summaryrefslogtreecommitdiffstats
path: root/OvmfPkg/PlatformPei/Xen.c
blob: 3a4358251e3889e7f4ef8a1e97ee56948a342e4e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
/**@file
  Xen Platform PEI support

  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
  Copyright (c) 2011, Andrei Warkentin <andreiw@motorola.com>

  This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

//
// The package level header files this module uses
//
#include <PiPei.h>

//
// The Library classes this module consumes
//
#include <Library/DebugLib.h>
#include <Library/HobLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/PcdLib.h>
#include <Guid/XenInfo.h>
#include <IndustryStandard/E820.h>
#include <Library/ResourcePublicationLib.h>
#include <Library/MtrrLib.h>

#include "Platform.h"
#include "Xen.h"

BOOLEAN mXen = FALSE;

STATIC UINT32 mXenLeaf = 0;

EFI_XEN_INFO mXenInfo;

/**
  Returns E820 map provided by Xen

  @param Entries      Pointer to E820 map
  @param Count        Number of entries

  @return EFI_STATUS
**/
EFI_STATUS
XenGetE820Map (
  EFI_E820_ENTRY64 **Entries,
  UINT32 *Count
  )
{
  EFI_XEN_OVMF_INFO *Info =
    (EFI_XEN_OVMF_INFO *)(UINTN) OVMF_INFO_PHYSICAL_ADDRESS;

  if (AsciiStrCmp ((CHAR8 *) Info->Signature, "XenHVMOVMF")) {
    return EFI_NOT_FOUND;
  }

  ASSERT (Info->E820 < MAX_ADDRESS);
  *Entries = (EFI_E820_ENTRY64 *)(UINTN) Info->E820;
  *Count = Info->E820EntriesCount;

  return EFI_SUCCESS;
}

/**
  Connects to the Hypervisor.
 
  @param  XenLeaf     CPUID index used to connect.

  @return EFI_STATUS

**/
EFI_STATUS
XenConnect (
  UINT32 XenLeaf
  )
{
  UINT32 Index;
  UINT32 TransferReg;
  UINT32 TransferPages;
  UINT32 XenVersion;

  AsmCpuid (XenLeaf + 2, &TransferPages, &TransferReg, NULL, NULL);
  mXenInfo.HyperPages = AllocatePages (TransferPages);
  if (!mXenInfo.HyperPages) {
    return EFI_OUT_OF_RESOURCES;
  }

  for (Index = 0; Index < TransferPages; Index++) {
    AsmWriteMsr64 (TransferReg,
                   (UINTN) mXenInfo.HyperPages +
                   (Index << EFI_PAGE_SHIFT) + Index);
  }

  AsmCpuid (XenLeaf + 1, &XenVersion, NULL, NULL, NULL);
  DEBUG ((EFI_D_ERROR, "Detected Xen version %d.%d\n",
          XenVersion >> 16, XenVersion & 0xFFFF));
  mXenInfo.VersionMajor = (UINT16)(XenVersion >> 16);
  mXenInfo.VersionMinor = (UINT16)(XenVersion & 0xFFFF);

  /* TBD: Locate hvm_info and reserve it away. */
  mXenInfo.HvmInfo = NULL;

  BuildGuidDataHob (
    &gEfiXenInfoGuid,
    &mXenInfo,
    sizeof(mXenInfo)
    );

  return EFI_SUCCESS;
}

/**
  Figures out if we are running inside Xen HVM.

  @retval TRUE   Xen was detected
  @retval FALSE  Xen was not detected

**/
BOOLEAN
XenDetect (
  VOID
  )
{
  UINT8 Signature[13];

  if (mXenLeaf != 0) {
    return TRUE;
  }

  Signature[12] = '\0';
  for (mXenLeaf = 0x40000000; mXenLeaf < 0x40010000; mXenLeaf += 0x100) {
    AsmCpuid (mXenLeaf,
              NULL,
              (UINT32 *) &Signature[0],
              (UINT32 *) &Signature[4],
              (UINT32 *) &Signature[8]);

    if (!AsciiStrCmp ((CHAR8 *) Signature, "XenVMMXenVMM")) {
      mXen = TRUE;
      return TRUE;
    }
  }

  mXenLeaf = 0;
  return FALSE;
}


VOID
XenPublishRamRegions (
  VOID
  )
{
  EFI_E820_ENTRY64  *E820Map;
  UINT32            E820EntriesCount;
  EFI_STATUS        Status;

  if (!mXen) {
    return;
  }

  DEBUG ((EFI_D_INFO, "Using memory map provided by Xen\n"));

  //
  // Parse RAM in E820 map
  //
  Status = XenGetE820Map (&E820Map, &E820EntriesCount);

  ASSERT_EFI_ERROR (Status);

  if (E820EntriesCount > 0) {
    EFI_E820_ENTRY64 *Entry;
    UINT32 Loop;

    for (Loop = 0; Loop < E820EntriesCount; Loop++) {
      Entry = E820Map + Loop;

      //
      // Only care about RAM
      //
      if (Entry->Type != EfiAcpiAddressRangeMemory) {
        continue;
      }

      AddMemoryBaseSizeHob (Entry->BaseAddr, Entry->Length);

      MtrrSetMemoryAttribute (Entry->BaseAddr, Entry->Length, CacheWriteBack);
    }
  }
}


/**
  Perform Xen PEI initialization.

  @return EFI_SUCCESS     Xen initialized successfully
  @return EFI_NOT_FOUND   Not running under Xen

**/
EFI_STATUS
InitializeXen (
  VOID
  )
{
  if (mXenLeaf == 0) {
    return EFI_NOT_FOUND;
  }

  XenConnect (mXenLeaf);

  //
  // Reserve away HVMLOADER reserved memory [0xFC000000,0xFD000000).
  // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE.
  //
  AddReservedMemoryBaseSizeHob (0xFC000000, 0x1000000, FALSE);

  PcdSetBool (PcdPciDisableBusEnumeration, TRUE);

  return EFI_SUCCESS;
}