFI_STATUS
  77 XenConnect (
  78   UINT32 XenLeaf
  79   )
  80 {
  81   UINT32 Index;
  82   UINT32 TransferReg;
  83   UINT32 TransferPages;
  84   UINT32 XenVersion;
  85
  86   AsmCpuid (XenLeaf + 2, &TransferPages, &TransferReg, NULL, NULL);
  87   mXenInfo.HyperPages = AllocatePages (TransferPages);
  88   if (!mXenInfo.HyperPages) {
  89     return EFI_OUT_OF_RESOURCES;
  90   }
  91
  92   for (Index = 0; Index < TransferPages; Index++) {
  93     AsmWriteMsr64 (TransferReg,
  94                    (UINTN) mXenInfo.HyperPages +
  95                    (Index << EFI_PAGE_SHIFT) + Index);
  96   }
  97
  98   AsmCpuid (XenLeaf + 1, &XenVersion, NULL, NULL, NULL);
  99   DEBUG ((EFI_D_ERROR, "Detected Xen version %d.%d\n",
 100           XenVersion >> 16, XenVersion & 0xFFFF));
 101   mXenInfo.VersionMajor = (UINT16)(XenVersion >> 16);
 102   mXenInfo.VersionMinor = (UINT16)(XenVersion & 0xFFFF);
 103
 104   /* TBD: Locate hvm_info and reserve it away. */
 105   mXenInfo.HvmInfo = NULL;
 106
 107   BuildGuidDataHob (
 108     &gEfiXenInfoGuid,
 109     &mXenInfo,
 110     sizeof(mXenInfo)
 111     );
 112
 113   return EFI_SUCCESS;
 114 }
 115
 116 /**
 117   Figures out if we are running inside Xen HVM.
 118
 119   @retval TRUE   Xen was detected
 120   @retval FALSE  Xen was not detected
 121
 122 **/
 123 BOOLEAN
 124 XenDetect (
 125   VOID
 126   )
 127 {
 128   UINT8 Signature[13];
 129
 130   if (mXenLeaf != 0) {
 131     return TRUE;
 132   }
 133
 134   Signature[12] = '\0';
 135   for (mXenLeaf = 0x40000000; mXenLeaf < 0x40010000; mXenLeaf += 0x100) {
 136     AsmCpuid (mXenLeaf,
 137               NULL,
 138               (UINT32 *) &Signature[0],
 139               (UINT32 *) &Signature[4],
 140               (UINT32 *) &Signature[8]);
 141
 142     if (!AsciiStrCmp ((CHAR8 *) Signature, "XenVMMXenVMM")) {
 143       mXen = TRUE;
 144       return TRUE;
 145     }
 146   }
 147
 148   mXenLeaf = 0;
 149   return FALSE;
 150 }
 151
 152 /**
 153   Perform Xen PEI initialization.
 154
 155   @return EFI_SUCCESS     Xen initialized successfully
 156   @return EFI_NOT_FOUND   Not running under Xen
 157
 158 **/
 159 EFI_STATUS
 160 InitializeXen (
 161   VOID
 162   )
 163 {
 164   if (mXenLeaf == 0) {
 165     return EFI_NOT_FOUND;
 166   }
 167
 168   XenConnect (mXenLeaf);
 169
 170   //
 171   // Reserve away HVMLOADER reserved memory [0xFC000000,0xFD000000).
 172   // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE.
 173   //
 174   AddReservedMemoryBaseSizeHob (0xFC000000, 0x1000000);
 175
 176   return EFI_SUCCESS;
 177 }