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