File:  [Qemu by Fabrice Bellard] / qemu / block_int.h
Revision 1.1.1.16 (vendor branch): download - view: text, annotated - select for diffs
Tue Apr 24 19:16:50 2018 UTC (3 years, 1 month ago) by root
Branches: qemu, MAIN
CVS tags: qemu1001, HEAD
qemu 1.0.1

    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: #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_OPT_SIZE          "size"
   38: #define BLOCK_OPT_ENCRYPT       "encryption"
   39: #define BLOCK_OPT_COMPAT6       "compat6"
   40: #define BLOCK_OPT_BACKING_FILE  "backing_file"
   41: #define BLOCK_OPT_BACKING_FMT   "backing_fmt"
   42: #define BLOCK_OPT_CLUSTER_SIZE  "cluster_size"
   43: #define BLOCK_OPT_TABLE_SIZE    "table_size"
   44: #define BLOCK_OPT_PREALLOC      "preallocation"
   45: #define BLOCK_OPT_SUBFMT        "subformat"
   46: 
   47: typedef struct AIOPool {
   48:     void (*cancel)(BlockDriverAIOCB *acb);
   49:     int aiocb_size;
   50:     BlockDriverAIOCB *free_aiocb;
   51: } AIOPool;
   52: 
   53: struct BlockDriver {
   54:     const char *format_name;
   55:     int instance_size;
   56:     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
   57:     int (*bdrv_probe_device)(const char *filename);
   58:     int (*bdrv_open)(BlockDriverState *bs, int flags);
   59:     int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, int flags);
   60:     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
   61:                      uint8_t *buf, int nb_sectors);
   62:     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
   63:                       const uint8_t *buf, int nb_sectors);
   64:     void (*bdrv_close)(BlockDriverState *bs);
   65:     int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
   66:     int (*bdrv_is_allocated)(BlockDriverState *bs, int64_t sector_num,
   67:                              int nb_sectors, int *pnum);
   68:     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
   69:     int (*bdrv_make_empty)(BlockDriverState *bs);
   70:     /* aio */
   71:     BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
   72:         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
   73:         BlockDriverCompletionFunc *cb, void *opaque);
   74:     BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
   75:         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
   76:         BlockDriverCompletionFunc *cb, void *opaque);
   77:     BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
   78:         BlockDriverCompletionFunc *cb, void *opaque);
   79:     BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
   80:         int64_t sector_num, int nb_sectors,
   81:         BlockDriverCompletionFunc *cb, void *opaque);
   82: 
   83:     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
   84:         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
   85:     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
   86:         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
   87:     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
   88:         int64_t sector_num, int nb_sectors);
   89: 
   90:     /*
   91:      * Invalidate any cached meta-data.
   92:      */
   93:     void (*bdrv_invalidate_cache)(BlockDriverState *bs);
   94: 
   95:     /*
   96:      * Flushes all data that was already written to the OS all the way down to
   97:      * the disk (for example raw-posix calls fsync()).
   98:      */
   99:     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
  100: 
  101:     /*
  102:      * Flushes all internal caches to the OS. The data may still sit in a
  103:      * writeback cache of the host OS, but it will survive a crash of the qemu
  104:      * process.
  105:      */
  106:     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
  107: 
  108:     int (*bdrv_aio_multiwrite)(BlockDriverState *bs, BlockRequest *reqs,
  109:         int num_reqs);
  110:     int (*bdrv_merge_requests)(BlockDriverState *bs, BlockRequest* a,
  111:         BlockRequest *b);
  112: 
  113: 
  114:     const char *protocol_name;
  115:     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
  116:     int64_t (*bdrv_getlength)(BlockDriverState *bs);
  117:     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
  118:     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
  119:                                  const uint8_t *buf, int nb_sectors);
  120: 
  121:     int (*bdrv_snapshot_create)(BlockDriverState *bs,
  122:                                 QEMUSnapshotInfo *sn_info);
  123:     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
  124:                               const char *snapshot_id);
  125:     int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
  126:     int (*bdrv_snapshot_list)(BlockDriverState *bs,
  127:                               QEMUSnapshotInfo **psn_info);
  128:     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
  129:                                   const char *snapshot_name);
  130:     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
  131: 
  132:     int (*bdrv_save_vmstate)(BlockDriverState *bs, const uint8_t *buf,
  133:                              int64_t pos, int size);
  134:     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
  135:                              int64_t pos, int size);
  136: 
  137:     int (*bdrv_change_backing_file)(BlockDriverState *bs,
  138:         const char *backing_file, const char *backing_fmt);
  139: 
  140:     /* removable device specific */
  141:     int (*bdrv_is_inserted)(BlockDriverState *bs);
  142:     int (*bdrv_media_changed)(BlockDriverState *bs);
  143:     void (*bdrv_eject)(BlockDriverState *bs, int eject_flag);
  144:     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
  145: 
  146:     /* to control generic scsi devices */
  147:     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
  148:     BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
  149:         unsigned long int req, void *buf,
  150:         BlockDriverCompletionFunc *cb, void *opaque);
  151: 
  152:     /* List of options for creating images, terminated by name == NULL */
  153:     QEMUOptionParameter *create_options;
  154: 
  155: 
  156:     /*
  157:      * Returns 0 for completed check, -errno for internal errors.
  158:      * The check results are stored in result.
  159:      */
  160:     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result);
  161: 
  162:     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
  163: 
  164:     /*
  165:      * Returns 1 if newly created images are guaranteed to contain only
  166:      * zeros, 0 otherwise.
  167:      */
  168:     int (*bdrv_has_zero_init)(BlockDriverState *bs);
  169: 
  170:     QLIST_ENTRY(BlockDriver) list;
  171: };
  172: 
  173: struct BlockDriverState {
  174:     int64_t total_sectors; /* if we are reading a disk image, give its
  175:                               size in sectors */
  176:     int read_only; /* if true, the media is read only */
  177:     int keep_read_only; /* if true, the media was requested to stay read only */
  178:     int open_flags; /* flags used to open the file, re-used for re-open */
  179:     int encrypted; /* if true, the media is encrypted */
  180:     int valid_key; /* if true, a valid encryption key has been set */
  181:     int sg;        /* if true, the device is a /dev/sg* */
  182: 
  183:     BlockDriver *drv; /* NULL means no media */
  184:     void *opaque;
  185: 
  186:     void *dev;                  /* attached device model, if any */
  187:     /* TODO change to DeviceState when all users are qdevified */
  188:     const BlockDevOps *dev_ops;
  189:     void *dev_opaque;
  190: 
  191:     char filename[1024];
  192:     char backing_file[1024]; /* if non zero, the image is a diff of
  193:                                 this file image */
  194:     char backing_format[16]; /* if non-zero and backing_file exists */
  195:     int is_temporary;
  196: 
  197:     BlockDriverState *backing_hd;
  198:     BlockDriverState *file;
  199: 
  200:     /* async read/write emulation */
  201: 
  202:     void *sync_aiocb;
  203: 
  204:     /* I/O stats (display with "info blockstats"). */
  205:     uint64_t nr_bytes[BDRV_MAX_IOTYPE];
  206:     uint64_t nr_ops[BDRV_MAX_IOTYPE];
  207:     uint64_t total_time_ns[BDRV_MAX_IOTYPE];
  208:     uint64_t wr_highest_sector;
  209: 
  210:     /* Whether the disk can expand beyond total_sectors */
  211:     int growable;
  212: 
  213:     /* the memory alignment required for the buffers handled by this driver */
  214:     int buffer_alignment;
  215: 
  216:     /* do we need to tell the quest if we have a volatile write cache? */
  217:     int enable_write_cache;
  218: 
  219:     /* NOTE: the following infos are only hints for real hardware
  220:        drivers. They are not used by the block driver */
  221:     int cyls, heads, secs, translation;
  222:     BlockErrorAction on_read_error, on_write_error;
  223:     bool iostatus_enabled;
  224:     BlockDeviceIoStatus iostatus;
  225:     char device_name[32];
  226:     unsigned long *dirty_bitmap;
  227:     int64_t dirty_count;
  228:     int in_use; /* users other than guest access, eg. block migration */
  229:     QTAILQ_ENTRY(BlockDriverState) list;
  230:     void *private;
  231: };
  232: 
  233: struct BlockDriverAIOCB {
  234:     AIOPool *pool;
  235:     BlockDriverState *bs;
  236:     BlockDriverCompletionFunc *cb;
  237:     void *opaque;
  238:     BlockDriverAIOCB *next;
  239: };
  240: 
  241: void get_tmp_filename(char *filename, int size);
  242: 
  243: void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
  244:                    BlockDriverCompletionFunc *cb, void *opaque);
  245: void qemu_aio_release(void *p);
  246: 
  247: #ifdef _WIN32
  248: int is_windows_drive(const char *filename);
  249: #endif
  250: 
  251: #endif /* BLOCK_INT_H */

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