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
  30 #define BLOCK_FLAG_ENCRYPT      1
  31 #define BLOCK_FLAG_COMPRESS     2
  32 #define BLOCK_FLAG_COMPAT6      4
  33
  34 #define BLOCK_OPT_SIZE          "size"
  35 #define BLOCK_OPT_ENCRYPT       "encryption"
  36 #define BLOCK_OPT_COMPAT6       "compat6"
  37 #define BLOCK_OPT_BACKING_FILE  "backing_file"
  38 #define BLOCK_OPT_BACKING_FMT   "backing_fmt"
  39 #define BLOCK_OPT_CLUSTER_SIZE  "cluster_size"
  40 #define BLOCK_OPT_PREALLOC      "preallocation"
  41
  42 typedef struct AIOPool {
  43     void (*cancel)(BlockDriverAIOCB *acb);
  44     int aiocb_size;
  45     BlockDriverAIOCB *free_aiocb;
  46 } AIOPool;
  47
  48 struct BlockDriver {
  49     const char *format_name;
  50     int instance_size;
  51     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
  52     int (*bdrv_probe_device)(const char *filename);
  53     int (*bdrv_open)(BlockDriverState *bs, const char *filename, int flags);
  54     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
  55                      uint8_t *buf, int nb_sectors);
  56     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
  57                       const uint8_t *buf, int nb_sectors);
  58     void (*bdrv_close)(BlockDriverState *bs);
  59     int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
  60     void (*bdrv_flush)(BlockDriverState *bs);
  61     int (*bdrv_is_allocated)(BlockDriverState *bs, int64_t sector_num,
  62                              int nb_sectors, int *pnum);
  63     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
  64     int (*bdrv_make_empty)(BlockDriverState *bs);
  65     /* aio */
  66     BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
  67         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
  68         BlockDriverCompletionFunc *cb, void *opaque);
  69     BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
  70         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
  71         BlockDriverCompletionFunc *cb, void *opaque);
  72     BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
  73         BlockDriverCompletionFunc *cb, void *opaque);
  74
  75     int (*bdrv_aio_multiwrite)(BlockDriverState *bs, BlockRequest *reqs,
  76         int num_reqs);
  77     int (*bdrv_merge_requests)(BlockDriverState *bs, BlockRequest* a,
  78         BlockRequest *b);
  79
  80
  81     const char *protocol_name;
  82     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
  83     int64_t (*bdrv_getlength)(BlockDriverState *bs);
  84     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
  85                                  const uint8_t *buf, int nb_sectors);
  86
  87     int (*bdrv_snapshot_create)(BlockDriverState *bs,
  88                                 QEMUSnapshotInfo *sn_info);
  89     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
  90                               const char *snapshot_id);
  91     int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
  92     int (*bdrv_snapshot_list)(BlockDriverState *bs,
  93                               QEMUSnapshotInfo **psn_info);
  94     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
  95
  96     int (*bdrv_save_vmstate)(BlockDriverState *bs, const uint8_t *buf,
  97                              int64_t pos, int size);
  98     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
  99                              int64_t pos, int size);
 100
 101     int (*bdrv_change_backing_file)(BlockDriverState *bs,
 102         const char *backing_file, const char *backing_fmt);
 103
 104     /* removable device specific */
 105     int (*bdrv_is_inserted)(BlockDriverState *bs);
 106     int (*bdrv_media_changed)(BlockDriverState *bs);
 107     int (*bdrv_eject)(BlockDriverState *bs, int eject_flag);
 108     int (*bdrv_set_locked)(BlockDriverState *bs, int locked);
 109
 110     /* to control generic scsi devices */
 111     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
 112     BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
 113         unsigned long int req, void *buf,
 114         BlockDriverCompletionFunc *cb, void *opaque);
 115
 116     /* List of options for creating images, terminated by name == NULL */
 117     QEMUOptionParameter *create_options;
 118
 119
 120     /* Returns number of errors in image, -errno for internal errors */
 121     int (*bdrv_check)(BlockDriverState* bs);
 122
 123     /* Set if newly created images are not guaranteed to contain only zeros */
 124     int no_zero_init;
 125
 126     struct BlockDriver *next;
 127 };
 128
 129 struct BlockDriverState {
 130     int64_t total_sectors; /* if we are reading a disk image, give its
 131                               size in sectors */
 132     int read_only; /* if true, the media is read only */
 133     int keep_read_only; /* if true, the media was requested to stay read only */
 134     int open_flags; /* flags used to open the file, re-used for re-open */
 135     int removable; /* if true, the media can be removed */
 136     int locked;    /* if true, the media cannot temporarily be ejected */
 137     int encrypted; /* if true, the media is encrypted */
 138     int valid_key; /* if true, a valid encryption key has been set */
 139     int sg;        /* if true, the device is a /dev/sg* */
 140     /* event callback when inserting/removing */
 141     void (*change_cb)(void *opaque);
 142     void *change_opaque;
 143
 144     BlockDriver *drv; /* NULL means no media */
 145     void *opaque;
 146
 147     char filename[1024];
 148     char backing_file[1024]; /* if non zero, the image is a diff of
 149                                 this file image */
 150     char backing_format[16]; /* if non-zero and backing_file exists */
 151     int is_temporary;
 152     int media_changed;
 153
 154     BlockDriverState *backing_hd;
 155     /* async read/write emulation */
 156
 157     void *sync_aiocb;
 158
 159     /* I/O stats (display with "info blockstats"). */
 160     uint64_t rd_bytes;
 161     uint64_t wr_bytes;
 162     uint64_t rd_ops;
 163     uint64_t wr_ops;
 164
 165     /* Whether the disk can expand beyond total_sectors */
 166     int growable;
 167
 168     /* the memory alignment required for the buffers handled by this driver */
 169     int buffer_alignment;
 170
 171     /* do we need to tell the quest if we have a volatile write cache? */
 172     int enable_write_cache;
 173
 174     /* NOTE: the following infos are only hints for real hardware
 175        drivers. They are not used by the block driver */
 176     int cyls, heads, secs, translation;
 177     int type;
 178     char device_name[32];
 179     unsigned long *dirty_bitmap;
 180     int64_t dirty_count;
 181     BlockDriverState *next;
 182     void *private;
 183 };
 184
 185 struct BlockDriverAIOCB {
 186     AIOPool *pool;
 187     BlockDriverState *bs;
 188     BlockDriverCompletionFunc *cb;
 189     void *opaque;
 190     BlockDriverAIOCB *next;
 191 };
 192
 193 void get_tmp_filename(char *filename, int size);
 194
 195 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
 196                    BlockDriverCompletionFunc *cb, void *opaque);
 197 void qemu_aio_release(void *p);
 198
 199 void *qemu_blockalign(BlockDriverState *bs, size_t size);
 200
 201 extern BlockDriverState *bdrv_first;
 202
 203 #ifdef _WIN32
 204 int is_windows_drive(const char *filename);
 205 #endif
 206
 207 struct DriveInfo;
 208
 209 typedef struct BlockConf {
 210     struct DriveInfo *dinfo;
 211     uint16_t physical_block_size;
 212     uint16_t logical_block_size;
 213     uint16_t min_io_size;
 214     uint32_t opt_io_size;
 215 } BlockConf;
 216
 217 static inline unsigned int get_physical_block_exp(BlockConf *conf)
 218 {
 219     unsigned int exp = 0, size;
 220
 221     for (size = conf->physical_block_size; size > 512; size >>= 1) {
 222         exp++;
 223     }
 224
 225     return exp;
 226 }
 227
 228 #define DEFINE_BLOCK_PROPERTIES(_state, _conf)                          \
 229     DEFINE_PROP_DRIVE("drive", _state, _conf.dinfo),                    \
 230     DEFINE_PROP_UINT16("logical_block_size", _state,                    \
 231                        _conf.logical_block_size, 512),                  \
 232     DEFINE_PROP_UINT16("physical_block_size", _state,                   \
 233                        _conf.physical_block_size, 512),                 \
 234     DEFINE_PROP_UINT16("min_io_size", _state, _conf.min_io_size, 512),  \
 235     DEFINE_PROP_UINT32("opt_io_size", _state, _conf.opt_io_size, 512)
 236
 237 #endif /* BLOCK_INT_H */