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Add KVM support for S390x
[qemu/agraf.git] / block.c
blob853f0256a7ed99f2d40d7bd83daf708a628adff6
1 /*
2 * QEMU System Emulator block driver
3 *
4 * Copyright (c) 2003 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24 #include "config-host.h"
25 #include "qemu-common.h"
26 #include "monitor.h"
27 #include "block_int.h"
28 #include "module.h"
29
30 #ifdef CONFIG_BSD
31 #include <sys/types.h>
32 #include <sys/stat.h>
33 #include <sys/ioctl.h>
34 #include <sys/queue.h>
35 #ifndef __DragonFly__
36 #include <sys/disk.h>
37 #endif
38 #endif
39
40 #ifdef _WIN32
41 #include <windows.h>
42 #endif
43
44 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
45 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
46 BlockDriverCompletionFunc *cb, void *opaque);
47 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
48 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
49 BlockDriverCompletionFunc *cb, void *opaque);
50 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
51 BlockDriverCompletionFunc *cb, void *opaque);
52 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
53 uint8_t *buf, int nb_sectors);
54 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
55 const uint8_t *buf, int nb_sectors);
56
57 BlockDriverState *bdrv_first;
58
59 static BlockDriver *first_drv;
60
61 /* If non-zero, use only whitelisted block drivers */
62 static int use_bdrv_whitelist;
63
64 int path_is_absolute(const char *path)
65 {
66 const char *p;
67 #ifdef _WIN32
68 /* specific case for names like: "\\.\d:" */
69 if (*path == '/' || *path == '\\')
70 return 1;
71 #endif
72 p = strchr(path, ':');
73 if (p)
74 p++;
75 else
76 p = path;
77 #ifdef _WIN32
78 return (*p == '/' || *p == '\\');
79 #else
80 return (*p == '/');
81 #endif
82 }
83
84 /* if filename is absolute, just copy it to dest. Otherwise, build a
85 path to it by considering it is relative to base_path. URL are
86 supported. */
87 void path_combine(char *dest, int dest_size,
88 const char *base_path,
89 const char *filename)
90 {
91 const char *p, *p1;
92 int len;
93
94 if (dest_size <= 0)
95 return;
96 if (path_is_absolute(filename)) {
97 pstrcpy(dest, dest_size, filename);
98 } else {
99 p = strchr(base_path, ':');
100 if (p)
101 p++;
102 else
103 p = base_path;
104 p1 = strrchr(base_path, '/');
105 #ifdef _WIN32
106 {
107 const char *p2;
108 p2 = strrchr(base_path, '\\');
109 if (!p1 || p2 > p1)
110 p1 = p2;
111 }
112 #endif
113 if (p1)
114 p1++;
115 else
116 p1 = base_path;
117 if (p1 > p)
118 p = p1;
119 len = p - base_path;
120 if (len > dest_size - 1)
121 len = dest_size - 1;
122 memcpy(dest, base_path, len);
123 dest[len] = '\0';
124 pstrcat(dest, dest_size, filename);
125 }
126 }
127
128 void bdrv_register(BlockDriver *bdrv)
129 {
130 if (!bdrv->bdrv_aio_readv) {
131 /* add AIO emulation layer */
132 bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
133 bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
134 } else if (!bdrv->bdrv_read) {
135 /* add synchronous IO emulation layer */
136 bdrv->bdrv_read = bdrv_read_em;
137 bdrv->bdrv_write = bdrv_write_em;
138 }
139
140 if (!bdrv->bdrv_aio_flush)
141 bdrv->bdrv_aio_flush = bdrv_aio_flush_em;
142
143 bdrv->next = first_drv;
144 first_drv = bdrv;
145 }
146
147 /* create a new block device (by default it is empty) */
148 BlockDriverState *bdrv_new(const char *device_name)
149 {
150 BlockDriverState **pbs, *bs;
151
152 bs = qemu_mallocz(sizeof(BlockDriverState));
153 pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
154 if (device_name[0] != '\0') {
155 /* insert at the end */
156 pbs = &bdrv_first;
157 while (*pbs != NULL)
158 pbs = &(*pbs)->next;
159 *pbs = bs;
160 }
161 return bs;
162 }
163
164 BlockDriver *bdrv_find_format(const char *format_name)
165 {
166 BlockDriver *drv1;
167 for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
168 if (!strcmp(drv1->format_name, format_name))
169 return drv1;
170 }
171 return NULL;
172 }
173
174 static int bdrv_is_whitelisted(BlockDriver *drv)
175 {
176 static const char *whitelist[] = {
177 CONFIG_BDRV_WHITELIST
178 };
179 const char **p;
180
181 if (!whitelist[0])
182 return 1; /* no whitelist, anything goes */
183
184 for (p = whitelist; *p; p++) {
185 if (!strcmp(drv->format_name, *p)) {
186 return 1;
187 }
188 }
189 return 0;
190 }
191
192 BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
193 {
194 BlockDriver *drv = bdrv_find_format(format_name);
195 return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
196 }
197
198 int bdrv_create(BlockDriver *drv, const char* filename,
199 QEMUOptionParameter *options)
200 {
201 if (!drv->bdrv_create)
202 return -ENOTSUP;
203
204 return drv->bdrv_create(filename, options);
205 }
206
207 #ifdef _WIN32
208 void get_tmp_filename(char *filename, int size)
209 {
210 char temp_dir[MAX_PATH];
211
212 GetTempPath(MAX_PATH, temp_dir);
213 GetTempFileName(temp_dir, "qem", 0, filename);
214 }
215 #else
216 void get_tmp_filename(char *filename, int size)
217 {
218 int fd;
219 const char *tmpdir;
220 /* XXX: race condition possible */
221 tmpdir = getenv("TMPDIR");
222 if (!tmpdir)
223 tmpdir = "/tmp";
224 snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
225 fd = mkstemp(filename);
226 close(fd);
227 }
228 #endif
229
230 #ifdef _WIN32
231 static int is_windows_drive_prefix(const char *filename)
232 {
233 return (((filename[0] >= 'a' && filename[0] <= 'z') ||
234 (filename[0] >= 'A' && filename[0] <= 'Z')) &&
235 filename[1] == ':');
236 }
237
238 int is_windows_drive(const char *filename)
239 {
240 if (is_windows_drive_prefix(filename) &&
241 filename[2] == '\0')
242 return 1;
243 if (strstart(filename, "\\\\.\\", NULL) ||
244 strstart(filename, "//./", NULL))
245 return 1;
246 return 0;
247 }
248 #endif
249
250 static BlockDriver *find_protocol(const char *filename)
251 {
252 BlockDriver *drv1;
253 char protocol[128];
254 int len;
255 const char *p;
256
257 #ifdef _WIN32
258 if (is_windows_drive(filename) ||
259 is_windows_drive_prefix(filename))
260 return bdrv_find_format("raw");
261 #endif
262 p = strchr(filename, ':');
263 if (!p)
264 return bdrv_find_format("raw");
265 len = p - filename;
266 if (len > sizeof(protocol) - 1)
267 len = sizeof(protocol) - 1;
268 memcpy(protocol, filename, len);
269 protocol[len] = '\0';
270 for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
271 if (drv1->protocol_name &&
272 !strcmp(drv1->protocol_name, protocol))
273 return drv1;
274 }
275 return NULL;
276 }
277
278 /*
279 * Detect host devices. By convention, /dev/cdrom[N] is always
280 * recognized as a host CDROM.
281 */
282 static BlockDriver *find_hdev_driver(const char *filename)
283 {
284 int score_max = 0, score;
285 BlockDriver *drv = NULL, *d;
286
287 for (d = first_drv; d; d = d->next) {
288 if (d->bdrv_probe_device) {
289 score = d->bdrv_probe_device(filename);
290 if (score > score_max) {
291 score_max = score;
292 drv = d;
293 }
294 }
295 }
296
297 return drv;
298 }
299
300 static BlockDriver *find_image_format(const char *filename)
301 {
302 int ret, score, score_max;
303 BlockDriver *drv1, *drv;
304 uint8_t buf[2048];
305 BlockDriverState *bs;
306
307 drv = find_protocol(filename);
308 /* no need to test disk image formats for vvfat */
309 if (drv && strcmp(drv->format_name, "vvfat") == 0)
310 return drv;
311
312 ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY);
313 if (ret < 0)
314 return NULL;
315 ret = bdrv_pread(bs, 0, buf, sizeof(buf));
316 bdrv_delete(bs);
317 if (ret < 0) {
318 return NULL;
319 }
320
321 score_max = 0;
322 for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
323 if (drv1->bdrv_probe) {
324 score = drv1->bdrv_probe(buf, ret, filename);
325 if (score > score_max) {
326 score_max = score;
327 drv = drv1;
328 }
329 }
330 }
331 return drv;
332 }
333
334 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
335 {
336 BlockDriverState *bs;
337 int ret;
338
339 bs = bdrv_new("");
340 ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
341 if (ret < 0) {
342 bdrv_delete(bs);
343 return ret;
344 }
345 bs->growable = 1;
346 *pbs = bs;
347 return 0;
348 }
349
350 int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
351 {
352 return bdrv_open2(bs, filename, flags, NULL);
353 }
354
355 int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
356 BlockDriver *drv)
357 {
358 int ret, open_flags, try_rw;
359 char tmp_filename[PATH_MAX];
360 char backing_filename[PATH_MAX];
361
362 bs->is_temporary = 0;
363 bs->encrypted = 0;
364 bs->valid_key = 0;
365 /* buffer_alignment defaulted to 512, drivers can change this value */
366 bs->buffer_alignment = 512;
367
368 if (flags & BDRV_O_SNAPSHOT) {
369 BlockDriverState *bs1;
370 int64_t total_size;
371 int is_protocol = 0;
372 BlockDriver *bdrv_qcow2;
373 QEMUOptionParameter *options;
374
375 /* if snapshot, we create a temporary backing file and open it
376 instead of opening 'filename' directly */
377
378 /* if there is a backing file, use it */
379 bs1 = bdrv_new("");
380 ret = bdrv_open2(bs1, filename, 0, drv);
381 if (ret < 0) {
382 bdrv_delete(bs1);
383 return ret;
384 }
385 total_size = bdrv_getlength(bs1) >> BDRV_SECTOR_BITS;
386
387 if (bs1->drv && bs1->drv->protocol_name)
388 is_protocol = 1;
389
390 bdrv_delete(bs1);
391
392 get_tmp_filename(tmp_filename, sizeof(tmp_filename));
393
394 /* Real path is meaningless for protocols */
395 if (is_protocol)
396 snprintf(backing_filename, sizeof(backing_filename),
397 "%s", filename);
398 else
399 realpath(filename, backing_filename);
400
401 bdrv_qcow2 = bdrv_find_format("qcow2");
402 options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);
403
404 set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size * 512);
405 set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename);
406 if (drv) {
407 set_option_parameter(options, BLOCK_OPT_BACKING_FMT,
408 drv->format_name);
409 }
410
411 ret = bdrv_create(bdrv_qcow2, tmp_filename, options);
412 if (ret < 0) {
413 return ret;
414 }
415
416 filename = tmp_filename;
417 drv = bdrv_qcow2;
418 bs->is_temporary = 1;
419 }
420
421 pstrcpy(bs->filename, sizeof(bs->filename), filename);
422 if (flags & BDRV_O_FILE) {
423 drv = find_protocol(filename);
424 } else if (!drv) {
425 drv = find_hdev_driver(filename);
426 if (!drv) {
427 drv = find_image_format(filename);
428 }
429 }
430 if (!drv) {
431 ret = -ENOENT;
432 goto unlink_and_fail;
433 }
434 bs->drv = drv;
435 bs->opaque = qemu_mallocz(drv->instance_size);
436
437 /*
438 * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
439 * write cache to the guest. We do need the fdatasync to flush
440 * out transactions for block allocations, and we maybe have a
441 * volatile write cache in our backing device to deal with.
442 */
443 if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
444 bs->enable_write_cache = 1;
445
446 /* Note: for compatibility, we open disk image files as RDWR, and
447 RDONLY as fallback */
448 try_rw = !bs->read_only || bs->is_temporary;
449 if (!(flags & BDRV_O_FILE))
450 open_flags = (try_rw ? BDRV_O_RDWR : 0) |
451 (flags & (BDRV_O_CACHE_MASK|BDRV_O_NATIVE_AIO));
452 else
453 open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
454 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv))
455 ret = -ENOTSUP;
456 else
457 ret = drv->bdrv_open(bs, filename, open_flags);
458 if ((ret == -EACCES || ret == -EPERM) && !(flags & BDRV_O_FILE)) {
459 ret = drv->bdrv_open(bs, filename, open_flags & ~BDRV_O_RDWR);
460 bs->read_only = 1;
461 }
462 if (ret < 0) {
463 qemu_free(bs->opaque);
464 bs->opaque = NULL;
465 bs->drv = NULL;
466 unlink_and_fail:
467 if (bs->is_temporary)
468 unlink(filename);
469 return ret;
470 }
471 if (drv->bdrv_getlength) {
472 bs->total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
473 }
474 #ifndef _WIN32
475 if (bs->is_temporary) {
476 unlink(filename);
477 }
478 #endif
479 if (bs->backing_file[0] != '\0') {
480 /* if there is a backing file, use it */
481 BlockDriver *back_drv = NULL;
482 bs->backing_hd = bdrv_new("");
483 /* pass on read_only property to the backing_hd */
484 bs->backing_hd->read_only = bs->read_only;
485 path_combine(backing_filename, sizeof(backing_filename),
486 filename, bs->backing_file);
487 if (bs->backing_format[0] != '\0')
488 back_drv = bdrv_find_format(bs->backing_format);
489 ret = bdrv_open2(bs->backing_hd, backing_filename, open_flags,
490 back_drv);
491 if (ret < 0) {
492 bdrv_close(bs);
493 return ret;
494 }
495 }
496
497 if (!bdrv_key_required(bs)) {
498 /* call the change callback */
499 bs->media_changed = 1;
500 if (bs->change_cb)
501 bs->change_cb(bs->change_opaque);
502 }
503 return 0;
504 }
505
506 void bdrv_close(BlockDriverState *bs)
507 {
508 if (bs->drv) {
509 if (bs->backing_hd)
510 bdrv_delete(bs->backing_hd);
511 bs->drv->bdrv_close(bs);
512 qemu_free(bs->opaque);
513 #ifdef _WIN32
514 if (bs->is_temporary) {
515 unlink(bs->filename);
516 }
517 #endif
518 bs->opaque = NULL;
519 bs->drv = NULL;
520
521 /* call the change callback */
522 bs->media_changed = 1;
523 if (bs->change_cb)
524 bs->change_cb(bs->change_opaque);
525 }
526 }
527
528 void bdrv_delete(BlockDriverState *bs)
529 {
530 BlockDriverState **pbs;
531
532 pbs = &bdrv_first;
533 while (*pbs != bs && *pbs != NULL)
534 pbs = &(*pbs)->next;
535 if (*pbs == bs)
536 *pbs = bs->next;
537
538 bdrv_close(bs);
539 qemu_free(bs);
540 }
541
542 /*
543 * Run consistency checks on an image
544 *
545 * Returns the number of errors or -errno when an internal error occurs
546 */
547 int bdrv_check(BlockDriverState *bs)
548 {
549 if (bs->drv->bdrv_check == NULL) {
550 return -ENOTSUP;
551 }
552
553 return bs->drv->bdrv_check(bs);
554 }
555
556 /* commit COW file into the raw image */
557 int bdrv_commit(BlockDriverState *bs)
558 {
559 BlockDriver *drv = bs->drv;
560 int64_t i, total_sectors;
561 int n, j;
562 unsigned char sector[512];
563
564 if (!drv)
565 return -ENOMEDIUM;
566
567 if (bs->read_only) {
568 return -EACCES;
569 }
570
571 if (!bs->backing_hd) {
572 return -ENOTSUP;
573 }
574
575 total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
576 for (i = 0; i < total_sectors;) {
577 if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
578 for(j = 0; j < n; j++) {
579 if (bdrv_read(bs, i, sector, 1) != 0) {
580 return -EIO;
581 }
582
583 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
584 return -EIO;
585 }
586 i++;
587 }
588 } else {
589 i += n;
590 }
591 }
592
593 if (drv->bdrv_make_empty)
594 return drv->bdrv_make_empty(bs);
595
596 return 0;
597 }
598
599 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
600 size_t size)
601 {
602 int64_t len;
603
604 if (!bdrv_is_inserted(bs))
605 return -ENOMEDIUM;
606
607 if (bs->growable)
608 return 0;
609
610 len = bdrv_getlength(bs);
611
612 if (offset < 0)
613 return -EIO;
614
615 if ((offset > len) || (len - offset < size))
616 return -EIO;
617
618 return 0;
619 }
620
621 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
622 int nb_sectors)
623 {
624 return bdrv_check_byte_request(bs, sector_num * 512, nb_sectors * 512);
625 }
626
627 /* return < 0 if error. See bdrv_write() for the return codes */
628 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
629 uint8_t *buf, int nb_sectors)
630 {
631 BlockDriver *drv = bs->drv;
632
633 if (!drv)
634 return -ENOMEDIUM;
635 if (bdrv_check_request(bs, sector_num, nb_sectors))
636 return -EIO;
637
638 return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
639 }
640
641 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
642 int nb_sectors, int dirty)
643 {
644 int64_t start, end;
645 unsigned long val, idx, bit;
646
647 start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
648 end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
649
650 for (; start <= end; start++) {
651 idx = start / (sizeof(unsigned long) * 8);
652 bit = start % (sizeof(unsigned long) * 8);
653 val = bs->dirty_bitmap[idx];
654 if (dirty) {
655 val |= 1 << bit;
656 } else {
657 val &= ~(1 << bit);
658 }
659 bs->dirty_bitmap[idx] = val;
660 }
661 }
662
663 /* Return < 0 if error. Important errors are:
664 -EIO generic I/O error (may happen for all errors)
665 -ENOMEDIUM No media inserted.
666 -EINVAL Invalid sector number or nb_sectors
667 -EACCES Trying to write a read-only device
668 */
669 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
670 const uint8_t *buf, int nb_sectors)
671 {
672 BlockDriver *drv = bs->drv;
673 if (!bs->drv)
674 return -ENOMEDIUM;
675 if (bs->read_only)
676 return -EACCES;
677 if (bdrv_check_request(bs, sector_num, nb_sectors))
678 return -EIO;
679
680 if (bs->dirty_bitmap) {
681 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
682 }
683
684 return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
685 }
686
687 int bdrv_pread(BlockDriverState *bs, int64_t offset,
688 void *buf, int count1)
689 {
690 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
691 int len, nb_sectors, count;
692 int64_t sector_num;
693
694 count = count1;
695 /* first read to align to sector start */
696 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
697 if (len > count)
698 len = count;
699 sector_num = offset >> BDRV_SECTOR_BITS;
700 if (len > 0) {
701 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
702 return -EIO;
703 memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
704 count -= len;
705 if (count == 0)
706 return count1;
707 sector_num++;
708 buf += len;
709 }
710
711 /* read the sectors "in place" */
712 nb_sectors = count >> BDRV_SECTOR_BITS;
713 if (nb_sectors > 0) {
714 if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
715 return -EIO;
716 sector_num += nb_sectors;
717 len = nb_sectors << BDRV_SECTOR_BITS;
718 buf += len;
719 count -= len;
720 }
721
722 /* add data from the last sector */
723 if (count > 0) {
724 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
725 return -EIO;
726 memcpy(buf, tmp_buf, count);
727 }
728 return count1;
729 }
730
731 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
732 const void *buf, int count1)
733 {
734 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
735 int len, nb_sectors, count;
736 int64_t sector_num;
737
738 count = count1;
739 /* first write to align to sector start */
740 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
741 if (len > count)
742 len = count;
743 sector_num = offset >> BDRV_SECTOR_BITS;
744 if (len > 0) {
745 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
746 return -EIO;
747 memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
748 if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
749 return -EIO;
750 count -= len;
751 if (count == 0)
752 return count1;
753 sector_num++;
754 buf += len;
755 }
756
757 /* write the sectors "in place" */
758 nb_sectors = count >> BDRV_SECTOR_BITS;
759 if (nb_sectors > 0) {
760 if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0)
761 return -EIO;
762 sector_num += nb_sectors;
763 len = nb_sectors << BDRV_SECTOR_BITS;
764 buf += len;
765 count -= len;
766 }
767
768 /* add data from the last sector */
769 if (count > 0) {
770 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
771 return -EIO;
772 memcpy(tmp_buf, buf, count);
773 if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
774 return -EIO;
775 }
776 return count1;
777 }
778
779 /**
780 * Truncate file to 'offset' bytes (needed only for file protocols)
781 */
782 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
783 {
784 BlockDriver *drv = bs->drv;
785 if (!drv)
786 return -ENOMEDIUM;
787 if (!drv->bdrv_truncate)
788 return -ENOTSUP;
789 if (bs->read_only)
790 return -EACCES;
791 return drv->bdrv_truncate(bs, offset);
792 }
793
794 /**
795 * Length of a file in bytes. Return < 0 if error or unknown.
796 */
797 int64_t bdrv_getlength(BlockDriverState *bs)
798 {
799 BlockDriver *drv = bs->drv;
800 if (!drv)
801 return -ENOMEDIUM;
802 if (!drv->bdrv_getlength) {
803 /* legacy mode */
804 return bs->total_sectors * BDRV_SECTOR_SIZE;
805 }
806 return drv->bdrv_getlength(bs);
807 }
808
809 /* return 0 as number of sectors if no device present or error */
810 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
811 {
812 int64_t length;
813 length = bdrv_getlength(bs);
814 if (length < 0)
815 length = 0;
816 else
817 length = length >> BDRV_SECTOR_BITS;
818 *nb_sectors_ptr = length;
819 }
820
821 struct partition {
822 uint8_t boot_ind; /* 0x80 - active */
823 uint8_t head; /* starting head */
824 uint8_t sector; /* starting sector */
825 uint8_t cyl; /* starting cylinder */
826 uint8_t sys_ind; /* What partition type */
827 uint8_t end_head; /* end head */
828 uint8_t end_sector; /* end sector */
829 uint8_t end_cyl; /* end cylinder */
830 uint32_t start_sect; /* starting sector counting from 0 */
831 uint32_t nr_sects; /* nr of sectors in partition */
832 } __attribute__((packed));
833
834 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
835 static int guess_disk_lchs(BlockDriverState *bs,
836 int *pcylinders, int *pheads, int *psectors)
837 {
838 uint8_t buf[512];
839 int ret, i, heads, sectors, cylinders;
840 struct partition *p;
841 uint32_t nr_sects;
842 uint64_t nb_sectors;
843
844 bdrv_get_geometry(bs, &nb_sectors);
845
846 ret = bdrv_read(bs, 0, buf, 1);
847 if (ret < 0)
848 return -1;
849 /* test msdos magic */
850 if (buf[510] != 0x55 || buf[511] != 0xaa)
851 return -1;
852 for(i = 0; i < 4; i++) {
853 p = ((struct partition *)(buf + 0x1be)) + i;
854 nr_sects = le32_to_cpu(p->nr_sects);
855 if (nr_sects && p->end_head) {
856 /* We make the assumption that the partition terminates on
857 a cylinder boundary */
858 heads = p->end_head + 1;
859 sectors = p->end_sector & 63;
860 if (sectors == 0)
861 continue;
862 cylinders = nb_sectors / (heads * sectors);
863 if (cylinders < 1 || cylinders > 16383)
864 continue;
865 *pheads = heads;
866 *psectors = sectors;
867 *pcylinders = cylinders;
868 #if 0
869 printf("guessed geometry: LCHS=%d %d %d\n",
870 cylinders, heads, sectors);
871 #endif
872 return 0;
873 }
874 }
875 return -1;
876 }
877
878 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
879 {
880 int translation, lba_detected = 0;
881 int cylinders, heads, secs;
882 uint64_t nb_sectors;
883
884 /* if a geometry hint is available, use it */
885 bdrv_get_geometry(bs, &nb_sectors);
886 bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
887 translation = bdrv_get_translation_hint(bs);
888 if (cylinders != 0) {
889 *pcyls = cylinders;
890 *pheads = heads;
891 *psecs = secs;
892 } else {
893 if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
894 if (heads > 16) {
895 /* if heads > 16, it means that a BIOS LBA
896 translation was active, so the default
897 hardware geometry is OK */
898 lba_detected = 1;
899 goto default_geometry;
900 } else {
901 *pcyls = cylinders;
902 *pheads = heads;
903 *psecs = secs;
904 /* disable any translation to be in sync with
905 the logical geometry */
906 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
907 bdrv_set_translation_hint(bs,
908 BIOS_ATA_TRANSLATION_NONE);
909 }
910 }
911 } else {
912 default_geometry:
913 /* if no geometry, use a standard physical disk geometry */
914 cylinders = nb_sectors / (16 * 63);
915
916 if (cylinders > 16383)
917 cylinders = 16383;
918 else if (cylinders < 2)
919 cylinders = 2;
920 *pcyls = cylinders;
921 *pheads = 16;
922 *psecs = 63;
923 if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
924 if ((*pcyls * *pheads) <= 131072) {
925 bdrv_set_translation_hint(bs,
926 BIOS_ATA_TRANSLATION_LARGE);
927 } else {
928 bdrv_set_translation_hint(bs,
929 BIOS_ATA_TRANSLATION_LBA);
930 }
931 }
932 }
933 bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
934 }
935 }
936
937 void bdrv_set_geometry_hint(BlockDriverState *bs,
938 int cyls, int heads, int secs)
939 {
940 bs->cyls = cyls;
941 bs->heads = heads;
942 bs->secs = secs;
943 }
944
945 void bdrv_set_type_hint(BlockDriverState *bs, int type)
946 {
947 bs->type = type;
948 bs->removable = ((type == BDRV_TYPE_CDROM ||
949 type == BDRV_TYPE_FLOPPY));
950 }
951
952 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
953 {
954 bs->translation = translation;
955 }
956
957 void bdrv_get_geometry_hint(BlockDriverState *bs,
958 int *pcyls, int *pheads, int *psecs)
959 {
960 *pcyls = bs->cyls;
961 *pheads = bs->heads;
962 *psecs = bs->secs;
963 }
964
965 int bdrv_get_type_hint(BlockDriverState *bs)
966 {
967 return bs->type;
968 }
969
970 int bdrv_get_translation_hint(BlockDriverState *bs)
971 {
972 return bs->translation;
973 }
974
975 int bdrv_is_removable(BlockDriverState *bs)
976 {
977 return bs->removable;
978 }
979
980 int bdrv_is_read_only(BlockDriverState *bs)
981 {
982 return bs->read_only;
983 }
984
985 int bdrv_set_read_only(BlockDriverState *bs, int read_only)
986 {
987 int ret = bs->read_only;
988 bs->read_only = read_only;
989 return ret;
990 }
991
992 int bdrv_is_sg(BlockDriverState *bs)
993 {
994 return bs->sg;
995 }
996
997 int bdrv_enable_write_cache(BlockDriverState *bs)
998 {
999 return bs->enable_write_cache;
1000 }
1001
1002 /* XXX: no longer used */
1003 void bdrv_set_change_cb(BlockDriverState *bs,
1004 void (*change_cb)(void *opaque), void *opaque)
1005 {
1006 bs->change_cb = change_cb;
1007 bs->change_opaque = opaque;
1008 }
1009
1010 int bdrv_is_encrypted(BlockDriverState *bs)
1011 {
1012 if (bs->backing_hd && bs->backing_hd->encrypted)
1013 return 1;
1014 return bs->encrypted;
1015 }
1016
1017 int bdrv_key_required(BlockDriverState *bs)
1018 {
1019 BlockDriverState *backing_hd = bs->backing_hd;
1020
1021 if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
1022 return 1;
1023 return (bs->encrypted && !bs->valid_key);
1024 }
1025
1026 int bdrv_set_key(BlockDriverState *bs, const char *key)
1027 {
1028 int ret;
1029 if (bs->backing_hd && bs->backing_hd->encrypted) {
1030 ret = bdrv_set_key(bs->backing_hd, key);
1031 if (ret < 0)
1032 return ret;
1033 if (!bs->encrypted)
1034 return 0;
1035 }
1036 if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
1037 return -1;
1038 ret = bs->drv->bdrv_set_key(bs, key);
1039 if (ret < 0) {
1040 bs->valid_key = 0;
1041 } else if (!bs->valid_key) {
1042 bs->valid_key = 1;
1043 /* call the change callback now, we skipped it on open */
1044 bs->media_changed = 1;
1045 if (bs->change_cb)
1046 bs->change_cb(bs->change_opaque);
1047 }
1048 return ret;
1049 }
1050
1051 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
1052 {
1053 if (!bs->drv) {
1054 buf[0] = '\0';
1055 } else {
1056 pstrcpy(buf, buf_size, bs->drv->format_name);
1057 }
1058 }
1059
1060 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
1061 void *opaque)
1062 {
1063 BlockDriver *drv;
1064
1065 for (drv = first_drv; drv != NULL; drv = drv->next) {
1066 it(opaque, drv->format_name);
1067 }
1068 }
1069
1070 BlockDriverState *bdrv_find(const char *name)
1071 {
1072 BlockDriverState *bs;
1073
1074 for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1075 if (!strcmp(name, bs->device_name))
1076 return bs;
1077 }
1078 return NULL;
1079 }
1080
1081 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
1082 {
1083 BlockDriverState *bs;
1084
1085 for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1086 it(opaque, bs);
1087 }
1088 }
1089
1090 const char *bdrv_get_device_name(BlockDriverState *bs)
1091 {
1092 return bs->device_name;
1093 }
1094
1095 void bdrv_flush(BlockDriverState *bs)
1096 {
1097 if (!bs->drv)
1098 return;
1099 if (bs->drv->bdrv_flush)
1100 bs->drv->bdrv_flush(bs);
1101 if (bs->backing_hd)
1102 bdrv_flush(bs->backing_hd);
1103 }
1104
1105 void bdrv_flush_all(void)
1106 {
1107 BlockDriverState *bs;
1108
1109 for (bs = bdrv_first; bs != NULL; bs = bs->next)
1110 if (bs->drv && !bdrv_is_read_only(bs) &&
1111 (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
1112 bdrv_flush(bs);
1113 }
1114
1115 /*
1116 * Returns true iff the specified sector is present in the disk image. Drivers
1117 * not implementing the functionality are assumed to not support backing files,
1118 * hence all their sectors are reported as allocated.
1119 *
1120 * 'pnum' is set to the number of sectors (including and immediately following
1121 * the specified sector) that are known to be in the same
1122 * allocated/unallocated state.
1123 *
1124 * 'nb_sectors' is the max value 'pnum' should be set to.
1125 */
1126 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
1127 int *pnum)
1128 {
1129 int64_t n;
1130 if (!bs->drv->bdrv_is_allocated) {
1131 if (sector_num >= bs->total_sectors) {
1132 *pnum = 0;
1133 return 0;
1134 }
1135 n = bs->total_sectors - sector_num;
1136 *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
1137 return 1;
1138 }
1139 return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
1140 }
1141
1142 void bdrv_info(Monitor *mon)
1143 {
1144 BlockDriverState *bs;
1145
1146 for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1147 monitor_printf(mon, "%s:", bs->device_name);
1148 monitor_printf(mon, " type=");
1149 switch(bs->type) {
1150 case BDRV_TYPE_HD:
1151 monitor_printf(mon, "hd");
1152 break;
1153 case BDRV_TYPE_CDROM:
1154 monitor_printf(mon, "cdrom");
1155 break;
1156 case BDRV_TYPE_FLOPPY:
1157 monitor_printf(mon, "floppy");
1158 break;
1159 }
1160 monitor_printf(mon, " removable=%d", bs->removable);
1161 if (bs->removable) {
1162 monitor_printf(mon, " locked=%d", bs->locked);
1163 }
1164 if (bs->drv) {
1165 monitor_printf(mon, " file=");
1166 monitor_print_filename(mon, bs->filename);
1167 if (bs->backing_file[0] != '\0') {
1168 monitor_printf(mon, " backing_file=");
1169 monitor_print_filename(mon, bs->backing_file);
1170 }
1171 monitor_printf(mon, " ro=%d", bs->read_only);
1172 monitor_printf(mon, " drv=%s", bs->drv->format_name);
1173 monitor_printf(mon, " encrypted=%d", bdrv_is_encrypted(bs));
1174 } else {
1175 monitor_printf(mon, " [not inserted]");
1176 }
1177 monitor_printf(mon, "\n");
1178 }
1179 }
1180
1181 /* The "info blockstats" command. */
1182 void bdrv_info_stats(Monitor *mon)
1183 {
1184 BlockDriverState *bs;
1185
1186 for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1187 monitor_printf(mon, "%s:"
1188 " rd_bytes=%" PRIu64
1189 " wr_bytes=%" PRIu64
1190 " rd_operations=%" PRIu64
1191 " wr_operations=%" PRIu64
1192 "\n",
1193 bs->device_name,
1194 bs->rd_bytes, bs->wr_bytes,
1195 bs->rd_ops, bs->wr_ops);
1196 }
1197 }
1198
1199 const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
1200 {
1201 if (bs->backing_hd && bs->backing_hd->encrypted)
1202 return bs->backing_file;
1203 else if (bs->encrypted)
1204 return bs->filename;
1205 else
1206 return NULL;
1207 }
1208
1209 void bdrv_get_backing_filename(BlockDriverState *bs,
1210 char *filename, int filename_size)
1211 {
1212 if (!bs->backing_hd) {
1213 pstrcpy(filename, filename_size, "");
1214 } else {
1215 pstrcpy(filename, filename_size, bs->backing_file);
1216 }
1217 }
1218
1219 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1220 const uint8_t *buf, int nb_sectors)
1221 {
1222 BlockDriver *drv = bs->drv;
1223 if (!drv)
1224 return -ENOMEDIUM;
1225 if (!drv->bdrv_write_compressed)
1226 return -ENOTSUP;
1227 if (bdrv_check_request(bs, sector_num, nb_sectors))
1228 return -EIO;
1229
1230 if (bs->dirty_bitmap) {
1231 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1232 }
1233
1234 return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1235 }
1236
1237 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1238 {
1239 BlockDriver *drv = bs->drv;
1240 if (!drv)
1241 return -ENOMEDIUM;
1242 if (!drv->bdrv_get_info)
1243 return -ENOTSUP;
1244 memset(bdi, 0, sizeof(*bdi));
1245 return drv->bdrv_get_info(bs, bdi);
1246 }
1247
1248 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
1249 int64_t pos, int size)
1250 {
1251 BlockDriver *drv = bs->drv;
1252 if (!drv)
1253 return -ENOMEDIUM;
1254 if (!drv->bdrv_save_vmstate)
1255 return -ENOTSUP;
1256 return drv->bdrv_save_vmstate(bs, buf, pos, size);
1257 }
1258
1259 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
1260 int64_t pos, int size)
1261 {
1262 BlockDriver *drv = bs->drv;
1263 if (!drv)
1264 return -ENOMEDIUM;
1265 if (!drv->bdrv_load_vmstate)
1266 return -ENOTSUP;
1267 return drv->bdrv_load_vmstate(bs, buf, pos, size);
1268 }
1269
1270 /**************************************************************/
1271 /* handling of snapshots */
1272
1273 int bdrv_snapshot_create(BlockDriverState *bs,
1274 QEMUSnapshotInfo *sn_info)
1275 {
1276 BlockDriver *drv = bs->drv;
1277 if (!drv)
1278 return -ENOMEDIUM;
1279 if (!drv->bdrv_snapshot_create)
1280 return -ENOTSUP;
1281 return drv->bdrv_snapshot_create(bs, sn_info);
1282 }
1283
1284 int bdrv_snapshot_goto(BlockDriverState *bs,
1285 const char *snapshot_id)
1286 {
1287 BlockDriver *drv = bs->drv;
1288 if (!drv)
1289 return -ENOMEDIUM;
1290 if (!drv->bdrv_snapshot_goto)
1291 return -ENOTSUP;
1292 return drv->bdrv_snapshot_goto(bs, snapshot_id);
1293 }
1294
1295 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1296 {
1297 BlockDriver *drv = bs->drv;
1298 if (!drv)
1299 return -ENOMEDIUM;
1300 if (!drv->bdrv_snapshot_delete)
1301 return -ENOTSUP;
1302 return drv->bdrv_snapshot_delete(bs, snapshot_id);
1303 }
1304
1305 int bdrv_snapshot_list(BlockDriverState *bs,
1306 QEMUSnapshotInfo **psn_info)
1307 {
1308 BlockDriver *drv = bs->drv;
1309 if (!drv)
1310 return -ENOMEDIUM;
1311 if (!drv->bdrv_snapshot_list)
1312 return -ENOTSUP;
1313 return drv->bdrv_snapshot_list(bs, psn_info);
1314 }
1315
1316 #define NB_SUFFIXES 4
1317
1318 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1319 {
1320 static const char suffixes[NB_SUFFIXES] = "KMGT";
1321 int64_t base;
1322 int i;
1323
1324 if (size <= 999) {
1325 snprintf(buf, buf_size, "%" PRId64, size);
1326 } else {
1327 base = 1024;
1328 for(i = 0; i < NB_SUFFIXES; i++) {
1329 if (size < (10 * base)) {
1330 snprintf(buf, buf_size, "%0.1f%c",
1331 (double)size / base,
1332 suffixes[i]);
1333 break;
1334 } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1335 snprintf(buf, buf_size, "%" PRId64 "%c",
1336 ((size + (base >> 1)) / base),
1337 suffixes[i]);
1338 break;
1339 }
1340 base = base * 1024;
1341 }
1342 }
1343 return buf;
1344 }
1345
1346 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1347 {
1348 char buf1[128], date_buf[128], clock_buf[128];
1349 #ifdef _WIN32
1350 struct tm *ptm;
1351 #else
1352 struct tm tm;
1353 #endif
1354 time_t ti;
1355 int64_t secs;
1356
1357 if (!sn) {
1358 snprintf(buf, buf_size,
1359 "%-10s%-20s%7s%20s%15s",
1360 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1361 } else {
1362 ti = sn->date_sec;
1363 #ifdef _WIN32
1364 ptm = localtime(&ti);
1365 strftime(date_buf, sizeof(date_buf),
1366 "%Y-%m-%d %H:%M:%S", ptm);
1367 #else
1368 localtime_r(&ti, &tm);
1369 strftime(date_buf, sizeof(date_buf),
1370 "%Y-%m-%d %H:%M:%S", &tm);
1371 #endif
1372 secs = sn->vm_clock_nsec / 1000000000;
1373 snprintf(clock_buf, sizeof(clock_buf),
1374 "%02d:%02d:%02d.%03d",
1375 (int)(secs / 3600),
1376 (int)((secs / 60) % 60),
1377 (int)(secs % 60),
1378 (int)((sn->vm_clock_nsec / 1000000) % 1000));
1379 snprintf(buf, buf_size,
1380 "%-10s%-20s%7s%20s%15s",
1381 sn->id_str, sn->name,
1382 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1383 date_buf,
1384 clock_buf);
1385 }
1386 return buf;
1387 }
1388
1389
1390 /**************************************************************/
1391 /* async I/Os */
1392
1393 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
1394 QEMUIOVector *qiov, int nb_sectors,
1395 BlockDriverCompletionFunc *cb, void *opaque)
1396 {
1397 BlockDriver *drv = bs->drv;
1398 BlockDriverAIOCB *ret;
1399
1400 if (!drv)
1401 return NULL;
1402 if (bdrv_check_request(bs, sector_num, nb_sectors))
1403 return NULL;
1404
1405 ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
1406 cb, opaque);
1407
1408 if (ret) {
1409 /* Update stats even though technically transfer has not happened. */
1410 bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
1411 bs->rd_ops ++;
1412 }
1413
1414 return ret;
1415 }
1416
1417 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
1418 QEMUIOVector *qiov, int nb_sectors,
1419 BlockDriverCompletionFunc *cb, void *opaque)
1420 {
1421 BlockDriver *drv = bs->drv;
1422 BlockDriverAIOCB *ret;
1423
1424 if (!drv)
1425 return NULL;
1426 if (bs->read_only)
1427 return NULL;
1428 if (bdrv_check_request(bs, sector_num, nb_sectors))
1429 return NULL;
1430
1431 if (bs->dirty_bitmap) {
1432 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1433 }
1434
1435 ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
1436 cb, opaque);
1437
1438 if (ret) {
1439 /* Update stats even though technically transfer has not happened. */
1440 bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
1441 bs->wr_ops ++;
1442 }
1443
1444 return ret;
1445 }
1446
1447
1448 typedef struct MultiwriteCB {
1449 int error;
1450 int num_requests;
1451 int num_callbacks;
1452 struct {
1453 BlockDriverCompletionFunc *cb;
1454 void *opaque;
1455 QEMUIOVector *free_qiov;
1456 void *free_buf;
1457 } callbacks[];
1458 } MultiwriteCB;
1459
1460 static void multiwrite_user_cb(MultiwriteCB *mcb)
1461 {
1462 int i;
1463
1464 for (i = 0; i < mcb->num_callbacks; i++) {
1465 mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
1466 qemu_free(mcb->callbacks[i].free_qiov);
1467 qemu_free(mcb->callbacks[i].free_buf);
1468 }
1469 }
1470
1471 static void multiwrite_cb(void *opaque, int ret)
1472 {
1473 MultiwriteCB *mcb = opaque;
1474
1475 if (ret < 0) {
1476 mcb->error = ret;
1477 multiwrite_user_cb(mcb);
1478 }
1479
1480 mcb->num_requests--;
1481 if (mcb->num_requests == 0) {
1482 if (mcb->error == 0) {
1483 multiwrite_user_cb(mcb);
1484 }
1485 qemu_free(mcb);
1486 }
1487 }
1488
1489 static int multiwrite_req_compare(const void *a, const void *b)
1490 {
1491 return (((BlockRequest*) a)->sector - ((BlockRequest*) b)->sector);
1492 }
1493
1494 /*
1495 * Takes a bunch of requests and tries to merge them. Returns the number of
1496 * requests that remain after merging.
1497 */
1498 static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
1499 int num_reqs, MultiwriteCB *mcb)
1500 {
1501 int i, outidx;
1502
1503 // Sort requests by start sector
1504 qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
1505
1506 // Check if adjacent requests touch the same clusters. If so, combine them,
1507 // filling up gaps with zero sectors.
1508 outidx = 0;
1509 for (i = 1; i < num_reqs; i++) {
1510 int merge = 0;
1511 int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
1512
1513 // This handles the cases that are valid for all block drivers, namely
1514 // exactly sequential writes and overlapping writes.
1515 if (reqs[i].sector <= oldreq_last) {
1516 merge = 1;
1517 }
1518
1519 // The block driver may decide that it makes sense to combine requests
1520 // even if there is a gap of some sectors between them. In this case,
1521 // the gap is filled with zeros (therefore only applicable for yet
1522 // unused space in format like qcow2).
1523 if (!merge && bs->drv->bdrv_merge_requests) {
1524 merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
1525 }
1526
1527 if (merge) {
1528 size_t size;
1529 QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
1530 qemu_iovec_init(qiov,
1531 reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
1532
1533 // Add the first request to the merged one. If the requests are
1534 // overlapping, drop the last sectors of the first request.
1535 size = (reqs[i].sector - reqs[outidx].sector) << 9;
1536 qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
1537
1538 // We might need to add some zeros between the two requests
1539 if (reqs[i].sector > oldreq_last) {
1540 size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
1541 uint8_t *buf = qemu_blockalign(bs, zero_bytes);
1542 memset(buf, 0, zero_bytes);
1543 qemu_iovec_add(qiov, buf, zero_bytes);
1544 mcb->callbacks[i].free_buf = buf;
1545 }
1546
1547 // Add the second request
1548 qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
1549
1550 reqs[outidx].nb_sectors += reqs[i].nb_sectors;
1551 reqs[outidx].qiov = qiov;
1552
1553 mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
1554 } else {
1555 outidx++;
1556 reqs[outidx].sector = reqs[i].sector;
1557 reqs[outidx].nb_sectors = reqs[i].nb_sectors;
1558 reqs[outidx].qiov = reqs[i].qiov;
1559 }
1560 }
1561
1562 return outidx + 1;
1563 }
1564
1565 /*
1566 * Submit multiple AIO write requests at once.
1567 *
1568 * On success, the function returns 0 and all requests in the reqs array have
1569 * been submitted. In error case this function returns -1, and any of the
1570 * requests may or may not be submitted yet. In particular, this means that the
1571 * callback will be called for some of the requests, for others it won't. The
1572 * caller must check the error field of the BlockRequest to wait for the right
1573 * callbacks (if error != 0, no callback will be called).
1574 *
1575 * The implementation may modify the contents of the reqs array, e.g. to merge
1576 * requests. However, the fields opaque and error are left unmodified as they
1577 * are used to signal failure for a single request to the caller.
1578 */
1579 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
1580 {
1581 BlockDriverAIOCB *acb;
1582 MultiwriteCB *mcb;
1583 int i;
1584
1585 if (num_reqs == 0) {
1586 return 0;
1587 }
1588
1589 // Create MultiwriteCB structure
1590 mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
1591 mcb->num_requests = 0;
1592 mcb->num_callbacks = num_reqs;
1593
1594 for (i = 0; i < num_reqs; i++) {
1595 mcb->callbacks[i].cb = reqs[i].cb;
1596 mcb->callbacks[i].opaque = reqs[i].opaque;
1597 }
1598
1599 // Check for mergable requests
1600 num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
1601
1602 // Run the aio requests
1603 for (i = 0; i < num_reqs; i++) {
1604 acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
1605 reqs[i].nb_sectors, multiwrite_cb, mcb);
1606
1607 if (acb == NULL) {
1608 // We can only fail the whole thing if no request has been
1609 // submitted yet. Otherwise we'll wait for the submitted AIOs to
1610 // complete and report the error in the callback.
1611 if (mcb->num_requests == 0) {
1612 reqs[i].error = EIO;
1613 goto fail;
1614 } else {
1615 mcb->error = EIO;
1616 break;
1617 }
1618 } else {
1619 mcb->num_requests++;
1620 }
1621 }
1622
1623 return 0;
1624
1625 fail:
1626 free(mcb);
1627 return -1;
1628 }
1629
1630 BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
1631 BlockDriverCompletionFunc *cb, void *opaque)
1632 {
1633 BlockDriver *drv = bs->drv;
1634
1635 if (!drv)
1636 return NULL;
1637
1638 /*
1639 * Note that unlike bdrv_flush the driver is reponsible for flushing a
1640 * backing image if it exists.
1641 */
1642 return drv->bdrv_aio_flush(bs, cb, opaque);
1643 }
1644
1645 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
1646 {
1647 acb->pool->cancel(acb);
1648 }
1649
1650
1651 /**************************************************************/
1652 /* async block device emulation */
1653
1654 typedef struct BlockDriverAIOCBSync {
1655 BlockDriverAIOCB common;
1656 QEMUBH *bh;
1657 int ret;
1658 /* vector translation state */
1659 QEMUIOVector *qiov;
1660 uint8_t *bounce;
1661 int is_write;
1662 } BlockDriverAIOCBSync;
1663
1664 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
1665 {
1666 BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
1667 qemu_bh_delete(acb->bh);
1668 acb->bh = NULL;
1669 qemu_aio_release(acb);
1670 }
1671
1672 static AIOPool bdrv_em_aio_pool = {
1673 .aiocb_size = sizeof(BlockDriverAIOCBSync),
1674 .cancel = bdrv_aio_cancel_em,
1675 };
1676
1677 static void bdrv_aio_bh_cb(void *opaque)
1678 {
1679 BlockDriverAIOCBSync *acb = opaque;
1680
1681 if (!acb->is_write)
1682 qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
1683 qemu_vfree(acb->bounce);
1684 acb->common.cb(acb->common.opaque, acb->ret);
1685 qemu_bh_delete(acb->bh);
1686 acb->bh = NULL;
1687 qemu_aio_release(acb);
1688 }
1689
1690 static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
1691 int64_t sector_num,
1692 QEMUIOVector *qiov,
1693 int nb_sectors,
1694 BlockDriverCompletionFunc *cb,
1695 void *opaque,
1696 int is_write)
1697
1698 {
1699 BlockDriverAIOCBSync *acb;
1700
1701 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
1702 acb->is_write = is_write;
1703 acb->qiov = qiov;
1704 acb->bounce = qemu_blockalign(bs, qiov->size);
1705
1706 if (!acb->bh)
1707 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1708
1709 if (is_write) {
1710 qemu_iovec_to_buffer(acb->qiov, acb->bounce);
1711 acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
1712 } else {
1713 acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
1714 }
1715
1716 qemu_bh_schedule(acb->bh);
1717
1718 return &acb->common;
1719 }
1720
1721 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
1722 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
1723 BlockDriverCompletionFunc *cb, void *opaque)
1724 {
1725 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
1726 }
1727
1728 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
1729 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
1730 BlockDriverCompletionFunc *cb, void *opaque)
1731 {
1732 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
1733 }
1734
1735 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
1736 BlockDriverCompletionFunc *cb, void *opaque)
1737 {
1738 BlockDriverAIOCBSync *acb;
1739
1740 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
1741 acb->is_write = 1; /* don't bounce in the completion hadler */
1742 acb->qiov = NULL;
1743 acb->bounce = NULL;
1744 acb->ret = 0;
1745
1746 if (!acb->bh)
1747 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1748
1749 bdrv_flush(bs);
1750 qemu_bh_schedule(acb->bh);
1751 return &acb->common;
1752 }
1753
1754 /**************************************************************/
1755 /* sync block device emulation */
1756
1757 static void bdrv_rw_em_cb(void *opaque, int ret)
1758 {
1759 *(int *)opaque = ret;
1760 }
1761
1762 #define NOT_DONE 0x7fffffff
1763
1764 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
1765 uint8_t *buf, int nb_sectors)
1766 {
1767 int async_ret;
1768 BlockDriverAIOCB *acb;
1769 struct iovec iov;
1770 QEMUIOVector qiov;
1771
1772 async_context_push();
1773
1774 async_ret = NOT_DONE;
1775 iov.iov_base = (void *)buf;
1776 iov.iov_len = nb_sectors * 512;
1777 qemu_iovec_init_external(&qiov, &iov, 1);
1778 acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
1779 bdrv_rw_em_cb, &async_ret);
1780 if (acb == NULL) {
1781 async_ret = -1;
1782 goto fail;
1783 }
1784
1785 while (async_ret == NOT_DONE) {
1786 qemu_aio_wait();
1787 }
1788
1789
1790 fail:
1791 async_context_pop();
1792 return async_ret;
1793 }
1794
1795 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
1796 const uint8_t *buf, int nb_sectors)
1797 {
1798 int async_ret;
1799 BlockDriverAIOCB *acb;
1800 struct iovec iov;
1801 QEMUIOVector qiov;
1802
1803 async_context_push();
1804
1805 async_ret = NOT_DONE;
1806 iov.iov_base = (void *)buf;
1807 iov.iov_len = nb_sectors * 512;
1808 qemu_iovec_init_external(&qiov, &iov, 1);
1809 acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
1810 bdrv_rw_em_cb, &async_ret);
1811 if (acb == NULL) {
1812 async_ret = -1;
1813 goto fail;
1814 }
1815 while (async_ret == NOT_DONE) {
1816 qemu_aio_wait();
1817 }
1818
1819 fail:
1820 async_context_pop();
1821 return async_ret;
1822 }
1823
1824 void bdrv_init(void)
1825 {
1826 module_call_init(MODULE_INIT_BLOCK);
1827 }
1828
1829 void bdrv_init_with_whitelist(void)
1830 {
1831 use_bdrv_whitelist = 1;
1832 bdrv_init();
1833 }
1834
1835 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
1836 BlockDriverCompletionFunc *cb, void *opaque)
1837 {
1838 BlockDriverAIOCB *acb;
1839
1840 if (pool->free_aiocb) {
1841 acb = pool->free_aiocb;
1842 pool->free_aiocb = acb->next;
1843 } else {
1844 acb = qemu_mallocz(pool->aiocb_size);
1845 acb->pool = pool;
1846 }
1847 acb->bs = bs;
1848 acb->cb = cb;
1849 acb->opaque = opaque;
1850 return acb;
1851 }
1852
1853 void qemu_aio_release(void *p)
1854 {
1855 BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
1856 AIOPool *pool = acb->pool;
1857 acb->next = pool->free_aiocb;
1858 pool->free_aiocb = acb;
1859 }
1860
1861 /**************************************************************/
1862 /* removable device support */
1863
1864 /**
1865 * Return TRUE if the media is present
1866 */
1867 int bdrv_is_inserted(BlockDriverState *bs)
1868 {
1869 BlockDriver *drv = bs->drv;
1870 int ret;
1871 if (!drv)
1872 return 0;
1873 if (!drv->bdrv_is_inserted)
1874 return 1;
1875 ret = drv->bdrv_is_inserted(bs);
1876 return ret;
1877 }
1878
1879 /**
1880 * Return TRUE if the media changed since the last call to this
1881 * function. It is currently only used for floppy disks
1882 */
1883 int bdrv_media_changed(BlockDriverState *bs)
1884 {
1885 BlockDriver *drv = bs->drv;
1886 int ret;
1887
1888 if (!drv || !drv->bdrv_media_changed)
1889 ret = -ENOTSUP;
1890 else
1891 ret = drv->bdrv_media_changed(bs);
1892 if (ret == -ENOTSUP)
1893 ret = bs->media_changed;
1894 bs->media_changed = 0;
1895 return ret;
1896 }
1897
1898 /**
1899 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
1900 */
1901 int bdrv_eject(BlockDriverState *bs, int eject_flag)
1902 {
1903 BlockDriver *drv = bs->drv;
1904 int ret;
1905
1906 if (bs->locked) {
1907 return -EBUSY;
1908 }
1909
1910 if (!drv || !drv->bdrv_eject) {
1911 ret = -ENOTSUP;
1912 } else {
1913 ret = drv->bdrv_eject(bs, eject_flag);
1914 }
1915 if (ret == -ENOTSUP) {
1916 if (eject_flag)
1917 bdrv_close(bs);
1918 ret = 0;
1919 }
1920
1921 return ret;
1922 }
1923
1924 int bdrv_is_locked(BlockDriverState *bs)
1925 {
1926 return bs->locked;
1927 }
1928
1929 /**
1930 * Lock or unlock the media (if it is locked, the user won't be able
1931 * to eject it manually).
1932 */
1933 void bdrv_set_locked(BlockDriverState *bs, int locked)
1934 {
1935 BlockDriver *drv = bs->drv;
1936
1937 bs->locked = locked;
1938 if (drv && drv->bdrv_set_locked) {
1939 drv->bdrv_set_locked(bs, locked);
1940 }
1941 }
1942
1943 /* needed for generic scsi interface */
1944
1945 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
1946 {
1947 BlockDriver *drv = bs->drv;
1948
1949 if (drv && drv->bdrv_ioctl)
1950 return drv->bdrv_ioctl(bs, req, buf);
1951 return -ENOTSUP;
1952 }
1953
1954 BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
1955 unsigned long int req, void *buf,
1956 BlockDriverCompletionFunc *cb, void *opaque)
1957 {
1958 BlockDriver *drv = bs->drv;
1959
1960 if (drv && drv->bdrv_aio_ioctl)
1961 return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
1962 return NULL;
1963 }
1964
1965
1966
1967 void *qemu_blockalign(BlockDriverState *bs, size_t size)
1968 {
1969 return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
1970 }
1971
1972 void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
1973 {
1974 int64_t bitmap_size;
1975
1976 if (enable) {
1977 if (!bs->dirty_bitmap) {
1978 bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
1979 BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
1980 bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
1981
1982 bs->dirty_bitmap = qemu_mallocz(bitmap_size);
1983 }
1984 } else {
1985 if (bs->dirty_bitmap) {
1986 qemu_free(bs->dirty_bitmap);
1987 bs->dirty_bitmap = NULL;
1988 }
1989 }
1990 }
1991
1992 int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
1993 {
1994 int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
1995
1996 if (bs->dirty_bitmap &&
1997 (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) {
1998 return bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] &
1999 (1 << (chunk % (sizeof(unsigned long) * 8)));
2000 } else {
2001 return 0;
2002 }
2003 }
2004
2005 void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
2006 int nr_sectors)
2007 {
2008 set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
2009 }
Qemu with PowerPC KVM improvements