OvmfPkg/PlatformPei/Xen.c

   1 /**@file
   2   Xen Platform PEI support
   3
   4   Copyright (c) 2006 - 2013, 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 EFI_XEN_INFO mXenInfo;
  35
  36 /**
  37   Returns E820 map provided by Xen
  38
  39   @param Entries      Pointer to E820 map
  40   @param Count        Number of entries
  41
  42   @return EFI_STATUS
  43 **/
  44 EFI_STATUS
  45 XenGetE820Map (
  46   EFI_E820_ENTRY64 **Entries,
  47   UINT32 *Count
  48   )
  49 {
  50   EFI_XEN_OVMF_INFO *Info =
  51     (EFI_XEN_OVMF_INFO *)(UINTN) OVMF_INFO_PHYSICAL_ADDRESS;
  52
  53   if (AsciiStrCmp ((CHAR8 *) Info->Signature, "XenHVMOVMF")) {
  54     return EFI_NOT_FOUND;
  55   }
  56
  57   ASSERT (Info->E820 < MAX_ADDRESS);
  58   *Entries = (EFI_E820_ENTRY64 *)(UINTN) Info->E820;
  59   *Count = Info->E820EntriesCount;
  60
  61   return EFI_SUCCESS;
  62 }
  63
  64 /**
  65   Connects to the Hypervisor.
  66
  67   @param  XenLeaf     CPUID index used to connect.
  68
  69   @return EFI_STATUS
  70
  71 **/
  72 EFI_STATUS
  73 XenConnect (
  74   UINT32 XenLeaf
  75   )
  76 {
  77   UINT32 Index;
  78   UINT32 TransferReg;
  79   UINT32 TransferPages;
  80   UINT32 XenVersion;
  81
  82   AsmCpuid (XenLeaf + 2, &TransferPages, &TransferReg, NULL, NULL);
  83   mXenInfo.HyperPages = AllocatePages (TransferPages);
  84   if (!mXenInfo.HyperPages) {
  85     return EFI_OUT_OF_RESOURCES;
  86   }
  87
  88   for (Index = 0; Index < TransferPages; Index++) {
  89     AsmWriteMsr64 (TransferReg,
  90                    (UINTN) mXenInfo.HyperPages +
  91                    (Index << EFI_PAGE_SHIFT) + Index);
  92   }
  93
  94   AsmCpuid (XenLeaf + 1, &XenVersion, NULL, NULL, NULL);
  95   DEBUG ((EFI_D_ERROR, "Detected Xen version %d.%d\n",
  96           XenVersion >> 16, XenVersion & 0xFFFF));
  97   mXenInfo.VersionMajor = (UINT16)(XenVersion >> 16);
  98   mXenInfo.VersionMinor = (UINT16)(XenVersion & 0xFFFF);
  99
 100   /* TBD: Locate hvm_info and reserve it away. */
 101   mXenInfo.HvmInfo = NULL;
 102
 103   BuildGuidDataHob (
 104     &gEfiXenInfoGuid,
 105     &mXenInfo,
 106     sizeof(mXenInfo)
 107     );
 108
 109   return EFI_SUCCESS;
 110 }
 111
 112 /**
 113   Figures out if we are running inside Xen HVM.
 114
 115   @return UINT32     CPUID index used to connect to HV.
 116
 117 **/
 118 UINT32
 119 XenDetect (
 120   VOID
 121   )
 122 {
 123
 124   UINT32 XenLeaf;
 125   UINT8 Signature[13];
 126
 127   for (XenLeaf = 0x40000000; XenLeaf < 0x40010000; XenLeaf += 0x100) {
 128     AsmCpuid (XenLeaf, NULL, (UINT32 *) &Signature[0],
 129               (UINT32 *) &Signature[4],
 130               (UINT32 *) &Signature[8]);
 131     Signature[12] = '\0';
 132
 133     if (!AsciiStrCmp ((CHAR8 *) Signature, "XenVMMXenVMM")) {
 134       return XenLeaf;
 135     }
 136   }
 137
 138   return 0;
 139 }
 140
 141 /**
 142   Perform Xen PEI initialization.
 143
 144   @return EFI_SUCCESS     Xen initialized successfully
 145   @return EFI_NOT_FOUND   Not running under Xen
 146
 147 **/
 148 EFI_STATUS
 149 InitializeXen (
 150   UINT32 XenLeaf
 151   )
 152 {
 153   XenConnect (XenLeaf);
 154
 155   //
 156   // Reserve away HVMLOADER reserved memory [0xFC000000,0xFD000000).
 157   // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE.
 158   //
 159   AddReservedMemoryBaseSizeHob (0xFC000000, 0x1000000);
 160
 161   return EFI_SUCCESS;
 162 }