qemu/include/block/block_int.h
<<
>>
Prefs
   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/block.h"
  28#include "qemu/option.h"
  29#include "qemu/queue.h"
  30#include "block/coroutine.h"
  31#include "qemu/timer.h"
  32#include "qapi-types.h"
  33#include "qapi/qmp/qerror.h"
  34#include "monitor/monitor.h"
  35#include "qemu/hbitmap.h"
  36#include "block/snapshot.h"
  37
  38#define BLOCK_FLAG_ENCRYPT          1
  39#define BLOCK_FLAG_COMPAT6          4
  40#define BLOCK_FLAG_LAZY_REFCOUNTS   8
  41
  42#define BLOCK_IO_LIMIT_READ     0
  43#define BLOCK_IO_LIMIT_WRITE    1
  44#define BLOCK_IO_LIMIT_TOTAL    2
  45
  46#define BLOCK_IO_SLICE_TIME     100000000
  47#define NANOSECONDS_PER_SECOND  1000000000.0
  48
  49#define BLOCK_OPT_SIZE              "size"
  50#define BLOCK_OPT_ENCRYPT           "encryption"
  51#define BLOCK_OPT_COMPAT6           "compat6"
  52#define BLOCK_OPT_BACKING_FILE      "backing_file"
  53#define BLOCK_OPT_BACKING_FMT       "backing_fmt"
  54#define BLOCK_OPT_CLUSTER_SIZE      "cluster_size"
  55#define BLOCK_OPT_TABLE_SIZE        "table_size"
  56#define BLOCK_OPT_PREALLOC          "preallocation"
  57#define BLOCK_OPT_SUBFMT            "subformat"
  58#define BLOCK_OPT_COMPAT_LEVEL      "compat"
  59#define BLOCK_OPT_LAZY_REFCOUNTS    "lazy_refcounts"
  60#define BLOCK_OPT_ADAPTER_TYPE      "adapter_type"
  61
  62typedef struct BdrvTrackedRequest {
  63    BlockDriverState *bs;
  64    int64_t sector_num;
  65    int nb_sectors;
  66    bool is_write;
  67    QLIST_ENTRY(BdrvTrackedRequest) list;
  68    Coroutine *co; /* owner, used for deadlock detection */
  69    CoQueue wait_queue; /* coroutines blocked on this request */
  70} BdrvTrackedRequest;
  71
  72
  73typedef struct BlockIOLimit {
  74    int64_t bps[3];
  75    int64_t iops[3];
  76} BlockIOLimit;
  77
  78typedef struct BlockIOBaseValue {
  79    uint64_t bytes[2];
  80    uint64_t ios[2];
  81} BlockIOBaseValue;
  82
  83struct BlockDriver {
  84    const char *format_name;
  85    int instance_size;
  86    int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
  87    int (*bdrv_probe_device)(const char *filename);
  88
  89    /* Any driver implementing this callback is expected to be able to handle
  90     * NULL file names in its .bdrv_open() implementation */
  91    void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
  92
  93    /* For handling image reopen for split or non-split files */
  94    int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
  95                               BlockReopenQueue *queue, Error **errp);
  96    void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
  97    void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
  98
  99    int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags);
 100    int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags);
 101    int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
 102                     uint8_t *buf, int nb_sectors);
 103    int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
 104                      const uint8_t *buf, int nb_sectors);
 105    void (*bdrv_close)(BlockDriverState *bs);
 106    void (*bdrv_rebind)(BlockDriverState *bs);
 107    int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
 108    int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
 109    int (*bdrv_make_empty)(BlockDriverState *bs);
 110    /* aio */
 111    BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
 112        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 113        BlockDriverCompletionFunc *cb, void *opaque);
 114    BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
 115        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 116        BlockDriverCompletionFunc *cb, void *opaque);
 117    BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
 118        BlockDriverCompletionFunc *cb, void *opaque);
 119    BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
 120        int64_t sector_num, int nb_sectors,
 121        BlockDriverCompletionFunc *cb, void *opaque);
 122
 123    int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
 124        int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 125    int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
 126        int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 127    /*
 128     * Efficiently zero a region of the disk image.  Typically an image format
 129     * would use a compact metadata representation to implement this.  This
 130     * function pointer may be NULL and .bdrv_co_writev() will be called
 131     * instead.
 132     */
 133    int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
 134        int64_t sector_num, int nb_sectors);
 135    int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
 136        int64_t sector_num, int nb_sectors);
 137    int coroutine_fn (*bdrv_co_is_allocated)(BlockDriverState *bs,
 138        int64_t sector_num, int nb_sectors, int *pnum);
 139
 140    /*
 141     * Invalidate any cached meta-data.
 142     */
 143    void (*bdrv_invalidate_cache)(BlockDriverState *bs);
 144
 145    /*
 146     * Flushes all data that was already written to the OS all the way down to
 147     * the disk (for example raw-posix calls fsync()).
 148     */
 149    int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 150
 151    /*
 152     * Flushes all internal caches to the OS. The data may still sit in a
 153     * writeback cache of the host OS, but it will survive a crash of the qemu
 154     * process.
 155     */
 156    int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 157
 158    const char *protocol_name;
 159    int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
 160    int64_t (*bdrv_getlength)(BlockDriverState *bs);
 161    int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 162    int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
 163                                 const uint8_t *buf, int nb_sectors);
 164
 165    int (*bdrv_snapshot_create)(BlockDriverState *bs,
 166                                QEMUSnapshotInfo *sn_info);
 167    int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 168                              const char *snapshot_id);
 169    int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
 170    int (*bdrv_snapshot_list)(BlockDriverState *bs,
 171                              QEMUSnapshotInfo **psn_info);
 172    int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 173                                  const char *snapshot_name);
 174    int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 175
 176    int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
 177                             int64_t pos);
 178    int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
 179                             int64_t pos, int size);
 180
 181    int (*bdrv_change_backing_file)(BlockDriverState *bs,
 182        const char *backing_file, const char *backing_fmt);
 183
 184    /* removable device specific */
 185    int (*bdrv_is_inserted)(BlockDriverState *bs);
 186    int (*bdrv_media_changed)(BlockDriverState *bs);
 187    void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
 188    void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 189
 190    /* to control generic scsi devices */
 191    int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
 192    BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 193        unsigned long int req, void *buf,
 194        BlockDriverCompletionFunc *cb, void *opaque);
 195
 196    /* List of options for creating images, terminated by name == NULL */
 197    QEMUOptionParameter *create_options;
 198
 199
 200    /*
 201     * Returns 0 for completed check, -errno for internal errors.
 202     * The check results are stored in result.
 203     */
 204    int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
 205        BdrvCheckMode fix);
 206
 207    void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
 208
 209    /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
 210    int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
 211        const char *tag);
 212    int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
 213    bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
 214
 215    /*
 216     * Returns 1 if newly created images are guaranteed to contain only
 217     * zeros, 0 otherwise.
 218     */
 219    int (*bdrv_has_zero_init)(BlockDriverState *bs);
 220
 221    QLIST_ENTRY(BlockDriver) list;
 222};
 223
 224/*
 225 * Note: the function bdrv_append() copies and swaps contents of
 226 * BlockDriverStates, so if you add new fields to this struct, please
 227 * inspect bdrv_append() to determine if the new fields need to be
 228 * copied as well.
 229 */
 230struct BlockDriverState {
 231    int64_t total_sectors; /* if we are reading a disk image, give its
 232                              size in sectors */
 233    int read_only; /* if true, the media is read only */
 234    int open_flags; /* flags used to open the file, re-used for re-open */
 235    int encrypted; /* if true, the media is encrypted */
 236    int valid_key; /* if true, a valid encryption key has been set */
 237    int sg;        /* if true, the device is a /dev/sg* */
 238    int copy_on_read; /* if true, copy read backing sectors into image
 239                         note this is a reference count */
 240
 241    BlockDriver *drv; /* NULL means no media */
 242    void *opaque;
 243
 244    void *dev;                  /* attached device model, if any */
 245    /* TODO change to DeviceState when all users are qdevified */
 246    const BlockDevOps *dev_ops;
 247    void *dev_opaque;
 248
 249    char filename[1024];
 250    char backing_file[1024]; /* if non zero, the image is a diff of
 251                                this file image */
 252    char backing_format[16]; /* if non-zero and backing_file exists */
 253    int is_temporary;
 254
 255    BlockDriverState *backing_hd;
 256    BlockDriverState *file;
 257
 258    NotifierList close_notifiers;
 259
 260    /* Callback before write request is processed */
 261    NotifierWithReturnList before_write_notifiers;
 262
 263    /* number of in-flight copy-on-read requests */
 264    unsigned int copy_on_read_in_flight;
 265
 266    /* the time for latest disk I/O */
 267    int64_t slice_start;
 268    int64_t slice_end;
 269    BlockIOLimit io_limits;
 270    BlockIOBaseValue slice_submitted;
 271    CoQueue      throttled_reqs;
 272    QEMUTimer    *block_timer;
 273    bool         io_limits_enabled;
 274
 275    /* I/O stats (display with "info blockstats"). */
 276    uint64_t nr_bytes[BDRV_MAX_IOTYPE];
 277    uint64_t nr_ops[BDRV_MAX_IOTYPE];
 278    uint64_t total_time_ns[BDRV_MAX_IOTYPE];
 279    uint64_t wr_highest_sector;
 280
 281    /* Whether the disk can expand beyond total_sectors */
 282    int growable;
 283
 284    /* the memory alignment required for the buffers handled by this driver */
 285    int buffer_alignment;
 286
 287    /* do we need to tell the quest if we have a volatile write cache? */
 288    int enable_write_cache;
 289
 290    /* NOTE: the following infos are only hints for real hardware
 291       drivers. They are not used by the block driver */
 292    BlockdevOnError on_read_error, on_write_error;
 293    bool iostatus_enabled;
 294    BlockDeviceIoStatus iostatus;
 295    char device_name[32];
 296    HBitmap *dirty_bitmap;
 297    int in_use; /* users other than guest access, eg. block migration */
 298    QTAILQ_ENTRY(BlockDriverState) list;
 299
 300    QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
 301
 302    /* long-running background operation */
 303    BlockJob *job;
 304
 305    QDict *options;
 306};
 307
 308int get_tmp_filename(char *filename, int size);
 309
 310void bdrv_set_io_limits(BlockDriverState *bs,
 311                        BlockIOLimit *io_limits);
 312
 313/**
 314 * bdrv_add_before_write_notifier:
 315 *
 316 * Register a callback that is invoked before write requests are processed but
 317 * after any throttling or waiting for overlapping requests.
 318 */
 319void bdrv_add_before_write_notifier(BlockDriverState *bs,
 320                                    NotifierWithReturn *notifier);
 321
 322/**
 323 * bdrv_get_aio_context:
 324 *
 325 * Returns: the currently bound #AioContext
 326 */
 327AioContext *bdrv_get_aio_context(BlockDriverState *bs);
 328
 329#ifdef _WIN32
 330int is_windows_drive(const char *filename);
 331#endif
 332void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv,
 333                               enum MonitorEvent ev,
 334                               BlockErrorAction action, bool is_read);
 335
 336/**
 337 * stream_start:
 338 * @bs: Block device to operate on.
 339 * @base: Block device that will become the new base, or %NULL to
 340 * flatten the whole backing file chain onto @bs.
 341 * @base_id: The file name that will be written to @bs as the new
 342 * backing file if the job completes.  Ignored if @base is %NULL.
 343 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 344 * @on_error: The action to take upon error.
 345 * @cb: Completion function for the job.
 346 * @opaque: Opaque pointer value passed to @cb.
 347 * @errp: Error object.
 348 *
 349 * Start a streaming operation on @bs.  Clusters that are unallocated
 350 * in @bs, but allocated in any image between @base and @bs (both
 351 * exclusive) will be written to @bs.  At the end of a successful
 352 * streaming job, the backing file of @bs will be changed to
 353 * @base_id in the written image and to @base in the live BlockDriverState.
 354 */
 355void stream_start(BlockDriverState *bs, BlockDriverState *base,
 356                  const char *base_id, int64_t speed, BlockdevOnError on_error,
 357                  BlockDriverCompletionFunc *cb,
 358                  void *opaque, Error **errp);
 359
 360/**
 361 * commit_start:
 362 * @bs: Top Block device
 363 * @base: Block device that will be written into, and become the new top
 364 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 365 * @on_error: The action to take upon error.
 366 * @cb: Completion function for the job.
 367 * @opaque: Opaque pointer value passed to @cb.
 368 * @errp: Error object.
 369 *
 370 */
 371void commit_start(BlockDriverState *bs, BlockDriverState *base,
 372                 BlockDriverState *top, int64_t speed,
 373                 BlockdevOnError on_error, BlockDriverCompletionFunc *cb,
 374                 void *opaque, Error **errp);
 375
 376/*
 377 * mirror_start:
 378 * @bs: Block device to operate on.
 379 * @target: Block device to write to.
 380 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 381 * @granularity: The chosen granularity for the dirty bitmap.
 382 * @buf_size: The amount of data that can be in flight at one time.
 383 * @mode: Whether to collapse all images in the chain to the target.
 384 * @on_source_error: The action to take upon error reading from the source.
 385 * @on_target_error: The action to take upon error writing to the target.
 386 * @cb: Completion function for the job.
 387 * @opaque: Opaque pointer value passed to @cb.
 388 * @errp: Error object.
 389 *
 390 * Start a mirroring operation on @bs.  Clusters that are allocated
 391 * in @bs will be written to @bs until the job is cancelled or
 392 * manually completed.  At the end of a successful mirroring job,
 393 * @bs will be switched to read from @target.
 394 */
 395void mirror_start(BlockDriverState *bs, BlockDriverState *target,
 396                  int64_t speed, int64_t granularity, int64_t buf_size,
 397                  MirrorSyncMode mode, BlockdevOnError on_source_error,
 398                  BlockdevOnError on_target_error,
 399                  BlockDriverCompletionFunc *cb,
 400                  void *opaque, Error **errp);
 401
 402/*
 403 * backup_start:
 404 * @bs: Block device to operate on.
 405 * @target: Block device to write to.
 406 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 407 * @sync_mode: What parts of the disk image should be copied to the destination.
 408 * @on_source_error: The action to take upon error reading from the source.
 409 * @on_target_error: The action to take upon error writing to the target.
 410 * @cb: Completion function for the job.
 411 * @opaque: Opaque pointer value passed to @cb.
 412 *
 413 * Start a backup operation on @bs.  Clusters in @bs are written to @target
 414 * until the job is cancelled or manually completed.
 415 */
 416void backup_start(BlockDriverState *bs, BlockDriverState *target,
 417                  int64_t speed, MirrorSyncMode sync_mode,
 418                  BlockdevOnError on_source_error,
 419                  BlockdevOnError on_target_error,
 420                  BlockDriverCompletionFunc *cb, void *opaque,
 421                  Error **errp);
 422
 423#endif /* BLOCK_INT_H */
 424