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 AIOPool {
  57     void (*cancel)(BlockDriverAIOCB *acb);
  58     int aiocb_size;
  59     BlockDriverAIOCB *free_aiocb;
  60 } AIOPool;
  61
  62 typedef struct BlockIOLimit {
  63     int64_t bps[3];
  64     int64_t iops[3];
  65 } BlockIOLimit;
  66
  67 typedef struct BlockIOBaseValue {
  68     uint64_t bytes[2];
  69     uint64_t ios[2];
  70 } BlockIOBaseValue;
  71
  72 struct BlockDriver {
  73     const char *format_name;
  74     int instance_size;
  75     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
  76     int (*bdrv_probe_device)(const char *filename);
  77     int (*bdrv_open)(BlockDriverState *bs, int flags);
  78     int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, int flags);
  79     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
  80                      uint8_t *buf, int nb_sectors);
  81     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
  82                       const uint8_t *buf, int nb_sectors);
  83     void (*bdrv_close)(BlockDriverState *bs);
  84     int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
  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     int coroutine_fn (*bdrv_co_is_allocated)(BlockDriverState *bs,
 107         int64_t sector_num, int nb_sectors, int *pnum);
 108
 109     /*
 110      * Invalidate any cached meta-data.
 111      */
 112     void (*bdrv_invalidate_cache)(BlockDriverState *bs);
 113
 114     /*
 115      * Flushes all data that was already written to the OS all the way down to
 116      * the disk (for example raw-posix calls fsync()).
 117      */
 118     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
 119
 120     /*
 121      * Flushes all internal caches to the OS. The data may still sit in a
 122      * writeback cache of the host OS, but it will survive a crash of the qemu
 123      * process.
 124      */
 125     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 126
 127     int (*bdrv_aio_multiwrite)(BlockDriverState *bs, BlockRequest *reqs,
 128         int num_reqs);
 129     int (*bdrv_merge_requests)(BlockDriverState *bs, BlockRequest* a,
 130         BlockRequest *b);
 131
 132
 133     const char *protocol_name;
 134     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
 135     int64_t (*bdrv_getlength)(BlockDriverState *bs);
 136     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
 137     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
 138                                  const uint8_t *buf, int nb_sectors);
 139
 140     int (*bdrv_snapshot_create)(BlockDriverState *bs,
 141                                 QEMUSnapshotInfo *sn_info);
 142     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
 143                               const char *snapshot_id);
 144     int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
 145     int (*bdrv_snapshot_list)(BlockDriverState *bs,
 146                               QEMUSnapshotInfo **psn_info);
 147     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
 148                                   const char *snapshot_name);
 149     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
 150
 151     int (*bdrv_save_vmstate)(BlockDriverState *bs, const uint8_t *buf,
 152                              int64_t pos, int size);
 153     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
 154                              int64_t pos, int size);
 155
 156     int (*bdrv_change_backing_file)(BlockDriverState *bs,
 157         const char *backing_file, const char *backing_fmt);
 158
 159     /* removable device specific */
 160     int (*bdrv_is_inserted)(BlockDriverState *bs);
 161     int (*bdrv_media_changed)(BlockDriverState *bs);
 162     void (*bdrv_eject)(BlockDriverState *bs, int eject_flag);
 163     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 164
 165     /* to control generic scsi devices */
 166     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
 167     BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 168         unsigned long int req, void *buf,
 169         BlockDriverCompletionFunc *cb, void *opaque);
 170
 171     /* List of options for creating images, terminated by name == NULL */
 172     QEMUOptionParameter *create_options;
 173
 174
 175     /*
 176      * Returns 0 for completed check, -errno for internal errors.
 177      * The check results are stored in result.
 178      */
 179     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result);
 180
 181     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
 182
 183     /*
 184      * Returns 1 if newly created images are guaranteed to contain only
 185      * zeros, 0 otherwise.
 186      */
 187     int (*bdrv_has_zero_init)(BlockDriverState *bs);
 188
 189     QLIST_ENTRY(BlockDriver) list;
 190 };
 191
 192 struct BlockDriverState {
 193     int64_t total_sectors; /* if we are reading a disk image, give its
 194                               size in sectors */
 195     int read_only; /* if true, the media is read only */
 196     int keep_read_only; /* if true, the media was requested to stay read only */
 197     int open_flags; /* flags used to open the file, re-used for re-open */
 198     int encrypted; /* if true, the media is encrypted */
 199     int valid_key; /* if true, a valid encryption key has been set */
 200     int sg;        /* if true, the device is a /dev/sg* */
 201     int copy_on_read; /* if true, copy read backing sectors into image
 202                          note this is a reference count */
 203
 204     BlockDriver *drv; /* NULL means no media */
 205     void *opaque;
 206
 207     void *dev;                  /* attached device model, if any */
 208     /* TODO change to DeviceState when all users are qdevified */
 209     const BlockDevOps *dev_ops;
 210     void *dev_opaque;
 211
 212     char filename[1024];
 213     char backing_file[1024]; /* if non zero, the image is a diff of
 214                                 this file image */
 215     char backing_format[16]; /* if non-zero and backing_file exists */
 216     int is_temporary;
 217
 218     BlockDriverState *backing_hd;
 219     BlockDriverState *file;
 220
 221     /* async read/write emulation */
 222
 223     void *sync_aiocb;
 224
 225     /* the time for latest disk I/O */
 226     int64_t slice_time;
 227     int64_t slice_start;
 228     int64_t slice_end;
 229     BlockIOLimit io_limits;
 230     BlockIOBaseValue  io_base;
 231     CoQueue      throttled_reqs;
 232     QEMUTimer    *block_timer;
 233     bool         io_limits_enabled;
 234
 235     /* I/O stats (display with "info blockstats"). */
 236     uint64_t nr_bytes[BDRV_MAX_IOTYPE];
 237     uint64_t nr_ops[BDRV_MAX_IOTYPE];
 238     uint64_t total_time_ns[BDRV_MAX_IOTYPE];
 239     uint64_t wr_highest_sector;
 240
 241     /* Whether the disk can expand beyond total_sectors */
 242     int growable;
 243
 244     /* the memory alignment required for the buffers handled by this driver */
 245     int buffer_alignment;
 246
 247     /* do we need to tell the quest if we have a volatile write cache? */
 248     int enable_write_cache;
 249
 250     /* NOTE: the following infos are only hints for real hardware
 251        drivers. They are not used by the block driver */
 252     int cyls, heads, secs, translation;
 253     BlockErrorAction on_read_error, on_write_error;
 254     bool iostatus_enabled;
 255     BlockDeviceIoStatus iostatus;
 256     char device_name[32];
 257     unsigned long *dirty_bitmap;
 258     int64_t dirty_count;
 259     int in_use; /* users other than guest access, eg. block migration */
 260     QTAILQ_ENTRY(BlockDriverState) list;
 261     void *private;
 262
 263     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
 264 };
 265
 266 struct BlockDriverAIOCB {
 267     AIOPool *pool;
 268     BlockDriverState *bs;
 269     BlockDriverCompletionFunc *cb;
 270     void *opaque;
 271     BlockDriverAIOCB *next;
 272 };
 273
 274 void get_tmp_filename(char *filename, int size);
 275
 276 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
 277                    BlockDriverCompletionFunc *cb, void *opaque);
 278 void qemu_aio_release(void *p);
 279
 280 void bdrv_set_io_limits(BlockDriverState *bs,
 281                         BlockIOLimit *io_limits);
 282
 283 #ifdef _WIN32
 284 int is_windows_drive(const char *filename);
 285 #endif
 286
 287 #endif /* BLOCK_INT_H */