include/sysemu/block-backend.h

   1 /*
   2  * QEMU Block backends
   3  *
   4  * Copyright (C) 2014-2016 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/iov.h"
  17 #include "block/throttle-groups.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, Error **errp);
  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 /* This struct is embedded in (the private) BlockBackend struct and contains
  64  * fields that must be public. This is in particular for QLIST_ENTRY() and
  65  * friends so that BlockBackends can be kept in lists outside block-backend.c */
  66 typedef struct BlockBackendPublic {
  67     /* I/O throttling has its own locking, but also some fields are
  68      * protected by the AioContext lock.
  69      */
  70
  71     /* Protected by AioContext lock.  */
  72     CoQueue      throttled_reqs[2];
  73
  74     /* Nonzero if the I/O limits are currently being ignored; generally
  75      * it is zero.  */
  76     unsigned int io_limits_disabled;
  77
  78     /* The following fields are protected by the ThrottleGroup lock.
  79      * See the ThrottleGroup documentation for details.
  80      * throttle_state tells us if I/O limits are configured. */
  81     ThrottleState *throttle_state;
  82     ThrottleTimers throttle_timers;
  83     unsigned       pending_reqs[2];
  84     QLIST_ENTRY(BlockBackendPublic) round_robin;
  85 } BlockBackendPublic;
  86
  87 BlockBackend *blk_new(uint64_t perm, uint64_t shared_perm);
  88 BlockBackend *blk_new_open(const char *filename, const char *reference,
  89                            QDict *options, int flags, Error **errp);
  90 int blk_get_refcnt(BlockBackend *blk);
  91 void blk_ref(BlockBackend *blk);
  92 void blk_unref(BlockBackend *blk);
  93 void blk_remove_all_bs(void);
  94 const char *blk_name(BlockBackend *blk);
  95 BlockBackend *blk_by_name(const char *name);
  96 BlockBackend *blk_next(BlockBackend *blk);
  97 bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp);
  98 void monitor_remove_blk(BlockBackend *blk);
  99
 100 BlockBackendPublic *blk_get_public(BlockBackend *blk);
 101 BlockBackend *blk_by_public(BlockBackendPublic *public);
 102
 103 BlockDriverState *blk_bs(BlockBackend *blk);
 104 void blk_remove_bs(BlockBackend *blk);
 105 int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp);
 106 bool bdrv_has_blk(BlockDriverState *bs);
 107 bool bdrv_is_root_node(BlockDriverState *bs);
 108 int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm,
 109                  Error **errp);
 110 void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm);
 111
 112 void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow);
 113 void blk_iostatus_enable(BlockBackend *blk);
 114 bool blk_iostatus_is_enabled(const BlockBackend *blk);
 115 BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk);
 116 void blk_iostatus_disable(BlockBackend *blk);
 117 void blk_iostatus_reset(BlockBackend *blk);
 118 void blk_iostatus_set_err(BlockBackend *blk, int error);
 119 int blk_attach_dev(BlockBackend *blk, DeviceState *dev);
 120 void blk_attach_dev_legacy(BlockBackend *blk, void *dev);
 121 void blk_detach_dev(BlockBackend *blk, void *dev);
 122 void *blk_get_attached_dev(BlockBackend *blk);
 123 BlockBackend *blk_by_dev(void *dev);
 124 BlockBackend *blk_by_qdev_id(const char *id, Error **errp);
 125 void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque);
 126 int blk_pread_unthrottled(BlockBackend *blk, int64_t offset, uint8_t *buf,
 127                           int count);
 128 int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
 129                                unsigned int bytes, QEMUIOVector *qiov,
 130                                BdrvRequestFlags flags);
 131 int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
 132                                unsigned int bytes, QEMUIOVector *qiov,
 133                                BdrvRequestFlags flags);
 134 int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 135                       int count, BdrvRequestFlags flags);
 136 BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 137                                   int count, BdrvRequestFlags flags,
 138                                   BlockCompletionFunc *cb, void *opaque);
 139 int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags);
 140 int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int count);
 141 int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int count,
 142                BdrvRequestFlags flags);
 143 int64_t blk_getlength(BlockBackend *blk);
 144 void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr);
 145 int64_t blk_nb_sectors(BlockBackend *blk);
 146 BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset,
 147                            QEMUIOVector *qiov, BdrvRequestFlags flags,
 148                            BlockCompletionFunc *cb, void *opaque);
 149 BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
 150                             QEMUIOVector *qiov, BdrvRequestFlags flags,
 151                             BlockCompletionFunc *cb, void *opaque);
 152 BlockAIOCB *blk_aio_flush(BlockBackend *blk,
 153                           BlockCompletionFunc *cb, void *opaque);
 154 BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int count,
 155                              BlockCompletionFunc *cb, void *opaque);
 156 void blk_aio_cancel(BlockAIOCB *acb);
 157 void blk_aio_cancel_async(BlockAIOCB *acb);
 158 int blk_co_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
 159 int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
 160 BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
 161                           BlockCompletionFunc *cb, void *opaque);
 162 int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int count);
 163 int blk_co_flush(BlockBackend *blk);
 164 int blk_flush(BlockBackend *blk);
 165 int blk_commit_all(void);
 166 void blk_drain(BlockBackend *blk);
 167 void blk_drain_all(void);
 168 void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
 169                       BlockdevOnError on_write_error);
 170 BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read);
 171 BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
 172                                       int error);
 173 void blk_error_action(BlockBackend *blk, BlockErrorAction action,
 174                       bool is_read, int error);
 175 int blk_is_read_only(BlockBackend *blk);
 176 int blk_is_sg(BlockBackend *blk);
 177 int blk_enable_write_cache(BlockBackend *blk);
 178 void blk_set_enable_write_cache(BlockBackend *blk, bool wce);
 179 void blk_invalidate_cache(BlockBackend *blk, Error **errp);
 180 bool blk_is_inserted(BlockBackend *blk);
 181 bool blk_is_available(BlockBackend *blk);
 182 void blk_lock_medium(BlockBackend *blk, bool locked);
 183 void blk_eject(BlockBackend *blk, bool eject_flag);
 184 int blk_get_flags(BlockBackend *blk);
 185 uint32_t blk_get_max_transfer(BlockBackend *blk);
 186 int blk_get_max_iov(BlockBackend *blk);
 187 void blk_set_guest_block_size(BlockBackend *blk, int align);
 188 void *blk_try_blockalign(BlockBackend *blk, size_t size);
 189 void *blk_blockalign(BlockBackend *blk, size_t size);
 190 bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp);
 191 void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason);
 192 void blk_op_block_all(BlockBackend *blk, Error *reason);
 193 void blk_op_unblock_all(BlockBackend *blk, Error *reason);
 194 AioContext *blk_get_aio_context(BlockBackend *blk);
 195 void blk_set_aio_context(BlockBackend *blk, AioContext *new_context);
 196 void blk_add_aio_context_notifier(BlockBackend *blk,
 197         void (*attached_aio_context)(AioContext *new_context, void *opaque),
 198         void (*detach_aio_context)(void *opaque), void *opaque);
 199 void blk_remove_aio_context_notifier(BlockBackend *blk,
 200                                      void (*attached_aio_context)(AioContext *,
 201                                                                   void *),
 202                                      void (*detach_aio_context)(void *),
 203                                      void *opaque);
 204 void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify);
 205 void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify);
 206 void blk_io_plug(BlockBackend *blk);
 207 void blk_io_unplug(BlockBackend *blk);
 208 BlockAcctStats *blk_get_stats(BlockBackend *blk);
 209 BlockBackendRootState *blk_get_root_state(BlockBackend *blk);
 210 void blk_update_root_state(BlockBackend *blk);
 211 bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk);
 212 int blk_get_open_flags_from_root_state(BlockBackend *blk);
 213
 214 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
 215                   BlockCompletionFunc *cb, void *opaque);
 216 int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 217                                       int count, BdrvRequestFlags flags);
 218 int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf,
 219                           int count);
 220 int blk_truncate(BlockBackend *blk, int64_t offset);
 221 int blk_pdiscard(BlockBackend *blk, int64_t offset, int count);
 222 int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
 223                      int64_t pos, int size);
 224 int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size);
 225 int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz);
 226 int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo);
 227 BlockAIOCB *blk_abort_aio_request(BlockBackend *blk,
 228                                   BlockCompletionFunc *cb,
 229                                   void *opaque, int ret);
 230
 231 void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg);
 232 void blk_io_limits_disable(BlockBackend *blk);
 233 void blk_io_limits_enable(BlockBackend *blk, const char *group);
 234 void blk_io_limits_update_group(BlockBackend *blk, const char *group);
 235
 236 #endif