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 EFI_XEN_INFO mXenInfo;
  37
  38 /**
  39   Returns E820 map provided by Xen
  40
  41   @param Entries      Pointer to E820 map
  42   @param Count        Number of entries
  43
  44   @return EFI_STATUS
  45 **/
  46 EFI_STATUS
  47 XenGetE820Map (
  48   EFI_E820_ENTRY64 **Entries,
  49   UINT32 *Count
  50   )
  51 {
  52   EFI_XEN_OVMF_INFO *Info =
  53     (EFI_XEN_OVMF_INFO *)(UINTN) OVMF_INFO_PHYSICAL_ADDRESS;
  54
  55   if (AsciiStrCmp ((CHAR8 *) Info->Signature, "XenHVMOVMF")) {
  56     return EFI_NOT_FOUND;
  57   }
  58
  59   ASSERT (Info->E820 < MAX_ADDRESS);
  60   *Entries = (EFI_E820_ENTRY64 *)(UINTN) Info->E820;
  61   *Count = Info->E820EntriesCount;
  62
  63   return EFI_SUCCESS;
  64 }
  65
  66 /**
  67   Connects to the Hypervisor.
  68
  69   @param  XenLeaf     CPUID index used to connect.
  70
  71   @return EFI_STATUS
  72
  73 **/
  74 EFI_STATUS
  75 XenConnect (
  76   UINT32 XenLeaf
  77   )
  78 {
  79   UINT32 Index;
  80   UINT32 TransferReg;
  81   UINT32 TransferPages;
  82   UINT32 XenVersion;
  83
  84   AsmCpuid (XenLeaf + 2, &TransferPages, &TransferReg, NULL, NULL);
  85   mXenInfo.HyperPages = AllocatePages (TransferPages);
  86   if (!mXenInfo.HyperPages) {
  87     return EFI_OUT_OF_RESOURCES;
  88   }
  89
  90   for (Index = 0; Index < TransferPages; Index++) {
  91     AsmWriteMsr64 (TransferReg,
  92                    (UINTN) mXenInfo.HyperPages +
  93                    (Index << EFI_PAGE_SHIFT) + Index);
  94   }
  95
  96   AsmCpuid (XenLeaf + 1, &XenVersion, NULL, NULL, NULL);
  97   DEBUG ((EFI_D_ERROR, "Detected Xen version %d.%d\n",
  98           XenVersion >> 16, XenVersion & 0xFFFF));
  99   mXenInfo.VersionMajor = (UINT16)(XenVersion >> 16);
 100   mXenInfo.VersionMinor = (UINT16)(XenVersion & 0xFFFF);
 101
 102   /* TBD: Locate hvm_info and reserve it away. */
 103   mXenInfo.HvmInfo = NULL;
 104
 105   BuildGuidDataHob (
 106     &gEfiXenInfoGuid,
 107     &mXenInfo,
 108     sizeof(mXenInfo)
 109     );
 110
 111   return EFI_SUCCESS;
 112 }
 113
 114 /**
 115   Figures out if we are running inside Xen HVM.
 116
 117   @return UINT32     CPUID index used to connect to HV.
 118
 119 **/
 120 UINT32
 121 XenDetect (
 122   VOID
 123   )
 124 {
 125
 126   UINT32 XenLeaf;
 127   UINT8 Signature[13];
 128
 129   for (XenLeaf = 0x40000000; XenLeaf < 0x40010000; XenLeaf += 0x100) {
 130     AsmCpuid (XenLeaf, NULL, (UINT32 *) &Signature[0],
 131               (UINT32 *) &Signature[4],
 132               (UINT32 *) &Signature[8]);
 133     Signature[12] = '\0';
 134
 135     if (!AsciiStrCmp ((CHAR8 *) Signature, "XenVMMXenVMM")) {
 136       mXen = TRUE;
 137       return XenLeaf;
 138     }
 139   }
 140
 141   return 0;
 142 }
 143
 144 /**
 145   Perform Xen PEI initialization.
 146
 147   @return EFI_SUCCESS     Xen initialized successfully
 148   @return EFI_NOT_FOUND   Not running under Xen
 149
 150 **/
 151 EFI_STATUS
 152 InitializeXen (
 153   UINT32 XenLeaf
 154   )
 155 {
 156   XenConnect (XenLeaf);
 157
 158   //
 159   // Reserve away HVMLOADER reserved memory [0xFC000000,0xFD000000).
 160   // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE.
 161   //
 162   AddReservedMemoryBaseSizeHob (0xFC000000, 0x1000000);
 163
 164   return EFI_SUCCESS;
 165 }