OvmfPkg/PlatformPei/Xen.c

   1 /**@file
   2   Xen Platform PEI support
   3
   4   Copyright (c) 2006 - 2011, 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
  33 EFI_XEN_INFO mXenInfo;
  34
  35
  36 /**
  37   Connects to the Hypervisor.
  38
  39   @param  XenLeaf     CPUID index used to connect.
  40
  41   @return EFI_STATUS
  42
  43 **/
  44 EFI_STATUS
  45 XenConnect (
  46   UINT32 XenLeaf
  47   )
  48 {
  49   UINT32 Index;
  50   UINT32 TransferReg;
  51   UINT32 TransferPages;
  52   UINT32 XenVersion;
  53
  54   AsmCpuid (XenLeaf + 2, &TransferPages, &TransferReg, NULL, NULL);
  55   mXenInfo.HyperPages = AllocatePages (TransferPages);
  56   if (!mXenInfo.HyperPages) {
  57     return EFI_OUT_OF_RESOURCES;
  58   }
  59
  60   for (Index = 0; Index < TransferPages; Index++) {
  61     AsmWriteMsr64 (TransferReg,
  62                    (UINTN) mXenInfo.HyperPages +
  63                    (Index << EFI_PAGE_SHIFT) + Index);
  64   }
  65
  66   AsmCpuid (XenLeaf + 1, &XenVersion, NULL, NULL, NULL);
  67   DEBUG ((EFI_D_ERROR, "Detected Xen version %d.%d\n",
  68           XenVersion >> 16, XenVersion & 0xFFFF));
  69   mXenInfo.VersionMajor = (UINT16)(XenVersion >> 16);
  70   mXenInfo.VersionMinor = (UINT16)(XenVersion & 0xFFFF);
  71
  72   /* TBD: Locate hvm_info and reserve it away. */
  73   mXenInfo.HvmInfo = NULL;
  74
  75   BuildGuidDataHob (
  76     &gEfiXenInfoGuid,
  77     &mXenInfo,
  78     sizeof(mXenInfo)
  79     );
  80
  81   return EFI_SUCCESS;
  82 }
  83
  84 /**
  85   Figures out if we are running inside Xen HVM.
  86
  87   @return UINT32     CPUID index used to connect to HV.
  88
  89 **/
  90 UINT32
  91 XenDetect (
  92   VOID
  93   )
  94 {
  95
  96   UINT32 XenLeaf;
  97   UINT8 Signature[13];
  98
  99   for (XenLeaf = 0x40000000; XenLeaf < 0x40010000; XenLeaf += 0x100) {
 100     AsmCpuid (XenLeaf, NULL, (UINT32 *) &Signature[0],
 101               (UINT32 *) &Signature[4],
 102               (UINT32 *) &Signature[8]);
 103     Signature[12] = '\0';
 104
 105     if (!AsciiStrCmp ((CHAR8 *) Signature, "XenVMMXenVMM")) {
 106       return XenLeaf;
 107     }
 108   }
 109
 110   return 0;
 111 }
 112
 113 /**
 114   Perform Xen PEI initialization.
 115
 116   @return EFI_SUCCESS     Xen initialized successfully
 117   @return EFI_NOT_FOUND   Not running under Xen
 118
 119 **/
 120 EFI_STATUS
 121 InitializeXen (
 122   VOID
 123   )
 124 {
 125   UINT32 XenLeaf;
 126
 127   XenLeaf = XenDetect ();
 128
 129   if (XenLeaf == 0) {
 130     return EFI_NOT_FOUND;
 131   }
 132
 133   DEBUG ((EFI_D_INFO, "Xen was detected\n"));
 134
 135   XenConnect (XenLeaf);
 136
 137   //
 138   // Reserve away HVMLOADER reserved memory [0xFC000000,0xFD000000).
 139   // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE.
 140   //
 141   AddReservedMemoryBaseSizeHob (0xFC000000, 0x1000000);
 142
 143   return EFI_SUCCESS;
 144 }