Merge tag 'qemu-macppc-20230206' of https://github.com/mcayland/qemu into staging
[qemu.git] / block / vdi.c
blob9c8736b26fb5e0346b94f7dc6c3b7a3e99042cb2
1 /*
2 * Block driver for the Virtual Disk Image (VDI) format
4 * Copyright (c) 2009, 2012 Stefan Weil
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.
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.
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/>.
19 * Reference:
20 * http://forums.virtualbox.org/viewtopic.php?t=8046
22 * This driver supports create / read / write operations on VDI images.
24 * Todo (see also TODO in code):
26 * Some features like snapshots are still missing.
28 * Deallocation of zero-filled blocks and shrinking images are missing, too
29 * (might be added to common block layer).
31 * Allocation of blocks could be optimized (less writes to block map and
32 * header).
34 * Read and write of adjacent blocks could be done in one operation
35 * (current code uses one operation per block (1 MiB).
37 * The code is not thread safe (missing locks for changes in header and
38 * block table, no problem with current QEMU).
40 * Hints:
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.
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.
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 #include "qemu/memalign.h"
69 /* Code configuration options. */
71 /* Enable debug messages. */
72 //~ #define CONFIG_VDI_DEBUG
74 /* Support write operations on VDI images. */
75 #define CONFIG_VDI_WRITE
77 /* Support non-standard block (cluster) size. This is untested.
78 * Maybe it will be needed for very large images.
80 //~ #define CONFIG_VDI_BLOCK_SIZE
82 /* Support static (fixed, pre-allocated) images. */
83 #define CONFIG_VDI_STATIC_IMAGE
85 /* Command line option for static images. */
86 #define BLOCK_OPT_STATIC "static"
88 #define SECTOR_SIZE 512
89 #define DEFAULT_CLUSTER_SIZE 1048576
90 /* Note: can't use 1 * MiB, because it's passed to stringify() */
92 #if defined(CONFIG_VDI_DEBUG)
93 #define VDI_DEBUG 1
94 #else
95 #define VDI_DEBUG 0
96 #endif
98 #define logout(fmt, ...) \
99 do { \
100 if (VDI_DEBUG) { \
101 fprintf(stderr, "vdi\t%-24s" fmt, __func__, ##__VA_ARGS__); \
103 } while (0)
105 /* Image signature. */
106 #define VDI_SIGNATURE 0xbeda107f
108 /* Image version. */
109 #define VDI_VERSION_1_1 0x00010001
111 /* Image type. */
112 #define VDI_TYPE_DYNAMIC 1
113 #define VDI_TYPE_STATIC 2
115 /* Innotek / SUN images use these strings in header.text:
116 * "<<< innotek VirtualBox Disk Image >>>\n"
117 * "<<< Sun xVM VirtualBox Disk Image >>>\n"
118 * "<<< Sun VirtualBox Disk Image >>>\n"
119 * The value does not matter, so QEMU created images use a different text.
121 #define VDI_TEXT "<<< QEMU VM Virtual Disk Image >>>\n"
123 /* A never-allocated block; semantically arbitrary content. */
124 #define VDI_UNALLOCATED 0xffffffffU
126 /* A discarded (no longer allocated) block; semantically zero-filled. */
127 #define VDI_DISCARDED 0xfffffffeU
129 #define VDI_IS_ALLOCATED(X) ((X) < VDI_DISCARDED)
131 /* The bmap will take up VDI_BLOCKS_IN_IMAGE_MAX * sizeof(uint32_t) bytes; since
132 * the bmap is read and written in a single operation, its size needs to be
133 * limited to INT_MAX; furthermore, when opening an image, the bmap size is
134 * rounded up to be aligned on BDRV_SECTOR_SIZE.
135 * Therefore this should satisfy the following:
136 * VDI_BLOCKS_IN_IMAGE_MAX * sizeof(uint32_t) + BDRV_SECTOR_SIZE == INT_MAX + 1
137 * (INT_MAX + 1 is the first value not representable as an int)
138 * This guarantees that any value below or equal to the constant will, when
139 * multiplied by sizeof(uint32_t) and rounded up to a BDRV_SECTOR_SIZE boundary,
140 * still be below or equal to INT_MAX. */
141 #define VDI_BLOCKS_IN_IMAGE_MAX \
142 ((unsigned)((INT_MAX + 1u - BDRV_SECTOR_SIZE) / sizeof(uint32_t)))
143 #define VDI_DISK_SIZE_MAX ((uint64_t)VDI_BLOCKS_IN_IMAGE_MAX * \
144 (uint64_t)DEFAULT_CLUSTER_SIZE)
146 static QemuOptsList vdi_create_opts;
148 typedef struct {
149 char text[0x40];
150 uint32_t signature;
151 uint32_t version;
152 uint32_t header_size;
153 uint32_t image_type;
154 uint32_t image_flags;
155 char description[256];
156 uint32_t offset_bmap;
157 uint32_t offset_data;
158 uint32_t cylinders; /* disk geometry, unused here */
159 uint32_t heads; /* disk geometry, unused here */
160 uint32_t sectors; /* disk geometry, unused here */
161 uint32_t sector_size;
162 uint32_t unused1;
163 uint64_t disk_size;
164 uint32_t block_size;
165 uint32_t block_extra; /* unused here */
166 uint32_t blocks_in_image;
167 uint32_t blocks_allocated;
168 QemuUUID uuid_image;
169 QemuUUID uuid_last_snap;
170 QemuUUID uuid_link;
171 QemuUUID uuid_parent;
172 uint64_t unused2[7];
173 } QEMU_PACKED VdiHeader;
175 QEMU_BUILD_BUG_ON(sizeof(VdiHeader) != 512);
177 typedef struct {
178 /* The block map entries are little endian (even in memory). */
179 uint32_t *bmap;
180 /* Size of block (bytes). */
181 uint32_t block_size;
182 /* First sector of block map. */
183 uint32_t bmap_sector;
184 /* VDI header (converted to host endianness). */
185 VdiHeader header;
187 CoRwlock bmap_lock;
189 Error *migration_blocker;
190 } BDRVVdiState;
192 static void vdi_header_to_cpu(VdiHeader *header)
194 header->signature = le32_to_cpu(header->signature);
195 header->version = le32_to_cpu(header->version);
196 header->header_size = le32_to_cpu(header->header_size);
197 header->image_type = le32_to_cpu(header->image_type);
198 header->image_flags = le32_to_cpu(header->image_flags);
199 header->offset_bmap = le32_to_cpu(header->offset_bmap);
200 header->offset_data = le32_to_cpu(header->offset_data);
201 header->cylinders = le32_to_cpu(header->cylinders);
202 header->heads = le32_to_cpu(header->heads);
203 header->sectors = le32_to_cpu(header->sectors);
204 header->sector_size = le32_to_cpu(header->sector_size);
205 header->disk_size = le64_to_cpu(header->disk_size);
206 header->block_size = le32_to_cpu(header->block_size);
207 header->block_extra = le32_to_cpu(header->block_extra);
208 header->blocks_in_image = le32_to_cpu(header->blocks_in_image);
209 header->blocks_allocated = le32_to_cpu(header->blocks_allocated);
210 header->uuid_image = qemu_uuid_bswap(header->uuid_image);
211 header->uuid_last_snap = qemu_uuid_bswap(header->uuid_last_snap);
212 header->uuid_link = qemu_uuid_bswap(header->uuid_link);
213 header->uuid_parent = qemu_uuid_bswap(header->uuid_parent);
216 static void vdi_header_to_le(VdiHeader *header)
218 header->signature = cpu_to_le32(header->signature);
219 header->version = cpu_to_le32(header->version);
220 header->header_size = cpu_to_le32(header->header_size);
221 header->image_type = cpu_to_le32(header->image_type);
222 header->image_flags = cpu_to_le32(header->image_flags);
223 header->offset_bmap = cpu_to_le32(header->offset_bmap);
224 header->offset_data = cpu_to_le32(header->offset_data);
225 header->cylinders = cpu_to_le32(header->cylinders);
226 header->heads = cpu_to_le32(header->heads);
227 header->sectors = cpu_to_le32(header->sectors);
228 header->sector_size = cpu_to_le32(header->sector_size);
229 header->disk_size = cpu_to_le64(header->disk_size);
230 header->block_size = cpu_to_le32(header->block_size);
231 header->block_extra = cpu_to_le32(header->block_extra);
232 header->blocks_in_image = cpu_to_le32(header->blocks_in_image);
233 header->blocks_allocated = cpu_to_le32(header->blocks_allocated);
234 header->uuid_image = qemu_uuid_bswap(header->uuid_image);
235 header->uuid_last_snap = qemu_uuid_bswap(header->uuid_last_snap);
236 header->uuid_link = qemu_uuid_bswap(header->uuid_link);
237 header->uuid_parent = qemu_uuid_bswap(header->uuid_parent);
240 static void vdi_header_print(VdiHeader *header)
242 char uuidstr[37];
243 QemuUUID uuid;
244 logout("text %s", header->text);
245 logout("signature 0x%08x\n", header->signature);
246 logout("header size 0x%04x\n", header->header_size);
247 logout("image type 0x%04x\n", header->image_type);
248 logout("image flags 0x%04x\n", header->image_flags);
249 logout("description %s\n", header->description);
250 logout("offset bmap 0x%04x\n", header->offset_bmap);
251 logout("offset data 0x%04x\n", header->offset_data);
252 logout("cylinders 0x%04x\n", header->cylinders);
253 logout("heads 0x%04x\n", header->heads);
254 logout("sectors 0x%04x\n", header->sectors);
255 logout("sector size 0x%04x\n", header->sector_size);
256 logout("image size 0x%" PRIx64 " B (%" PRIu64 " MiB)\n",
257 header->disk_size, header->disk_size / MiB);
258 logout("block size 0x%04x\n", header->block_size);
259 logout("block extra 0x%04x\n", header->block_extra);
260 logout("blocks tot. 0x%04x\n", header->blocks_in_image);
261 logout("blocks all. 0x%04x\n", header->blocks_allocated);
262 uuid = header->uuid_image;
263 qemu_uuid_unparse(&uuid, uuidstr);
264 logout("uuid image %s\n", uuidstr);
265 uuid = header->uuid_last_snap;
266 qemu_uuid_unparse(&uuid, uuidstr);
267 logout("uuid snap %s\n", uuidstr);
268 uuid = header->uuid_link;
269 qemu_uuid_unparse(&uuid, uuidstr);
270 logout("uuid link %s\n", uuidstr);
271 uuid = header->uuid_parent;
272 qemu_uuid_unparse(&uuid, uuidstr);
273 logout("uuid parent %s\n", uuidstr);
276 static int coroutine_fn vdi_co_check(BlockDriverState *bs, BdrvCheckResult *res,
277 BdrvCheckMode fix)
279 /* TODO: additional checks possible. */
280 BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
281 uint32_t blocks_allocated = 0;
282 uint32_t block;
283 uint32_t *bmap;
284 logout("\n");
286 if (fix) {
287 return -ENOTSUP;
290 bmap = g_try_new(uint32_t, s->header.blocks_in_image);
291 if (s->header.blocks_in_image && bmap == NULL) {
292 res->check_errors++;
293 return -ENOMEM;
296 memset(bmap, 0xff, s->header.blocks_in_image * sizeof(uint32_t));
298 /* Check block map and value of blocks_allocated. */
299 for (block = 0; block < s->header.blocks_in_image; block++) {
300 uint32_t bmap_entry = le32_to_cpu(s->bmap[block]);
301 if (VDI_IS_ALLOCATED(bmap_entry)) {
302 if (bmap_entry < s->header.blocks_in_image) {
303 blocks_allocated++;
304 if (!VDI_IS_ALLOCATED(bmap[bmap_entry])) {
305 bmap[bmap_entry] = bmap_entry;
306 } else {
307 fprintf(stderr, "ERROR: block index %" PRIu32
308 " also used by %" PRIu32 "\n", bmap[bmap_entry], bmap_entry);
309 res->corruptions++;
311 } else {
312 fprintf(stderr, "ERROR: block index %" PRIu32
313 " too large, is %" PRIu32 "\n", block, bmap_entry);
314 res->corruptions++;
318 if (blocks_allocated != s->header.blocks_allocated) {
319 fprintf(stderr, "ERROR: allocated blocks mismatch, is %" PRIu32
320 ", should be %" PRIu32 "\n",
321 blocks_allocated, s->header.blocks_allocated);
322 res->corruptions++;
325 g_free(bmap);
327 return 0;
330 static int coroutine_fn
331 vdi_co_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
333 /* TODO: vdi_co_get_info would be needed for machine snapshots.
334 vm_state_offset is still missing. */
335 BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
336 logout("\n");
337 bdi->cluster_size = s->block_size;
338 bdi->vm_state_offset = 0;
339 return 0;
342 static int vdi_make_empty(BlockDriverState *bs)
344 /* TODO: missing code. */
345 logout("\n");
346 /* The return value for missing code must be 0, see block.c. */
347 return 0;
350 static int vdi_probe(const uint8_t *buf, int buf_size, const char *filename)
352 const VdiHeader *header = (const VdiHeader *)buf;
353 int ret = 0;
355 logout("\n");
357 if (buf_size < sizeof(*header)) {
358 /* Header too small, no VDI. */
359 } else if (le32_to_cpu(header->signature) == VDI_SIGNATURE) {
360 ret = 100;
363 if (ret == 0) {
364 logout("no vdi image\n");
365 } else {
366 logout("%s", header->text);
369 return ret;
372 static int vdi_open(BlockDriverState *bs, QDict *options, int flags,
373 Error **errp)
375 BDRVVdiState *s = bs->opaque;
376 VdiHeader header;
377 size_t bmap_size;
378 int ret;
379 QemuUUID uuid_link, uuid_parent;
381 ret = bdrv_open_file_child(NULL, options, "file", bs, errp);
382 if (ret < 0) {
383 return ret;
386 logout("\n");
388 ret = bdrv_pread(bs->file, 0, sizeof(header), &header, 0);
389 if (ret < 0) {
390 goto fail;
393 vdi_header_to_cpu(&header);
394 if (VDI_DEBUG) {
395 vdi_header_print(&header);
398 if (header.disk_size > VDI_DISK_SIZE_MAX) {
399 error_setg(errp, "Unsupported VDI image size (size is 0x%" PRIx64
400 ", max supported is 0x%" PRIx64 ")",
401 header.disk_size, VDI_DISK_SIZE_MAX);
402 ret = -ENOTSUP;
403 goto fail;
406 uuid_link = header.uuid_link;
407 uuid_parent = header.uuid_parent;
409 if (header.disk_size % SECTOR_SIZE != 0) {
410 /* 'VBoxManage convertfromraw' can create images with odd disk sizes.
411 We accept them but round the disk size to the next multiple of
412 SECTOR_SIZE. */
413 logout("odd disk size %" PRIu64 " B, round up\n", header.disk_size);
414 header.disk_size = ROUND_UP(header.disk_size, SECTOR_SIZE);
417 if (header.signature != VDI_SIGNATURE) {
418 error_setg(errp, "Image not in VDI format (bad signature %08" PRIx32
419 ")", header.signature);
420 ret = -EINVAL;
421 goto fail;
422 } else if (header.version != VDI_VERSION_1_1) {
423 error_setg(errp, "unsupported VDI image (version %" PRIu32 ".%" PRIu32
424 ")", header.version >> 16, header.version & 0xffff);
425 ret = -ENOTSUP;
426 goto fail;
427 } else if (header.offset_bmap % SECTOR_SIZE != 0) {
428 /* We only support block maps which start on a sector boundary. */
429 error_setg(errp, "unsupported VDI image (unaligned block map offset "
430 "0x%" PRIx32 ")", header.offset_bmap);
431 ret = -ENOTSUP;
432 goto fail;
433 } else if (header.offset_data % SECTOR_SIZE != 0) {
434 /* We only support data blocks which start on a sector boundary. */
435 error_setg(errp, "unsupported VDI image (unaligned data offset 0x%"
436 PRIx32 ")", header.offset_data);
437 ret = -ENOTSUP;
438 goto fail;
439 } else if (header.sector_size != SECTOR_SIZE) {
440 error_setg(errp, "unsupported VDI image (sector size %" PRIu32
441 " is not %u)", header.sector_size, SECTOR_SIZE);
442 ret = -ENOTSUP;
443 goto fail;
444 } else if (header.block_size != DEFAULT_CLUSTER_SIZE) {
445 error_setg(errp, "unsupported VDI image (block size %" PRIu32
446 " is not %" PRIu32 ")",
447 header.block_size, DEFAULT_CLUSTER_SIZE);
448 ret = -ENOTSUP;
449 goto fail;
450 } else if (header.disk_size >
451 (uint64_t)header.blocks_in_image * header.block_size) {
452 error_setg(errp, "unsupported VDI image (disk size %" PRIu64 ", "
453 "image bitmap has room for %" PRIu64 ")",
454 header.disk_size,
455 (uint64_t)header.blocks_in_image * header.block_size);
456 ret = -ENOTSUP;
457 goto fail;
458 } else if (!qemu_uuid_is_null(&uuid_link)) {
459 error_setg(errp, "unsupported VDI image (non-NULL link UUID)");
460 ret = -ENOTSUP;
461 goto fail;
462 } else if (!qemu_uuid_is_null(&uuid_parent)) {
463 error_setg(errp, "unsupported VDI image (non-NULL parent UUID)");
464 ret = -ENOTSUP;
465 goto fail;
466 } else if (header.blocks_in_image > VDI_BLOCKS_IN_IMAGE_MAX) {
467 error_setg(errp, "unsupported VDI image "
468 "(too many blocks %u, max is %u)",
469 header.blocks_in_image, VDI_BLOCKS_IN_IMAGE_MAX);
470 ret = -ENOTSUP;
471 goto fail;
474 bs->total_sectors = header.disk_size / SECTOR_SIZE;
476 s->block_size = header.block_size;
477 s->bmap_sector = header.offset_bmap / SECTOR_SIZE;
478 s->header = header;
480 bmap_size = header.blocks_in_image * sizeof(uint32_t);
481 bmap_size = DIV_ROUND_UP(bmap_size, SECTOR_SIZE);
482 s->bmap = qemu_try_blockalign(bs->file->bs, bmap_size * SECTOR_SIZE);
483 if (s->bmap == NULL) {
484 ret = -ENOMEM;
485 goto fail;
488 ret = bdrv_pread(bs->file, header.offset_bmap, bmap_size * SECTOR_SIZE,
489 s->bmap, 0);
490 if (ret < 0) {
491 goto fail_free_bmap;
494 /* Disable migration when vdi images are used */
495 error_setg(&s->migration_blocker, "The vdi format used by node '%s' "
496 "does not support live migration",
497 bdrv_get_device_or_node_name(bs));
498 ret = migrate_add_blocker(s->migration_blocker, errp);
499 if (ret < 0) {
500 error_free(s->migration_blocker);
501 goto fail_free_bmap;
504 qemu_co_rwlock_init(&s->bmap_lock);
506 return 0;
508 fail_free_bmap:
509 qemu_vfree(s->bmap);
511 fail:
512 return ret;
515 static int vdi_reopen_prepare(BDRVReopenState *state,
516 BlockReopenQueue *queue, Error **errp)
518 return 0;
521 static int coroutine_fn vdi_co_block_status(BlockDriverState *bs,
522 bool want_zero,
523 int64_t offset, int64_t bytes,
524 int64_t *pnum, int64_t *map,
525 BlockDriverState **file)
527 BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
528 size_t bmap_index = offset / s->block_size;
529 size_t index_in_block = offset % s->block_size;
530 uint32_t bmap_entry = le32_to_cpu(s->bmap[bmap_index]);
531 int result;
533 logout("%p, %" PRId64 ", %" PRId64 ", %p\n", bs, offset, bytes, pnum);
534 *pnum = MIN(s->block_size - index_in_block, bytes);
535 result = VDI_IS_ALLOCATED(bmap_entry);
536 if (!result) {
537 return BDRV_BLOCK_ZERO;
540 *map = s->header.offset_data + (uint64_t)bmap_entry * s->block_size +
541 index_in_block;
542 *file = bs->file->bs;
543 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID |
544 (s->header.image_type == VDI_TYPE_STATIC ? BDRV_BLOCK_RECURSE : 0);
547 static int coroutine_fn
548 vdi_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
549 QEMUIOVector *qiov, BdrvRequestFlags flags)
551 BDRVVdiState *s = bs->opaque;
552 QEMUIOVector local_qiov;
553 uint32_t bmap_entry;
554 uint32_t block_index;
555 uint32_t offset_in_block;
556 uint32_t n_bytes;
557 uint64_t bytes_done = 0;
558 int ret = 0;
560 logout("\n");
562 qemu_iovec_init(&local_qiov, qiov->niov);
564 while (ret >= 0 && bytes > 0) {
565 block_index = offset / s->block_size;
566 offset_in_block = offset % s->block_size;
567 n_bytes = MIN(bytes, s->block_size - offset_in_block);
569 logout("will read %u bytes starting at offset %" PRIu64 "\n",
570 n_bytes, offset);
572 /* prepare next AIO request */
573 qemu_co_rwlock_rdlock(&s->bmap_lock);
574 bmap_entry = le32_to_cpu(s->bmap[block_index]);
575 qemu_co_rwlock_unlock(&s->bmap_lock);
576 if (!VDI_IS_ALLOCATED(bmap_entry)) {
577 /* Block not allocated, return zeros, no need to wait. */
578 qemu_iovec_memset(qiov, bytes_done, 0, n_bytes);
579 ret = 0;
580 } else {
581 uint64_t data_offset = s->header.offset_data +
582 (uint64_t)bmap_entry * s->block_size +
583 offset_in_block;
585 qemu_iovec_reset(&local_qiov);
586 qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes);
588 ret = bdrv_co_preadv(bs->file, data_offset, n_bytes,
589 &local_qiov, 0);
591 logout("%u bytes read\n", n_bytes);
593 bytes -= n_bytes;
594 offset += n_bytes;
595 bytes_done += n_bytes;
598 qemu_iovec_destroy(&local_qiov);
600 return ret;
603 static int coroutine_fn
604 vdi_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
605 QEMUIOVector *qiov, BdrvRequestFlags flags)
607 BDRVVdiState *s = bs->opaque;
608 QEMUIOVector local_qiov;
609 uint32_t bmap_entry;
610 uint32_t block_index;
611 uint32_t offset_in_block;
612 uint32_t n_bytes;
613 uint64_t data_offset;
614 uint32_t bmap_first = VDI_UNALLOCATED;
615 uint32_t bmap_last = VDI_UNALLOCATED;
616 uint8_t *block = NULL;
617 uint64_t bytes_done = 0;
618 int ret = 0;
620 logout("\n");
622 qemu_iovec_init(&local_qiov, qiov->niov);
624 while (ret >= 0 && bytes > 0) {
625 block_index = offset / s->block_size;
626 offset_in_block = offset % s->block_size;
627 n_bytes = MIN(bytes, s->block_size - offset_in_block);
629 logout("will write %u bytes starting at offset %" PRIu64 "\n",
630 n_bytes, offset);
632 /* prepare next AIO request */
633 qemu_co_rwlock_rdlock(&s->bmap_lock);
634 bmap_entry = le32_to_cpu(s->bmap[block_index]);
635 if (!VDI_IS_ALLOCATED(bmap_entry)) {
636 /* Allocate new block and write to it. */
637 uint64_t data_offset;
638 qemu_co_rwlock_upgrade(&s->bmap_lock);
639 bmap_entry = le32_to_cpu(s->bmap[block_index]);
640 if (VDI_IS_ALLOCATED(bmap_entry)) {
641 /* A concurrent allocation did the work for us. */
642 qemu_co_rwlock_downgrade(&s->bmap_lock);
643 goto nonallocating_write;
646 bmap_entry = s->header.blocks_allocated;
647 s->bmap[block_index] = cpu_to_le32(bmap_entry);
648 s->header.blocks_allocated++;
649 data_offset = s->header.offset_data +
650 (uint64_t)bmap_entry * s->block_size;
651 if (block == NULL) {
652 block = g_malloc(s->block_size);
653 bmap_first = block_index;
655 bmap_last = block_index;
656 /* Copy data to be written to new block and zero unused parts. */
657 memset(block, 0, offset_in_block);
658 qemu_iovec_to_buf(qiov, bytes_done, block + offset_in_block,
659 n_bytes);
660 memset(block + offset_in_block + n_bytes, 0,
661 s->block_size - n_bytes - offset_in_block);
663 /* Write the new block under CoRwLock write-side protection,
664 * so this full-cluster write does not overlap a partial write
665 * of the same cluster, issued from the "else" branch.
667 ret = bdrv_co_pwrite(bs->file, data_offset, s->block_size, block,
669 qemu_co_rwlock_unlock(&s->bmap_lock);
670 } else {
671 nonallocating_write:
672 data_offset = s->header.offset_data +
673 (uint64_t)bmap_entry * s->block_size +
674 offset_in_block;
675 qemu_co_rwlock_unlock(&s->bmap_lock);
677 qemu_iovec_reset(&local_qiov);
678 qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes);
680 ret = bdrv_co_pwritev(bs->file, data_offset, n_bytes,
681 &local_qiov, 0);
684 bytes -= n_bytes;
685 offset += n_bytes;
686 bytes_done += n_bytes;
688 logout("%u bytes written\n", n_bytes);
691 qemu_iovec_destroy(&local_qiov);
693 logout("finished data write\n");
694 if (ret < 0) {
695 g_free(block);
696 return ret;
699 if (block) {
700 /* One or more new blocks were allocated. */
701 VdiHeader *header;
702 uint8_t *base;
703 uint64_t offset;
704 uint32_t n_sectors;
706 g_free(block);
707 header = g_malloc(sizeof(*header));
709 logout("now writing modified header\n");
710 assert(VDI_IS_ALLOCATED(bmap_first));
711 *header = s->header;
712 vdi_header_to_le(header);
713 ret = bdrv_co_pwrite(bs->file, 0, sizeof(*header), header, 0);
714 g_free(header);
716 if (ret < 0) {
717 return ret;
720 logout("now writing modified block map entry %u...%u\n",
721 bmap_first, bmap_last);
722 /* Write modified sectors from block map. */
723 bmap_first /= (SECTOR_SIZE / sizeof(uint32_t));
724 bmap_last /= (SECTOR_SIZE / sizeof(uint32_t));
725 n_sectors = bmap_last - bmap_first + 1;
726 offset = s->bmap_sector + bmap_first;
727 base = ((uint8_t *)&s->bmap[0]) + bmap_first * SECTOR_SIZE;
728 logout("will write %u block map sectors starting from entry %u\n",
729 n_sectors, bmap_first);
730 ret = bdrv_co_pwrite(bs->file, offset * SECTOR_SIZE,
731 n_sectors * SECTOR_SIZE, base, 0);
734 return ret;
737 static int coroutine_fn vdi_co_do_create(BlockdevCreateOptions *create_options,
738 size_t block_size, Error **errp)
740 BlockdevCreateOptionsVdi *vdi_opts;
741 int ret = 0;
742 uint64_t bytes = 0;
743 uint32_t blocks;
744 uint32_t image_type;
745 VdiHeader header;
746 size_t i;
747 size_t bmap_size;
748 int64_t offset = 0;
749 BlockDriverState *bs_file = NULL;
750 BlockBackend *blk = NULL;
751 uint32_t *bmap = NULL;
752 QemuUUID uuid;
754 assert(create_options->driver == BLOCKDEV_DRIVER_VDI);
755 vdi_opts = &create_options->u.vdi;
757 logout("\n");
759 /* Validate options and set default values */
760 bytes = vdi_opts->size;
762 if (!vdi_opts->has_preallocation) {
763 vdi_opts->preallocation = PREALLOC_MODE_OFF;
765 switch (vdi_opts->preallocation) {
766 case PREALLOC_MODE_OFF:
767 image_type = VDI_TYPE_DYNAMIC;
768 break;
769 case PREALLOC_MODE_METADATA:
770 image_type = VDI_TYPE_STATIC;
771 break;
772 default:
773 error_setg(errp, "Preallocation mode not supported for vdi");
774 return -EINVAL;
777 #ifndef CONFIG_VDI_STATIC_IMAGE
778 if (image_type == VDI_TYPE_STATIC) {
779 ret = -ENOTSUP;
780 error_setg(errp, "Statically allocated images cannot be created in "
781 "this build");
782 goto exit;
784 #endif
785 #ifndef CONFIG_VDI_BLOCK_SIZE
786 if (block_size != DEFAULT_CLUSTER_SIZE) {
787 ret = -ENOTSUP;
788 error_setg(errp,
789 "A non-default cluster size is not supported in this build");
790 goto exit;
792 #endif
794 if (bytes > VDI_DISK_SIZE_MAX) {
795 ret = -ENOTSUP;
796 error_setg(errp, "Unsupported VDI image size (size is 0x%" PRIx64
797 ", max supported is 0x%" PRIx64 ")",
798 bytes, VDI_DISK_SIZE_MAX);
799 goto exit;
802 /* Create BlockBackend to write to the image */
803 bs_file = bdrv_open_blockdev_ref(vdi_opts->file, errp);
804 if (!bs_file) {
805 ret = -EIO;
806 goto exit;
809 blk = blk_new_with_bs(bs_file, BLK_PERM_WRITE | BLK_PERM_RESIZE,
810 BLK_PERM_ALL, errp);
811 if (!blk) {
812 ret = -EPERM;
813 goto exit;
816 blk_set_allow_write_beyond_eof(blk, true);
818 /* We need enough blocks to store the given disk size,
819 so always round up. */
820 blocks = DIV_ROUND_UP(bytes, block_size);
822 bmap_size = blocks * sizeof(uint32_t);
823 bmap_size = ROUND_UP(bmap_size, SECTOR_SIZE);
825 memset(&header, 0, sizeof(header));
826 pstrcpy(header.text, sizeof(header.text), VDI_TEXT);
827 header.signature = VDI_SIGNATURE;
828 header.version = VDI_VERSION_1_1;
829 header.header_size = 0x180;
830 header.image_type = image_type;
831 header.offset_bmap = 0x200;
832 header.offset_data = 0x200 + bmap_size;
833 header.sector_size = SECTOR_SIZE;
834 header.disk_size = bytes;
835 header.block_size = block_size;
836 header.blocks_in_image = blocks;
837 if (image_type == VDI_TYPE_STATIC) {
838 header.blocks_allocated = blocks;
840 qemu_uuid_generate(&uuid);
841 header.uuid_image = uuid;
842 qemu_uuid_generate(&uuid);
843 header.uuid_last_snap = uuid;
844 /* There is no need to set header.uuid_link or header.uuid_parent here. */
845 if (VDI_DEBUG) {
846 vdi_header_print(&header);
848 vdi_header_to_le(&header);
849 ret = blk_co_pwrite(blk, offset, sizeof(header), &header, 0);
850 if (ret < 0) {
851 error_setg(errp, "Error writing header");
852 goto exit;
854 offset += sizeof(header);
856 if (bmap_size > 0) {
857 bmap = g_try_malloc0(bmap_size);
858 if (bmap == NULL) {
859 ret = -ENOMEM;
860 error_setg(errp, "Could not allocate bmap");
861 goto exit;
863 for (i = 0; i < blocks; i++) {
864 if (image_type == VDI_TYPE_STATIC) {
865 bmap[i] = i;
866 } else {
867 bmap[i] = VDI_UNALLOCATED;
870 ret = blk_co_pwrite(blk, offset, bmap_size, bmap, 0);
871 if (ret < 0) {
872 error_setg(errp, "Error writing bmap");
873 goto exit;
875 offset += bmap_size;
878 if (image_type == VDI_TYPE_STATIC) {
879 ret = blk_co_truncate(blk, offset + blocks * block_size, false,
880 PREALLOC_MODE_OFF, 0, errp);
881 if (ret < 0) {
882 error_prepend(errp, "Failed to statically allocate file");
883 goto exit;
887 ret = 0;
888 exit:
889 blk_unref(blk);
890 bdrv_unref(bs_file);
891 g_free(bmap);
892 return ret;
895 static int coroutine_fn vdi_co_create(BlockdevCreateOptions *create_options,
896 Error **errp)
898 return vdi_co_do_create(create_options, DEFAULT_CLUSTER_SIZE, errp);
901 static int coroutine_fn vdi_co_create_opts(BlockDriver *drv,
902 const char *filename,
903 QemuOpts *opts,
904 Error **errp)
906 QDict *qdict = NULL;
907 BlockdevCreateOptions *create_options = NULL;
908 BlockDriverState *bs_file = NULL;
909 uint64_t block_size = DEFAULT_CLUSTER_SIZE;
910 bool is_static = false;
911 Visitor *v;
912 int ret;
914 /* Parse options and convert legacy syntax.
916 * Since CONFIG_VDI_BLOCK_SIZE is disabled by default,
917 * cluster-size is not part of the QAPI schema; therefore we have
918 * to parse it before creating the QAPI object. */
919 #if defined(CONFIG_VDI_BLOCK_SIZE)
920 block_size = qemu_opt_get_size_del(opts,
921 BLOCK_OPT_CLUSTER_SIZE,
922 DEFAULT_CLUSTER_SIZE);
923 if (block_size < BDRV_SECTOR_SIZE || block_size > UINT32_MAX ||
924 !is_power_of_2(block_size))
926 error_setg(errp, "Invalid cluster size");
927 ret = -EINVAL;
928 goto done;
930 #endif
931 if (qemu_opt_get_bool_del(opts, BLOCK_OPT_STATIC, false)) {
932 is_static = true;
935 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &vdi_create_opts, true);
937 /* Create and open the file (protocol layer) */
938 ret = bdrv_co_create_file(filename, opts, errp);
939 if (ret < 0) {
940 goto done;
943 bs_file = bdrv_open(filename, NULL, NULL,
944 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
945 if (!bs_file) {
946 ret = -EIO;
947 goto done;
950 qdict_put_str(qdict, "driver", "vdi");
951 qdict_put_str(qdict, "file", bs_file->node_name);
952 if (is_static) {
953 qdict_put_str(qdict, "preallocation", "metadata");
956 /* Get the QAPI object */
957 v = qobject_input_visitor_new_flat_confused(qdict, errp);
958 if (!v) {
959 ret = -EINVAL;
960 goto done;
962 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp);
963 visit_free(v);
964 if (!create_options) {
965 ret = -EINVAL;
966 goto done;
969 /* Silently round up size */
970 assert(create_options->driver == BLOCKDEV_DRIVER_VDI);
971 create_options->u.vdi.size = ROUND_UP(create_options->u.vdi.size,
972 BDRV_SECTOR_SIZE);
974 /* Create the vdi image (format layer) */
975 ret = vdi_co_do_create(create_options, block_size, errp);
976 done:
977 qobject_unref(qdict);
978 qapi_free_BlockdevCreateOptions(create_options);
979 bdrv_unref(bs_file);
980 return ret;
983 static void vdi_close(BlockDriverState *bs)
985 BDRVVdiState *s = bs->opaque;
987 qemu_vfree(s->bmap);
989 migrate_del_blocker(s->migration_blocker);
990 error_free(s->migration_blocker);
993 static int vdi_has_zero_init(BlockDriverState *bs)
995 BDRVVdiState *s = bs->opaque;
997 if (s->header.image_type == VDI_TYPE_STATIC) {
998 return bdrv_has_zero_init(bs->file->bs);
999 } else {
1000 return 1;
1004 static QemuOptsList vdi_create_opts = {
1005 .name = "vdi-create-opts",
1006 .head = QTAILQ_HEAD_INITIALIZER(vdi_create_opts.head),
1007 .desc = {
1009 .name = BLOCK_OPT_SIZE,
1010 .type = QEMU_OPT_SIZE,
1011 .help = "Virtual disk size"
1013 #if defined(CONFIG_VDI_BLOCK_SIZE)
1015 .name = BLOCK_OPT_CLUSTER_SIZE,
1016 .type = QEMU_OPT_SIZE,
1017 .help = "VDI cluster (block) size",
1018 .def_value_str = stringify(DEFAULT_CLUSTER_SIZE)
1020 #endif
1021 #if defined(CONFIG_VDI_STATIC_IMAGE)
1023 .name = BLOCK_OPT_STATIC,
1024 .type = QEMU_OPT_BOOL,
1025 .help = "VDI static (pre-allocated) image",
1026 .def_value_str = "off"
1028 #endif
1029 /* TODO: An additional option to set UUID values might be useful. */
1030 { /* end of list */ }
1034 static BlockDriver bdrv_vdi = {
1035 .format_name = "vdi",
1036 .instance_size = sizeof(BDRVVdiState),
1037 .bdrv_probe = vdi_probe,
1038 .bdrv_open = vdi_open,
1039 .bdrv_close = vdi_close,
1040 .bdrv_reopen_prepare = vdi_reopen_prepare,
1041 .bdrv_child_perm = bdrv_default_perms,
1042 .bdrv_co_create = vdi_co_create,
1043 .bdrv_co_create_opts = vdi_co_create_opts,
1044 .bdrv_has_zero_init = vdi_has_zero_init,
1045 .bdrv_co_block_status = vdi_co_block_status,
1046 .bdrv_make_empty = vdi_make_empty,
1048 .bdrv_co_preadv = vdi_co_preadv,
1049 #if defined(CONFIG_VDI_WRITE)
1050 .bdrv_co_pwritev = vdi_co_pwritev,
1051 #endif
1053 .bdrv_co_get_info = vdi_co_get_info,
1055 .is_format = true,
1056 .create_opts = &vdi_create_opts,
1057 .bdrv_co_check = vdi_co_check,
1060 static void bdrv_vdi_init(void)
1062 logout("\n");
1063 bdrv_register(&bdrv_vdi);
1066 block_init(bdrv_vdi_init);