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1.1 root 1: /*
2: * Block driver for the Virtual Disk Image (VDI) format
3: *
4: * Copyright (c) 2009 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 adjacents 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-common.h"
53: #include "block_int.h"
54: #include "module.h"
55:
56: #if defined(CONFIG_UUID)
57: #include <uuid/uuid.h>
58: #else
59: /* TODO: move uuid emulation to some central place in QEMU. */
60: #include "sysemu.h" /* UUID_FMT */
61: typedef unsigned char uuid_t[16];
62: void uuid_generate(uuid_t out);
63: int uuid_is_null(const uuid_t uu);
64: void uuid_unparse(const uuid_t uu, char *out);
65: #endif
66:
67: /* Code configuration options. */
68:
69: /* Enable debug messages. */
70: //~ #define CONFIG_VDI_DEBUG
71:
72: /* Support write operations on VDI images. */
73: #define CONFIG_VDI_WRITE
74:
75: /* Support non-standard block (cluster) size. This is untested.
76: * Maybe it will be needed for very large images.
77: */
78: //~ #define CONFIG_VDI_BLOCK_SIZE
79:
80: /* Support static (fixed, pre-allocated) images. */
81: #define CONFIG_VDI_STATIC_IMAGE
82:
83: /* Command line option for static images. */
84: #define BLOCK_OPT_STATIC "static"
85:
86: #define KiB 1024
87: #define MiB (KiB * KiB)
88:
89: #define SECTOR_SIZE 512
90:
91: #if defined(CONFIG_VDI_DEBUG)
92: #define logout(fmt, ...) \
93: fprintf(stderr, "vdi\t%-24s" fmt, __func__, ##__VA_ARGS__)
94: #else
95: #define logout(fmt, ...) ((void)0)
96: #endif
97:
98: /* Image signature. */
99: #define VDI_SIGNATURE 0xbeda107f
100:
101: /* Image version. */
102: #define VDI_VERSION_1_1 0x00010001
103:
104: /* Image type. */
105: #define VDI_TYPE_DYNAMIC 1
106: #define VDI_TYPE_STATIC 2
107:
108: /* Innotek / SUN images use these strings in header.text:
109: * "<<< innotek VirtualBox Disk Image >>>\n"
110: * "<<< Sun xVM VirtualBox Disk Image >>>\n"
111: * "<<< Sun VirtualBox Disk Image >>>\n"
112: * The value does not matter, so QEMU created images use a different text.
113: */
114: #define VDI_TEXT "<<< QEMU VM Virtual Disk Image >>>\n"
115:
116: /* Unallocated blocks use this index (no need to convert endianess). */
117: #define VDI_UNALLOCATED UINT32_MAX
118:
119: #if !defined(CONFIG_UUID)
120: void uuid_generate(uuid_t out)
121: {
122: memset(out, 0, sizeof(out));
123: }
124:
125: int uuid_is_null(const uuid_t uu)
126: {
127: uuid_t null_uuid = { 0 };
128: return memcmp(uu, null_uuid, sizeof(uu)) == 0;
129: }
130:
131: void uuid_unparse(const uuid_t uu, char *out)
132: {
133: snprintf(out, 37, UUID_FMT,
134: uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6], uu[7],
135: uu[8], uu[9], uu[10], uu[11], uu[12], uu[13], uu[14], uu[15]);
136: }
137: #endif
138:
139: typedef struct {
140: BlockDriverAIOCB common;
141: int64_t sector_num;
142: QEMUIOVector *qiov;
143: uint8_t *buf;
144: /* Total number of sectors. */
145: int nb_sectors;
146: /* Number of sectors for current AIO. */
147: int n_sectors;
148: /* New allocated block map entry. */
149: uint32_t bmap_first;
150: uint32_t bmap_last;
151: /* Buffer for new allocated block. */
152: void *block_buffer;
153: void *orig_buf;
154: int header_modified;
155: BlockDriverAIOCB *hd_aiocb;
156: struct iovec hd_iov;
157: QEMUIOVector hd_qiov;
158: QEMUBH *bh;
159: } VdiAIOCB;
160:
161: typedef struct {
162: char text[0x40];
163: uint32_t signature;
164: uint32_t version;
165: uint32_t header_size;
166: uint32_t image_type;
167: uint32_t image_flags;
168: char description[256];
169: uint32_t offset_bmap;
170: uint32_t offset_data;
171: uint32_t cylinders; /* disk geometry, unused here */
172: uint32_t heads; /* disk geometry, unused here */
173: uint32_t sectors; /* disk geometry, unused here */
174: uint32_t sector_size;
175: uint32_t unused1;
176: uint64_t disk_size;
177: uint32_t block_size;
178: uint32_t block_extra; /* unused here */
179: uint32_t blocks_in_image;
180: uint32_t blocks_allocated;
181: uuid_t uuid_image;
182: uuid_t uuid_last_snap;
183: uuid_t uuid_link;
184: uuid_t uuid_parent;
185: uint64_t unused2[7];
186: } VdiHeader;
187:
188: typedef struct {
189: BlockDriverState *hd;
190: /* The block map entries are little endian (even in memory). */
191: uint32_t *bmap;
192: /* Size of block (bytes). */
193: uint32_t block_size;
194: /* Size of block (sectors). */
195: uint32_t block_sectors;
196: /* First sector of block map. */
197: uint32_t bmap_sector;
198: /* VDI header (converted to host endianess). */
199: VdiHeader header;
200: } BDRVVdiState;
201:
202: /* Change UUID from little endian (IPRT = VirtualBox format) to big endian
203: * format (network byte order, standard, see RFC 4122) and vice versa.
204: */
205: static void uuid_convert(uuid_t uuid)
206: {
207: bswap32s((uint32_t *)&uuid[0]);
208: bswap16s((uint16_t *)&uuid[4]);
209: bswap16s((uint16_t *)&uuid[6]);
210: }
211:
212: static void vdi_header_to_cpu(VdiHeader *header)
213: {
214: le32_to_cpus(&header->signature);
215: le32_to_cpus(&header->version);
216: le32_to_cpus(&header->header_size);
217: le32_to_cpus(&header->image_type);
218: le32_to_cpus(&header->image_flags);
219: le32_to_cpus(&header->offset_bmap);
220: le32_to_cpus(&header->offset_data);
221: le32_to_cpus(&header->cylinders);
222: le32_to_cpus(&header->heads);
223: le32_to_cpus(&header->sectors);
224: le32_to_cpus(&header->sector_size);
225: le64_to_cpus(&header->disk_size);
226: le32_to_cpus(&header->block_size);
227: le32_to_cpus(&header->block_extra);
228: le32_to_cpus(&header->blocks_in_image);
229: le32_to_cpus(&header->blocks_allocated);
230: uuid_convert(header->uuid_image);
231: uuid_convert(header->uuid_last_snap);
232: uuid_convert(header->uuid_link);
233: uuid_convert(header->uuid_parent);
234: }
235:
236: static void vdi_header_to_le(VdiHeader *header)
237: {
238: cpu_to_le32s(&header->signature);
239: cpu_to_le32s(&header->version);
240: cpu_to_le32s(&header->header_size);
241: cpu_to_le32s(&header->image_type);
242: cpu_to_le32s(&header->image_flags);
243: cpu_to_le32s(&header->offset_bmap);
244: cpu_to_le32s(&header->offset_data);
245: cpu_to_le32s(&header->cylinders);
246: cpu_to_le32s(&header->heads);
247: cpu_to_le32s(&header->sectors);
248: cpu_to_le32s(&header->sector_size);
249: cpu_to_le64s(&header->disk_size);
250: cpu_to_le32s(&header->block_size);
251: cpu_to_le32s(&header->block_extra);
252: cpu_to_le32s(&header->blocks_in_image);
253: cpu_to_le32s(&header->blocks_allocated);
254: cpu_to_le32s(&header->blocks_allocated);
255: uuid_convert(header->uuid_image);
256: uuid_convert(header->uuid_last_snap);
257: uuid_convert(header->uuid_link);
258: uuid_convert(header->uuid_parent);
259: }
260:
261: #if defined(CONFIG_VDI_DEBUG)
262: static void vdi_header_print(VdiHeader *header)
263: {
264: char uuid[37];
265: logout("text %s", header->text);
266: logout("signature 0x%04x\n", header->signature);
267: logout("header size 0x%04x\n", header->header_size);
268: logout("image type 0x%04x\n", header->image_type);
269: logout("image flags 0x%04x\n", header->image_flags);
270: logout("description %s\n", header->description);
271: logout("offset bmap 0x%04x\n", header->offset_bmap);
272: logout("offset data 0x%04x\n", header->offset_data);
273: logout("cylinders 0x%04x\n", header->cylinders);
274: logout("heads 0x%04x\n", header->heads);
275: logout("sectors 0x%04x\n", header->sectors);
276: logout("sector size 0x%04x\n", header->sector_size);
277: logout("image size 0x%" PRIx64 " B (%" PRIu64 " MiB)\n",
278: header->disk_size, header->disk_size / MiB);
279: logout("block size 0x%04x\n", header->block_size);
280: logout("block extra 0x%04x\n", header->block_extra);
281: logout("blocks tot. 0x%04x\n", header->blocks_in_image);
282: logout("blocks all. 0x%04x\n", header->blocks_allocated);
283: uuid_unparse(header->uuid_image, uuid);
284: logout("uuid image %s\n", uuid);
285: uuid_unparse(header->uuid_last_snap, uuid);
286: logout("uuid snap %s\n", uuid);
287: uuid_unparse(header->uuid_link, uuid);
288: logout("uuid link %s\n", uuid);
289: uuid_unparse(header->uuid_parent, uuid);
290: logout("uuid parent %s\n", uuid);
291: }
292: #endif
293:
1.1.1.3 ! root 294: static int vdi_check(BlockDriverState *bs, BdrvCheckResult *res)
1.1 root 295: {
296: /* TODO: additional checks possible. */
297: BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
298: uint32_t blocks_allocated = 0;
299: uint32_t block;
300: uint32_t *bmap;
301: logout("\n");
302:
303: bmap = qemu_malloc(s->header.blocks_in_image * sizeof(uint32_t));
304: memset(bmap, 0xff, s->header.blocks_in_image * sizeof(uint32_t));
305:
306: /* Check block map and value of blocks_allocated. */
307: for (block = 0; block < s->header.blocks_in_image; block++) {
308: uint32_t bmap_entry = le32_to_cpu(s->bmap[block]);
309: if (bmap_entry != VDI_UNALLOCATED) {
310: if (bmap_entry < s->header.blocks_in_image) {
311: blocks_allocated++;
312: if (bmap[bmap_entry] == VDI_UNALLOCATED) {
313: bmap[bmap_entry] = bmap_entry;
314: } else {
315: fprintf(stderr, "ERROR: block index %" PRIu32
316: " also used by %" PRIu32 "\n", bmap[bmap_entry], bmap_entry);
1.1.1.3 ! root 317: res->corruptions++;
1.1 root 318: }
319: } else {
320: fprintf(stderr, "ERROR: block index %" PRIu32
321: " too large, is %" PRIu32 "\n", block, bmap_entry);
1.1.1.3 ! root 322: res->corruptions++;
1.1 root 323: }
324: }
325: }
326: if (blocks_allocated != s->header.blocks_allocated) {
327: fprintf(stderr, "ERROR: allocated blocks mismatch, is %" PRIu32
328: ", should be %" PRIu32 "\n",
329: blocks_allocated, s->header.blocks_allocated);
1.1.1.3 ! root 330: res->corruptions++;
1.1 root 331: }
332:
333: qemu_free(bmap);
334:
1.1.1.3 ! root 335: return 0;
1.1 root 336: }
337:
338: static int vdi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
339: {
340: /* TODO: vdi_get_info would be needed for machine snapshots.
341: vm_state_offset is still missing. */
342: BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
343: logout("\n");
344: bdi->cluster_size = s->block_size;
345: bdi->vm_state_offset = 0;
346: return 0;
347: }
348:
349: static int vdi_make_empty(BlockDriverState *bs)
350: {
351: /* TODO: missing code. */
352: logout("\n");
353: /* The return value for missing code must be 0, see block.c. */
354: return 0;
355: }
356:
357: static int vdi_probe(const uint8_t *buf, int buf_size, const char *filename)
358: {
359: const VdiHeader *header = (const VdiHeader *)buf;
360: int result = 0;
361:
362: logout("\n");
363:
364: if (buf_size < sizeof(*header)) {
365: /* Header too small, no VDI. */
366: } else if (le32_to_cpu(header->signature) == VDI_SIGNATURE) {
367: result = 100;
368: }
369:
370: if (result == 0) {
371: logout("no vdi image\n");
372: } else {
373: logout("%s", header->text);
374: }
375:
376: return result;
377: }
378:
1.1.1.3 ! root 379: static int vdi_open(BlockDriverState *bs, int flags)
1.1 root 380: {
381: BDRVVdiState *s = bs->opaque;
382: VdiHeader header;
383: size_t bmap_size;
384:
385: logout("\n");
386:
1.1.1.3 ! root 387: if (bdrv_read(bs->file, 0, (uint8_t *)&header, 1) < 0) {
1.1 root 388: goto fail;
389: }
390:
391: vdi_header_to_cpu(&header);
392: #if defined(CONFIG_VDI_DEBUG)
393: vdi_header_print(&header);
394: #endif
395:
1.1.1.2 root 396: if (header.disk_size % SECTOR_SIZE != 0) {
397: /* 'VBoxManage convertfromraw' can create images with odd disk sizes.
398: We accept them but round the disk size to the next multiple of
399: SECTOR_SIZE. */
400: logout("odd disk size %" PRIu64 " B, round up\n", header.disk_size);
401: header.disk_size += SECTOR_SIZE - 1;
402: header.disk_size &= ~(SECTOR_SIZE - 1);
403: }
404:
1.1 root 405: if (header.version != VDI_VERSION_1_1) {
406: logout("unsupported version %u.%u\n",
407: header.version >> 16, header.version & 0xffff);
408: goto fail;
409: } else if (header.offset_bmap % SECTOR_SIZE != 0) {
410: /* We only support block maps which start on a sector boundary. */
411: logout("unsupported block map offset 0x%x B\n", header.offset_bmap);
412: goto fail;
413: } else if (header.offset_data % SECTOR_SIZE != 0) {
414: /* We only support data blocks which start on a sector boundary. */
415: logout("unsupported data offset 0x%x B\n", header.offset_data);
416: goto fail;
417: } else if (header.sector_size != SECTOR_SIZE) {
418: logout("unsupported sector size %u B\n", header.sector_size);
419: goto fail;
420: } else if (header.block_size != 1 * MiB) {
421: logout("unsupported block size %u B\n", header.block_size);
422: goto fail;
1.1.1.2 root 423: } else if (header.disk_size >
1.1 root 424: (uint64_t)header.blocks_in_image * header.block_size) {
1.1.1.2 root 425: logout("unsupported disk size %" PRIu64 " B\n", header.disk_size);
1.1 root 426: goto fail;
427: } else if (!uuid_is_null(header.uuid_link)) {
428: logout("link uuid != 0, unsupported\n");
429: goto fail;
430: } else if (!uuid_is_null(header.uuid_parent)) {
431: logout("parent uuid != 0, unsupported\n");
432: goto fail;
433: }
434:
435: bs->total_sectors = header.disk_size / SECTOR_SIZE;
436:
437: s->block_size = header.block_size;
438: s->block_sectors = header.block_size / SECTOR_SIZE;
439: s->bmap_sector = header.offset_bmap / SECTOR_SIZE;
440: s->header = header;
441:
442: bmap_size = header.blocks_in_image * sizeof(uint32_t);
443: bmap_size = (bmap_size + SECTOR_SIZE - 1) / SECTOR_SIZE;
1.1.1.3 ! root 444: if (bmap_size > 0) {
! 445: s->bmap = qemu_malloc(bmap_size * SECTOR_SIZE);
! 446: }
! 447: if (bdrv_read(bs->file, s->bmap_sector, (uint8_t *)s->bmap, bmap_size) < 0) {
1.1 root 448: goto fail_free_bmap;
449: }
450:
451: return 0;
452:
453: fail_free_bmap:
454: qemu_free(s->bmap);
455:
456: fail:
457: return -1;
458: }
459:
460: static int vdi_is_allocated(BlockDriverState *bs, int64_t sector_num,
461: int nb_sectors, int *pnum)
462: {
463: /* TODO: Check for too large sector_num (in bdrv_is_allocated or here). */
464: BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
465: size_t bmap_index = sector_num / s->block_sectors;
466: size_t sector_in_block = sector_num % s->block_sectors;
467: int n_sectors = s->block_sectors - sector_in_block;
468: uint32_t bmap_entry = le32_to_cpu(s->bmap[bmap_index]);
469: logout("%p, %" PRId64 ", %d, %p\n", bs, sector_num, nb_sectors, pnum);
470: if (n_sectors > nb_sectors) {
471: n_sectors = nb_sectors;
472: }
473: *pnum = n_sectors;
474: return bmap_entry != VDI_UNALLOCATED;
475: }
476:
477: static void vdi_aio_cancel(BlockDriverAIOCB *blockacb)
478: {
479: /* TODO: This code is untested. How can I get it executed? */
1.1.1.3 ! root 480: VdiAIOCB *acb = container_of(blockacb, VdiAIOCB, common);
1.1 root 481: logout("\n");
482: if (acb->hd_aiocb) {
483: bdrv_aio_cancel(acb->hd_aiocb);
484: }
485: qemu_aio_release(acb);
486: }
487:
488: static AIOPool vdi_aio_pool = {
489: .aiocb_size = sizeof(VdiAIOCB),
490: .cancel = vdi_aio_cancel,
491: };
492:
493: static VdiAIOCB *vdi_aio_setup(BlockDriverState *bs, int64_t sector_num,
494: QEMUIOVector *qiov, int nb_sectors,
495: BlockDriverCompletionFunc *cb, void *opaque, int is_write)
496: {
497: VdiAIOCB *acb;
498:
499: logout("%p, %" PRId64 ", %p, %d, %p, %p, %d\n",
500: bs, sector_num, qiov, nb_sectors, cb, opaque, is_write);
501:
502: acb = qemu_aio_get(&vdi_aio_pool, bs, cb, opaque);
503: if (acb) {
504: acb->hd_aiocb = NULL;
505: acb->sector_num = sector_num;
506: acb->qiov = qiov;
507: if (qiov->niov > 1) {
508: acb->buf = qemu_blockalign(bs, qiov->size);
509: acb->orig_buf = acb->buf;
510: if (is_write) {
511: qemu_iovec_to_buffer(qiov, acb->buf);
512: }
513: } else {
514: acb->buf = (uint8_t *)qiov->iov->iov_base;
515: }
516: acb->nb_sectors = nb_sectors;
517: acb->n_sectors = 0;
518: acb->bmap_first = VDI_UNALLOCATED;
519: acb->bmap_last = VDI_UNALLOCATED;
520: acb->block_buffer = NULL;
521: acb->header_modified = 0;
522: }
523: return acb;
524: }
525:
526: static int vdi_schedule_bh(QEMUBHFunc *cb, VdiAIOCB *acb)
527: {
528: logout("\n");
529:
530: if (acb->bh) {
531: return -EIO;
532: }
533:
534: acb->bh = qemu_bh_new(cb, acb);
535: if (!acb->bh) {
536: return -EIO;
537: }
538:
539: qemu_bh_schedule(acb->bh);
540:
541: return 0;
542: }
543:
544: static void vdi_aio_read_cb(void *opaque, int ret);
545:
546: static void vdi_aio_read_bh(void *opaque)
547: {
548: VdiAIOCB *acb = opaque;
549: logout("\n");
550: qemu_bh_delete(acb->bh);
551: acb->bh = NULL;
552: vdi_aio_read_cb(opaque, 0);
553: }
554:
555: static void vdi_aio_read_cb(void *opaque, int ret)
556: {
557: VdiAIOCB *acb = opaque;
558: BlockDriverState *bs = acb->common.bs;
559: BDRVVdiState *s = bs->opaque;
560: uint32_t bmap_entry;
561: uint32_t block_index;
562: uint32_t sector_in_block;
563: uint32_t n_sectors;
564:
565: logout("%u sectors read\n", acb->n_sectors);
566:
567: acb->hd_aiocb = NULL;
568:
569: if (ret < 0) {
570: goto done;
571: }
572:
573: acb->nb_sectors -= acb->n_sectors;
574:
575: if (acb->nb_sectors == 0) {
576: /* request completed */
577: ret = 0;
578: goto done;
579: }
580:
581: acb->sector_num += acb->n_sectors;
582: acb->buf += acb->n_sectors * SECTOR_SIZE;
583:
584: block_index = acb->sector_num / s->block_sectors;
585: sector_in_block = acb->sector_num % s->block_sectors;
586: n_sectors = s->block_sectors - sector_in_block;
587: if (n_sectors > acb->nb_sectors) {
588: n_sectors = acb->nb_sectors;
589: }
590:
591: logout("will read %u sectors starting at sector %" PRIu64 "\n",
592: n_sectors, acb->sector_num);
593:
594: /* prepare next AIO request */
595: acb->n_sectors = n_sectors;
596: bmap_entry = le32_to_cpu(s->bmap[block_index]);
597: if (bmap_entry == VDI_UNALLOCATED) {
598: /* Block not allocated, return zeros, no need to wait. */
599: memset(acb->buf, 0, n_sectors * SECTOR_SIZE);
600: ret = vdi_schedule_bh(vdi_aio_read_bh, acb);
601: if (ret < 0) {
602: goto done;
603: }
604: } else {
605: uint64_t offset = s->header.offset_data / SECTOR_SIZE +
606: (uint64_t)bmap_entry * s->block_sectors +
607: sector_in_block;
608: acb->hd_iov.iov_base = (void *)acb->buf;
609: acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE;
610: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
1.1.1.3 ! root 611: acb->hd_aiocb = bdrv_aio_readv(bs->file, offset, &acb->hd_qiov,
1.1 root 612: n_sectors, vdi_aio_read_cb, acb);
613: if (acb->hd_aiocb == NULL) {
614: goto done;
615: }
616: }
617: return;
618: done:
619: if (acb->qiov->niov > 1) {
620: qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);
621: qemu_vfree(acb->orig_buf);
622: }
623: acb->common.cb(acb->common.opaque, ret);
624: qemu_aio_release(acb);
625: }
626:
627: static BlockDriverAIOCB *vdi_aio_readv(BlockDriverState *bs,
628: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
629: BlockDriverCompletionFunc *cb, void *opaque)
630: {
631: VdiAIOCB *acb;
632: logout("\n");
633: acb = vdi_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
634: if (!acb) {
635: return NULL;
636: }
637: vdi_aio_read_cb(acb, 0);
638: return &acb->common;
639: }
640:
641: static void vdi_aio_write_cb(void *opaque, int ret)
642: {
643: VdiAIOCB *acb = opaque;
644: BlockDriverState *bs = acb->common.bs;
645: BDRVVdiState *s = bs->opaque;
646: uint32_t bmap_entry;
647: uint32_t block_index;
648: uint32_t sector_in_block;
649: uint32_t n_sectors;
650:
651: acb->hd_aiocb = NULL;
652:
653: if (ret < 0) {
654: goto done;
655: }
656:
657: acb->nb_sectors -= acb->n_sectors;
658: acb->sector_num += acb->n_sectors;
659: acb->buf += acb->n_sectors * SECTOR_SIZE;
660:
661: if (acb->nb_sectors == 0) {
662: logout("finished data write\n");
663: acb->n_sectors = 0;
664: if (acb->header_modified) {
665: VdiHeader *header = acb->block_buffer;
666: logout("now writing modified header\n");
667: assert(acb->bmap_first != VDI_UNALLOCATED);
668: *header = s->header;
669: vdi_header_to_le(header);
670: acb->header_modified = 0;
671: acb->hd_iov.iov_base = acb->block_buffer;
672: acb->hd_iov.iov_len = SECTOR_SIZE;
673: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
1.1.1.3 ! root 674: acb->hd_aiocb = bdrv_aio_writev(bs->file, 0, &acb->hd_qiov, 1,
1.1 root 675: vdi_aio_write_cb, acb);
676: if (acb->hd_aiocb == NULL) {
677: goto done;
678: }
679: return;
680: } else if (acb->bmap_first != VDI_UNALLOCATED) {
681: /* One or more new blocks were allocated. */
682: uint64_t offset;
683: uint32_t bmap_first;
684: uint32_t bmap_last;
685: qemu_free(acb->block_buffer);
686: acb->block_buffer = NULL;
687: bmap_first = acb->bmap_first;
688: bmap_last = acb->bmap_last;
689: logout("now writing modified block map entry %u...%u\n",
690: bmap_first, bmap_last);
691: /* Write modified sectors from block map. */
692: bmap_first /= (SECTOR_SIZE / sizeof(uint32_t));
693: bmap_last /= (SECTOR_SIZE / sizeof(uint32_t));
694: n_sectors = bmap_last - bmap_first + 1;
695: offset = s->bmap_sector + bmap_first;
696: acb->bmap_first = VDI_UNALLOCATED;
697: acb->hd_iov.iov_base = (void *)((uint8_t *)&s->bmap[0] +
698: bmap_first * SECTOR_SIZE);
699: acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE;
700: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
701: logout("will write %u block map sectors starting from entry %u\n",
702: n_sectors, bmap_first);
1.1.1.3 ! root 703: acb->hd_aiocb = bdrv_aio_writev(bs->file, offset, &acb->hd_qiov,
1.1 root 704: n_sectors, vdi_aio_write_cb, acb);
705: if (acb->hd_aiocb == NULL) {
706: goto done;
707: }
708: return;
709: }
710: ret = 0;
711: goto done;
712: }
713:
714: logout("%u sectors written\n", acb->n_sectors);
715:
716: block_index = acb->sector_num / s->block_sectors;
717: sector_in_block = acb->sector_num % s->block_sectors;
718: n_sectors = s->block_sectors - sector_in_block;
719: if (n_sectors > acb->nb_sectors) {
720: n_sectors = acb->nb_sectors;
721: }
722:
723: logout("will write %u sectors starting at sector %" PRIu64 "\n",
724: n_sectors, acb->sector_num);
725:
726: /* prepare next AIO request */
727: acb->n_sectors = n_sectors;
728: bmap_entry = le32_to_cpu(s->bmap[block_index]);
729: if (bmap_entry == VDI_UNALLOCATED) {
730: /* Allocate new block and write to it. */
731: uint64_t offset;
732: uint8_t *block;
733: bmap_entry = s->header.blocks_allocated;
734: s->bmap[block_index] = cpu_to_le32(bmap_entry);
735: s->header.blocks_allocated++;
736: offset = s->header.offset_data / SECTOR_SIZE +
737: (uint64_t)bmap_entry * s->block_sectors;
738: block = acb->block_buffer;
739: if (block == NULL) {
740: block = qemu_mallocz(s->block_size);
741: acb->block_buffer = block;
742: acb->bmap_first = block_index;
743: assert(!acb->header_modified);
744: acb->header_modified = 1;
745: }
746: acb->bmap_last = block_index;
747: memcpy(block + sector_in_block * SECTOR_SIZE,
748: acb->buf, n_sectors * SECTOR_SIZE);
749: acb->hd_iov.iov_base = (void *)block;
750: acb->hd_iov.iov_len = s->block_size;
751: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
1.1.1.3 ! root 752: acb->hd_aiocb = bdrv_aio_writev(bs->file, offset,
1.1 root 753: &acb->hd_qiov, s->block_sectors,
754: vdi_aio_write_cb, acb);
755: if (acb->hd_aiocb == NULL) {
756: goto done;
757: }
758: } else {
759: uint64_t offset = s->header.offset_data / SECTOR_SIZE +
760: (uint64_t)bmap_entry * s->block_sectors +
761: sector_in_block;
762: acb->hd_iov.iov_base = (void *)acb->buf;
763: acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE;
764: qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
1.1.1.3 ! root 765: acb->hd_aiocb = bdrv_aio_writev(bs->file, offset, &acb->hd_qiov,
1.1 root 766: n_sectors, vdi_aio_write_cb, acb);
767: if (acb->hd_aiocb == NULL) {
768: goto done;
769: }
770: }
771:
772: return;
773:
774: done:
775: if (acb->qiov->niov > 1) {
776: qemu_vfree(acb->orig_buf);
777: }
778: acb->common.cb(acb->common.opaque, ret);
779: qemu_aio_release(acb);
780: }
781:
782: static BlockDriverAIOCB *vdi_aio_writev(BlockDriverState *bs,
783: int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
784: BlockDriverCompletionFunc *cb, void *opaque)
785: {
786: VdiAIOCB *acb;
787: logout("\n");
788: acb = vdi_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
789: if (!acb) {
790: return NULL;
791: }
792: vdi_aio_write_cb(acb, 0);
793: return &acb->common;
794: }
795:
796: static int vdi_create(const char *filename, QEMUOptionParameter *options)
797: {
798: int fd;
799: int result = 0;
800: uint64_t bytes = 0;
801: uint32_t blocks;
802: size_t block_size = 1 * MiB;
803: uint32_t image_type = VDI_TYPE_DYNAMIC;
804: VdiHeader header;
805: size_t i;
806: size_t bmap_size;
807: uint32_t *bmap;
808:
809: logout("\n");
810:
811: /* Read out options. */
812: while (options && options->name) {
813: if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
814: bytes = options->value.n;
815: #if defined(CONFIG_VDI_BLOCK_SIZE)
816: } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) {
817: if (options->value.n) {
818: /* TODO: Additional checks (SECTOR_SIZE * 2^n, ...). */
819: block_size = options->value.n;
820: }
821: #endif
822: #if defined(CONFIG_VDI_STATIC_IMAGE)
823: } else if (!strcmp(options->name, BLOCK_OPT_STATIC)) {
824: if (options->value.n) {
825: image_type = VDI_TYPE_STATIC;
826: }
827: #endif
828: }
829: options++;
830: }
831:
832: fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
833: 0644);
834: if (fd < 0) {
835: return -errno;
836: }
837:
1.1.1.2 root 838: /* We need enough blocks to store the given disk size,
839: so always round up. */
840: blocks = (bytes + block_size - 1) / block_size;
841:
1.1 root 842: bmap_size = blocks * sizeof(uint32_t);
843: bmap_size = ((bmap_size + SECTOR_SIZE - 1) & ~(SECTOR_SIZE -1));
844:
845: memset(&header, 0, sizeof(header));
846: pstrcpy(header.text, sizeof(header.text), VDI_TEXT);
847: header.signature = VDI_SIGNATURE;
848: header.version = VDI_VERSION_1_1;
849: header.header_size = 0x180;
850: header.image_type = image_type;
851: header.offset_bmap = 0x200;
852: header.offset_data = 0x200 + bmap_size;
853: header.sector_size = SECTOR_SIZE;
854: header.disk_size = bytes;
855: header.block_size = block_size;
856: header.blocks_in_image = blocks;
857: if (image_type == VDI_TYPE_STATIC) {
858: header.blocks_allocated = blocks;
859: }
860: uuid_generate(header.uuid_image);
861: uuid_generate(header.uuid_last_snap);
862: /* There is no need to set header.uuid_link or header.uuid_parent here. */
863: #if defined(CONFIG_VDI_DEBUG)
864: vdi_header_print(&header);
865: #endif
866: vdi_header_to_le(&header);
867: if (write(fd, &header, sizeof(header)) < 0) {
868: result = -errno;
869: }
870:
1.1.1.3 ! root 871: bmap = NULL;
! 872: if (bmap_size > 0) {
! 873: bmap = (uint32_t *)qemu_mallocz(bmap_size);
! 874: }
1.1 root 875: for (i = 0; i < blocks; i++) {
876: if (image_type == VDI_TYPE_STATIC) {
877: bmap[i] = i;
878: } else {
879: bmap[i] = VDI_UNALLOCATED;
880: }
881: }
882: if (write(fd, bmap, bmap_size) < 0) {
883: result = -errno;
884: }
885: qemu_free(bmap);
886: if (image_type == VDI_TYPE_STATIC) {
887: if (ftruncate(fd, sizeof(header) + bmap_size + blocks * block_size)) {
888: result = -errno;
889: }
890: }
891:
892: if (close(fd) < 0) {
893: result = -errno;
894: }
895:
896: return result;
897: }
898:
899: static void vdi_close(BlockDriverState *bs)
900: {
901: }
902:
903: static void vdi_flush(BlockDriverState *bs)
904: {
905: logout("\n");
1.1.1.3 ! root 906: bdrv_flush(bs->file);
1.1 root 907: }
908:
909:
910: static QEMUOptionParameter vdi_create_options[] = {
911: {
912: .name = BLOCK_OPT_SIZE,
913: .type = OPT_SIZE,
914: .help = "Virtual disk size"
915: },
916: #if defined(CONFIG_VDI_BLOCK_SIZE)
917: {
918: .name = BLOCK_OPT_CLUSTER_SIZE,
919: .type = OPT_SIZE,
920: .help = "VDI cluster (block) size"
921: },
922: #endif
923: #if defined(CONFIG_VDI_STATIC_IMAGE)
924: {
925: .name = BLOCK_OPT_STATIC,
926: .type = OPT_FLAG,
927: .help = "VDI static (pre-allocated) image"
928: },
929: #endif
930: /* TODO: An additional option to set UUID values might be useful. */
931: { NULL }
932: };
933:
934: static BlockDriver bdrv_vdi = {
935: .format_name = "vdi",
936: .instance_size = sizeof(BDRVVdiState),
937: .bdrv_probe = vdi_probe,
938: .bdrv_open = vdi_open,
939: .bdrv_close = vdi_close,
940: .bdrv_create = vdi_create,
941: .bdrv_flush = vdi_flush,
942: .bdrv_is_allocated = vdi_is_allocated,
943: .bdrv_make_empty = vdi_make_empty,
944:
945: .bdrv_aio_readv = vdi_aio_readv,
946: #if defined(CONFIG_VDI_WRITE)
947: .bdrv_aio_writev = vdi_aio_writev,
948: #endif
949:
950: .bdrv_get_info = vdi_get_info,
951:
952: .create_options = vdi_create_options,
953: .bdrv_check = vdi_check,
954: };
955:
956: static void bdrv_vdi_init(void)
957: {
958: logout("\n");
959: bdrv_register(&bdrv_vdi);
960: }
961:
962: block_init(bdrv_vdi_init);
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