include/sysemu/block-backend.h

   1 /*
   2  * QEMU Block backends
   3  *
   4  * Copyright (C) 2014 Red Hat, Inc.
   5  *
   6  * Authors:
   7  *  Markus Armbruster <armbru@redhat.com>,
   8  *
   9  * This work is licensed under the terms of the GNU LGPL, version 2.1
  10  * or later.  See the COPYING.LIB file in the top-level directory.
  11  */
  12
  13 #ifndef BLOCK_BACKEND_H
  14 #define BLOCK_BACKEND_H
  15
  16 #include "qemu/typedefs.h"
  17 #include "qapi/error.h"
  18
  19 /*
  20  * TODO Have to include block/block.h for a bunch of block layer
  21  * types.  Unfortunately, this pulls in the whole BlockDriverState
  22  * API, which we don't want used by many BlockBackend users.  Some of
  23  * the types belong here, and the rest should be split into a common
  24  * header and one for the BlockDriverState API.
  25  */
  26 #include "block/block.h"
  27
  28 /* Callbacks for block device models */
  29 typedef struct BlockDevOps {
  30     /*
  31      * Runs when virtual media changed (monitor commands eject, change)
  32      * Argument load is true on load and false on eject.
  33      * Beware: doesn't run when a host device's physical media
  34      * changes.  Sure would be useful if it did.
  35      * Device models with removable media must implement this callback.
  36      */
  37     void (*change_media_cb)(void *opaque, bool load);
  38     /*
  39      * Runs when an eject request is issued from the monitor, the tray
  40      * is closed, and the medium is locked.
  41      * Device models that do not implement is_medium_locked will not need
  42      * this callback.  Device models that can lock the medium or tray might
  43      * want to implement the callback and unlock the tray when "force" is
  44      * true, even if they do not support eject requests.
  45      */
  46     void (*eject_request_cb)(void *opaque, bool force);
  47     /*
  48      * Is the virtual tray open?
  49      * Device models implement this only when the device has a tray.
  50      */
  51     bool (*is_tray_open)(void *opaque);
  52     /*
  53      * Is the virtual medium locked into the device?
  54      * Device models implement this only when device has such a lock.
  55      */
  56     bool (*is_medium_locked)(void *opaque);
  57     /*
  58      * Runs when the size changed (e.g. monitor command block_resize)
  59      */
  60     void (*resize_cb)(void *opaque);
  61 } BlockDevOps;
  62
  63 BlockBackend *blk_new(const char *name, Error **errp);
  64 BlockBackend *blk_new_with_bs(const char *name, Error **errp);
  65 void blk_ref(BlockBackend *blk);
  66 void blk_unref(BlockBackend *blk);
  67 const char *blk_name(BlockBackend *blk);
  68 BlockBackend *blk_by_name(const char *name);
  69 BlockBackend *blk_next(BlockBackend *blk);
  70
  71 BlockDriverState *blk_bs(BlockBackend *blk);
  72
  73 void blk_hide_on_behalf_of_do_drive_del(BlockBackend *blk);
  74
  75 void blk_iostatus_enable(BlockBackend *blk);
  76 int blk_attach_dev(BlockBackend *blk, void *dev);
  77 void blk_attach_dev_nofail(BlockBackend *blk, void *dev);
  78 void blk_detach_dev(BlockBackend *blk, void *dev);
  79 void *blk_get_attached_dev(BlockBackend *blk);
  80 void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque);
  81 int blk_read(BlockBackend *blk, int64_t sector_num, uint8_t *buf,
  82              int nb_sectors);
  83 int blk_read_unthrottled(BlockBackend *blk, int64_t sector_num, uint8_t *buf,
  84                          int nb_sectors);
  85 int blk_write(BlockBackend *blk, int64_t sector_num, const uint8_t *buf,
  86               int nb_sectors);
  87 BlockAIOCB *blk_aio_write_zeroes(BlockBackend *blk, int64_t sector_num,
  88                                  int nb_sectors, BdrvRequestFlags flags,
  89                                  BlockCompletionFunc *cb, void *opaque);
  90 int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int count);
  91 int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int count);
  92 int64_t blk_getlength(BlockBackend *blk);
  93 void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr);
  94 BlockAIOCB *blk_aio_readv(BlockBackend *blk, int64_t sector_num,
  95                           QEMUIOVector *iov, int nb_sectors,
  96                           BlockCompletionFunc *cb, void *opaque);
  97 BlockAIOCB *blk_aio_writev(BlockBackend *blk, int64_t sector_num,
  98                            QEMUIOVector *iov, int nb_sectors,
  99                            BlockCompletionFunc *cb, void *opaque);
 100 BlockAIOCB *blk_aio_flush(BlockBackend *blk,
 101                           BlockCompletionFunc *cb, void *opaque);
 102 BlockAIOCB *blk_aio_discard(BlockBackend *blk,
 103                             int64_t sector_num, int nb_sectors,
 104                             BlockCompletionFunc *cb, void *opaque);
 105 void blk_aio_cancel(BlockAIOCB *acb);
 106 void blk_aio_cancel_async(BlockAIOCB *acb);
 107 int blk_aio_multiwrite(BlockBackend *blk, BlockRequest *reqs, int num_reqs);
 108 int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
 109 BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
 110                           BlockCompletionFunc *cb, void *opaque);
 111 int blk_co_discard(BlockBackend *blk, int64_t sector_num, int nb_sectors);
 112 int blk_co_flush(BlockBackend *blk);
 113 int blk_flush(BlockBackend *blk);
 114 int blk_flush_all(void);
 115 void blk_drain_all(void);
 116 BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read);
 117 BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
 118                                       int error);
 119 void blk_error_action(BlockBackend *blk, BlockErrorAction action,
 120                       bool is_read, int error);
 121 int blk_is_read_only(BlockBackend *blk);
 122 int blk_is_sg(BlockBackend *blk);
 123 int blk_enable_write_cache(BlockBackend *blk);
 124 void blk_set_enable_write_cache(BlockBackend *blk, bool wce);
 125 void blk_invalidate_cache(BlockBackend *blk, Error **errp);
 126 int blk_is_inserted(BlockBackend *blk);
 127 void blk_lock_medium(BlockBackend *blk, bool locked);
 128 void blk_eject(BlockBackend *blk, bool eject_flag);
 129 int blk_get_flags(BlockBackend *blk);
 130 int blk_get_max_transfer_length(BlockBackend *blk);
 131 void blk_set_guest_block_size(BlockBackend *blk, int align);
 132 void *blk_blockalign(BlockBackend *blk, size_t size);
 133 bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp);
 134 void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason);
 135 void blk_op_block_all(BlockBackend *blk, Error *reason);
 136 void blk_op_unblock_all(BlockBackend *blk, Error *reason);
 137 AioContext *blk_get_aio_context(BlockBackend *blk);
 138 void blk_set_aio_context(BlockBackend *blk, AioContext *new_context);
 139 void blk_add_aio_context_notifier(BlockBackend *blk,
 140         void (*attached_aio_context)(AioContext *new_context, void *opaque),
 141         void (*detach_aio_context)(void *opaque), void *opaque);
 142 void blk_remove_aio_context_notifier(BlockBackend *blk,
 143                                      void (*attached_aio_context)(AioContext *,
 144                                                                   void *),
 145                                      void (*detach_aio_context)(void *),
 146                                      void *opaque);
 147 void blk_add_close_notifier(BlockBackend *blk, Notifier *notify);
 148 void blk_io_plug(BlockBackend *blk);
 149 void blk_io_unplug(BlockBackend *blk);
 150 BlockAcctStats *blk_get_stats(BlockBackend *blk);
 151
 152 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
 153                   BlockCompletionFunc *cb, void *opaque);
 154
 155 #endif