File:  [Qemu by Fabrice Bellard] / qemu / block_int.h
Revision 1.1.1.15 (vendor branch): download - view: text, annotated - select for diffs
Tue Apr 24 18:55:46 2018 UTC (3 years, 1 month ago) by root
Branches: qemu, MAIN
CVS tags: qemu1000, qemu0151, HEAD
qemu 0.15.1

    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_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_TABLE_SIZE    "table_size"
   41: #define BLOCK_OPT_PREALLOC      "preallocation"
   42: #define BLOCK_OPT_SUBFMT        "subformat"
   43: 
   44: typedef struct AIOPool {
   45:     void (*cancel)(BlockDriverAIOCB *acb);
   46:     int aiocb_size;
   47:     BlockDriverAIOCB *free_aiocb;
   48: } AIOPool;
   49: 
   50: struct BlockDriver {
   51:     const char *format_name;
   52:     int instance_size;
   53:     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
   54:     int (*bdrv_probe_device)(const char *filename);
   55:     int (*bdrv_open)(BlockDriverState *bs, int flags);
   56:     int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, int flags);
   57:     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
   58:                      uint8_t *buf, int nb_sectors);
   59:     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
   60:                       const uint8_t *buf, int nb_sectors);
   61:     void (*bdrv_close)(BlockDriverState *bs);
   62:     int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
   63:     int (*bdrv_flush)(BlockDriverState *bs);
   64:     int (*bdrv_is_allocated)(BlockDriverState *bs, int64_t sector_num,
   65:                              int nb_sectors, int *pnum);
   66:     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
   67:     int (*bdrv_make_empty)(BlockDriverState *bs);
   68:     /* aio */
   69:     BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
   70:         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
   71:         BlockDriverCompletionFunc *cb, void *opaque);
   72:     BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
   73:         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
   74:         BlockDriverCompletionFunc *cb, void *opaque);
   75:     BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
   76:         BlockDriverCompletionFunc *cb, void *opaque);
   77:     int (*bdrv_discard)(BlockDriverState *bs, int64_t sector_num,
   78:                         int nb_sectors);
   79: 
   80:     int (*bdrv_aio_multiwrite)(BlockDriverState *bs, BlockRequest *reqs,
   81:         int num_reqs);
   82:     int (*bdrv_merge_requests)(BlockDriverState *bs, BlockRequest* a,
   83:         BlockRequest *b);
   84: 
   85: 
   86:     const char *protocol_name;
   87:     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
   88:     int64_t (*bdrv_getlength)(BlockDriverState *bs);
   89:     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
   90:     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
   91:                                  const uint8_t *buf, int nb_sectors);
   92: 
   93:     int (*bdrv_snapshot_create)(BlockDriverState *bs,
   94:                                 QEMUSnapshotInfo *sn_info);
   95:     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
   96:                               const char *snapshot_id);
   97:     int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
   98:     int (*bdrv_snapshot_list)(BlockDriverState *bs,
   99:                               QEMUSnapshotInfo **psn_info);
  100:     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
  101:                                   const char *snapshot_name);
  102:     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
  103: 
  104:     int (*bdrv_save_vmstate)(BlockDriverState *bs, const uint8_t *buf,
  105:                              int64_t pos, int size);
  106:     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
  107:                              int64_t pos, int size);
  108: 
  109:     int (*bdrv_change_backing_file)(BlockDriverState *bs,
  110:         const char *backing_file, const char *backing_fmt);
  111: 
  112:     /* removable device specific */
  113:     int (*bdrv_is_inserted)(BlockDriverState *bs);
  114:     int (*bdrv_media_changed)(BlockDriverState *bs);
  115:     int (*bdrv_eject)(BlockDriverState *bs, int eject_flag);
  116:     int (*bdrv_set_locked)(BlockDriverState *bs, int locked);
  117: 
  118:     /* to control generic scsi devices */
  119:     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
  120:     BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
  121:         unsigned long int req, void *buf,
  122:         BlockDriverCompletionFunc *cb, void *opaque);
  123: 
  124:     /* List of options for creating images, terminated by name == NULL */
  125:     QEMUOptionParameter *create_options;
  126: 
  127: 
  128:     /*
  129:      * Returns 0 for completed check, -errno for internal errors.
  130:      * The check results are stored in result.
  131:      */
  132:     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result);
  133: 
  134:     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
  135: 
  136:     /*
  137:      * Returns 1 if newly created images are guaranteed to contain only
  138:      * zeros, 0 otherwise.
  139:      */
  140:     int (*bdrv_has_zero_init)(BlockDriverState *bs);
  141: 
  142:     QLIST_ENTRY(BlockDriver) list;
  143: };
  144: 
  145: struct BlockDriverState {
  146:     int64_t total_sectors; /* if we are reading a disk image, give its
  147:                               size in sectors */
  148:     int read_only; /* if true, the media is read only */
  149:     int keep_read_only; /* if true, the media was requested to stay read only */
  150:     int open_flags; /* flags used to open the file, re-used for re-open */
  151:     int removable; /* if true, the media can be removed */
  152:     int locked;    /* if true, the media cannot temporarily be ejected */
  153:     int tray_open; /* if true, the virtual tray is open */
  154:     int encrypted; /* if true, the media is encrypted */
  155:     int valid_key; /* if true, a valid encryption key has been set */
  156:     int sg;        /* if true, the device is a /dev/sg* */
  157:     /* event callback when inserting/removing */
  158:     void (*change_cb)(void *opaque, int reason);
  159:     void *change_opaque;
  160: 
  161:     BlockDriver *drv; /* NULL means no media */
  162:     void *opaque;
  163: 
  164:     DeviceState *peer;
  165: 
  166:     char filename[1024];
  167:     char backing_file[1024]; /* if non zero, the image is a diff of
  168:                                 this file image */
  169:     char backing_format[16]; /* if non-zero and backing_file exists */
  170:     int is_temporary;
  171:     int media_changed;
  172: 
  173:     BlockDriverState *backing_hd;
  174:     BlockDriverState *file;
  175: 
  176:     /* async read/write emulation */
  177: 
  178:     void *sync_aiocb;
  179: 
  180:     /* I/O stats (display with "info blockstats"). */
  181:     uint64_t rd_bytes;
  182:     uint64_t wr_bytes;
  183:     uint64_t rd_ops;
  184:     uint64_t wr_ops;
  185:     uint64_t wr_highest_sector;
  186: 
  187:     /* Whether the disk can expand beyond total_sectors */
  188:     int growable;
  189: 
  190:     /* the memory alignment required for the buffers handled by this driver */
  191:     int buffer_alignment;
  192: 
  193:     /* do we need to tell the quest if we have a volatile write cache? */
  194:     int enable_write_cache;
  195: 
  196:     /* NOTE: the following infos are only hints for real hardware
  197:        drivers. They are not used by the block driver */
  198:     int cyls, heads, secs, translation;
  199:     BlockErrorAction on_read_error, on_write_error;
  200:     char device_name[32];
  201:     unsigned long *dirty_bitmap;
  202:     int64_t dirty_count;
  203:     int in_use; /* users other than guest access, eg. block migration */
  204:     QTAILQ_ENTRY(BlockDriverState) list;
  205:     void *private;
  206: };
  207: 
  208: #define CHANGE_MEDIA    0x01
  209: #define CHANGE_SIZE     0x02
  210: 
  211: struct BlockDriverAIOCB {
  212:     AIOPool *pool;
  213:     BlockDriverState *bs;
  214:     BlockDriverCompletionFunc *cb;
  215:     void *opaque;
  216:     BlockDriverAIOCB *next;
  217: };
  218: 
  219: void get_tmp_filename(char *filename, int size);
  220: 
  221: void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
  222:                    BlockDriverCompletionFunc *cb, void *opaque);
  223: void qemu_aio_release(void *p);
  224: 
  225: void *qemu_blockalign(BlockDriverState *bs, size_t size);
  226: 
  227: #ifdef _WIN32
  228: int is_windows_drive(const char *filename);
  229: #endif
  230: 
  231: typedef struct BlockConf {
  232:     BlockDriverState *bs;
  233:     uint16_t physical_block_size;
  234:     uint16_t logical_block_size;
  235:     uint16_t min_io_size;
  236:     uint32_t opt_io_size;
  237:     int32_t bootindex;
  238:     uint32_t discard_granularity;
  239: } BlockConf;
  240: 
  241: static inline unsigned int get_physical_block_exp(BlockConf *conf)
  242: {
  243:     unsigned int exp = 0, size;
  244: 
  245:     for (size = conf->physical_block_size;
  246:         size > conf->logical_block_size;
  247:         size >>= 1) {
  248:         exp++;
  249:     }
  250: 
  251:     return exp;
  252: }
  253: 
  254: #define DEFINE_BLOCK_PROPERTIES(_state, _conf)                          \
  255:     DEFINE_PROP_DRIVE("drive", _state, _conf.bs),                       \
  256:     DEFINE_PROP_UINT16("logical_block_size", _state,                    \
  257:                        _conf.logical_block_size, 512),                  \
  258:     DEFINE_PROP_UINT16("physical_block_size", _state,                   \
  259:                        _conf.physical_block_size, 512),                 \
  260:     DEFINE_PROP_UINT16("min_io_size", _state, _conf.min_io_size, 0),  \
  261:     DEFINE_PROP_UINT32("opt_io_size", _state, _conf.opt_io_size, 0),    \
  262:     DEFINE_PROP_INT32("bootindex", _state, _conf.bootindex, -1),        \
  263:     DEFINE_PROP_UINT32("discard_granularity", _state, \
  264:                        _conf.discard_granularity, 0)
  265: 
  266: #endif /* BLOCK_INT_H */

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