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