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      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 
     31 #define BLOCK_FLAG_ENCRYPT	1
     32 #define BLOCK_FLAG_COMPRESS	2
     33 #define BLOCK_FLAG_COMPAT6	4
     34 
     35 #define BLOCK_OPT_SIZE          "size"
     36 #define BLOCK_OPT_ENCRYPT       "encryption"
     37 #define BLOCK_OPT_COMPAT6       "compat6"
     38 #define BLOCK_OPT_BACKING_FILE  "backing_file"
     39 #define BLOCK_OPT_BACKING_FMT   "backing_fmt"
     40 #define BLOCK_OPT_CLUSTER_SIZE  "cluster_size"
     41 #define BLOCK_OPT_PREALLOC      "preallocation"
     42 
     43 typedef struct AIOPool {
     44     void (*cancel)(BlockDriverAIOCB *acb);
     45     int aiocb_size;
     46     BlockDriverAIOCB *free_aiocb;
     47 } AIOPool;
     48 
     49 struct BlockDriver {
     50     const char *format_name;
     51     int instance_size;
     52     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
     53     int (*bdrv_probe_device)(const char *filename);
     54     int (*bdrv_open)(BlockDriverState *bs, int flags);
     55     int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, int flags);
     56     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
     57                      uint8_t *buf, int nb_sectors);
     58     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
     59                       const uint8_t *buf, int nb_sectors);
     60     void (*bdrv_close)(BlockDriverState *bs);
     61     int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
     62     void (*bdrv_flush)(BlockDriverState *bs);
     63     int (*bdrv_is_allocated)(BlockDriverState *bs, int64_t sector_num,
     64                              int nb_sectors, int *pnum);
     65     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
     66     int (*bdrv_make_empty)(BlockDriverState *bs);
     67     /* aio */
     68     BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
     69         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
     70         BlockDriverCompletionFunc *cb, void *opaque);
     71     BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
     72         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
     73         BlockDriverCompletionFunc *cb, void *opaque);
     74     BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
     75         BlockDriverCompletionFunc *cb, void *opaque);
     76 
     77     int (*bdrv_aio_multiwrite)(BlockDriverState *bs, BlockRequest *reqs,
     78         int num_reqs);
     79     int (*bdrv_merge_requests)(BlockDriverState *bs, BlockRequest* a,
     80         BlockRequest *b);
     81 
     82 
     83     const char *protocol_name;
     84     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
     85     int64_t (*bdrv_getlength)(BlockDriverState *bs);
     86     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
     87                                  const uint8_t *buf, int nb_sectors);
     88 
     89     int (*bdrv_snapshot_create)(BlockDriverState *bs,
     90                                 QEMUSnapshotInfo *sn_info);
     91     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
     92                               const char *snapshot_id);
     93     int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
     94     int (*bdrv_snapshot_list)(BlockDriverState *bs,
     95                               QEMUSnapshotInfo **psn_info);
     96     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
     97 
     98     int (*bdrv_save_vmstate)(BlockDriverState *bs, const uint8_t *buf,
     99                              int64_t pos, int size);
    100     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
    101                              int64_t pos, int size);
    102 
    103     int (*bdrv_change_backing_file)(BlockDriverState *bs,
    104         const char *backing_file, const char *backing_fmt);
    105 
    106     /* removable device specific */
    107     int (*bdrv_is_inserted)(BlockDriverState *bs);
    108     int (*bdrv_media_changed)(BlockDriverState *bs);
    109     int (*bdrv_eject)(BlockDriverState *bs, int eject_flag);
    110     int (*bdrv_set_locked)(BlockDriverState *bs, int locked);
    111 
    112     /* to control generic scsi devices */
    113     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
    114     BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
    115         unsigned long int req, void *buf,
    116         BlockDriverCompletionFunc *cb, void *opaque);
    117 
    118     /* List of options for creating images, terminated by name == NULL */
    119     QEMUOptionParameter *create_options;
    120 
    121 
    122     /*
    123      * Returns 0 for completed check, -errno for internal errors.
    124      * The check results are stored in result.
    125      */
    126     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result);
    127 
    128     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
    129 
    130     /*
    131      * Returns 1 if newly created images are guaranteed to contain only
    132      * zeros, 0 otherwise.
    133      */
    134     int (*bdrv_has_zero_init)(BlockDriverState *bs);
    135 
    136     QLIST_ENTRY(BlockDriver) list;
    137 };
    138 
    139 struct BlockDriverState {
    140     int64_t total_sectors; /* if we are reading a disk image, give its
    141                               size in sectors */
    142     int read_only; /* if true, the media is read only */
    143     int keep_read_only; /* if true, the media was requested to stay read only */
    144     int open_flags; /* flags used to open the file, re-used for re-open */
    145     int removable; /* if true, the media can be removed */
    146     int locked;    /* if true, the media cannot temporarily be ejected */
    147     int tray_open; /* if true, the virtual tray is open */
    148     int encrypted; /* if true, the media is encrypted */
    149     int valid_key; /* if true, a valid encryption key has been set */
    150     int sg;        /* if true, the device is a /dev/sg* */
    151     int probed;    /* if true, format was probed automatically */
    152     /* event callback when inserting/removing */
    153     void (*change_cb)(void *opaque);
    154     void *change_opaque;
    155 
    156     BlockDriver *drv; /* NULL means no media */
    157     void *opaque;
    158 
    159     DeviceState *peer;
    160 
    161     char filename[1024];
    162     char backing_file[1024]; /* if non zero, the image is a diff of
    163                                 this file image */
    164     char backing_format[16]; /* if non-zero and backing_file exists */
    165     int is_temporary;
    166     int media_changed;
    167 
    168     BlockDriverState *backing_hd;
    169     BlockDriverState *file;
    170 
    171     /* async read/write emulation */
    172 
    173     void *sync_aiocb;
    174 
    175     /* I/O stats (display with "info blockstats"). */
    176     uint64_t rd_bytes;
    177     uint64_t wr_bytes;
    178     uint64_t rd_ops;
    179     uint64_t wr_ops;
    180     uint64_t wr_highest_sector;
    181 
    182     /* Whether the disk can expand beyond total_sectors */
    183     int growable;
    184 
    185     /* the memory alignment required for the buffers handled by this driver */
    186     int buffer_alignment;
    187 
    188     /* do we need to tell the quest if we have a volatile write cache? */
    189     int enable_write_cache;
    190 
    191     /* NOTE: the following infos are only hints for real hardware
    192        drivers. They are not used by the block driver */
    193     int cyls, heads, secs, translation;
    194     int type;
    195     BlockErrorAction on_read_error, on_write_error;
    196     char device_name[32];
    197     unsigned long *dirty_bitmap;
    198     int64_t dirty_count;
    199     QTAILQ_ENTRY(BlockDriverState) list;
    200     void *private;
    201 };
    202 
    203 struct BlockDriverAIOCB {
    204     AIOPool *pool;
    205     BlockDriverState *bs;
    206     BlockDriverCompletionFunc *cb;
    207     void *opaque;
    208     BlockDriverAIOCB *next;
    209 };
    210 
    211 void get_tmp_filename(char *filename, int size);
    212 
    213 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
    214                    BlockDriverCompletionFunc *cb, void *opaque);
    215 void qemu_aio_release(void *p);
    216 
    217 void *qemu_blockalign(BlockDriverState *bs, size_t size);
    218 
    219 #ifdef _WIN32
    220 int is_windows_drive(const char *filename);
    221 #endif
    222 
    223 typedef struct BlockConf {
    224     BlockDriverState *bs;
    225     uint16_t physical_block_size;
    226     uint16_t logical_block_size;
    227     uint16_t min_io_size;
    228     uint32_t opt_io_size;
    229 } BlockConf;
    230 
    231 static inline unsigned int get_physical_block_exp(BlockConf *conf)
    232 {
    233     unsigned int exp = 0, size;
    234 
    235     for (size = conf->physical_block_size;
    236         size > conf->logical_block_size;
    237         size >>= 1) {
    238         exp++;
    239     }
    240 
    241     return exp;
    242 }
    243 
    244 #define DEFINE_BLOCK_PROPERTIES(_state, _conf)                          \
    245     DEFINE_PROP_DRIVE("drive", _state, _conf.bs),                       \
    246     DEFINE_PROP_UINT16("logical_block_size", _state,                    \
    247                        _conf.logical_block_size, 512),                  \
    248     DEFINE_PROP_UINT16("physical_block_size", _state,                   \
    249                        _conf.physical_block_size, 512),                 \
    250     DEFINE_PROP_UINT16("min_io_size", _state, _conf.min_io_size, 0),  \
    251     DEFINE_PROP_UINT32("opt_io_size", _state, _conf.opt_io_size, 0)
    252 
    253 #endif /* BLOCK_INT_H */
    254