summaryrefslogtreecommitdiff
path: root/OvmfPkg/XenBusDxe/XenBus.c
blob: ee9526c332529679c84f6c04f1b9ec0540c5ab72 (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
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
/** @file
  XenBus Bus driver implemtation.

  This file implement the necessary to discover and enumerate Xen PV devices
  through XenStore.

  Copyright (C) 2010 Spectra Logic Corporation
  Copyright (C) 2008 Doug Rabson
  Copyright (C) 2005 Rusty Russell, IBM Corporation
  Copyright (C) 2005 Mike Wray, Hewlett-Packard
  Copyright (C) 2005 XenSource Ltd
  Copyright (C) 2014, Citrix Ltd.

  This file may be distributed separately from the Linux kernel, or
  incorporated into other software packages, subject to the following license:

  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this source file (the "Software"), to deal in the Software without
  restriction, including without limitation the rights to use, copy, modify,
  merge, publish, distribute, sublicense, and/or sell copies of the Software,
  and to permit persons to whom the Software is furnished to do so, subject to
  the following conditions:

  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  IN THE SOFTWARE.
**/

#include <Library/PrintLib.h>

#include "XenBus.h"
#include "GrantTable.h"
#include "XenStore.h"
#include "EventChannel.h"

#include <IndustryStandard/Xen/io/xenbus.h>

STATIC XENBUS_PRIVATE_DATA gXenBusPrivateData;

STATIC XENBUS_DEVICE_PATH gXenBusDevicePathTemplate = {
  {                                                 // Vendor
    {                                               // Vendor.Header
      HARDWARE_DEVICE_PATH,                         // Vendor.Header.Type
      HW_VENDOR_DP,                                 // Vendor.Header.SubType
      {
        (UINT8) (sizeof (XENBUS_DEVICE_PATH)),      // Vendor.Header.Length[0]
        (UINT8) (sizeof (XENBUS_DEVICE_PATH) >> 8), // Vendor.Header.Length[1]
      }
    },
    XENBUS_PROTOCOL_GUID,                           // Vendor.Guid
  },
  0,                                                // Type
  0                                                 // DeviceId
};


/**
  Search our internal record of configured devices (not the XenStore) to
  determine if the XenBus device indicated by Node is known to the system.

  @param Dev   The XENBUS_DEVICE instance to search for device children.
  @param Node  The XenStore node path for the device to find.

  @return  The XENBUS_PRIVATE_DATA of the found device if any, or NULL.
 */
STATIC
XENBUS_PRIVATE_DATA *
XenBusDeviceInitialized (
  IN XENBUS_DEVICE *Dev,
  IN CONST CHAR8 *Node
  )
{
  LIST_ENTRY *Entry;
  XENBUS_PRIVATE_DATA *Child;
  XENBUS_PRIVATE_DATA *Result;

  if (IsListEmpty (&Dev->ChildList)) {
    return NULL;
  }

  Result = NULL;
  for (Entry = GetFirstNode (&Dev->ChildList);
       !IsNodeAtEnd (&Dev->ChildList, Entry);
       Entry = GetNextNode (&Dev->ChildList, Entry)) {
    Child = XENBUS_PRIVATE_DATA_FROM_LINK (Entry);
    if (!AsciiStrCmp (Child->XenBusIo.Node, Node)) {
      Result = Child;
      break;
    }
  }

  return (Result);
}

STATIC
XenbusState
XenBusReadDriverState (
  IN CONST CHAR8 *Path
  )
{
  XenbusState State;
  CHAR8 *Ptr = NULL;
  XENSTORE_STATUS Status;

  Status = XenStoreRead (XST_NIL, Path, "state", NULL, (VOID **)&Ptr);
  if (Status != XENSTORE_STATUS_SUCCESS) {
    State = XenbusStateClosed;
  } else {
    State = AsciiStrDecimalToUintn (Ptr);
  }

  if (Ptr != NULL) {
    FreePool (Ptr);
  }

  return State;
}

//
// Callers should ensure that they are only one calling XenBusAddDevice.
//
STATIC
EFI_STATUS
XenBusAddDevice (
  XENBUS_DEVICE *Dev,
  CONST CHAR8 *Type,
  CONST CHAR8 *Id)
{
  CHAR8 DevicePath[XENSTORE_ABS_PATH_MAX];
  XENSTORE_STATUS StatusXenStore;
  XENBUS_PRIVATE_DATA *Private;
  EFI_STATUS Status;
  XENBUS_DEVICE_PATH *TempXenBusPath;
  VOID *ChildXenIo;

  AsciiSPrint (DevicePath, sizeof (DevicePath),
               "device/%a/%a", Type, Id);

  if (XenStorePathExists (XST_NIL, DevicePath, "")) {
    XENBUS_PRIVATE_DATA *Child;
    enum xenbus_state State;
    CHAR8 *BackendPath;

    Child = XenBusDeviceInitialized (Dev, DevicePath);
    if (Child != NULL) {
      /*
       * We are already tracking this node
       */
      Status = EFI_SUCCESS;
      goto out;
    }

    State = XenBusReadDriverState (DevicePath);
    if (State != XenbusStateInitialising) {
      /*
       * Device is not new, so ignore it. This can
       * happen if a device is going away after
       * switching to Closed.
       */
      DEBUG ((EFI_D_INFO, "XenBus: Device %a ignored. "
              "State %d\n", DevicePath, State));
      Status = EFI_SUCCESS;
      goto out;
    }

    StatusXenStore = XenStoreRead (XST_NIL, DevicePath, "backend",
                                   NULL, (VOID **) &BackendPath);
    if (StatusXenStore != XENSTORE_STATUS_SUCCESS) {
      DEBUG ((EFI_D_ERROR, "xenbus: %a no backend path.\n", DevicePath));
      Status = EFI_NOT_FOUND;
      goto out;
    }

    Private = AllocateCopyPool (sizeof (*Private), &gXenBusPrivateData);
    Private->XenBusIo.Type = AsciiStrDup (Type);
    Private->XenBusIo.Node = AsciiStrDup (DevicePath);
    Private->XenBusIo.Backend = BackendPath;
    Private->XenBusIo.DeviceId = (UINT16)AsciiStrDecimalToUintn (Id);
    Private->Dev = Dev;

    TempXenBusPath = AllocateCopyPool (sizeof (XENBUS_DEVICE_PATH),
                                       &gXenBusDevicePathTemplate);
    if (!AsciiStrCmp (Private->XenBusIo.Type, "vbd")) {
      TempXenBusPath->Type = XENBUS_DEVICE_PATH_TYPE_VBD;
    }
    TempXenBusPath->DeviceId = Private->XenBusIo.DeviceId;
    Private->DevicePath = (XENBUS_DEVICE_PATH *)AppendDevicePathNode (
                            Dev->DevicePath,
                            &TempXenBusPath->Vendor.Header);
    FreePool (TempXenBusPath);

    InsertTailList (&Dev->ChildList, &Private->Link);

    Status = gBS->InstallMultipleProtocolInterfaces (
               &Private->Handle,
               &gEfiDevicePathProtocolGuid, Private->DevicePath,
               &gXenBusProtocolGuid, &Private->XenBusIo,
               NULL);
    if (EFI_ERROR (Status)) {
      goto ErrorInstallProtocol;
    }

    Status = gBS->OpenProtocol (Dev->ControllerHandle,
               &gXenIoProtocolGuid,
               &ChildXenIo, Dev->This->DriverBindingHandle,
               Private->Handle,
               EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER);
    if (EFI_ERROR (Status)) {
      DEBUG ((EFI_D_ERROR, "open by child controller fail (%r)\n",
              Status));
      goto ErrorOpenProtocolByChild;
    }
  } else {
    DEBUG ((EFI_D_ERROR, "XenBus: does not exist: %a\n", DevicePath));
    Status = EFI_NOT_FOUND;
  }

  return Status;

ErrorOpenProtocolByChild:
  gBS->UninstallMultipleProtocolInterfaces (
    &Private->Handle,
    &gEfiDevicePathProtocolGuid, Private->DevicePath,
    &gXenBusProtocolGuid, &Private->XenBusIo,
    NULL);
ErrorInstallProtocol:
  RemoveEntryList (&Private->Link);
  FreePool (Private->DevicePath);
  FreePool ((VOID *) Private->XenBusIo.Backend);
  FreePool ((VOID *) Private->XenBusIo.Node);
  FreePool ((VOID *) Private->XenBusIo.Type);
  FreePool (Private);
out:
  return Status;
}

/**
  Enumerate all devices of the given type on this bus.

  @param Dev   A XENBUS_DEVICE instance.
  @param Type  String indicating the device sub-tree (e.g. "vfb", "vif")
               to enumerate.

  Devices that are found are been initialize via XenBusAddDevice ().
  XenBusAddDevice () ignores duplicate detects and ignores duplicate devices,
  so it can be called unconditionally for any device found in the XenStore.
 */
STATIC
VOID
XenBusEnumerateDeviceType (
  XENBUS_DEVICE *Dev,
  CONST CHAR8 *Type
  )
{
  CONST CHAR8 **Directory;
  UINTN Index;
  UINT32 Count;
  XENSTORE_STATUS Status;

  Status = XenStoreListDirectory (XST_NIL,
                                  "device", Type,
                                  &Count, &Directory);
  if (Status != XENSTORE_STATUS_SUCCESS) {
    return;
  }
  for (Index = 0; Index < Count; Index++) {
    XenBusAddDevice (Dev, Type, Directory[Index]);
  }

  FreePool ((VOID*)Directory);
}


/**
  Enumerate the devices on a XenBus bus and install a XenBus Protocol instance.

  Caller should ensure that it is the only one to call this function. This
  function cannot be called concurrently.

  @param Dev   A XENBUS_DEVICE instance.

  @return  On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value
           indicating the type of failure.
 */
XENSTORE_STATUS
XenBusEnumerateBus (
  XENBUS_DEVICE *Dev
  )
{
  CONST CHAR8 **Types;
  UINTN Index;
  UINT32 Count;
  XENSTORE_STATUS Status;

  Status = XenStoreListDirectory (XST_NIL,
                                  "device", "",
                                  &Count, &Types);
  if (Status != XENSTORE_STATUS_SUCCESS) {
    return Status;
  }

  for (Index = 0; Index < Count; Index++) {
    XenBusEnumerateDeviceType (Dev, Types[Index]);
  }

  FreePool ((VOID*)Types);

  return XENSTORE_STATUS_SUCCESS;
}

STATIC
XENSTORE_STATUS
EFIAPI
XenBusSetState (
  IN XENBUS_PROTOCOL      *This,
  IN CONST XENSTORE_TRANSACTION *Transaction,
  IN enum xenbus_state    NewState
  )
{
  enum xenbus_state CurrentState;
  XENSTORE_STATUS Status;
  CHAR8 *Temp;

  DEBUG ((EFI_D_INFO, "XenBus: Set state to %d\n", NewState));

  Status = XenStoreRead (Transaction, This->Node, "state", NULL, (VOID **)&Temp);
  if (Status != XENSTORE_STATUS_SUCCESS) {
    goto Out;
  }
  CurrentState = AsciiStrDecimalToUintn (Temp);
  FreePool (Temp);
  if (CurrentState == NewState) {
    goto Out;
  }

  do {
    Status = XenStoreSPrint (Transaction, This->Node, "state", "%d", NewState);
  } while (Status == XENSTORE_STATUS_EAGAIN);
  if (Status != XENSTORE_STATUS_SUCCESS) {
    DEBUG ((EFI_D_ERROR, "XenBus: failed to write new state\n"));
    goto Out;
  }
  DEBUG ((EFI_D_INFO, "XenBus: Set state to %d, done\n", NewState));

Out:
  return Status;
}

STATIC XENBUS_PRIVATE_DATA gXenBusPrivateData = {
  XENBUS_PRIVATE_DATA_SIGNATURE,    // Signature
  { NULL, NULL },                   // Link
  NULL,                             // Handle
  {                                 // XenBusIo
    XenBusXenStoreRead,             // XenBusIo.XsRead
    XenBusXenStoreBackendRead,      // XenBusIo.XsBackendRead
    XenBusXenStoreSPrint,           // XenBusIo.XsPrintf
    XenBusXenStoreRemove,           // XenBusIo.XsRemove
    XenBusXenStoreTransactionStart, // XenBusIo.XsTransactionStart
    XenBusXenStoreTransactionEnd,   // XenBusIo.XsTransactionEnd
    XenBusSetState,                 // XenBusIo.SetState
    XenBusGrantAccess,              // XenBusIo.GrantAccess
    XenBusGrantEndAccess,           // XenBusIo.GrantEndAccess
    XenBusEventChannelAllocate,     // XenBusIo.EventChannelAllocate
    XenBusEventChannelNotify,       // XenBusIo.EventChannelNotify
    XenBusEventChannelClose,        // XenBusIo.EventChannelClose
    XenBusRegisterWatch,            // XenBusIo.RegisterWatch
    XenBusRegisterWatchBackend,     // XenBusIo.RegisterWatchBackend
    XenBusUnregisterWatch,          // XenBusIo.UnregisterWatch
    XenBusWaitForWatch,             // XenBusIo.WaitForWatch

    NULL,                           // XenBusIo.Type
    0,                              // XenBusIo.DeviceId
    NULL,                           // XenBusIo.Node
    NULL,                           // XenBusIo.Backend
  },

  NULL,                             // Dev
  NULL                              // DevicePath
};