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
  43 #define BLOCK_OPT_SIZE          "size"
  44 #define BLOCK_OPT_ENCRYPT       "encryption"
  45 #define BLOCK_OPT_COMPAT6       "compat6"
  46 #define BLOCK_OPT_BACKING_FILE  "backing_file"
  47 #define BLOCK_OPT_BACKING_FMT   "backing_fmt"
  48 #define BLOCK_OPT_CLUSTER_SIZE  "cluster_size"
  49 #define BLOCK_OPT_TABLE_SIZE    "table_size"
  50 #define BLOCK_OPT_PREALLOC      "preallocation"
  51 #define BLOCK_OPT_SUBFMT        "subformat"
  52
  53 typedef struct AIOPool {
  54     void (*cancel)(BlockDriverAIOCB *acb);
  55     int aiocb_size;
  56     BlockDriverAIOCB *free_aiocb;
  57 } AIOPool;
  58
  59 typedef struct BlockIOLimit {
  60     int64_t bps[3];
  61     int64_t iops[3];
  62 } BlockIOLimit;
  63
  64 typedef struct BlockIOBaseValue {
  65     uint64_t bytes[2];
  66     uint64_t ios[2];
  67 } BlockIOBaseValue;
  68
  69 struct BlockDriver {
  70     const char *format_name;
  71     int instance_size;
  72     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
  73     int (*bdrv_probe_device)(const char *filename);
  74     int (*bdrv_open)(BlockDriverState *bs, int flags);
  75     int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, int flags);
  76     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
  77                      uint8_t *buf, int nb_sectors);
  78     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
  79                       const uint8_t *buf, int nb_sectors);
  80     void (*bdrv_close)(BlockDriverState *bs);
  81     int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
  82     int (*bdrv_is_allocated)(BlockDriverState *bs, int64_t sector_num,
  83                              int nb_sectors, int *pnum);
  84     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
  85     int (*bdrv_make_empty)(BlockDriverState *bs);
  86     /* aio */
  87     BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
  88         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
  89         BlockDriverCompletionFunc *cb, void *opaque);
  90     BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
  91         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
  92         BlockDriverCompletionFunc *cb, void *opaque);
  93     BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
  94         BlockDriverCompletionFunc *cb, void *opaque);
  95     BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
  96         int64_t sector_num, int nb_sectors,
  97         BlockDriverCompletionFunc *cb, void *opaque);
  98
  99     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
 100         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 101     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
 102         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
 103     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
 104         int64_t sector_num, int nb_sectors);
 105
 106     /*
 107      * Invalidate any cached meta-data.
 108      */
 109     void (*bdrv_invalidate_cache)(BlockDriverState *bs);
 110
 111     /*
 112      * Flushes all data that was already written to the OS all the way down to
 113      * the disk (for example raw-posix calls fsync()).
 114      */
 115     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 116
 117     /*
 118      * Flushes all internal caches to the OS. The data may still sit in a
 119      * writeback cache of the host OS, but it will survive a crash of the qemu
 120      * process.
 121      */
 122     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 123
 124     int (*bdrv_aio_multiwrite)(BlockDriverState *bs, BlockRequest *reqs,
 125         int num_reqs);
 126     int (*bdrv_merge_requests)(BlockDriverState *bs, BlockRequest* a,
 127         BlockRequest *b);
 128
 129
 130     const char *protocol_name;
 131     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
 132     int64_t (*bdrv_getlength)(BlockDriverState *bs);
 133     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 134     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
 135                                  const uint8_t *buf, int nb_sectors);
 136
 137     int (*bdrv_snapshot_create)(BlockDriverState *bs,
 138                                 QEMUSnapshotInfo *sn_info);
 139     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 140                               const char *snapshot_id);
 141     int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
 142     int (*bdrv_snapshot_list)(BlockDriverState *bs,
 143                               QEMUSnapshotInfo **psn_info);
 144     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 145                                   const char *snapshot_name);
 146     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 147
 148     int (*bdrv_save_vmstate)(BlockDriverState *bs, const uint8_t *buf,
 149                              int64_t pos, int size);
 150     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
 151                              int64_t pos, int size);
 152
 153     int (*bdrv_change_backing_file)(BlockDriverState *bs,
 154         const char *backing_file, const char *backing_fmt);
 155
 156     /* removable device specific */
 157     int (*bdrv_is_inserted)(BlockDriverState *bs);
 158     int (*bdrv_media_changed)(BlockDriverState *bs);
 159     void (*bdrv_eject)(BlockDriverState *bs, int eject_flag);
 160     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 161
 162     /* to control generic scsi devices */
 163     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
 164     BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 165         unsigned long int req, void *buf,
 166         BlockDriverCompletionFunc *cb, void *opaque);
 167
 168     /* List of options for creating images, terminated by name == NULL */
 169     QEMUOptionParameter *create_options;
 170
 171
 172     /*
 173      * Returns 0 for completed check, -errno for internal errors.
 174      * The check results are stored in result.
 175      */
 176     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result);
 177
 178     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
 179
 180     /*
 181      * Returns 1 if newly created images are guaranteed to contain only
 182      * zeros, 0 otherwise.
 183      */
 184     int (*bdrv_has_zero_init)(BlockDriverState *bs);
 185
 186     QLIST_ENTRY(BlockDriver) list;
 187 };
 188
 189 struct BlockDriverState {
 190     int64_t total_sectors; /* if we are reading a disk image, give its
 191                               size in sectors */
 192     int read_only; /* if true, the media is read only */
 193     int keep_read_only; /* if true, the media was requested to stay read only */
 194     int open_flags; /* flags used to open the file, re-used for re-open */
 195     int encrypted; /* if true, the media is encrypted */
 196     int valid_key; /* if true, a valid encryption key has been set */
 197     int sg;        /* if true, the device is a /dev/sg* */
 198
 199     BlockDriver *drv; /* NULL means no media */
 200     void *opaque;
 201
 202     void *dev;                  /* attached device model, if any */
 203     /* TODO change to DeviceState when all users are qdevified */
 204     const BlockDevOps *dev_ops;
 205     void *dev_opaque;
 206
 207     char filename[1024];
 208     char backing_file[1024]; /* if non zero, the image is a diff of
 209                                 this file image */
 210     char backing_format[16]; /* if non-zero and backing_file exists */
 211     int is_temporary;
 212
 213     BlockDriverState *backing_hd;
 214     BlockDriverState *file;
 215
 216     /* async read/write emulation */
 217
 218     void *sync_aiocb;
 219
 220     /* the time for latest disk I/O */
 221     int64_t slice_time;
 222     int64_t slice_start;
 223     int64_t slice_end;
 224     BlockIOLimit io_limits;
 225     BlockIOBaseValue  io_base;
 226     CoQueue      throttled_reqs;
 227     QEMUTimer    *block_timer;
 228     bool         io_limits_enabled;
 229
 230     /* I/O stats (display with "info blockstats"). */
 231     uint64_t nr_bytes[BDRV_MAX_IOTYPE];
 232     uint64_t nr_ops[BDRV_MAX_IOTYPE];
 233     uint64_t total_time_ns[BDRV_MAX_IOTYPE];
 234     uint64_t wr_highest_sector;
 235
 236     /* Whether the disk can expand beyond total_sectors */
 237     int growable;
 238
 239     /* the memory alignment required for the buffers handled by this driver */
 240     int buffer_alignment;
 241
 242     /* do we need to tell the quest if we have a volatile write cache? */
 243     int enable_write_cache;
 244
 245     /* NOTE: the following infos are only hints for real hardware
 246        drivers. They are not used by the block driver */
 247     int cyls, heads, secs, translation;
 248     BlockErrorAction on_read_error, on_write_error;
 249     bool iostatus_enabled;
 250     BlockDeviceIoStatus iostatus;
 251     char device_name[32];
 252     unsigned long *dirty_bitmap;
 253     int64_t dirty_count;
 254     int in_use; /* users other than guest access, eg. block migration */
 255     QTAILQ_ENTRY(BlockDriverState) list;
 256     void *private;
 257 };
 258
 259 struct BlockDriverAIOCB {
 260     AIOPool *pool;
 261     BlockDriverState *bs;
 262     BlockDriverCompletionFunc *cb;
 263     void *opaque;
 264     BlockDriverAIOCB *next;
 265 };
 266
 267 void get_tmp_filename(char *filename, int size);
 268
 269 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
 270                    BlockDriverCompletionFunc *cb, void *opaque);
 271 void qemu_aio_release(void *p);
 272
 273 void bdrv_set_io_limits(BlockDriverState *bs,
 274                         BlockIOLimit *io_limits);
 275
 276 #ifdef _WIN32
 277 int is_windows_drive(const char *filename);
 278 #endif
 279
 280 #endif /* BLOCK_INT_H */