1 #ifndef BLOCK_H 2 #define BLOCK_H 3 4 #include "block/aio.h" 5 #include "qapi/qapi-types-block-core.h" 6 #include "qemu/iov.h" 7 #include "qemu/coroutine.h" 8 #include "block/accounting.h" 9 #include "block/dirty-bitmap.h" 10 #include "block/blockjob.h" 11 #include "qemu/hbitmap.h" 12 13 /* block.c */ 14 typedef struct BlockDriver BlockDriver; 15 typedef struct BdrvChild BdrvChild; 16 typedef struct BdrvChildRole BdrvChildRole; 17 18 typedef struct BlockDriverInfo { 19 /* in bytes, 0 if irrelevant */ 20 int cluster_size; 21 /* offset at which the VM state can be saved (0 if not possible) */ 22 int64_t vm_state_offset; 23 bool is_dirty; 24 /* 25 * True if unallocated blocks read back as zeroes. This is equivalent 26 * to the LBPRZ flag in the SCSI logical block provisioning page. 27 */ 28 bool unallocated_blocks_are_zero; 29 /* 30 * True if this block driver only supports compressed writes 31 */ 32 bool needs_compressed_writes; 33 } BlockDriverInfo; 34 35 typedef struct BlockFragInfo { 36 uint64_t allocated_clusters; 37 uint64_t total_clusters; 38 uint64_t fragmented_clusters; 39 uint64_t compressed_clusters; 40 } BlockFragInfo; 41 42 typedef enum { 43 BDRV_REQ_COPY_ON_READ = 0x1, 44 BDRV_REQ_ZERO_WRITE = 0x2, 45 /* The BDRV_REQ_MAY_UNMAP flag is used to indicate that the block driver 46 * is allowed to optimize a write zeroes request by unmapping (discarding) 47 * blocks if it is guaranteed that the result will read back as 48 * zeroes. The flag is only passed to the driver if the block device is 49 * opened with BDRV_O_UNMAP. 50 */ 51 BDRV_REQ_MAY_UNMAP = 0x4, 52 BDRV_REQ_NO_SERIALISING = 0x8, 53 BDRV_REQ_FUA = 0x10, 54 BDRV_REQ_WRITE_COMPRESSED = 0x20, 55 56 /* Mask of valid flags */ 57 BDRV_REQ_MASK = 0x3f, 58 } BdrvRequestFlags; 59 60 typedef struct BlockSizes { 61 uint32_t phys; 62 uint32_t log; 63 } BlockSizes; 64 65 typedef struct HDGeometry { 66 uint32_t heads; 67 uint32_t sectors; 68 uint32_t cylinders; 69 } HDGeometry; 70 71 #define BDRV_O_RDWR 0x0002 72 #define BDRV_O_RESIZE 0x0004 /* request permission for resizing the node */ 73 #define BDRV_O_SNAPSHOT 0x0008 /* open the file read only and save writes in a snapshot */ 74 #define BDRV_O_TEMPORARY 0x0010 /* delete the file after use */ 75 #define BDRV_O_NOCACHE 0x0020 /* do not use the host page cache */ 76 #define BDRV_O_NATIVE_AIO 0x0080 /* use native AIO instead of the thread pool */ 77 #define BDRV_O_NO_BACKING 0x0100 /* don't open the backing file */ 78 #define BDRV_O_NO_FLUSH 0x0200 /* disable flushing on this disk */ 79 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */ 80 #define BDRV_O_INACTIVE 0x0800 /* consistency hint for migration handoff */ 81 #define BDRV_O_CHECK 0x1000 /* open solely for consistency check */ 82 #define BDRV_O_ALLOW_RDWR 0x2000 /* allow reopen to change from r/o to r/w */ 83 #define BDRV_O_UNMAP 0x4000 /* execute guest UNMAP/TRIM operations */ 84 #define BDRV_O_PROTOCOL 0x8000 /* if no block driver is explicitly given: 85 select an appropriate protocol driver, 86 ignoring the format layer */ 87 #define BDRV_O_NO_IO 0x10000 /* don't initialize for I/O */ 88 89 #define BDRV_O_CACHE_MASK (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH) 90 91 92 /* Option names of options parsed by the block layer */ 93 94 #define BDRV_OPT_CACHE_WB "cache.writeback" 95 #define BDRV_OPT_CACHE_DIRECT "cache.direct" 96 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush" 97 #define BDRV_OPT_READ_ONLY "read-only" 98 #define BDRV_OPT_DISCARD "discard" 99 #define BDRV_OPT_FORCE_SHARE "force-share" 100 101 102 #define BDRV_SECTOR_BITS 9 103 #define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS) 104 #define BDRV_SECTOR_MASK ~(BDRV_SECTOR_SIZE - 1) 105 106 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \ 107 INT_MAX >> BDRV_SECTOR_BITS) 108 #define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) 109 110 /* 111 * Allocation status flags for bdrv_block_status() and friends. 112 * 113 * Public flags: 114 * BDRV_BLOCK_DATA: allocation for data at offset is tied to this layer 115 * BDRV_BLOCK_ZERO: offset reads as zero 116 * BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data 117 * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this 118 * layer (short for DATA || ZERO), set by block layer 119 * BDRV_BLOCK_EOF: the returned pnum covers through end of file for this layer 120 * 121 * Internal flag: 122 * BDRV_BLOCK_RAW: for use by passthrough drivers, such as raw, to request 123 * that the block layer recompute the answer from the returned 124 * BDS; must be accompanied by just BDRV_BLOCK_OFFSET_VALID. 125 * 126 * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 (BDRV_BLOCK_OFFSET_MASK) of 127 * the return value (old interface) or the entire map parameter (new 128 * interface) represent the offset in the returned BDS that is allocated for 129 * the corresponding raw data. However, whether that offset actually 130 * contains data also depends on BDRV_BLOCK_DATA, as follows: 131 * 132 * DATA ZERO OFFSET_VALID 133 * t t t sectors read as zero, returned file is zero at offset 134 * t f t sectors read as valid from file at offset 135 * f t t sectors preallocated, read as zero, returned file not 136 * necessarily zero at offset 137 * f f t sectors preallocated but read from backing_hd, 138 * returned file contains garbage at offset 139 * t t f sectors preallocated, read as zero, unknown offset 140 * t f f sectors read from unknown file or offset 141 * f t f not allocated or unknown offset, read as zero 142 * f f f not allocated or unknown offset, read from backing_hd 143 */ 144 #define BDRV_BLOCK_DATA 0x01 145 #define BDRV_BLOCK_ZERO 0x02 146 #define BDRV_BLOCK_OFFSET_VALID 0x04 147 #define BDRV_BLOCK_RAW 0x08 148 #define BDRV_BLOCK_ALLOCATED 0x10 149 #define BDRV_BLOCK_EOF 0x20 150 #define BDRV_BLOCK_OFFSET_MASK BDRV_SECTOR_MASK 151 152 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue; 153 154 typedef struct BDRVReopenState { 155 BlockDriverState *bs; 156 int flags; 157 uint64_t perm, shared_perm; 158 QDict *options; 159 QDict *explicit_options; 160 void *opaque; 161 } BDRVReopenState; 162 163 /* 164 * Block operation types 165 */ 166 typedef enum BlockOpType { 167 BLOCK_OP_TYPE_BACKUP_SOURCE, 168 BLOCK_OP_TYPE_BACKUP_TARGET, 169 BLOCK_OP_TYPE_CHANGE, 170 BLOCK_OP_TYPE_COMMIT_SOURCE, 171 BLOCK_OP_TYPE_COMMIT_TARGET, 172 BLOCK_OP_TYPE_DATAPLANE, 173 BLOCK_OP_TYPE_DRIVE_DEL, 174 BLOCK_OP_TYPE_EJECT, 175 BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT, 176 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT, 177 BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE, 178 BLOCK_OP_TYPE_MIRROR_SOURCE, 179 BLOCK_OP_TYPE_MIRROR_TARGET, 180 BLOCK_OP_TYPE_RESIZE, 181 BLOCK_OP_TYPE_STREAM, 182 BLOCK_OP_TYPE_REPLACE, 183 BLOCK_OP_TYPE_MAX, 184 } BlockOpType; 185 186 /* Block node permission constants */ 187 enum { 188 /** 189 * A user that has the "permission" of consistent reads is guaranteed that 190 * their view of the contents of the block device is complete and 191 * self-consistent, representing the contents of a disk at a specific 192 * point. 193 * 194 * For most block devices (including their backing files) this is true, but 195 * the property cannot be maintained in a few situations like for 196 * intermediate nodes of a commit block job. 197 */ 198 BLK_PERM_CONSISTENT_READ = 0x01, 199 200 /** This permission is required to change the visible disk contents. */ 201 BLK_PERM_WRITE = 0x02, 202 203 /** 204 * This permission (which is weaker than BLK_PERM_WRITE) is both enough and 205 * required for writes to the block node when the caller promises that 206 * the visible disk content doesn't change. 207 */ 208 BLK_PERM_WRITE_UNCHANGED = 0x04, 209 210 /** This permission is required to change the size of a block node. */ 211 BLK_PERM_RESIZE = 0x08, 212 213 /** 214 * This permission is required to change the node that this BdrvChild 215 * points to. 216 */ 217 BLK_PERM_GRAPH_MOD = 0x10, 218 219 BLK_PERM_ALL = 0x1f, 220 }; 221 222 char *bdrv_perm_names(uint64_t perm); 223 224 /* disk I/O throttling */ 225 void bdrv_init(void); 226 void bdrv_init_with_whitelist(void); 227 bool bdrv_uses_whitelist(void); 228 BlockDriver *bdrv_find_protocol(const char *filename, 229 bool allow_protocol_prefix, 230 Error **errp); 231 BlockDriver *bdrv_find_format(const char *format_name); 232 int bdrv_create(BlockDriver *drv, const char* filename, 233 QemuOpts *opts, Error **errp); 234 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp); 235 BlockDriverState *bdrv_new(void); 236 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top, 237 Error **errp); 238 void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, 239 Error **errp); 240 241 int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough); 242 int bdrv_parse_discard_flags(const char *mode, int *flags); 243 BdrvChild *bdrv_open_child(const char *filename, 244 QDict *options, const char *bdref_key, 245 BlockDriverState* parent, 246 const BdrvChildRole *child_role, 247 bool allow_none, Error **errp); 248 void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, 249 Error **errp); 250 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, 251 const char *bdref_key, Error **errp); 252 BlockDriverState *bdrv_open(const char *filename, const char *reference, 253 QDict *options, int flags, Error **errp); 254 BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name, 255 int flags, Error **errp); 256 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, 257 BlockDriverState *bs, 258 QDict *options, int flags); 259 int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **errp); 260 int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp); 261 int bdrv_reopen_prepare(BDRVReopenState *reopen_state, 262 BlockReopenQueue *queue, Error **errp); 263 void bdrv_reopen_commit(BDRVReopenState *reopen_state); 264 void bdrv_reopen_abort(BDRVReopenState *reopen_state); 265 int bdrv_read(BdrvChild *child, int64_t sector_num, 266 uint8_t *buf, int nb_sectors); 267 int bdrv_write(BdrvChild *child, int64_t sector_num, 268 const uint8_t *buf, int nb_sectors); 269 int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset, 270 int bytes, BdrvRequestFlags flags); 271 int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags); 272 int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes); 273 int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov); 274 int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes); 275 int bdrv_pwritev(BdrvChild *child, int64_t offset, QEMUIOVector *qiov); 276 int bdrv_pwrite_sync(BdrvChild *child, int64_t offset, 277 const void *buf, int count); 278 int coroutine_fn bdrv_co_readv(BdrvChild *child, int64_t sector_num, 279 int nb_sectors, QEMUIOVector *qiov); 280 int coroutine_fn bdrv_co_writev(BdrvChild *child, int64_t sector_num, 281 int nb_sectors, QEMUIOVector *qiov); 282 /* 283 * Efficiently zero a region of the disk image. Note that this is a regular 284 * I/O request like read or write and should have a reasonable size. This 285 * function is not suitable for zeroing the entire image in a single request 286 * because it may allocate memory for the entire region. 287 */ 288 int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset, 289 int bytes, BdrvRequestFlags flags); 290 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, 291 const char *backing_file); 292 void bdrv_refresh_filename(BlockDriverState *bs); 293 int bdrv_truncate(BdrvChild *child, int64_t offset, PreallocMode prealloc, 294 Error **errp); 295 int64_t bdrv_nb_sectors(BlockDriverState *bs); 296 int64_t bdrv_getlength(BlockDriverState *bs); 297 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs); 298 BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts, 299 BlockDriverState *in_bs, Error **errp); 300 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr); 301 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp); 302 int bdrv_commit(BlockDriverState *bs); 303 int bdrv_change_backing_file(BlockDriverState *bs, 304 const char *backing_file, const char *backing_fmt); 305 void bdrv_register(BlockDriver *bdrv); 306 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, 307 const char *backing_file_str); 308 BlockDriverState *bdrv_find_overlay(BlockDriverState *active, 309 BlockDriverState *bs); 310 BlockDriverState *bdrv_find_base(BlockDriverState *bs); 311 312 313 typedef struct BdrvCheckResult { 314 int corruptions; 315 int leaks; 316 int check_errors; 317 int corruptions_fixed; 318 int leaks_fixed; 319 int64_t image_end_offset; 320 BlockFragInfo bfi; 321 } BdrvCheckResult; 322 323 typedef enum { 324 BDRV_FIX_LEAKS = 1, 325 BDRV_FIX_ERRORS = 2, 326 } BdrvCheckMode; 327 328 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix); 329 330 /* The units of offset and total_work_size may be chosen arbitrarily by the 331 * block driver; total_work_size may change during the course of the amendment 332 * operation */ 333 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset, 334 int64_t total_work_size, void *opaque); 335 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts, 336 BlockDriverAmendStatusCB *status_cb, void *cb_opaque); 337 338 /* external snapshots */ 339 bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs, 340 BlockDriverState *candidate); 341 bool bdrv_is_first_non_filter(BlockDriverState *candidate); 342 343 /* check if a named node can be replaced when doing drive-mirror */ 344 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs, 345 const char *node_name, Error **errp); 346 347 /* async block I/O */ 348 void bdrv_aio_cancel(BlockAIOCB *acb); 349 void bdrv_aio_cancel_async(BlockAIOCB *acb); 350 351 /* sg packet commands */ 352 int bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf); 353 354 /* Invalidate any cached metadata used by image formats */ 355 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp); 356 void bdrv_invalidate_cache_all(Error **errp); 357 int bdrv_inactivate_all(void); 358 359 /* Ensure contents are flushed to disk. */ 360 int bdrv_flush(BlockDriverState *bs); 361 int coroutine_fn bdrv_co_flush(BlockDriverState *bs); 362 int bdrv_flush_all(void); 363 void bdrv_close_all(void); 364 void bdrv_drain(BlockDriverState *bs); 365 void coroutine_fn bdrv_co_drain(BlockDriverState *bs); 366 void bdrv_drain_all_begin(void); 367 void bdrv_drain_all_end(void); 368 void bdrv_drain_all(void); 369 370 #define BDRV_POLL_WHILE(bs, cond) ({ \ 371 bool waited_ = false; \ 372 bool busy_ = true; \ 373 BlockDriverState *bs_ = (bs); \ 374 AioContext *ctx_ = bdrv_get_aio_context(bs_); \ 375 if (aio_context_in_iothread(ctx_)) { \ 376 while ((cond) || busy_) { \ 377 busy_ = aio_poll(ctx_, (cond)); \ 378 waited_ |= !!(cond) | busy_; \ 379 } \ 380 } else { \ 381 assert(qemu_get_current_aio_context() == \ 382 qemu_get_aio_context()); \ 383 /* Ask bdrv_dec_in_flight to wake up the main \ 384 * QEMU AioContext. Extra I/O threads never take \ 385 * other I/O threads' AioContexts (see for example \ 386 * block_job_defer_to_main_loop for how to do it). \ 387 */ \ 388 assert(!bs_->wakeup); \ 389 /* Set bs->wakeup before evaluating cond. */ \ 390 atomic_mb_set(&bs_->wakeup, true); \ 391 while (busy_) { \ 392 if ((cond)) { \ 393 waited_ = busy_ = true; \ 394 aio_context_release(ctx_); \ 395 aio_poll(qemu_get_aio_context(), true); \ 396 aio_context_acquire(ctx_); \ 397 } else { \ 398 busy_ = aio_poll(ctx_, false); \ 399 waited_ |= busy_; \ 400 } \ 401 } \ 402 atomic_set(&bs_->wakeup, false); \ 403 } \ 404 waited_; }) 405 406 int bdrv_pdiscard(BlockDriverState *bs, int64_t offset, int bytes); 407 int bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes); 408 int bdrv_has_zero_init_1(BlockDriverState *bs); 409 int bdrv_has_zero_init(BlockDriverState *bs); 410 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs); 411 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs); 412 int bdrv_block_status(BlockDriverState *bs, int64_t offset, 413 int64_t bytes, int64_t *pnum, int64_t *map, 414 BlockDriverState **file); 415 int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base, 416 int64_t offset, int64_t bytes, int64_t *pnum, 417 int64_t *map, BlockDriverState **file); 418 int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes, 419 int64_t *pnum); 420 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base, 421 int64_t offset, int64_t bytes, int64_t *pnum); 422 423 bool bdrv_is_read_only(BlockDriverState *bs); 424 int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, 425 bool ignore_allow_rdw, Error **errp); 426 int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp); 427 bool bdrv_is_sg(BlockDriverState *bs); 428 bool bdrv_is_inserted(BlockDriverState *bs); 429 void bdrv_lock_medium(BlockDriverState *bs, bool locked); 430 void bdrv_eject(BlockDriverState *bs, bool eject_flag); 431 const char *bdrv_get_format_name(BlockDriverState *bs); 432 BlockDriverState *bdrv_find_node(const char *node_name); 433 BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp); 434 BlockDriverState *bdrv_lookup_bs(const char *device, 435 const char *node_name, 436 Error **errp); 437 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base); 438 BlockDriverState *bdrv_next_node(BlockDriverState *bs); 439 440 typedef struct BdrvNextIterator { 441 enum { 442 BDRV_NEXT_BACKEND_ROOTS, 443 BDRV_NEXT_MONITOR_OWNED, 444 } phase; 445 BlockBackend *blk; 446 BlockDriverState *bs; 447 } BdrvNextIterator; 448 449 BlockDriverState *bdrv_first(BdrvNextIterator *it); 450 BlockDriverState *bdrv_next(BdrvNextIterator *it); 451 void bdrv_next_cleanup(BdrvNextIterator *it); 452 453 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs); 454 bool bdrv_is_encrypted(BlockDriverState *bs); 455 void bdrv_iterate_format(void (*it)(void *opaque, const char *name), 456 void *opaque); 457 const char *bdrv_get_node_name(const BlockDriverState *bs); 458 const char *bdrv_get_device_name(const BlockDriverState *bs); 459 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs); 460 int bdrv_get_flags(BlockDriverState *bs); 461 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi); 462 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs); 463 void bdrv_round_to_clusters(BlockDriverState *bs, 464 int64_t offset, int64_t bytes, 465 int64_t *cluster_offset, 466 int64_t *cluster_bytes); 467 468 const char *bdrv_get_encrypted_filename(BlockDriverState *bs); 469 void bdrv_get_backing_filename(BlockDriverState *bs, 470 char *filename, int filename_size); 471 void bdrv_get_full_backing_filename(BlockDriverState *bs, 472 char *dest, size_t sz, Error **errp); 473 void bdrv_get_full_backing_filename_from_filename(const char *backed, 474 const char *backing, 475 char *dest, size_t sz, 476 Error **errp); 477 478 int path_has_protocol(const char *path); 479 int path_is_absolute(const char *path); 480 void path_combine(char *dest, int dest_size, 481 const char *base_path, 482 const char *filename); 483 484 int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos); 485 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos); 486 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, 487 int64_t pos, int size); 488 489 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, 490 int64_t pos, int size); 491 492 void bdrv_img_create(const char *filename, const char *fmt, 493 const char *base_filename, const char *base_fmt, 494 char *options, uint64_t img_size, int flags, 495 bool quiet, Error **errp); 496 497 /* Returns the alignment in bytes that is required so that no bounce buffer 498 * is required throughout the stack */ 499 size_t bdrv_min_mem_align(BlockDriverState *bs); 500 /* Returns optimal alignment in bytes for bounce buffer */ 501 size_t bdrv_opt_mem_align(BlockDriverState *bs); 502 void *qemu_blockalign(BlockDriverState *bs, size_t size); 503 void *qemu_blockalign0(BlockDriverState *bs, size_t size); 504 void *qemu_try_blockalign(BlockDriverState *bs, size_t size); 505 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size); 506 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov); 507 508 void bdrv_enable_copy_on_read(BlockDriverState *bs); 509 void bdrv_disable_copy_on_read(BlockDriverState *bs); 510 511 void bdrv_ref(BlockDriverState *bs); 512 void bdrv_unref(BlockDriverState *bs); 513 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child); 514 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, 515 BlockDriverState *child_bs, 516 const char *child_name, 517 const BdrvChildRole *child_role, 518 Error **errp); 519 520 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp); 521 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason); 522 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason); 523 void bdrv_op_block_all(BlockDriverState *bs, Error *reason); 524 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason); 525 bool bdrv_op_blocker_is_empty(BlockDriverState *bs); 526 527 #define BLKDBG_EVENT(child, evt) \ 528 do { \ 529 if (child) { \ 530 bdrv_debug_event(child->bs, evt); \ 531 } \ 532 } while (0) 533 534 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event); 535 536 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, 537 const char *tag); 538 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag); 539 int bdrv_debug_resume(BlockDriverState *bs, const char *tag); 540 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag); 541 542 /** 543 * bdrv_get_aio_context: 544 * 545 * Returns: the currently bound #AioContext 546 */ 547 AioContext *bdrv_get_aio_context(BlockDriverState *bs); 548 549 /** 550 * Transfer control to @co in the aio context of @bs 551 */ 552 void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co); 553 554 /** 555 * bdrv_set_aio_context: 556 * 557 * Changes the #AioContext used for fd handlers, timers, and BHs by this 558 * BlockDriverState and all its children. 559 * 560 * This function must be called with iothread lock held. 561 */ 562 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context); 563 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz); 564 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo); 565 566 void bdrv_io_plug(BlockDriverState *bs); 567 void bdrv_io_unplug(BlockDriverState *bs); 568 569 /** 570 * bdrv_parent_drained_begin: 571 * 572 * Begin a quiesced section of all users of @bs. This is part of 573 * bdrv_drained_begin. 574 */ 575 void bdrv_parent_drained_begin(BlockDriverState *bs, BdrvChild *ignore); 576 577 /** 578 * bdrv_parent_drained_end: 579 * 580 * End a quiesced section of all users of @bs. This is part of 581 * bdrv_drained_end. 582 */ 583 void bdrv_parent_drained_end(BlockDriverState *bs, BdrvChild *ignore); 584 585 /** 586 * bdrv_drained_begin: 587 * 588 * Begin a quiesced section for exclusive access to the BDS, by disabling 589 * external request sources including NBD server and device model. Note that 590 * this doesn't block timers or coroutines from submitting more requests, which 591 * means block_job_pause is still necessary. 592 * 593 * This function can be recursive. 594 */ 595 void bdrv_drained_begin(BlockDriverState *bs); 596 597 /** 598 * Like bdrv_drained_begin, but recursively begins a quiesced section for 599 * exclusive access to all child nodes as well. 600 */ 601 void bdrv_subtree_drained_begin(BlockDriverState *bs); 602 603 /** 604 * bdrv_drained_end: 605 * 606 * End a quiescent section started by bdrv_drained_begin(). 607 */ 608 void bdrv_drained_end(BlockDriverState *bs); 609 610 /** 611 * End a quiescent section started by bdrv_subtree_drained_begin(). 612 */ 613 void bdrv_subtree_drained_end(BlockDriverState *bs); 614 615 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child, 616 Error **errp); 617 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp); 618 619 bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name, 620 uint32_t granularity, Error **errp); 621 /** 622 * 623 * bdrv_register_buf/bdrv_unregister_buf: 624 * 625 * Register/unregister a buffer for I/O. For example, VFIO drivers are 626 * interested to know the memory areas that would later be used for I/O, so 627 * that they can prepare IOMMU mapping etc., to get better performance. 628 */ 629 void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size); 630 void bdrv_unregister_buf(BlockDriverState *bs, void *host); 631 #endif 632