block_int.h

   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.h"
  28 #include "qemu-option.h"
  29 #include "qemu-queue.h"
  30 #include "qemu-coroutine.h"
  31 #include "qemu-timer.h"
  32 #include "qapi-types.h"
  33
  34 #define BLOCK_FLAG_ENCRYPT      1
  35 #define BLOCK_FLAG_COMPAT6      4
  36
  37 #define BLOCK_IO_LIMIT_READ     0
  38 #define BLOCK_IO_LIMIT_WRITE    1
  39 #define BLOCK_IO_LIMIT_TOTAL    2
  40
  41 #define BLOCK_IO_SLICE_TIME     100000000
  42 #define NANOSECONDS_PER_SECOND  1000000000.0
  43
  44 #define BLOCK_OPT_SIZE          "size"
  45 #define BLOCK_OPT_ENCRYPT       "encryption"
  46 #define BLOCK_OPT_COMPAT6       "compat6"
  47 #define BLOCK_OPT_BACKING_FILE  "backing_file"
  48 #define BLOCK_OPT_BACKING_FMT   "backing_fmt"
  49 #define BLOCK_OPT_CLUSTER_SIZE  "cluster_size"
  50 #define BLOCK_OPT_TABLE_SIZE    "table_size"
  51 #define BLOCK_OPT_PREALLOC      "preallocation"
  52 #define BLOCK_OPT_SUBFMT        "subformat"
  53
  54 typedef struct BdrvTrackedRequest BdrvTrackedRequest;
  55
  56 typedef struct BlockIOLimit {
  57     int64_t bps[3];
  58     int64_t iops[3];
  59 } BlockIOLimit;
  60
  61 typedef struct BlockIOBaseValue {
  62     uint64_t bytes[2];
  63     uint64_t ios[2];
  64 } BlockIOBaseValue;
  65
  66 typedef void BlockJobCancelFunc(void *opaque);
  67 typedef struct BlockJob BlockJob;
  68 typedef struct BlockJobType {
  69     /** Derived BlockJob struct size */
  70     size_t instance_size;
  71
  72     /** String describing the operation, part of query-block-jobs QMP API */
  73     const char *job_type;
  74
  75     /** Optional callback for job types that support setting a speed limit */
  76     int (*set_speed)(BlockJob *job, int64_t value);
  77 } BlockJobType;
  78
  79 /**
  80  * Long-running operation on a BlockDriverState
  81  */
  82 struct BlockJob {
  83     const BlockJobType *job_type;
  84     BlockDriverState *bs;
  85     bool cancelled;
  86     bool busy;
  87
  88     /* These fields are published by the query-block-jobs QMP API */
  89     int64_t offset;
  90     int64_t len;
  91     int64_t speed;
  92
  93     BlockDriverCompletionFunc *cb;
  94     void *opaque;
  95 };
  96
  97 struct BlockDriver {
  98     const char *format_name;
  99     int instance_size;
 100     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
 101     int (*bdrv_probe_device)(const char *filename);
 102     int (*bdrv_open)(BlockDriverState *bs, int flags);
 103     int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, int flags);
 104     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
 105                      uint8_t *buf, int nb_sectors);
 106     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
 107                       const uint8_t *buf, int nb_sectors);
 108     void (*bdrv_close)(BlockDriverState *bs);
 109     int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
 110     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
 111     int (*bdrv_make_empty)(BlockDriverState *bs);
 112     /* aio */
 113     BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
 114         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 115         BlockDriverCompletionFunc *cb, void *opaque);
 116     BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
 117         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 118         BlockDriverCompletionFunc *cb, void *opaque);
 119     BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
 120         BlockDriverCompletionFunc *cb, void *opaque);
 121     BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
 122         int64_t sector_num, int nb_sectors,
 123         BlockDriverCompletionFunc *cb, void *opaque);
 124
 125     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
 126         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 127     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
 128         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 129     /*
 130      * Efficiently zero a region of the disk image.  Typically an image format
 131      * would use a compact metadata representation to implement this.  This
 132      * function pointer may be NULL and .bdrv_co_writev() will be called
 133      * instead.
 134      */
 135     int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
 136         int64_t sector_num, int nb_sectors);
 137     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
 138         int64_t sector_num, int nb_sectors);
 139     int coroutine_fn (*bdrv_co_is_allocated)(BlockDriverState *bs,
 140         int64_t sector_num, int nb_sectors, int *pnum);
 141
 142     /*
 143      * Invalidate any cached meta-data.
 144      */
 145     void (*bdrv_invalidate_cache)(BlockDriverState *bs);
 146
 147     /*
 148      * Flushes all data that was already written to the OS all the way down to
 149      * the disk (for example raw-posix calls fsync()).
 150      */
 151     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 152
 153     /*
 154      * Flushes all internal caches to the OS. The data may still sit in a
 155      * writeback cache of the host OS, but it will survive a crash of the qemu
 156      * process.
 157      */
 158     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 159
 160     const char *protocol_name;
 161     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
 162     int64_t (*bdrv_getlength)(BlockDriverState *bs);
 163     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 164     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
 165                                  const uint8_t *buf, int nb_sectors);
 166
 167     int (*bdrv_snapshot_create)(BlockDriverState *bs,
 168                                 QEMUSnapshotInfo *sn_info);
 169     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 170                               const char *snapshot_id);
 171     int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
 172     int (*bdrv_snapshot_list)(BlockDriverState *bs,
 173                               QEMUSnapshotInfo **psn_info);
 174     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 175                                   const char *snapshot_name);
 176     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 177
 178     int (*bdrv_save_vmstate)(BlockDriverState *bs, const uint8_t *buf,
 179                              int64_t pos, int size);
 180     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
 181                              int64_t pos, int size);
 182
 183     int (*bdrv_change_backing_file)(BlockDriverState *bs,
 184         const char *backing_file, const char *backing_fmt);
 185
 186     /* removable device specific */
 187     int (*bdrv_is_inserted)(BlockDriverState *bs);
 188     int (*bdrv_media_changed)(BlockDriverState *bs);
 189     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
 190     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 191
 192     /* to control generic scsi devices */
 193     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
 194     BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 195         unsigned long int req, void *buf,
 196         BlockDriverCompletionFunc *cb, void *opaque);
 197
 198     /* List of options for creating images, terminated by name == NULL */
 199     QEMUOptionParameter *create_options;
 200
 201
 202     /*
 203      * Returns 0 for completed check, -errno for internal errors.
 204      * The check results are stored in result.
 205      */
 206     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result);
 207
 208     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
 209
 210     /*
 211      * Returns 1 if newly created images are guaranteed to contain only
 212      * zeros, 0 otherwise.
 213      */
 214     int (*bdrv_has_zero_init)(BlockDriverState *bs);
 215
 216     QLIST_ENTRY(BlockDriver) list;
 217 };
 218
 219 /*
 220  * Note: the function bdrv_append() copies and swaps contents of
 221  * BlockDriverStates, so if you add new fields to this struct, please
 222  * inspect bdrv_append() to determine if the new fields need to be
 223  * copied as well.
 224  */
 225 struct BlockDriverState {
 226     int64_t total_sectors; /* if we are reading a disk image, give its
 227                               size in sectors */
 228     int read_only; /* if true, the media is read only */
 229     int keep_read_only; /* if true, the media was requested to stay read only */
 230     int open_flags; /* flags used to open the file, re-used for re-open */
 231     int encrypted; /* if true, the media is encrypted */
 232     int valid_key; /* if true, a valid encryption key has been set */
 233     int sg;        /* if true, the device is a /dev/sg* */
 234     int copy_on_read; /* if true, copy read backing sectors into image
 235                          note this is a reference count */
 236
 237     BlockDriver *drv; /* NULL means no media */
 238     void *opaque;
 239
 240     void *dev;                  /* attached device model, if any */
 241     /* TODO change to DeviceState when all users are qdevified */
 242     const BlockDevOps *dev_ops;
 243     void *dev_opaque;
 244
 245     char filename[1024];
 246     char backing_file[1024]; /* if non zero, the image is a diff of
 247                                 this file image */
 248     char backing_format[16]; /* if non-zero and backing_file exists */
 249     int is_temporary;
 250
 251     BlockDriverState *backing_hd;
 252     BlockDriverState *file;
 253
 254     /* number of in-flight copy-on-read requests */
 255     unsigned int copy_on_read_in_flight;
 256
 257     /* the time for latest disk I/O */
 258     int64_t slice_time;
 259     int64_t slice_start;
 260     int64_t slice_end;
 261     BlockIOLimit io_limits;
 262     BlockIOBaseValue  io_base;
 263     CoQueue      throttled_reqs;
 264     QEMUTimer    *block_timer;
 265     bool         io_limits_enabled;
 266
 267     /* I/O stats (display with "info blockstats"). */
 268     uint64_t nr_bytes[BDRV_MAX_IOTYPE];
 269     uint64_t nr_ops[BDRV_MAX_IOTYPE];
 270     uint64_t total_time_ns[BDRV_MAX_IOTYPE];
 271     uint64_t wr_highest_sector;
 272
 273     /* Whether the disk can expand beyond total_sectors */
 274     int growable;
 275
 276     /* the memory alignment required for the buffers handled by this driver */
 277     int buffer_alignment;
 278
 279     /* do we need to tell the quest if we have a volatile write cache? */
 280     int enable_write_cache;
 281
 282     /* NOTE: the following infos are only hints for real hardware
 283        drivers. They are not used by the block driver */
 284     int cyls, heads, secs, translation;
 285     BlockErrorAction on_read_error, on_write_error;
 286     bool iostatus_enabled;
 287     BlockDeviceIoStatus iostatus;
 288     char device_name[32];
 289     unsigned long *dirty_bitmap;
 290     int64_t dirty_count;
 291     int in_use; /* users other than guest access, eg. block migration */
 292     QTAILQ_ENTRY(BlockDriverState) list;
 293
 294     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
 295
 296     /* long-running background operation */
 297     BlockJob *job;
 298 };
 299
 300 void get_tmp_filename(char *filename, int size);
 301
 302 void bdrv_set_io_limits(BlockDriverState *bs,
 303                         BlockIOLimit *io_limits);
 304
 305 #ifdef _WIN32
 306 int is_windows_drive(const char *filename);
 307 #endif
 308
 309 void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs,
 310                        BlockDriverCompletionFunc *cb, void *opaque);
 311 void block_job_complete(BlockJob *job, int ret);
 312 int block_job_set_speed(BlockJob *job, int64_t value);
 313 void block_job_cancel(BlockJob *job);
 314 bool block_job_is_cancelled(BlockJob *job);
 315 void block_job_cancel_sync(BlockJob *job);
 316
 317 int stream_start(BlockDriverState *bs, BlockDriverState *base,
 318                  const char *base_id, BlockDriverCompletionFunc *cb,
 319                  void *opaque);
 320
 321 #endif /* BLOCK_INT_H */