jcs.org
qemu with hax to log dma reads & writes
jcs.org/2018/11/12/vfio
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#ifndef BLOCK_INT_H
25#define BLOCK_INT_H
26
27#include "block/accounting.h"
28#include "block/block.h"
29#include "block/aio-wait.h"
30#include "qemu/queue.h"
31#include "qemu/coroutine.h"
32#include "qemu/stats64.h"
33#include "qemu/timer.h"
34#include "qemu/hbitmap.h"
35#include "block/snapshot.h"
36#include "qemu/throttle.h"
37
38#define BLOCK_FLAG_LAZY_REFCOUNTS 8
39
40#define BLOCK_OPT_SIZE "size"
41#define BLOCK_OPT_ENCRYPT "encryption"
42#define BLOCK_OPT_ENCRYPT_FORMAT "encrypt.format"
43#define BLOCK_OPT_COMPAT6 "compat6"
44#define BLOCK_OPT_HWVERSION "hwversion"
45#define BLOCK_OPT_BACKING_FILE "backing_file"
46#define BLOCK_OPT_BACKING_FMT "backing_fmt"
47#define BLOCK_OPT_CLUSTER_SIZE "cluster_size"
48#define BLOCK_OPT_TABLE_SIZE "table_size"
49#define BLOCK_OPT_PREALLOC "preallocation"
50#define BLOCK_OPT_SUBFMT "subformat"
51#define BLOCK_OPT_COMPAT_LEVEL "compat"
52#define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts"
53#define BLOCK_OPT_ADAPTER_TYPE "adapter_type"
54#define BLOCK_OPT_REDUNDANCY "redundancy"
55#define BLOCK_OPT_NOCOW "nocow"
56#define BLOCK_OPT_OBJECT_SIZE "object_size"
57#define BLOCK_OPT_REFCOUNT_BITS "refcount_bits"
58#define BLOCK_OPT_DATA_FILE "data_file"
59#define BLOCK_OPT_DATA_FILE_RAW "data_file_raw"
60#define BLOCK_OPT_COMPRESSION_TYPE "compression_type"
61
62#define BLOCK_PROBE_BUF_SIZE 512
63
64enum BdrvTrackedRequestType {
65 BDRV_TRACKED_READ,
66 BDRV_TRACKED_WRITE,
67 BDRV_TRACKED_DISCARD,
68 BDRV_TRACKED_TRUNCATE,
69};
70
71typedef struct BdrvTrackedRequest {
72 BlockDriverState *bs;
73 int64_t offset;
74 uint64_t bytes;
75 enum BdrvTrackedRequestType type;
76
77 bool serialising;
78 int64_t overlap_offset;
79 uint64_t overlap_bytes;
80
81 QLIST_ENTRY(BdrvTrackedRequest) list;
82 Coroutine *co; /* owner, used for deadlock detection */
83 CoQueue wait_queue; /* coroutines blocked on this request */
84
85 struct BdrvTrackedRequest *waiting_for;
86} BdrvTrackedRequest;
87
88struct BlockDriver {
89 const char *format_name;
90 int instance_size;
91
92 /* set to true if the BlockDriver is a block filter. Block filters pass
93 * certain callbacks that refer to data (see block.c) to their bs->file if
94 * the driver doesn't implement them. Drivers that do not wish to forward
95 * must implement them and return -ENOTSUP.
96 */
97 bool is_filter;
98 /*
99 * Set to true if the BlockDriver is a format driver. Format nodes
100 * generally do not expect their children to be other format nodes
101 * (except for backing files), and so format probing is disabled
102 * on those children.
103 */
104 bool is_format;
105 /*
106 * Return true if @to_replace can be replaced by a BDS with the
107 * same data as @bs without it affecting @bs's behavior (that is,
108 * without it being visible to @bs's parents).
109 */
110 bool (*bdrv_recurse_can_replace)(BlockDriverState *bs,
111 BlockDriverState *to_replace);
112
113 int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
114 int (*bdrv_probe_device)(const char *filename);
115
116 /* Any driver implementing this callback is expected to be able to handle
117 * NULL file names in its .bdrv_open() implementation */
118 void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
119 /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
120 * this field set to true, except ones that are defined only by their
121 * child's bs.
122 * An example of the last type will be the quorum block driver.
123 */
124 bool bdrv_needs_filename;
125
126 /*
127 * Set if a driver can support backing files. This also implies the
128 * following semantics:
129 *
130 * - Return status 0 of .bdrv_co_block_status means that corresponding
131 * blocks are not allocated in this layer of backing-chain
132 * - For such (unallocated) blocks, read will:
133 * - fill buffer with zeros if there is no backing file
134 * - read from the backing file otherwise, where the block layer
135 * takes care of reading zeros beyond EOF if backing file is short
136 */
137 bool supports_backing;
138
139 /* For handling image reopen for split or non-split files */
140 int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
141 BlockReopenQueue *queue, Error **errp);
142 void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
143 void (*bdrv_reopen_commit_post)(BDRVReopenState *reopen_state);
144 void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
145 void (*bdrv_join_options)(QDict *options, QDict *old_options);
146
147 int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
148 Error **errp);
149
150 /* Protocol drivers should implement this instead of bdrv_open */
151 int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
152 Error **errp);
153 void (*bdrv_close)(BlockDriverState *bs);
154
155
156 int coroutine_fn (*bdrv_co_create)(BlockdevCreateOptions *opts,
157 Error **errp);
158 int coroutine_fn (*bdrv_co_create_opts)(BlockDriver *drv,
159 const char *filename,
160 QemuOpts *opts,
161 Error **errp);
162
163 int coroutine_fn (*bdrv_co_amend)(BlockDriverState *bs,
164 BlockdevAmendOptions *opts,
165 bool force,
166 Error **errp);
167
168 int (*bdrv_amend_options)(BlockDriverState *bs,
169 QemuOpts *opts,
170 BlockDriverAmendStatusCB *status_cb,
171 void *cb_opaque,
172 bool force,
173 Error **errp);
174
175 int (*bdrv_make_empty)(BlockDriverState *bs);
176
177 /*
178 * Refreshes the bs->exact_filename field. If that is impossible,
179 * bs->exact_filename has to be left empty.
180 */
181 void (*bdrv_refresh_filename)(BlockDriverState *bs);
182
183 /*
184 * Gathers the open options for all children into @target.
185 * A simple format driver (without backing file support) might
186 * implement this function like this:
187 *
188 * QINCREF(bs->file->bs->full_open_options);
189 * qdict_put(target, "file", bs->file->bs->full_open_options);
190 *
191 * If not specified, the generic implementation will simply put
192 * all children's options under their respective name.
193 *
194 * @backing_overridden is true when bs->backing seems not to be
195 * the child that would result from opening bs->backing_file.
196 * Therefore, if it is true, the backing child's options should be
197 * gathered; otherwise, there is no need since the backing child
198 * is the one implied by the image header.
199 *
200 * Note that ideally this function would not be needed. Every
201 * block driver which implements it is probably doing something
202 * shady regarding its runtime option structure.
203 */
204 void (*bdrv_gather_child_options)(BlockDriverState *bs, QDict *target,
205 bool backing_overridden);
206
207 /*
208 * Returns an allocated string which is the directory name of this BDS: It
209 * will be used to make relative filenames absolute by prepending this
210 * function's return value to them.
211 */
212 char *(*bdrv_dirname)(BlockDriverState *bs, Error **errp);
213
214 /* aio */
215 BlockAIOCB *(*bdrv_aio_preadv)(BlockDriverState *bs,
216 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags,
217 BlockCompletionFunc *cb, void *opaque);
218 BlockAIOCB *(*bdrv_aio_pwritev)(BlockDriverState *bs,
219 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags,
220 BlockCompletionFunc *cb, void *opaque);
221 BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
222 BlockCompletionFunc *cb, void *opaque);
223 BlockAIOCB *(*bdrv_aio_pdiscard)(BlockDriverState *bs,
224 int64_t offset, int bytes,
225 BlockCompletionFunc *cb, void *opaque);
226
227 int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
228 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
229
230 /**
231 * @offset: position in bytes to read at
232 * @bytes: number of bytes to read
233 * @qiov: the buffers to fill with read data
234 * @flags: currently unused, always 0
235 *
236 * @offset and @bytes will be a multiple of 'request_alignment',
237 * but the length of individual @qiov elements does not have to
238 * be a multiple.
239 *
240 * @bytes will always equal the total size of @qiov, and will be
241 * no larger than 'max_transfer'.
242 *
243 * The buffer in @qiov may point directly to guest memory.
244 */
245 int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs,
246 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
247 int coroutine_fn (*bdrv_co_preadv_part)(BlockDriverState *bs,
248 uint64_t offset, uint64_t bytes,
249 QEMUIOVector *qiov, size_t qiov_offset, int flags);
250 int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
251 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags);
252 /**
253 * @offset: position in bytes to write at
254 * @bytes: number of bytes to write
255 * @qiov: the buffers containing data to write
256 * @flags: zero or more bits allowed by 'supported_write_flags'
257 *
258 * @offset and @bytes will be a multiple of 'request_alignment',
259 * but the length of individual @qiov elements does not have to
260 * be a multiple.
261 *
262 * @bytes will always equal the total size of @qiov, and will be
263 * no larger than 'max_transfer'.
264 *
265 * The buffer in @qiov may point directly to guest memory.
266 */
267 int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs,
268 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
269 int coroutine_fn (*bdrv_co_pwritev_part)(BlockDriverState *bs,
270 uint64_t offset, uint64_t bytes,
271 QEMUIOVector *qiov, size_t qiov_offset, int flags);
272
273 /*
274 * Efficiently zero a region of the disk image. Typically an image format
275 * would use a compact metadata representation to implement this. This
276 * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev()
277 * will be called instead.
278 */
279 int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs,
280 int64_t offset, int bytes, BdrvRequestFlags flags);
281 int coroutine_fn (*bdrv_co_pdiscard)(BlockDriverState *bs,
282 int64_t offset, int bytes);
283
284 /* Map [offset, offset + nbytes) range onto a child of @bs to copy from,
285 * and invoke bdrv_co_copy_range_from(child, ...), or invoke
286 * bdrv_co_copy_range_to() if @bs is the leaf child to copy data from.
287 *
288 * See the comment of bdrv_co_copy_range for the parameter and return value
289 * semantics.
290 */
291 int coroutine_fn (*bdrv_co_copy_range_from)(BlockDriverState *bs,
292 BdrvChild *src,
293 uint64_t offset,
294 BdrvChild *dst,
295 uint64_t dst_offset,
296 uint64_t bytes,
297 BdrvRequestFlags read_flags,
298 BdrvRequestFlags write_flags);
299
300 /* Map [offset, offset + nbytes) range onto a child of bs to copy data to,
301 * and invoke bdrv_co_copy_range_to(child, src, ...), or perform the copy
302 * operation if @bs is the leaf and @src has the same BlockDriver. Return
303 * -ENOTSUP if @bs is the leaf but @src has a different BlockDriver.
304 *
305 * See the comment of bdrv_co_copy_range for the parameter and return value
306 * semantics.
307 */
308 int coroutine_fn (*bdrv_co_copy_range_to)(BlockDriverState *bs,
309 BdrvChild *src,
310 uint64_t src_offset,
311 BdrvChild *dst,
312 uint64_t dst_offset,
313 uint64_t bytes,
314 BdrvRequestFlags read_flags,
315 BdrvRequestFlags write_flags);
316
317 /*
318 * Building block for bdrv_block_status[_above] and
319 * bdrv_is_allocated[_above]. The driver should answer only
320 * according to the current layer, and should only need to set
321 * BDRV_BLOCK_DATA, BDRV_BLOCK_ZERO, BDRV_BLOCK_OFFSET_VALID,
322 * and/or BDRV_BLOCK_RAW; if the current layer defers to a backing
323 * layer, the result should be 0 (and not BDRV_BLOCK_ZERO). See
324 * block.h for the overall meaning of the bits. As a hint, the
325 * flag want_zero is true if the caller cares more about precise
326 * mappings (favor accurate _OFFSET_VALID/_ZERO) or false for
327 * overall allocation (favor larger *pnum, perhaps by reporting
328 * _DATA instead of _ZERO). The block layer guarantees input
329 * clamped to bdrv_getlength() and aligned to request_alignment,
330 * as well as non-NULL pnum, map, and file; in turn, the driver
331 * must return an error or set pnum to an aligned non-zero value.
332 */
333 int coroutine_fn (*bdrv_co_block_status)(BlockDriverState *bs,
334 bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum,
335 int64_t *map, BlockDriverState **file);
336
337 /*
338 * Invalidate any cached meta-data.
339 */
340 void coroutine_fn (*bdrv_co_invalidate_cache)(BlockDriverState *bs,
341 Error **errp);
342 int (*bdrv_inactivate)(BlockDriverState *bs);
343
344 /*
345 * Flushes all data for all layers by calling bdrv_co_flush for underlying
346 * layers, if needed. This function is needed for deterministic
347 * synchronization of the flush finishing callback.
348 */
349 int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs);
350
351 /* Delete a created file. */
352 int coroutine_fn (*bdrv_co_delete_file)(BlockDriverState *bs,
353 Error **errp);
354
355 /*
356 * Flushes all data that was already written to the OS all the way down to
357 * the disk (for example file-posix.c calls fsync()).
358 */
359 int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
360
361 /*
362 * Flushes all internal caches to the OS. The data may still sit in a
363 * writeback cache of the host OS, but it will survive a crash of the qemu
364 * process.
365 */
366 int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
367
368 /*
369 * Drivers setting this field must be able to work with just a plain
370 * filename with '<protocol_name>:' as a prefix, and no other options.
371 * Options may be extracted from the filename by implementing
372 * bdrv_parse_filename.
373 */
374 const char *protocol_name;
375
376 /*
377 * Truncate @bs to @offset bytes using the given @prealloc mode
378 * when growing. Modes other than PREALLOC_MODE_OFF should be
379 * rejected when shrinking @bs.
380 *
381 * If @exact is true, @bs must be resized to exactly @offset.
382 * Otherwise, it is sufficient for @bs (if it is a host block
383 * device and thus there is no way to resize it) to be at least
384 * @offset bytes in length.
385 *
386 * If @exact is true and this function fails but would succeed
387 * with @exact = false, it should return -ENOTSUP.
388 */
389 int coroutine_fn (*bdrv_co_truncate)(BlockDriverState *bs, int64_t offset,
390 bool exact, PreallocMode prealloc,
391 BdrvRequestFlags flags, Error **errp);
392
393 int64_t (*bdrv_getlength)(BlockDriverState *bs);
394 bool has_variable_length;
395 int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
396 BlockMeasureInfo *(*bdrv_measure)(QemuOpts *opts, BlockDriverState *in_bs,
397 Error **errp);
398
399 int coroutine_fn (*bdrv_co_pwritev_compressed)(BlockDriverState *bs,
400 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov);
401 int coroutine_fn (*bdrv_co_pwritev_compressed_part)(BlockDriverState *bs,
402 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov,
403 size_t qiov_offset);
404
405 int (*bdrv_snapshot_create)(BlockDriverState *bs,
406 QEMUSnapshotInfo *sn_info);
407 int (*bdrv_snapshot_goto)(BlockDriverState *bs,
408 const char *snapshot_id);
409 int (*bdrv_snapshot_delete)(BlockDriverState *bs,
410 const char *snapshot_id,
411 const char *name,
412 Error **errp);
413 int (*bdrv_snapshot_list)(BlockDriverState *bs,
414 QEMUSnapshotInfo **psn_info);
415 int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
416 const char *snapshot_id,
417 const char *name,
418 Error **errp);
419 int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
420 ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs,
421 Error **errp);
422 BlockStatsSpecific *(*bdrv_get_specific_stats)(BlockDriverState *bs);
423
424 int coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs,
425 QEMUIOVector *qiov,
426 int64_t pos);
427 int coroutine_fn (*bdrv_load_vmstate)(BlockDriverState *bs,
428 QEMUIOVector *qiov,
429 int64_t pos);
430
431 int (*bdrv_change_backing_file)(BlockDriverState *bs,
432 const char *backing_file, const char *backing_fmt);
433
434 /* removable device specific */
435 bool (*bdrv_is_inserted)(BlockDriverState *bs);
436 void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
437 void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
438
439 /* to control generic scsi devices */
440 BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
441 unsigned long int req, void *buf,
442 BlockCompletionFunc *cb, void *opaque);
443 int coroutine_fn (*bdrv_co_ioctl)(BlockDriverState *bs,
444 unsigned long int req, void *buf);
445
446 /* List of options for creating images, terminated by name == NULL */
447 QemuOptsList *create_opts;
448
449 /* List of options for image amend */
450 QemuOptsList *amend_opts;
451
452 /*
453 * If this driver supports reopening images this contains a
454 * NULL-terminated list of the runtime options that can be
455 * modified. If an option in this list is unspecified during
456 * reopen then it _must_ be reset to its default value or return
457 * an error.
458 */
459 const char *const *mutable_opts;
460
461 /*
462 * Returns 0 for completed check, -errno for internal errors.
463 * The check results are stored in result.
464 */
465 int coroutine_fn (*bdrv_co_check)(BlockDriverState *bs,
466 BdrvCheckResult *result,
467 BdrvCheckMode fix);
468
469 void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
470
471 /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
472 int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
473 const char *tag);
474 int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
475 const char *tag);
476 int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
477 bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
478
479 void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
480
481 /*
482 * Returns 1 if newly created images are guaranteed to contain only
483 * zeros, 0 otherwise.
484 */
485 int (*bdrv_has_zero_init)(BlockDriverState *bs);
486
487 /* Remove fd handlers, timers, and other event loop callbacks so the event
488 * loop is no longer in use. Called with no in-flight requests and in
489 * depth-first traversal order with parents before child nodes.
490 */
491 void (*bdrv_detach_aio_context)(BlockDriverState *bs);
492
493 /* Add fd handlers, timers, and other event loop callbacks so I/O requests
494 * can be processed again. Called with no in-flight requests and in
495 * depth-first traversal order with child nodes before parent nodes.
496 */
497 void (*bdrv_attach_aio_context)(BlockDriverState *bs,
498 AioContext *new_context);
499
500 /* io queue for linux-aio */
501 void (*bdrv_io_plug)(BlockDriverState *bs);
502 void (*bdrv_io_unplug)(BlockDriverState *bs);
503
504 /**
505 * Try to get @bs's logical and physical block size.
506 * On success, store them in @bsz and return zero.
507 * On failure, return negative errno.
508 */
509 int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
510 /**
511 * Try to get @bs's geometry (cyls, heads, sectors)
512 * On success, store them in @geo and return 0.
513 * On failure return -errno.
514 * Only drivers that want to override guest geometry implement this
515 * callback; see hd_geometry_guess().
516 */
517 int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
518
519 /**
520 * bdrv_co_drain_begin is called if implemented in the beginning of a
521 * drain operation to drain and stop any internal sources of requests in
522 * the driver.
523 * bdrv_co_drain_end is called if implemented at the end of the drain.
524 *
525 * They should be used by the driver to e.g. manage scheduled I/O
526 * requests, or toggle an internal state. After the end of the drain new
527 * requests will continue normally.
528 */
529 void coroutine_fn (*bdrv_co_drain_begin)(BlockDriverState *bs);
530 void coroutine_fn (*bdrv_co_drain_end)(BlockDriverState *bs);
531
532 void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
533 Error **errp);
534 void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child,
535 Error **errp);
536
537 /**
538 * Informs the block driver that a permission change is intended. The
539 * driver checks whether the change is permissible and may take other
540 * preparations for the change (e.g. get file system locks). This operation
541 * is always followed either by a call to either .bdrv_set_perm or
542 * .bdrv_abort_perm_update.
543 *
544 * Checks whether the requested set of cumulative permissions in @perm
545 * can be granted for accessing @bs and whether no other users are using
546 * permissions other than those given in @shared (both arguments take
547 * BLK_PERM_* bitmasks).
548 *
549 * If both conditions are met, 0 is returned. Otherwise, -errno is returned
550 * and errp is set to an error describing the conflict.
551 */
552 int (*bdrv_check_perm)(BlockDriverState *bs, uint64_t perm,
553 uint64_t shared, Error **errp);
554
555 /**
556 * Called to inform the driver that the set of cumulative set of used
557 * permissions for @bs has changed to @perm, and the set of sharable
558 * permission to @shared. The driver can use this to propagate changes to
559 * its children (i.e. request permissions only if a parent actually needs
560 * them).
561 *
562 * This function is only invoked after bdrv_check_perm(), so block drivers
563 * may rely on preparations made in their .bdrv_check_perm implementation.
564 */
565 void (*bdrv_set_perm)(BlockDriverState *bs, uint64_t perm, uint64_t shared);
566
567 /*
568 * Called to inform the driver that after a previous bdrv_check_perm()
569 * call, the permission update is not performed and any preparations made
570 * for it (e.g. taken file locks) need to be undone.
571 *
572 * This function can be called even for nodes that never saw a
573 * bdrv_check_perm() call. It is a no-op then.
574 */
575 void (*bdrv_abort_perm_update)(BlockDriverState *bs);
576
577 /**
578 * Returns in @nperm and @nshared the permissions that the driver for @bs
579 * needs on its child @c, based on the cumulative permissions requested by
580 * the parents in @parent_perm and @parent_shared.
581 *
582 * If @c is NULL, return the permissions for attaching a new child for the
583 * given @child_class and @role.
584 *
585 * If @reopen_queue is non-NULL, don't return the currently needed
586 * permissions, but those that will be needed after applying the
587 * @reopen_queue.
588 */
589 void (*bdrv_child_perm)(BlockDriverState *bs, BdrvChild *c,
590 BdrvChildRole role,
591 BlockReopenQueue *reopen_queue,
592 uint64_t parent_perm, uint64_t parent_shared,
593 uint64_t *nperm, uint64_t *nshared);
594
595 bool (*bdrv_supports_persistent_dirty_bitmap)(BlockDriverState *bs);
596 bool (*bdrv_co_can_store_new_dirty_bitmap)(BlockDriverState *bs,
597 const char *name,
598 uint32_t granularity,
599 Error **errp);
600 int (*bdrv_co_remove_persistent_dirty_bitmap)(BlockDriverState *bs,
601 const char *name,
602 Error **errp);
603
604 /**
605 * Register/unregister a buffer for I/O. For example, when the driver is
606 * interested to know the memory areas that will later be used in iovs, so
607 * that it can do IOMMU mapping with VFIO etc., in order to get better
608 * performance. In the case of VFIO drivers, this callback is used to do
609 * DMA mapping for hot buffers.
610 */
611 void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size);
612 void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host);
613 QLIST_ENTRY(BlockDriver) list;
614
615 /* Pointer to a NULL-terminated array of names of strong options
616 * that can be specified for bdrv_open(). A strong option is one
617 * that changes the data of a BDS.
618 * If this pointer is NULL, the array is considered empty.
619 * "filename" and "driver" are always considered strong. */
620 const char *const *strong_runtime_opts;
621};
622
623static inline bool block_driver_can_compress(BlockDriver *drv)
624{
625 return drv->bdrv_co_pwritev_compressed ||
626 drv->bdrv_co_pwritev_compressed_part;
627}
628
629typedef struct BlockLimits {
630 /* Alignment requirement, in bytes, for offset/length of I/O
631 * requests. Must be a power of 2 less than INT_MAX; defaults to
632 * 1 for drivers with modern byte interfaces, and to 512
633 * otherwise. */
634 uint32_t request_alignment;
635
636 /* Maximum number of bytes that can be discarded at once (since it
637 * is signed, it must be < 2G, if set). Must be multiple of
638 * pdiscard_alignment, but need not be power of 2. May be 0 if no
639 * inherent 32-bit limit */
640 int32_t max_pdiscard;
641
642 /* Optimal alignment for discard requests in bytes. A power of 2
643 * is best but not mandatory. Must be a multiple of
644 * bl.request_alignment, and must be less than max_pdiscard if
645 * that is set. May be 0 if bl.request_alignment is good enough */
646 uint32_t pdiscard_alignment;
647
648 /* Maximum number of bytes that can zeroized at once (since it is
649 * signed, it must be < 2G, if set). Must be multiple of
650 * pwrite_zeroes_alignment. May be 0 if no inherent 32-bit limit */
651 int32_t max_pwrite_zeroes;
652
653 /* Optimal alignment for write zeroes requests in bytes. A power
654 * of 2 is best but not mandatory. Must be a multiple of
655 * bl.request_alignment, and must be less than max_pwrite_zeroes
656 * if that is set. May be 0 if bl.request_alignment is good
657 * enough */
658 uint32_t pwrite_zeroes_alignment;
659
660 /* Optimal transfer length in bytes. A power of 2 is best but not
661 * mandatory. Must be a multiple of bl.request_alignment, or 0 if
662 * no preferred size */
663 uint32_t opt_transfer;
664
665 /* Maximal transfer length in bytes. Need not be power of 2, but
666 * must be multiple of opt_transfer and bl.request_alignment, or 0
667 * for no 32-bit limit. For now, anything larger than INT_MAX is
668 * clamped down. */
669 uint32_t max_transfer;
670
671 /* memory alignment, in bytes so that no bounce buffer is needed */
672 size_t min_mem_alignment;
673
674 /* memory alignment, in bytes, for bounce buffer */
675 size_t opt_mem_alignment;
676
677 /* maximum number of iovec elements */
678 int max_iov;
679} BlockLimits;
680
681typedef struct BdrvOpBlocker BdrvOpBlocker;
682
683typedef struct BdrvAioNotifier {
684 void (*attached_aio_context)(AioContext *new_context, void *opaque);
685 void (*detach_aio_context)(void *opaque);
686
687 void *opaque;
688 bool deleted;
689
690 QLIST_ENTRY(BdrvAioNotifier) list;
691} BdrvAioNotifier;
692
693struct BdrvChildClass {
694 /* If true, bdrv_replace_node() doesn't change the node this BdrvChild
695 * points to. */
696 bool stay_at_node;
697
698 /* If true, the parent is a BlockDriverState and bdrv_next_all_states()
699 * will return it. This information is used for drain_all, where every node
700 * will be drained separately, so the drain only needs to be propagated to
701 * non-BDS parents. */
702 bool parent_is_bds;
703
704 void (*inherit_options)(BdrvChildRole role, bool parent_is_format,
705 int *child_flags, QDict *child_options,
706 int parent_flags, QDict *parent_options);
707
708 void (*change_media)(BdrvChild *child, bool load);
709 void (*resize)(BdrvChild *child);
710
711 /* Returns a name that is supposedly more useful for human users than the
712 * node name for identifying the node in question (in particular, a BB
713 * name), or NULL if the parent can't provide a better name. */
714 const char *(*get_name)(BdrvChild *child);
715
716 /* Returns a malloced string that describes the parent of the child for a
717 * human reader. This could be a node-name, BlockBackend name, qdev ID or
718 * QOM path of the device owning the BlockBackend, job type and ID etc. The
719 * caller is responsible for freeing the memory. */
720 char *(*get_parent_desc)(BdrvChild *child);
721
722 /*
723 * If this pair of functions is implemented, the parent doesn't issue new
724 * requests after returning from .drained_begin() until .drained_end() is
725 * called.
726 *
727 * These functions must not change the graph (and therefore also must not
728 * call aio_poll(), which could change the graph indirectly).
729 *
730 * If drained_end() schedules background operations, it must atomically
731 * increment *drained_end_counter for each such operation and atomically
732 * decrement it once the operation has settled.
733 *
734 * Note that this can be nested. If drained_begin() was called twice, new
735 * I/O is allowed only after drained_end() was called twice, too.
736 */
737 void (*drained_begin)(BdrvChild *child);
738 void (*drained_end)(BdrvChild *child, int *drained_end_counter);
739
740 /*
741 * Returns whether the parent has pending requests for the child. This
742 * callback is polled after .drained_begin() has been called until all
743 * activity on the child has stopped.
744 */
745 bool (*drained_poll)(BdrvChild *child);
746
747 /* Notifies the parent that the child has been activated/inactivated (e.g.
748 * when migration is completing) and it can start/stop requesting
749 * permissions and doing I/O on it. */
750 void (*activate)(BdrvChild *child, Error **errp);
751 int (*inactivate)(BdrvChild *child);
752
753 void (*attach)(BdrvChild *child);
754 void (*detach)(BdrvChild *child);
755
756 /* Notifies the parent that the filename of its child has changed (e.g.
757 * because the direct child was removed from the backing chain), so that it
758 * can update its reference. */
759 int (*update_filename)(BdrvChild *child, BlockDriverState *new_base,
760 const char *filename, Error **errp);
761
762 bool (*can_set_aio_ctx)(BdrvChild *child, AioContext *ctx,
763 GSList **ignore, Error **errp);
764 void (*set_aio_ctx)(BdrvChild *child, AioContext *ctx, GSList **ignore);
765};
766
767extern const BdrvChildClass child_of_bds;
768
769struct BdrvChild {
770 BlockDriverState *bs;
771 char *name;
772 const BdrvChildClass *klass;
773 BdrvChildRole role;
774 void *opaque;
775
776 /**
777 * Granted permissions for operating on this BdrvChild (BLK_PERM_* bitmask)
778 */
779 uint64_t perm;
780
781 /**
782 * Permissions that can still be granted to other users of @bs while this
783 * BdrvChild is still attached to it. (BLK_PERM_* bitmask)
784 */
785 uint64_t shared_perm;
786
787 /* backup of permissions during permission update procedure */
788 bool has_backup_perm;
789 uint64_t backup_perm;
790 uint64_t backup_shared_perm;
791
792 /*
793 * This link is frozen: the child can neither be replaced nor
794 * detached from the parent.
795 */
796 bool frozen;
797
798 /*
799 * How many times the parent of this child has been drained
800 * (through klass->drained_*).
801 * Usually, this is equal to bs->quiesce_counter (potentially
802 * reduced by bdrv_drain_all_count). It may differ while the
803 * child is entering or leaving a drained section.
804 */
805 int parent_quiesce_counter;
806
807 QLIST_ENTRY(BdrvChild) next;
808 QLIST_ENTRY(BdrvChild) next_parent;
809};
810
811/*
812 * Note: the function bdrv_append() copies and swaps contents of
813 * BlockDriverStates, so if you add new fields to this struct, please
814 * inspect bdrv_append() to determine if the new fields need to be
815 * copied as well.
816 */
817struct BlockDriverState {
818 /* Protected by big QEMU lock or read-only after opening. No special
819 * locking needed during I/O...
820 */
821 int open_flags; /* flags used to open the file, re-used for re-open */
822 bool read_only; /* if true, the media is read only */
823 bool encrypted; /* if true, the media is encrypted */
824 bool sg; /* if true, the device is a /dev/sg* */
825 bool probed; /* if true, format was probed rather than specified */
826 bool force_share; /* if true, always allow all shared permissions */
827 bool implicit; /* if true, this filter node was automatically inserted */
828
829 BlockDriver *drv; /* NULL means no media */
830 void *opaque;
831
832 AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
833 /* long-running tasks intended to always use the same AioContext as this
834 * BDS may register themselves in this list to be notified of changes
835 * regarding this BDS's context */
836 QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
837 bool walking_aio_notifiers; /* to make removal during iteration safe */
838
839 char filename[PATH_MAX];
840 char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
841 this file image */
842 /* The backing filename indicated by the image header; if we ever
843 * open this file, then this is replaced by the resulting BDS's
844 * filename (i.e. after a bdrv_refresh_filename() run). */
845 char auto_backing_file[PATH_MAX];
846 char backing_format[16]; /* if non-zero and backing_file exists */
847
848 QDict *full_open_options;
849 char exact_filename[PATH_MAX];
850
851 BdrvChild *backing;
852 BdrvChild *file;
853
854 /* I/O Limits */
855 BlockLimits bl;
856
857 /* Flags honored during pwrite (so far: BDRV_REQ_FUA,
858 * BDRV_REQ_WRITE_UNCHANGED).
859 * If a driver does not support BDRV_REQ_WRITE_UNCHANGED, those
860 * writes will be issued as normal writes without the flag set.
861 * This is important to note for drivers that do not explicitly
862 * request a WRITE permission for their children and instead take
863 * the same permissions as their parent did (this is commonly what
864 * block filters do). Such drivers have to be aware that the
865 * parent may have taken a WRITE_UNCHANGED permission only and is
866 * issuing such requests. Drivers either must make sure that
867 * these requests do not result in plain WRITE accesses (usually
868 * by supporting BDRV_REQ_WRITE_UNCHANGED, and then forwarding
869 * every incoming write request as-is, including potentially that
870 * flag), or they have to explicitly take the WRITE permission for
871 * their children. */
872 unsigned int supported_write_flags;
873 /* Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA,
874 * BDRV_REQ_MAY_UNMAP, BDRV_REQ_WRITE_UNCHANGED) */
875 unsigned int supported_zero_flags;
876 /*
877 * Flags honoured during truncate (so far: BDRV_REQ_ZERO_WRITE).
878 *
879 * If BDRV_REQ_ZERO_WRITE is given, the truncate operation must make sure
880 * that any added space reads as all zeros. If this can't be guaranteed,
881 * the operation must fail.
882 */
883 unsigned int supported_truncate_flags;
884
885 /* the following member gives a name to every node on the bs graph. */
886 char node_name[32];
887 /* element of the list of named nodes building the graph */
888 QTAILQ_ENTRY(BlockDriverState) node_list;
889 /* element of the list of all BlockDriverStates (all_bdrv_states) */
890 QTAILQ_ENTRY(BlockDriverState) bs_list;
891 /* element of the list of monitor-owned BDS */
892 QTAILQ_ENTRY(BlockDriverState) monitor_list;
893 int refcnt;
894
895 /* operation blockers */
896 QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
897
898 /* The node that this node inherited default options from (and a reopen on
899 * which can affect this node by changing these defaults). This is always a
900 * parent node of this node. */
901 BlockDriverState *inherits_from;
902 QLIST_HEAD(, BdrvChild) children;
903 QLIST_HEAD(, BdrvChild) parents;
904
905 QDict *options;
906 QDict *explicit_options;
907 BlockdevDetectZeroesOptions detect_zeroes;
908
909 /* The error object in use for blocking operations on backing_hd */
910 Error *backing_blocker;
911
912 /* Protected by AioContext lock */
913
914 /* If we are reading a disk image, give its size in sectors.
915 * Generally read-only; it is written to by load_snapshot and
916 * save_snaphost, but the block layer is quiescent during those.
917 */
918 int64_t total_sectors;
919
920 /* Callback before write request is processed */
921 NotifierWithReturnList before_write_notifiers;
922
923 /* threshold limit for writes, in bytes. "High water mark". */
924 uint64_t write_threshold_offset;
925 NotifierWithReturn write_threshold_notifier;
926
927 /* Writing to the list requires the BQL _and_ the dirty_bitmap_mutex.
928 * Reading from the list can be done with either the BQL or the
929 * dirty_bitmap_mutex. Modifying a bitmap only requires
930 * dirty_bitmap_mutex. */
931 QemuMutex dirty_bitmap_mutex;
932 QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
933
934 /* Offset after the highest byte written to */
935 Stat64 wr_highest_offset;
936
937 /* If true, copy read backing sectors into image. Can be >1 if more
938 * than one client has requested copy-on-read. Accessed with atomic
939 * ops.
940 */
941 int copy_on_read;
942
943 /* number of in-flight requests; overall and serialising.
944 * Accessed with atomic ops.
945 */
946 unsigned int in_flight;
947 unsigned int serialising_in_flight;
948
949 /* counter for nested bdrv_io_plug.
950 * Accessed with atomic ops.
951 */
952 unsigned io_plugged;
953
954 /* do we need to tell the quest if we have a volatile write cache? */
955 int enable_write_cache;
956
957 /* Accessed with atomic ops. */
958 int quiesce_counter;
959 int recursive_quiesce_counter;
960
961 unsigned int write_gen; /* Current data generation */
962
963 /* Protected by reqs_lock. */
964 CoMutex reqs_lock;
965 QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
966 CoQueue flush_queue; /* Serializing flush queue */
967 bool active_flush_req; /* Flush request in flight? */
968
969 /* Only read/written by whoever has set active_flush_req to true. */
970 unsigned int flushed_gen; /* Flushed write generation */
971
972 /* BdrvChild links to this node may never be frozen */
973 bool never_freeze;
974};
975
976struct BlockBackendRootState {
977 int open_flags;
978 bool read_only;
979 BlockdevDetectZeroesOptions detect_zeroes;
980};
981
982typedef enum BlockMirrorBackingMode {
983 /* Reuse the existing backing chain from the source for the target.
984 * - sync=full: Set backing BDS to NULL.
985 * - sync=top: Use source's backing BDS.
986 * - sync=none: Use source as the backing BDS. */
987 MIRROR_SOURCE_BACKING_CHAIN,
988
989 /* Open the target's backing chain completely anew */
990 MIRROR_OPEN_BACKING_CHAIN,
991
992 /* Do not change the target's backing BDS after job completion */
993 MIRROR_LEAVE_BACKING_CHAIN,
994} BlockMirrorBackingMode;
995
996static inline BlockDriverState *backing_bs(BlockDriverState *bs)
997{
998 return bs->backing ? bs->backing->bs : NULL;
999}
1000
1001
1002/* Essential block drivers which must always be statically linked into qemu, and
1003 * which therefore can be accessed without using bdrv_find_format() */
1004extern BlockDriver bdrv_file;
1005extern BlockDriver bdrv_raw;
1006extern BlockDriver bdrv_qcow2;
1007
1008int coroutine_fn bdrv_co_preadv(BdrvChild *child,
1009 int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
1010 BdrvRequestFlags flags);
1011int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
1012 int64_t offset, unsigned int bytes,
1013 QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
1014int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
1015 int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
1016 BdrvRequestFlags flags);
1017int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
1018 int64_t offset, unsigned int bytes,
1019 QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);
1020
1021static inline int coroutine_fn bdrv_co_pread(BdrvChild *child,
1022 int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags)
1023{
1024 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
1025
1026 return bdrv_co_preadv(child, offset, bytes, &qiov, flags);
1027}
1028
1029static inline int coroutine_fn bdrv_co_pwrite(BdrvChild *child,
1030 int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags)
1031{
1032 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
1033
1034 return bdrv_co_pwritev(child, offset, bytes, &qiov, flags);
1035}
1036
1037extern unsigned int bdrv_drain_all_count;
1038void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent);
1039void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent);
1040
1041bool coroutine_fn bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align);
1042BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs);
1043
1044int get_tmp_filename(char *filename, int size);
1045BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
1046 const char *filename);
1047
1048void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix,
1049 QDict *options);
1050
1051
1052/**
1053 * bdrv_add_before_write_notifier:
1054 *
1055 * Register a callback that is invoked before write requests are processed but
1056 * after any throttling or waiting for overlapping requests.
1057 */
1058void bdrv_add_before_write_notifier(BlockDriverState *bs,
1059 NotifierWithReturn *notifier);
1060
1061/**
1062 * bdrv_add_aio_context_notifier:
1063 *
1064 * If a long-running job intends to be always run in the same AioContext as a
1065 * certain BDS, it may use this function to be notified of changes regarding the
1066 * association of the BDS to an AioContext.
1067 *
1068 * attached_aio_context() is called after the target BDS has been attached to a
1069 * new AioContext; detach_aio_context() is called before the target BDS is being
1070 * detached from its old AioContext.
1071 */
1072void bdrv_add_aio_context_notifier(BlockDriverState *bs,
1073 void (*attached_aio_context)(AioContext *new_context, void *opaque),
1074 void (*detach_aio_context)(void *opaque), void *opaque);
1075
1076/**
1077 * bdrv_remove_aio_context_notifier:
1078 *
1079 * Unsubscribe of change notifications regarding the BDS's AioContext. The
1080 * parameters given here have to be the same as those given to
1081 * bdrv_add_aio_context_notifier().
1082 */
1083void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
1084 void (*aio_context_attached)(AioContext *,
1085 void *),
1086 void (*aio_context_detached)(void *),
1087 void *opaque);
1088
1089/**
1090 * bdrv_wakeup:
1091 * @bs: The BlockDriverState for which an I/O operation has been completed.
1092 *
1093 * Wake up the main thread if it is waiting on BDRV_POLL_WHILE. During
1094 * synchronous I/O on a BlockDriverState that is attached to another
1095 * I/O thread, the main thread lets the I/O thread's event loop run,
1096 * waiting for the I/O operation to complete. A bdrv_wakeup will wake
1097 * up the main thread if necessary.
1098 *
1099 * Manual calls to bdrv_wakeup are rarely necessary, because
1100 * bdrv_dec_in_flight already calls it.
1101 */
1102void bdrv_wakeup(BlockDriverState *bs);
1103
1104#ifdef _WIN32
1105int is_windows_drive(const char *filename);
1106#endif
1107
1108/**
1109 * stream_start:
1110 * @job_id: The id of the newly-created job, or %NULL to use the
1111 * device name of @bs.
1112 * @bs: Block device to operate on.
1113 * @base: Block device that will become the new base, or %NULL to
1114 * flatten the whole backing file chain onto @bs.
1115 * @backing_file_str: The file name that will be written to @bs as the
1116 * the new backing file if the job completes. Ignored if @base is %NULL.
1117 * @creation_flags: Flags that control the behavior of the Job lifetime.
1118 * See @BlockJobCreateFlags
1119 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1120 * @on_error: The action to take upon error.
1121 * @errp: Error object.
1122 *
1123 * Start a streaming operation on @bs. Clusters that are unallocated
1124 * in @bs, but allocated in any image between @base and @bs (both
1125 * exclusive) will be written to @bs. At the end of a successful
1126 * streaming job, the backing file of @bs will be changed to
1127 * @backing_file_str in the written image and to @base in the live
1128 * BlockDriverState.
1129 */
1130void stream_start(const char *job_id, BlockDriverState *bs,
1131 BlockDriverState *base, const char *backing_file_str,
1132 int creation_flags, int64_t speed,
1133 BlockdevOnError on_error, Error **errp);
1134
1135/**
1136 * commit_start:
1137 * @job_id: The id of the newly-created job, or %NULL to use the
1138 * device name of @bs.
1139 * @bs: Active block device.
1140 * @top: Top block device to be committed.
1141 * @base: Block device that will be written into, and become the new top.
1142 * @creation_flags: Flags that control the behavior of the Job lifetime.
1143 * See @BlockJobCreateFlags
1144 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1145 * @on_error: The action to take upon error.
1146 * @backing_file_str: String to use as the backing file in @top's overlay
1147 * @filter_node_name: The node name that should be assigned to the filter
1148 * driver that the commit job inserts into the graph above @top. NULL means
1149 * that a node name should be autogenerated.
1150 * @errp: Error object.
1151 *
1152 */
1153void commit_start(const char *job_id, BlockDriverState *bs,
1154 BlockDriverState *base, BlockDriverState *top,
1155 int creation_flags, int64_t speed,
1156 BlockdevOnError on_error, const char *backing_file_str,
1157 const char *filter_node_name, Error **errp);
1158/**
1159 * commit_active_start:
1160 * @job_id: The id of the newly-created job, or %NULL to use the
1161 * device name of @bs.
1162 * @bs: Active block device to be committed.
1163 * @base: Block device that will be written into, and become the new top.
1164 * @creation_flags: Flags that control the behavior of the Job lifetime.
1165 * See @BlockJobCreateFlags
1166 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1167 * @on_error: The action to take upon error.
1168 * @filter_node_name: The node name that should be assigned to the filter
1169 * driver that the commit job inserts into the graph above @bs. NULL means that
1170 * a node name should be autogenerated.
1171 * @cb: Completion function for the job.
1172 * @opaque: Opaque pointer value passed to @cb.
1173 * @auto_complete: Auto complete the job.
1174 * @errp: Error object.
1175 *
1176 */
1177BlockJob *commit_active_start(const char *job_id, BlockDriverState *bs,
1178 BlockDriverState *base, int creation_flags,
1179 int64_t speed, BlockdevOnError on_error,
1180 const char *filter_node_name,
1181 BlockCompletionFunc *cb, void *opaque,
1182 bool auto_complete, Error **errp);
1183/*
1184 * mirror_start:
1185 * @job_id: The id of the newly-created job, or %NULL to use the
1186 * device name of @bs.
1187 * @bs: Block device to operate on.
1188 * @target: Block device to write to.
1189 * @replaces: Block graph node name to replace once the mirror is done. Can
1190 * only be used when full mirroring is selected.
1191 * @creation_flags: Flags that control the behavior of the Job lifetime.
1192 * See @BlockJobCreateFlags
1193 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1194 * @granularity: The chosen granularity for the dirty bitmap.
1195 * @buf_size: The amount of data that can be in flight at one time.
1196 * @mode: Whether to collapse all images in the chain to the target.
1197 * @backing_mode: How to establish the target's backing chain after completion.
1198 * @zero_target: Whether the target should be explicitly zero-initialized
1199 * @on_source_error: The action to take upon error reading from the source.
1200 * @on_target_error: The action to take upon error writing to the target.
1201 * @unmap: Whether to unmap target where source sectors only contain zeroes.
1202 * @filter_node_name: The node name that should be assigned to the filter
1203 * driver that the mirror job inserts into the graph above @bs. NULL means that
1204 * a node name should be autogenerated.
1205 * @copy_mode: When to trigger writes to the target.
1206 * @errp: Error object.
1207 *
1208 * Start a mirroring operation on @bs. Clusters that are allocated
1209 * in @bs will be written to @target until the job is cancelled or
1210 * manually completed. At the end of a successful mirroring job,
1211 * @bs will be switched to read from @target.
1212 */
1213void mirror_start(const char *job_id, BlockDriverState *bs,
1214 BlockDriverState *target, const char *replaces,
1215 int creation_flags, int64_t speed,
1216 uint32_t granularity, int64_t buf_size,
1217 MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
1218 bool zero_target,
1219 BlockdevOnError on_source_error,
1220 BlockdevOnError on_target_error,
1221 bool unmap, const char *filter_node_name,
1222 MirrorCopyMode copy_mode, Error **errp);
1223
1224/*
1225 * backup_job_create:
1226 * @job_id: The id of the newly-created job, or %NULL to use the
1227 * device name of @bs.
1228 * @bs: Block device to operate on.
1229 * @target: Block device to write to.
1230 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1231 * @sync_mode: What parts of the disk image should be copied to the destination.
1232 * @sync_bitmap: The dirty bitmap if sync_mode is 'bitmap' or 'incremental'
1233 * @bitmap_mode: The bitmap synchronization policy to use.
1234 * @on_source_error: The action to take upon error reading from the source.
1235 * @on_target_error: The action to take upon error writing to the target.
1236 * @creation_flags: Flags that control the behavior of the Job lifetime.
1237 * See @BlockJobCreateFlags
1238 * @cb: Completion function for the job.
1239 * @opaque: Opaque pointer value passed to @cb.
1240 * @txn: Transaction that this job is part of (may be NULL).
1241 *
1242 * Create a backup operation on @bs. Clusters in @bs are written to @target
1243 * until the job is cancelled or manually completed.
1244 */
1245BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
1246 BlockDriverState *target, int64_t speed,
1247 MirrorSyncMode sync_mode,
1248 BdrvDirtyBitmap *sync_bitmap,
1249 BitmapSyncMode bitmap_mode,
1250 bool compress,
1251 const char *filter_node_name,
1252 BlockdevOnError on_source_error,
1253 BlockdevOnError on_target_error,
1254 int creation_flags,
1255 BlockCompletionFunc *cb, void *opaque,
1256 JobTxn *txn, Error **errp);
1257
1258BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
1259 const char *child_name,
1260 const BdrvChildClass *child_class,
1261 BdrvChildRole child_role,
1262 AioContext *ctx,
1263 uint64_t perm, uint64_t shared_perm,
1264 void *opaque, Error **errp);
1265void bdrv_root_unref_child(BdrvChild *child);
1266
1267void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
1268 uint64_t *shared_perm);
1269
1270/**
1271 * Sets a BdrvChild's permissions. Avoid if the parent is a BDS; use
1272 * bdrv_child_refresh_perms() instead and make the parent's
1273 * .bdrv_child_perm() implementation return the correct values.
1274 */
1275int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
1276 Error **errp);
1277
1278/**
1279 * Calls bs->drv->bdrv_child_perm() and updates the child's permission
1280 * masks with the result.
1281 * Drivers should invoke this function whenever an event occurs that
1282 * makes their .bdrv_child_perm() implementation return different
1283 * values than before, but which will not result in the block layer
1284 * automatically refreshing the permissions.
1285 */
1286int bdrv_child_refresh_perms(BlockDriverState *bs, BdrvChild *c, Error **errp);
1287
1288bool bdrv_recurse_can_replace(BlockDriverState *bs,
1289 BlockDriverState *to_replace);
1290
1291/*
1292 * Default implementation for BlockDriver.bdrv_child_perm() that can
1293 * be used by block filters and image formats, as long as they use the
1294 * child_of_bds child class and set an appropriate BdrvChildRole.
1295 */
1296void bdrv_default_perms(BlockDriverState *bs, BdrvChild *c,
1297 BdrvChildRole role, BlockReopenQueue *reopen_queue,
1298 uint64_t perm, uint64_t shared,
1299 uint64_t *nperm, uint64_t *nshared);
1300
1301/*
1302 * Default implementation for drivers to pass bdrv_co_block_status() to
1303 * their file.
1304 */
1305int coroutine_fn bdrv_co_block_status_from_file(BlockDriverState *bs,
1306 bool want_zero,
1307 int64_t offset,
1308 int64_t bytes,
1309 int64_t *pnum,
1310 int64_t *map,
1311 BlockDriverState **file);
1312/*
1313 * Default implementation for drivers to pass bdrv_co_block_status() to
1314 * their backing file.
1315 */
1316int coroutine_fn bdrv_co_block_status_from_backing(BlockDriverState *bs,
1317 bool want_zero,
1318 int64_t offset,
1319 int64_t bytes,
1320 int64_t *pnum,
1321 int64_t *map,
1322 BlockDriverState **file);
1323const char *bdrv_get_parent_name(const BlockDriverState *bs);
1324void blk_dev_change_media_cb(BlockBackend *blk, bool load, Error **errp);
1325bool blk_dev_has_removable_media(BlockBackend *blk);
1326bool blk_dev_has_tray(BlockBackend *blk);
1327void blk_dev_eject_request(BlockBackend *blk, bool force);
1328bool blk_dev_is_tray_open(BlockBackend *blk);
1329bool blk_dev_is_medium_locked(BlockBackend *blk);
1330
1331void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes);
1332
1333void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
1334void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup);
1335bool bdrv_dirty_bitmap_merge_internal(BdrvDirtyBitmap *dest,
1336 const BdrvDirtyBitmap *src,
1337 HBitmap **backup, bool lock);
1338
1339void bdrv_inc_in_flight(BlockDriverState *bs);
1340void bdrv_dec_in_flight(BlockDriverState *bs);
1341
1342void blockdev_close_all_bdrv_states(void);
1343
1344int coroutine_fn bdrv_co_copy_range_from(BdrvChild *src, uint64_t src_offset,
1345 BdrvChild *dst, uint64_t dst_offset,
1346 uint64_t bytes,
1347 BdrvRequestFlags read_flags,
1348 BdrvRequestFlags write_flags);
1349int coroutine_fn bdrv_co_copy_range_to(BdrvChild *src, uint64_t src_offset,
1350 BdrvChild *dst, uint64_t dst_offset,
1351 uint64_t bytes,
1352 BdrvRequestFlags read_flags,
1353 BdrvRequestFlags write_flags);
1354
1355int refresh_total_sectors(BlockDriverState *bs, int64_t hint);
1356
1357void bdrv_set_monitor_owned(BlockDriverState *bs);
1358BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp);
1359
1360/**
1361 * Simple implementation of bdrv_co_create_opts for protocol drivers
1362 * which only support creation via opening a file
1363 * (usually existing raw storage device)
1364 */
1365int coroutine_fn bdrv_co_create_opts_simple(BlockDriver *drv,
1366 const char *filename,
1367 QemuOpts *opts,
1368 Error **errp);
1369extern QemuOptsList bdrv_create_opts_simple;
1370
1371BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node,
1372 const char *name,
1373 BlockDriverState **pbs,
1374 Error **errp);
1375BdrvDirtyBitmap *block_dirty_bitmap_merge(const char *node, const char *target,
1376 BlockDirtyBitmapMergeSourceList *bms,
1377 HBitmap **backup, Error **errp);
1378BdrvDirtyBitmap *block_dirty_bitmap_remove(const char *node, const char *name,
1379 bool release,
1380 BlockDriverState **bitmap_bs,
1381 Error **errp);
1382
1383#endif /* BLOCK_INT_H */