1 | /* |
2 | * Block driver for the Virtual Disk Image (VDI) format |
3 | * |
4 | * Copyright (c) 2009, 2012 Stefan Weil |
5 | * |
6 | * This program is free software: you can redistribute it and/or modify |
7 | * it under the terms of the GNU General Public License as published by |
8 | * the Free Software Foundation, either version 2 of the License, or |
9 | * (at your option) version 3 or any later version. |
10 | * |
11 | * This program is distributed in the hope that it will be useful, |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | * GNU General Public License for more details. |
15 | * |
16 | * You should have received a copy of the GNU General Public License |
17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
18 | * |
19 | * Reference: |
20 | * http://forums.virtualbox.org/viewtopic.php?t=8046 |
21 | * |
22 | * This driver supports create / read / write operations on VDI images. |
23 | * |
24 | * Todo (see also TODO in code): |
25 | * |
26 | * Some features like snapshots are still missing. |
27 | * |
28 | * Deallocation of zero-filled blocks and shrinking images are missing, too |
29 | * (might be added to common block layer). |
30 | * |
31 | * Allocation of blocks could be optimized (less writes to block map and |
32 | * header). |
33 | * |
34 | * Read and write of adjacent blocks could be done in one operation |
35 | * (current code uses one operation per block (1 MiB). |
36 | * |
37 | * The code is not thread safe (missing locks for changes in header and |
38 | * block table, no problem with current QEMU). |
39 | * |
40 | * Hints: |
41 | * |
42 | * Blocks (VDI documentation) correspond to clusters (QEMU). |
43 | * QEMU's backing files could be implemented using VDI snapshot files (TODO). |
44 | * VDI snapshot files may also contain the complete machine state. |
45 | * Maybe this machine state can be converted to QEMU PC machine snapshot data. |
46 | * |
47 | * The driver keeps a block cache (little endian entries) in memory. |
48 | * For the standard block size (1 MiB), a 1 TiB disk will use 4 MiB RAM, |
49 | * so this seems to be reasonable. |
50 | */ |
51 | |
52 | #include "qemu/osdep.h" |
53 | #include "qemu/units.h" |
54 | #include "qapi/error.h" |
55 | #include "qapi/qobject-input-visitor.h" |
56 | #include "qapi/qapi-visit-block-core.h" |
57 | #include "block/block_int.h" |
58 | #include "block/qdict.h" |
59 | #include "sysemu/block-backend.h" |
60 | #include "qemu/module.h" |
61 | #include "qemu/option.h" |
62 | #include "qemu/bswap.h" |
63 | #include "migration/blocker.h" |
64 | #include "qemu/coroutine.h" |
65 | #include "qemu/cutils.h" |
66 | #include "qemu/uuid.h" |
67 | |
68 | /* Code configuration options. */ |
69 | |
70 | /* Enable debug messages. */ |
71 | //~ #define CONFIG_VDI_DEBUG |
72 | |
73 | /* Support write operations on VDI images. */ |
74 | #define CONFIG_VDI_WRITE |
75 | |
76 | /* Support non-standard block (cluster) size. This is untested. |
77 | * Maybe it will be needed for very large images. |
78 | */ |
79 | //~ #define CONFIG_VDI_BLOCK_SIZE |
80 | |
81 | /* Support static (fixed, pre-allocated) images. */ |
82 | #define CONFIG_VDI_STATIC_IMAGE |
83 | |
84 | /* Command line option for static images. */ |
85 | #define BLOCK_OPT_STATIC "static" |
86 | |
87 | #define SECTOR_SIZE 512 |
88 | #define DEFAULT_CLUSTER_SIZE 1048576 |
89 | /* Note: can't use 1 * MiB, because it's passed to stringify() */ |
90 | |
91 | #if defined(CONFIG_VDI_DEBUG) |
92 | #define VDI_DEBUG 1 |
93 | #else |
94 | #define VDI_DEBUG 0 |
95 | #endif |
96 | |
97 | #define logout(fmt, ...) \ |
98 | do { \ |
99 | if (VDI_DEBUG) { \ |
100 | fprintf(stderr, "vdi\t%-24s" fmt, __func__, ##__VA_ARGS__); \ |
101 | } \ |
102 | } while (0) |
103 | |
104 | /* Image signature. */ |
105 | #define VDI_SIGNATURE 0xbeda107f |
106 | |
107 | /* Image version. */ |
108 | #define VDI_VERSION_1_1 0x00010001 |
109 | |
110 | /* Image type. */ |
111 | #define VDI_TYPE_DYNAMIC 1 |
112 | #define VDI_TYPE_STATIC 2 |
113 | |
114 | /* Innotek / SUN images use these strings in header.text: |
115 | * "<<< innotek VirtualBox Disk Image >>>\n" |
116 | * "<<< Sun xVM VirtualBox Disk Image >>>\n" |
117 | * "<<< Sun VirtualBox Disk Image >>>\n" |
118 | * The value does not matter, so QEMU created images use a different text. |
119 | */ |
120 | #define VDI_TEXT "<<< QEMU VM Virtual Disk Image >>>\n" |
121 | |
122 | /* A never-allocated block; semantically arbitrary content. */ |
123 | #define VDI_UNALLOCATED 0xffffffffU |
124 | |
125 | /* A discarded (no longer allocated) block; semantically zero-filled. */ |
126 | #define VDI_DISCARDED 0xfffffffeU |
127 | |
128 | #define VDI_IS_ALLOCATED(X) ((X) < VDI_DISCARDED) |
129 | |
130 | /* The bmap will take up VDI_BLOCKS_IN_IMAGE_MAX * sizeof(uint32_t) bytes; since |
131 | * the bmap is read and written in a single operation, its size needs to be |
132 | * limited to INT_MAX; furthermore, when opening an image, the bmap size is |
133 | * rounded up to be aligned on BDRV_SECTOR_SIZE. |
134 | * Therefore this should satisfy the following: |
135 | * VDI_BLOCKS_IN_IMAGE_MAX * sizeof(uint32_t) + BDRV_SECTOR_SIZE == INT_MAX + 1 |
136 | * (INT_MAX + 1 is the first value not representable as an int) |
137 | * This guarantees that any value below or equal to the constant will, when |
138 | * multiplied by sizeof(uint32_t) and rounded up to a BDRV_SECTOR_SIZE boundary, |
139 | * still be below or equal to INT_MAX. */ |
140 | #define VDI_BLOCKS_IN_IMAGE_MAX \ |
141 | ((unsigned)((INT_MAX + 1u - BDRV_SECTOR_SIZE) / sizeof(uint32_t))) |
142 | #define VDI_DISK_SIZE_MAX ((uint64_t)VDI_BLOCKS_IN_IMAGE_MAX * \ |
143 | (uint64_t)DEFAULT_CLUSTER_SIZE) |
144 | |
145 | static QemuOptsList vdi_create_opts; |
146 | |
147 | typedef struct { |
148 | char text[0x40]; |
149 | uint32_t signature; |
150 | uint32_t version; |
151 | uint32_t ; |
152 | uint32_t image_type; |
153 | uint32_t image_flags; |
154 | char description[256]; |
155 | uint32_t offset_bmap; |
156 | uint32_t offset_data; |
157 | uint32_t cylinders; /* disk geometry, unused here */ |
158 | uint32_t heads; /* disk geometry, unused here */ |
159 | uint32_t sectors; /* disk geometry, unused here */ |
160 | uint32_t sector_size; |
161 | uint32_t unused1; |
162 | uint64_t disk_size; |
163 | uint32_t block_size; |
164 | uint32_t ; /* unused here */ |
165 | uint32_t blocks_in_image; |
166 | uint32_t blocks_allocated; |
167 | QemuUUID uuid_image; |
168 | QemuUUID uuid_last_snap; |
169 | QemuUUID uuid_link; |
170 | QemuUUID uuid_parent; |
171 | uint64_t unused2[7]; |
172 | } QEMU_PACKED ; |
173 | |
174 | QEMU_BUILD_BUG_ON(sizeof(VdiHeader) != 512); |
175 | |
176 | typedef struct { |
177 | /* The block map entries are little endian (even in memory). */ |
178 | uint32_t *bmap; |
179 | /* Size of block (bytes). */ |
180 | uint32_t block_size; |
181 | /* First sector of block map. */ |
182 | uint32_t bmap_sector; |
183 | /* VDI header (converted to host endianness). */ |
184 | VdiHeader ; |
185 | |
186 | CoRwlock bmap_lock; |
187 | |
188 | Error *migration_blocker; |
189 | } BDRVVdiState; |
190 | |
191 | static void (VdiHeader *) |
192 | { |
193 | header->signature = le32_to_cpu(header->signature); |
194 | header->version = le32_to_cpu(header->version); |
195 | header->header_size = le32_to_cpu(header->header_size); |
196 | header->image_type = le32_to_cpu(header->image_type); |
197 | header->image_flags = le32_to_cpu(header->image_flags); |
198 | header->offset_bmap = le32_to_cpu(header->offset_bmap); |
199 | header->offset_data = le32_to_cpu(header->offset_data); |
200 | header->cylinders = le32_to_cpu(header->cylinders); |
201 | header->heads = le32_to_cpu(header->heads); |
202 | header->sectors = le32_to_cpu(header->sectors); |
203 | header->sector_size = le32_to_cpu(header->sector_size); |
204 | header->disk_size = le64_to_cpu(header->disk_size); |
205 | header->block_size = le32_to_cpu(header->block_size); |
206 | header->block_extra = le32_to_cpu(header->block_extra); |
207 | header->blocks_in_image = le32_to_cpu(header->blocks_in_image); |
208 | header->blocks_allocated = le32_to_cpu(header->blocks_allocated); |
209 | header->uuid_image = qemu_uuid_bswap(header->uuid_image); |
210 | header->uuid_last_snap = qemu_uuid_bswap(header->uuid_last_snap); |
211 | header->uuid_link = qemu_uuid_bswap(header->uuid_link); |
212 | header->uuid_parent = qemu_uuid_bswap(header->uuid_parent); |
213 | } |
214 | |
215 | static void (VdiHeader *) |
216 | { |
217 | header->signature = cpu_to_le32(header->signature); |
218 | header->version = cpu_to_le32(header->version); |
219 | header->header_size = cpu_to_le32(header->header_size); |
220 | header->image_type = cpu_to_le32(header->image_type); |
221 | header->image_flags = cpu_to_le32(header->image_flags); |
222 | header->offset_bmap = cpu_to_le32(header->offset_bmap); |
223 | header->offset_data = cpu_to_le32(header->offset_data); |
224 | header->cylinders = cpu_to_le32(header->cylinders); |
225 | header->heads = cpu_to_le32(header->heads); |
226 | header->sectors = cpu_to_le32(header->sectors); |
227 | header->sector_size = cpu_to_le32(header->sector_size); |
228 | header->disk_size = cpu_to_le64(header->disk_size); |
229 | header->block_size = cpu_to_le32(header->block_size); |
230 | header->block_extra = cpu_to_le32(header->block_extra); |
231 | header->blocks_in_image = cpu_to_le32(header->blocks_in_image); |
232 | header->blocks_allocated = cpu_to_le32(header->blocks_allocated); |
233 | header->uuid_image = qemu_uuid_bswap(header->uuid_image); |
234 | header->uuid_last_snap = qemu_uuid_bswap(header->uuid_last_snap); |
235 | header->uuid_link = qemu_uuid_bswap(header->uuid_link); |
236 | header->uuid_parent = qemu_uuid_bswap(header->uuid_parent); |
237 | } |
238 | |
239 | static void (VdiHeader *) |
240 | { |
241 | char uuidstr[37]; |
242 | QemuUUID uuid; |
243 | logout("text %s" , header->text); |
244 | logout("signature 0x%08x\n" , header->signature); |
245 | logout("header size 0x%04x\n" , header->header_size); |
246 | logout("image type 0x%04x\n" , header->image_type); |
247 | logout("image flags 0x%04x\n" , header->image_flags); |
248 | logout("description %s\n" , header->description); |
249 | logout("offset bmap 0x%04x\n" , header->offset_bmap); |
250 | logout("offset data 0x%04x\n" , header->offset_data); |
251 | logout("cylinders 0x%04x\n" , header->cylinders); |
252 | logout("heads 0x%04x\n" , header->heads); |
253 | logout("sectors 0x%04x\n" , header->sectors); |
254 | logout("sector size 0x%04x\n" , header->sector_size); |
255 | logout("image size 0x%" PRIx64 " B (%" PRIu64 " MiB)\n" , |
256 | header->disk_size, header->disk_size / MiB); |
257 | logout("block size 0x%04x\n" , header->block_size); |
258 | logout("block extra 0x%04x\n" , header->block_extra); |
259 | logout("blocks tot. 0x%04x\n" , header->blocks_in_image); |
260 | logout("blocks all. 0x%04x\n" , header->blocks_allocated); |
261 | uuid = header->uuid_image; |
262 | qemu_uuid_unparse(&uuid, uuidstr); |
263 | logout("uuid image %s\n" , uuidstr); |
264 | uuid = header->uuid_last_snap; |
265 | qemu_uuid_unparse(&uuid, uuidstr); |
266 | logout("uuid snap %s\n" , uuidstr); |
267 | uuid = header->uuid_link; |
268 | qemu_uuid_unparse(&uuid, uuidstr); |
269 | logout("uuid link %s\n" , uuidstr); |
270 | uuid = header->uuid_parent; |
271 | qemu_uuid_unparse(&uuid, uuidstr); |
272 | logout("uuid parent %s\n" , uuidstr); |
273 | } |
274 | |
275 | static int coroutine_fn vdi_co_check(BlockDriverState *bs, BdrvCheckResult *res, |
276 | BdrvCheckMode fix) |
277 | { |
278 | /* TODO: additional checks possible. */ |
279 | BDRVVdiState *s = (BDRVVdiState *)bs->opaque; |
280 | uint32_t blocks_allocated = 0; |
281 | uint32_t block; |
282 | uint32_t *bmap; |
283 | logout("\n" ); |
284 | |
285 | if (fix) { |
286 | return -ENOTSUP; |
287 | } |
288 | |
289 | bmap = g_try_new(uint32_t, s->header.blocks_in_image); |
290 | if (s->header.blocks_in_image && bmap == NULL) { |
291 | res->check_errors++; |
292 | return -ENOMEM; |
293 | } |
294 | |
295 | memset(bmap, 0xff, s->header.blocks_in_image * sizeof(uint32_t)); |
296 | |
297 | /* Check block map and value of blocks_allocated. */ |
298 | for (block = 0; block < s->header.blocks_in_image; block++) { |
299 | uint32_t bmap_entry = le32_to_cpu(s->bmap[block]); |
300 | if (VDI_IS_ALLOCATED(bmap_entry)) { |
301 | if (bmap_entry < s->header.blocks_in_image) { |
302 | blocks_allocated++; |
303 | if (!VDI_IS_ALLOCATED(bmap[bmap_entry])) { |
304 | bmap[bmap_entry] = bmap_entry; |
305 | } else { |
306 | fprintf(stderr, "ERROR: block index %" PRIu32 |
307 | " also used by %" PRIu32 "\n" , bmap[bmap_entry], bmap_entry); |
308 | res->corruptions++; |
309 | } |
310 | } else { |
311 | fprintf(stderr, "ERROR: block index %" PRIu32 |
312 | " too large, is %" PRIu32 "\n" , block, bmap_entry); |
313 | res->corruptions++; |
314 | } |
315 | } |
316 | } |
317 | if (blocks_allocated != s->header.blocks_allocated) { |
318 | fprintf(stderr, "ERROR: allocated blocks mismatch, is %" PRIu32 |
319 | ", should be %" PRIu32 "\n" , |
320 | blocks_allocated, s->header.blocks_allocated); |
321 | res->corruptions++; |
322 | } |
323 | |
324 | g_free(bmap); |
325 | |
326 | return 0; |
327 | } |
328 | |
329 | static int vdi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
330 | { |
331 | /* TODO: vdi_get_info would be needed for machine snapshots. |
332 | vm_state_offset is still missing. */ |
333 | BDRVVdiState *s = (BDRVVdiState *)bs->opaque; |
334 | logout("\n" ); |
335 | bdi->cluster_size = s->block_size; |
336 | bdi->vm_state_offset = 0; |
337 | bdi->unallocated_blocks_are_zero = true; |
338 | return 0; |
339 | } |
340 | |
341 | static int vdi_make_empty(BlockDriverState *bs) |
342 | { |
343 | /* TODO: missing code. */ |
344 | logout("\n" ); |
345 | /* The return value for missing code must be 0, see block.c. */ |
346 | return 0; |
347 | } |
348 | |
349 | static int vdi_probe(const uint8_t *buf, int buf_size, const char *filename) |
350 | { |
351 | const VdiHeader * = (const VdiHeader *)buf; |
352 | int ret = 0; |
353 | |
354 | logout("\n" ); |
355 | |
356 | if (buf_size < sizeof(*header)) { |
357 | /* Header too small, no VDI. */ |
358 | } else if (le32_to_cpu(header->signature) == VDI_SIGNATURE) { |
359 | ret = 100; |
360 | } |
361 | |
362 | if (ret == 0) { |
363 | logout("no vdi image\n" ); |
364 | } else { |
365 | logout("%s" , header->text); |
366 | } |
367 | |
368 | return ret; |
369 | } |
370 | |
371 | static int vdi_open(BlockDriverState *bs, QDict *options, int flags, |
372 | Error **errp) |
373 | { |
374 | BDRVVdiState *s = bs->opaque; |
375 | VdiHeader ; |
376 | size_t bmap_size; |
377 | int ret; |
378 | Error *local_err = NULL; |
379 | QemuUUID uuid_link, uuid_parent; |
380 | |
381 | bs->file = bdrv_open_child(NULL, options, "file" , bs, &child_file, |
382 | false, errp); |
383 | if (!bs->file) { |
384 | return -EINVAL; |
385 | } |
386 | |
387 | logout("\n" ); |
388 | |
389 | ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); |
390 | if (ret < 0) { |
391 | goto fail; |
392 | } |
393 | |
394 | vdi_header_to_cpu(&header); |
395 | if (VDI_DEBUG) { |
396 | vdi_header_print(&header); |
397 | } |
398 | |
399 | if (header.disk_size > VDI_DISK_SIZE_MAX) { |
400 | error_setg(errp, "Unsupported VDI image size (size is 0x%" PRIx64 |
401 | ", max supported is 0x%" PRIx64 ")" , |
402 | header.disk_size, VDI_DISK_SIZE_MAX); |
403 | ret = -ENOTSUP; |
404 | goto fail; |
405 | } |
406 | |
407 | uuid_link = header.uuid_link; |
408 | uuid_parent = header.uuid_parent; |
409 | |
410 | if (header.disk_size % SECTOR_SIZE != 0) { |
411 | /* 'VBoxManage convertfromraw' can create images with odd disk sizes. |
412 | We accept them but round the disk size to the next multiple of |
413 | SECTOR_SIZE. */ |
414 | logout("odd disk size %" PRIu64 " B, round up\n" , header.disk_size); |
415 | header.disk_size = ROUND_UP(header.disk_size, SECTOR_SIZE); |
416 | } |
417 | |
418 | if (header.signature != VDI_SIGNATURE) { |
419 | error_setg(errp, "Image not in VDI format (bad signature %08" PRIx32 |
420 | ")" , header.signature); |
421 | ret = -EINVAL; |
422 | goto fail; |
423 | } else if (header.version != VDI_VERSION_1_1) { |
424 | error_setg(errp, "unsupported VDI image (version %" PRIu32 ".%" PRIu32 |
425 | ")" , header.version >> 16, header.version & 0xffff); |
426 | ret = -ENOTSUP; |
427 | goto fail; |
428 | } else if (header.offset_bmap % SECTOR_SIZE != 0) { |
429 | /* We only support block maps which start on a sector boundary. */ |
430 | error_setg(errp, "unsupported VDI image (unaligned block map offset " |
431 | "0x%" PRIx32 ")" , header.offset_bmap); |
432 | ret = -ENOTSUP; |
433 | goto fail; |
434 | } else if (header.offset_data % SECTOR_SIZE != 0) { |
435 | /* We only support data blocks which start on a sector boundary. */ |
436 | error_setg(errp, "unsupported VDI image (unaligned data offset 0x%" |
437 | PRIx32 ")" , header.offset_data); |
438 | ret = -ENOTSUP; |
439 | goto fail; |
440 | } else if (header.sector_size != SECTOR_SIZE) { |
441 | error_setg(errp, "unsupported VDI image (sector size %" PRIu32 |
442 | " is not %u)" , header.sector_size, SECTOR_SIZE); |
443 | ret = -ENOTSUP; |
444 | goto fail; |
445 | } else if (header.block_size != DEFAULT_CLUSTER_SIZE) { |
446 | error_setg(errp, "unsupported VDI image (block size %" PRIu32 |
447 | " is not %" PRIu32 ")" , |
448 | header.block_size, DEFAULT_CLUSTER_SIZE); |
449 | ret = -ENOTSUP; |
450 | goto fail; |
451 | } else if (header.disk_size > |
452 | (uint64_t)header.blocks_in_image * header.block_size) { |
453 | error_setg(errp, "unsupported VDI image (disk size %" PRIu64 ", " |
454 | "image bitmap has room for %" PRIu64 ")" , |
455 | header.disk_size, |
456 | (uint64_t)header.blocks_in_image * header.block_size); |
457 | ret = -ENOTSUP; |
458 | goto fail; |
459 | } else if (!qemu_uuid_is_null(&uuid_link)) { |
460 | error_setg(errp, "unsupported VDI image (non-NULL link UUID)" ); |
461 | ret = -ENOTSUP; |
462 | goto fail; |
463 | } else if (!qemu_uuid_is_null(&uuid_parent)) { |
464 | error_setg(errp, "unsupported VDI image (non-NULL parent UUID)" ); |
465 | ret = -ENOTSUP; |
466 | goto fail; |
467 | } else if (header.blocks_in_image > VDI_BLOCKS_IN_IMAGE_MAX) { |
468 | error_setg(errp, "unsupported VDI image " |
469 | "(too many blocks %u, max is %u)" , |
470 | header.blocks_in_image, VDI_BLOCKS_IN_IMAGE_MAX); |
471 | ret = -ENOTSUP; |
472 | goto fail; |
473 | } |
474 | |
475 | bs->total_sectors = header.disk_size / SECTOR_SIZE; |
476 | |
477 | s->block_size = header.block_size; |
478 | s->bmap_sector = header.offset_bmap / SECTOR_SIZE; |
479 | s->header = header; |
480 | |
481 | bmap_size = header.blocks_in_image * sizeof(uint32_t); |
482 | bmap_size = DIV_ROUND_UP(bmap_size, SECTOR_SIZE); |
483 | s->bmap = qemu_try_blockalign(bs->file->bs, bmap_size * SECTOR_SIZE); |
484 | if (s->bmap == NULL) { |
485 | ret = -ENOMEM; |
486 | goto fail; |
487 | } |
488 | |
489 | ret = bdrv_pread(bs->file, header.offset_bmap, s->bmap, |
490 | bmap_size * SECTOR_SIZE); |
491 | if (ret < 0) { |
492 | goto fail_free_bmap; |
493 | } |
494 | |
495 | /* Disable migration when vdi images are used */ |
496 | error_setg(&s->migration_blocker, "The vdi format used by node '%s' " |
497 | "does not support live migration" , |
498 | bdrv_get_device_or_node_name(bs)); |
499 | ret = migrate_add_blocker(s->migration_blocker, &local_err); |
500 | if (local_err) { |
501 | error_propagate(errp, local_err); |
502 | error_free(s->migration_blocker); |
503 | goto fail_free_bmap; |
504 | } |
505 | |
506 | qemu_co_rwlock_init(&s->bmap_lock); |
507 | |
508 | return 0; |
509 | |
510 | fail_free_bmap: |
511 | qemu_vfree(s->bmap); |
512 | |
513 | fail: |
514 | return ret; |
515 | } |
516 | |
517 | static int vdi_reopen_prepare(BDRVReopenState *state, |
518 | BlockReopenQueue *queue, Error **errp) |
519 | { |
520 | return 0; |
521 | } |
522 | |
523 | static int coroutine_fn vdi_co_block_status(BlockDriverState *bs, |
524 | bool want_zero, |
525 | int64_t offset, int64_t bytes, |
526 | int64_t *pnum, int64_t *map, |
527 | BlockDriverState **file) |
528 | { |
529 | BDRVVdiState *s = (BDRVVdiState *)bs->opaque; |
530 | size_t bmap_index = offset / s->block_size; |
531 | size_t index_in_block = offset % s->block_size; |
532 | uint32_t bmap_entry = le32_to_cpu(s->bmap[bmap_index]); |
533 | int result; |
534 | |
535 | logout("%p, %" PRId64 ", %" PRId64 ", %p\n" , bs, offset, bytes, pnum); |
536 | *pnum = MIN(s->block_size - index_in_block, bytes); |
537 | result = VDI_IS_ALLOCATED(bmap_entry); |
538 | if (!result) { |
539 | return 0; |
540 | } |
541 | |
542 | *map = s->header.offset_data + (uint64_t)bmap_entry * s->block_size + |
543 | index_in_block; |
544 | *file = bs->file->bs; |
545 | return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | |
546 | (s->header.image_type == VDI_TYPE_STATIC ? BDRV_BLOCK_RECURSE : 0); |
547 | } |
548 | |
549 | static int coroutine_fn |
550 | vdi_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, |
551 | QEMUIOVector *qiov, int flags) |
552 | { |
553 | BDRVVdiState *s = bs->opaque; |
554 | QEMUIOVector local_qiov; |
555 | uint32_t bmap_entry; |
556 | uint32_t block_index; |
557 | uint32_t offset_in_block; |
558 | uint32_t n_bytes; |
559 | uint64_t bytes_done = 0; |
560 | int ret = 0; |
561 | |
562 | logout("\n" ); |
563 | |
564 | qemu_iovec_init(&local_qiov, qiov->niov); |
565 | |
566 | while (ret >= 0 && bytes > 0) { |
567 | block_index = offset / s->block_size; |
568 | offset_in_block = offset % s->block_size; |
569 | n_bytes = MIN(bytes, s->block_size - offset_in_block); |
570 | |
571 | logout("will read %u bytes starting at offset %" PRIu64 "\n" , |
572 | n_bytes, offset); |
573 | |
574 | /* prepare next AIO request */ |
575 | qemu_co_rwlock_rdlock(&s->bmap_lock); |
576 | bmap_entry = le32_to_cpu(s->bmap[block_index]); |
577 | qemu_co_rwlock_unlock(&s->bmap_lock); |
578 | if (!VDI_IS_ALLOCATED(bmap_entry)) { |
579 | /* Block not allocated, return zeros, no need to wait. */ |
580 | qemu_iovec_memset(qiov, bytes_done, 0, n_bytes); |
581 | ret = 0; |
582 | } else { |
583 | uint64_t data_offset = s->header.offset_data + |
584 | (uint64_t)bmap_entry * s->block_size + |
585 | offset_in_block; |
586 | |
587 | qemu_iovec_reset(&local_qiov); |
588 | qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes); |
589 | |
590 | ret = bdrv_co_preadv(bs->file, data_offset, n_bytes, |
591 | &local_qiov, 0); |
592 | } |
593 | logout("%u bytes read\n" , n_bytes); |
594 | |
595 | bytes -= n_bytes; |
596 | offset += n_bytes; |
597 | bytes_done += n_bytes; |
598 | } |
599 | |
600 | qemu_iovec_destroy(&local_qiov); |
601 | |
602 | return ret; |
603 | } |
604 | |
605 | static int coroutine_fn |
606 | vdi_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes, |
607 | QEMUIOVector *qiov, int flags) |
608 | { |
609 | BDRVVdiState *s = bs->opaque; |
610 | QEMUIOVector local_qiov; |
611 | uint32_t bmap_entry; |
612 | uint32_t block_index; |
613 | uint32_t offset_in_block; |
614 | uint32_t n_bytes; |
615 | uint64_t data_offset; |
616 | uint32_t bmap_first = VDI_UNALLOCATED; |
617 | uint32_t bmap_last = VDI_UNALLOCATED; |
618 | uint8_t *block = NULL; |
619 | uint64_t bytes_done = 0; |
620 | int ret = 0; |
621 | |
622 | logout("\n" ); |
623 | |
624 | qemu_iovec_init(&local_qiov, qiov->niov); |
625 | |
626 | while (ret >= 0 && bytes > 0) { |
627 | block_index = offset / s->block_size; |
628 | offset_in_block = offset % s->block_size; |
629 | n_bytes = MIN(bytes, s->block_size - offset_in_block); |
630 | |
631 | logout("will write %u bytes starting at offset %" PRIu64 "\n" , |
632 | n_bytes, offset); |
633 | |
634 | /* prepare next AIO request */ |
635 | qemu_co_rwlock_rdlock(&s->bmap_lock); |
636 | bmap_entry = le32_to_cpu(s->bmap[block_index]); |
637 | if (!VDI_IS_ALLOCATED(bmap_entry)) { |
638 | /* Allocate new block and write to it. */ |
639 | uint64_t data_offset; |
640 | qemu_co_rwlock_upgrade(&s->bmap_lock); |
641 | bmap_entry = le32_to_cpu(s->bmap[block_index]); |
642 | if (VDI_IS_ALLOCATED(bmap_entry)) { |
643 | /* A concurrent allocation did the work for us. */ |
644 | qemu_co_rwlock_downgrade(&s->bmap_lock); |
645 | goto nonallocating_write; |
646 | } |
647 | |
648 | bmap_entry = s->header.blocks_allocated; |
649 | s->bmap[block_index] = cpu_to_le32(bmap_entry); |
650 | s->header.blocks_allocated++; |
651 | data_offset = s->header.offset_data + |
652 | (uint64_t)bmap_entry * s->block_size; |
653 | if (block == NULL) { |
654 | block = g_malloc(s->block_size); |
655 | bmap_first = block_index; |
656 | } |
657 | bmap_last = block_index; |
658 | /* Copy data to be written to new block and zero unused parts. */ |
659 | memset(block, 0, offset_in_block); |
660 | qemu_iovec_to_buf(qiov, bytes_done, block + offset_in_block, |
661 | n_bytes); |
662 | memset(block + offset_in_block + n_bytes, 0, |
663 | s->block_size - n_bytes - offset_in_block); |
664 | |
665 | /* Write the new block under CoRwLock write-side protection, |
666 | * so this full-cluster write does not overlap a partial write |
667 | * of the same cluster, issued from the "else" branch. |
668 | */ |
669 | ret = bdrv_pwrite(bs->file, data_offset, block, s->block_size); |
670 | qemu_co_rwlock_unlock(&s->bmap_lock); |
671 | } else { |
672 | nonallocating_write: |
673 | data_offset = s->header.offset_data + |
674 | (uint64_t)bmap_entry * s->block_size + |
675 | offset_in_block; |
676 | qemu_co_rwlock_unlock(&s->bmap_lock); |
677 | |
678 | qemu_iovec_reset(&local_qiov); |
679 | qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes); |
680 | |
681 | ret = bdrv_co_pwritev(bs->file, data_offset, n_bytes, |
682 | &local_qiov, 0); |
683 | } |
684 | |
685 | bytes -= n_bytes; |
686 | offset += n_bytes; |
687 | bytes_done += n_bytes; |
688 | |
689 | logout("%u bytes written\n" , n_bytes); |
690 | } |
691 | |
692 | qemu_iovec_destroy(&local_qiov); |
693 | |
694 | logout("finished data write\n" ); |
695 | if (ret < 0) { |
696 | return ret; |
697 | } |
698 | |
699 | if (block) { |
700 | /* One or more new blocks were allocated. */ |
701 | VdiHeader * = (VdiHeader *) block; |
702 | uint8_t *base; |
703 | uint64_t offset; |
704 | uint32_t n_sectors; |
705 | |
706 | logout("now writing modified header\n" ); |
707 | assert(VDI_IS_ALLOCATED(bmap_first)); |
708 | *header = s->header; |
709 | vdi_header_to_le(header); |
710 | ret = bdrv_pwrite(bs->file, 0, block, sizeof(VdiHeader)); |
711 | g_free(block); |
712 | block = NULL; |
713 | |
714 | if (ret < 0) { |
715 | return ret; |
716 | } |
717 | |
718 | logout("now writing modified block map entry %u...%u\n" , |
719 | bmap_first, bmap_last); |
720 | /* Write modified sectors from block map. */ |
721 | bmap_first /= (SECTOR_SIZE / sizeof(uint32_t)); |
722 | bmap_last /= (SECTOR_SIZE / sizeof(uint32_t)); |
723 | n_sectors = bmap_last - bmap_first + 1; |
724 | offset = s->bmap_sector + bmap_first; |
725 | base = ((uint8_t *)&s->bmap[0]) + bmap_first * SECTOR_SIZE; |
726 | logout("will write %u block map sectors starting from entry %u\n" , |
727 | n_sectors, bmap_first); |
728 | ret = bdrv_pwrite(bs->file, offset * SECTOR_SIZE, base, |
729 | n_sectors * SECTOR_SIZE); |
730 | } |
731 | |
732 | return ret < 0 ? ret : 0; |
733 | } |
734 | |
735 | static int coroutine_fn vdi_co_do_create(BlockdevCreateOptions *create_options, |
736 | size_t block_size, Error **errp) |
737 | { |
738 | BlockdevCreateOptionsVdi *vdi_opts; |
739 | int ret = 0; |
740 | uint64_t bytes = 0; |
741 | uint32_t blocks; |
742 | uint32_t image_type; |
743 | VdiHeader ; |
744 | size_t i; |
745 | size_t bmap_size; |
746 | int64_t offset = 0; |
747 | BlockDriverState *bs_file = NULL; |
748 | BlockBackend *blk = NULL; |
749 | uint32_t *bmap = NULL; |
750 | QemuUUID uuid; |
751 | |
752 | assert(create_options->driver == BLOCKDEV_DRIVER_VDI); |
753 | vdi_opts = &create_options->u.vdi; |
754 | |
755 | logout("\n" ); |
756 | |
757 | /* Validate options and set default values */ |
758 | bytes = vdi_opts->size; |
759 | |
760 | if (!vdi_opts->has_preallocation) { |
761 | vdi_opts->preallocation = PREALLOC_MODE_OFF; |
762 | } |
763 | switch (vdi_opts->preallocation) { |
764 | case PREALLOC_MODE_OFF: |
765 | image_type = VDI_TYPE_DYNAMIC; |
766 | break; |
767 | case PREALLOC_MODE_METADATA: |
768 | image_type = VDI_TYPE_STATIC; |
769 | break; |
770 | default: |
771 | error_setg(errp, "Preallocation mode not supported for vdi" ); |
772 | return -EINVAL; |
773 | } |
774 | |
775 | #ifndef CONFIG_VDI_STATIC_IMAGE |
776 | if (image_type == VDI_TYPE_STATIC) { |
777 | ret = -ENOTSUP; |
778 | error_setg(errp, "Statically allocated images cannot be created in " |
779 | "this build" ); |
780 | goto exit; |
781 | } |
782 | #endif |
783 | #ifndef CONFIG_VDI_BLOCK_SIZE |
784 | if (block_size != DEFAULT_CLUSTER_SIZE) { |
785 | ret = -ENOTSUP; |
786 | error_setg(errp, |
787 | "A non-default cluster size is not supported in this build" ); |
788 | goto exit; |
789 | } |
790 | #endif |
791 | |
792 | if (bytes > VDI_DISK_SIZE_MAX) { |
793 | ret = -ENOTSUP; |
794 | error_setg(errp, "Unsupported VDI image size (size is 0x%" PRIx64 |
795 | ", max supported is 0x%" PRIx64 ")" , |
796 | bytes, VDI_DISK_SIZE_MAX); |
797 | goto exit; |
798 | } |
799 | |
800 | /* Create BlockBackend to write to the image */ |
801 | bs_file = bdrv_open_blockdev_ref(vdi_opts->file, errp); |
802 | if (!bs_file) { |
803 | ret = -EIO; |
804 | goto exit; |
805 | } |
806 | |
807 | blk = blk_new(bdrv_get_aio_context(bs_file), |
808 | BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL); |
809 | ret = blk_insert_bs(blk, bs_file, errp); |
810 | if (ret < 0) { |
811 | goto exit; |
812 | } |
813 | |
814 | blk_set_allow_write_beyond_eof(blk, true); |
815 | |
816 | /* We need enough blocks to store the given disk size, |
817 | so always round up. */ |
818 | blocks = DIV_ROUND_UP(bytes, block_size); |
819 | |
820 | bmap_size = blocks * sizeof(uint32_t); |
821 | bmap_size = ROUND_UP(bmap_size, SECTOR_SIZE); |
822 | |
823 | memset(&header, 0, sizeof(header)); |
824 | pstrcpy(header.text, sizeof(header.text), VDI_TEXT); |
825 | header.signature = VDI_SIGNATURE; |
826 | header.version = VDI_VERSION_1_1; |
827 | header.header_size = 0x180; |
828 | header.image_type = image_type; |
829 | header.offset_bmap = 0x200; |
830 | header.offset_data = 0x200 + bmap_size; |
831 | header.sector_size = SECTOR_SIZE; |
832 | header.disk_size = bytes; |
833 | header.block_size = block_size; |
834 | header.blocks_in_image = blocks; |
835 | if (image_type == VDI_TYPE_STATIC) { |
836 | header.blocks_allocated = blocks; |
837 | } |
838 | qemu_uuid_generate(&uuid); |
839 | header.uuid_image = uuid; |
840 | qemu_uuid_generate(&uuid); |
841 | header.uuid_last_snap = uuid; |
842 | /* There is no need to set header.uuid_link or header.uuid_parent here. */ |
843 | if (VDI_DEBUG) { |
844 | vdi_header_print(&header); |
845 | } |
846 | vdi_header_to_le(&header); |
847 | ret = blk_pwrite(blk, offset, &header, sizeof(header), 0); |
848 | if (ret < 0) { |
849 | error_setg(errp, "Error writing header" ); |
850 | goto exit; |
851 | } |
852 | offset += sizeof(header); |
853 | |
854 | if (bmap_size > 0) { |
855 | bmap = g_try_malloc0(bmap_size); |
856 | if (bmap == NULL) { |
857 | ret = -ENOMEM; |
858 | error_setg(errp, "Could not allocate bmap" ); |
859 | goto exit; |
860 | } |
861 | for (i = 0; i < blocks; i++) { |
862 | if (image_type == VDI_TYPE_STATIC) { |
863 | bmap[i] = i; |
864 | } else { |
865 | bmap[i] = VDI_UNALLOCATED; |
866 | } |
867 | } |
868 | ret = blk_pwrite(blk, offset, bmap, bmap_size, 0); |
869 | if (ret < 0) { |
870 | error_setg(errp, "Error writing bmap" ); |
871 | goto exit; |
872 | } |
873 | offset += bmap_size; |
874 | } |
875 | |
876 | if (image_type == VDI_TYPE_STATIC) { |
877 | ret = blk_truncate(blk, offset + blocks * block_size, |
878 | PREALLOC_MODE_OFF, errp); |
879 | if (ret < 0) { |
880 | error_prepend(errp, "Failed to statically allocate file" ); |
881 | goto exit; |
882 | } |
883 | } |
884 | |
885 | ret = 0; |
886 | exit: |
887 | blk_unref(blk); |
888 | bdrv_unref(bs_file); |
889 | g_free(bmap); |
890 | return ret; |
891 | } |
892 | |
893 | static int coroutine_fn vdi_co_create(BlockdevCreateOptions *create_options, |
894 | Error **errp) |
895 | { |
896 | return vdi_co_do_create(create_options, DEFAULT_CLUSTER_SIZE, errp); |
897 | } |
898 | |
899 | static int coroutine_fn vdi_co_create_opts(const char *filename, QemuOpts *opts, |
900 | Error **errp) |
901 | { |
902 | QDict *qdict = NULL; |
903 | BlockdevCreateOptions *create_options = NULL; |
904 | BlockDriverState *bs_file = NULL; |
905 | uint64_t block_size = DEFAULT_CLUSTER_SIZE; |
906 | bool is_static = false; |
907 | Visitor *v; |
908 | Error *local_err = NULL; |
909 | int ret; |
910 | |
911 | /* Parse options and convert legacy syntax. |
912 | * |
913 | * Since CONFIG_VDI_BLOCK_SIZE is disabled by default, |
914 | * cluster-size is not part of the QAPI schema; therefore we have |
915 | * to parse it before creating the QAPI object. */ |
916 | #if defined(CONFIG_VDI_BLOCK_SIZE) |
917 | block_size = qemu_opt_get_size_del(opts, |
918 | BLOCK_OPT_CLUSTER_SIZE, |
919 | DEFAULT_CLUSTER_SIZE); |
920 | if (block_size < BDRV_SECTOR_SIZE || block_size > UINT32_MAX || |
921 | !is_power_of_2(block_size)) |
922 | { |
923 | error_setg(errp, "Invalid cluster size" ); |
924 | ret = -EINVAL; |
925 | goto done; |
926 | } |
927 | #endif |
928 | if (qemu_opt_get_bool_del(opts, BLOCK_OPT_STATIC, false)) { |
929 | is_static = true; |
930 | } |
931 | |
932 | qdict = qemu_opts_to_qdict_filtered(opts, NULL, &vdi_create_opts, true); |
933 | |
934 | /* Create and open the file (protocol layer) */ |
935 | ret = bdrv_create_file(filename, opts, errp); |
936 | if (ret < 0) { |
937 | goto done; |
938 | } |
939 | |
940 | bs_file = bdrv_open(filename, NULL, NULL, |
941 | BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); |
942 | if (!bs_file) { |
943 | ret = -EIO; |
944 | goto done; |
945 | } |
946 | |
947 | qdict_put_str(qdict, "driver" , "vdi" ); |
948 | qdict_put_str(qdict, "file" , bs_file->node_name); |
949 | if (is_static) { |
950 | qdict_put_str(qdict, "preallocation" , "metadata" ); |
951 | } |
952 | |
953 | /* Get the QAPI object */ |
954 | v = qobject_input_visitor_new_flat_confused(qdict, errp); |
955 | if (!v) { |
956 | ret = -EINVAL; |
957 | goto done; |
958 | } |
959 | visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err); |
960 | visit_free(v); |
961 | |
962 | if (local_err) { |
963 | error_propagate(errp, local_err); |
964 | ret = -EINVAL; |
965 | goto done; |
966 | } |
967 | |
968 | /* Silently round up size */ |
969 | assert(create_options->driver == BLOCKDEV_DRIVER_VDI); |
970 | create_options->u.vdi.size = ROUND_UP(create_options->u.vdi.size, |
971 | BDRV_SECTOR_SIZE); |
972 | |
973 | /* Create the vdi image (format layer) */ |
974 | ret = vdi_co_do_create(create_options, block_size, errp); |
975 | done: |
976 | qobject_unref(qdict); |
977 | qapi_free_BlockdevCreateOptions(create_options); |
978 | bdrv_unref(bs_file); |
979 | return ret; |
980 | } |
981 | |
982 | static void vdi_close(BlockDriverState *bs) |
983 | { |
984 | BDRVVdiState *s = bs->opaque; |
985 | |
986 | qemu_vfree(s->bmap); |
987 | |
988 | migrate_del_blocker(s->migration_blocker); |
989 | error_free(s->migration_blocker); |
990 | } |
991 | |
992 | static int vdi_has_zero_init(BlockDriverState *bs) |
993 | { |
994 | BDRVVdiState *s = bs->opaque; |
995 | |
996 | if (s->header.image_type == VDI_TYPE_STATIC) { |
997 | return bdrv_has_zero_init(bs->file->bs); |
998 | } else { |
999 | return 1; |
1000 | } |
1001 | } |
1002 | |
1003 | static QemuOptsList vdi_create_opts = { |
1004 | .name = "vdi-create-opts" , |
1005 | .head = QTAILQ_HEAD_INITIALIZER(vdi_create_opts.head), |
1006 | .desc = { |
1007 | { |
1008 | .name = BLOCK_OPT_SIZE, |
1009 | .type = QEMU_OPT_SIZE, |
1010 | .help = "Virtual disk size" |
1011 | }, |
1012 | #if defined(CONFIG_VDI_BLOCK_SIZE) |
1013 | { |
1014 | .name = BLOCK_OPT_CLUSTER_SIZE, |
1015 | .type = QEMU_OPT_SIZE, |
1016 | .help = "VDI cluster (block) size" , |
1017 | .def_value_str = stringify(DEFAULT_CLUSTER_SIZE) |
1018 | }, |
1019 | #endif |
1020 | #if defined(CONFIG_VDI_STATIC_IMAGE) |
1021 | { |
1022 | .name = BLOCK_OPT_STATIC, |
1023 | .type = QEMU_OPT_BOOL, |
1024 | .help = "VDI static (pre-allocated) image" , |
1025 | .def_value_str = "off" |
1026 | }, |
1027 | #endif |
1028 | /* TODO: An additional option to set UUID values might be useful. */ |
1029 | { /* end of list */ } |
1030 | } |
1031 | }; |
1032 | |
1033 | static BlockDriver bdrv_vdi = { |
1034 | .format_name = "vdi" , |
1035 | .instance_size = sizeof(BDRVVdiState), |
1036 | .bdrv_probe = vdi_probe, |
1037 | .bdrv_open = vdi_open, |
1038 | .bdrv_close = vdi_close, |
1039 | .bdrv_reopen_prepare = vdi_reopen_prepare, |
1040 | .bdrv_child_perm = bdrv_format_default_perms, |
1041 | .bdrv_co_create = vdi_co_create, |
1042 | .bdrv_co_create_opts = vdi_co_create_opts, |
1043 | .bdrv_has_zero_init = vdi_has_zero_init, |
1044 | .bdrv_co_block_status = vdi_co_block_status, |
1045 | .bdrv_make_empty = vdi_make_empty, |
1046 | |
1047 | .bdrv_co_preadv = vdi_co_preadv, |
1048 | #if defined(CONFIG_VDI_WRITE) |
1049 | .bdrv_co_pwritev = vdi_co_pwritev, |
1050 | #endif |
1051 | |
1052 | .bdrv_get_info = vdi_get_info, |
1053 | |
1054 | .create_opts = &vdi_create_opts, |
1055 | .bdrv_co_check = vdi_co_check, |
1056 | }; |
1057 | |
1058 | static void bdrv_vdi_init(void) |
1059 | { |
1060 | logout("\n" ); |
1061 | bdrv_register(&bdrv_vdi); |
1062 | } |
1063 | |
1064 | block_init(bdrv_vdi_init); |
1065 | |