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 */
  13#ifndef BLOCK_BACKEND_H
  14#define BLOCK_BACKEND_H
  16#include "qemu/iov.h"
  17#include "block/throttle-groups.h"
  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"
  28/* Callbacks for block device models */
  29typedef 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    /*
  62     * Runs when the backend receives a drain request.
  63     */
  64    void (*drained_begin)(void *opaque);
  65    /*
  66     * Runs when the backend's last drain request ends.
  67     */
  68    void (*drained_end)(void *opaque);
  69    /*
  70     * Is the device still busy?
  71     */
  72    bool (*drained_poll)(void *opaque);
  73} BlockDevOps;
  75/* This struct is embedded in (the private) BlockBackend struct and contains
  76 * fields that must be public. This is in particular for QLIST_ENTRY() and
  77 * friends so that BlockBackends can be kept in lists outside block-backend.c
  78 * */
  79typedef struct BlockBackendPublic {
  80    ThrottleGroupMember throttle_group_member;
  81} BlockBackendPublic;
  83BlockBackend *blk_new(AioContext *ctx, uint64_t perm, uint64_t shared_perm);
  84BlockBackend *blk_new_with_bs(BlockDriverState *bs, uint64_t perm,
  85                              uint64_t shared_perm, Error **errp);
  86BlockBackend *blk_new_open(const char *filename, const char *reference,
  87                           QDict *options, int flags, Error **errp);
  88int blk_get_refcnt(BlockBackend *blk);
  89void blk_ref(BlockBackend *blk);
  90void blk_unref(BlockBackend *blk);
  91void blk_remove_all_bs(void);
  92const char *blk_name(const BlockBackend *blk);
  93BlockBackend *blk_by_name(const char *name);
  94BlockBackend *blk_next(BlockBackend *blk);
  95BlockBackend *blk_all_next(BlockBackend *blk);
  96bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp);
  97void monitor_remove_blk(BlockBackend *blk);
  99BlockBackendPublic *blk_get_public(BlockBackend *blk);
 100BlockBackend *blk_by_public(BlockBackendPublic *public);
 102BlockDriverState *blk_bs(BlockBackend *blk);
 103void blk_remove_bs(BlockBackend *blk);
 104int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp);
 105int blk_replace_bs(BlockBackend *blk, BlockDriverState *new_bs, Error **errp);
 106bool bdrv_has_blk(BlockDriverState *bs);
 107bool bdrv_is_root_node(BlockDriverState *bs);
 108int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm,
 109                 Error **errp);
 110void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm);
 112void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow);
 113void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow);
 114void blk_set_disable_request_queuing(BlockBackend *blk, bool disable);
 115void blk_iostatus_enable(BlockBackend *blk);
 116bool blk_iostatus_is_enabled(const BlockBackend *blk);
 117BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk);
 118void blk_iostatus_disable(BlockBackend *blk);
 119void blk_iostatus_reset(BlockBackend *blk);
 120void blk_iostatus_set_err(BlockBackend *blk, int error);
 121int blk_attach_dev(BlockBackend *blk, DeviceState *dev);
 122void blk_detach_dev(BlockBackend *blk, DeviceState *dev);
 123DeviceState *blk_get_attached_dev(BlockBackend *blk);
 124char *blk_get_attached_dev_id(BlockBackend *blk);
 125BlockBackend *blk_by_dev(void *dev);
 126BlockBackend *blk_by_qdev_id(const char *id, Error **errp);
 127void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque);
 128int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
 129                               int64_t bytes, QEMUIOVector *qiov,
 130                               BdrvRequestFlags flags);
 131int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
 132                                     int64_t bytes,
 133                                     QEMUIOVector *qiov, size_t qiov_offset,
 134                                     BdrvRequestFlags flags);
 135int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
 136                               int64_t bytes, QEMUIOVector *qiov,
 137                               BdrvRequestFlags flags);
 139static inline int coroutine_fn blk_co_pread(BlockBackend *blk, int64_t offset,
 140                                            int64_t bytes, void *buf,
 141                                            BdrvRequestFlags flags)
 143    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
 145    assert(bytes <= SIZE_MAX);
 147    return blk_co_preadv(blk, offset, bytes, &qiov, flags);
 150static inline int coroutine_fn blk_co_pwrite(BlockBackend *blk, int64_t offset,
 151                                             int64_t bytes, void *buf,
 152                                             BdrvRequestFlags flags)
 154    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
 156    assert(bytes <= SIZE_MAX);
 158    return blk_co_pwritev(blk, offset, bytes, &qiov, flags);
 161int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 162                      int64_t bytes, BdrvRequestFlags flags);
 163BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 164                                  int64_t bytes, BdrvRequestFlags flags,
 165                                  BlockCompletionFunc *cb, void *opaque);
 166int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags);
 167int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int bytes);
 168int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes,
 169               BdrvRequestFlags flags);
 170int64_t blk_getlength(BlockBackend *blk);
 171void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr);
 172int64_t blk_nb_sectors(BlockBackend *blk);
 173BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset,
 174                           QEMUIOVector *qiov, BdrvRequestFlags flags,
 175                           BlockCompletionFunc *cb, void *opaque);
 176BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
 177                            QEMUIOVector *qiov, BdrvRequestFlags flags,
 178                            BlockCompletionFunc *cb, void *opaque);
 179BlockAIOCB *blk_aio_flush(BlockBackend *blk,
 180                          BlockCompletionFunc *cb, void *opaque);
 181BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int64_t bytes,
 182                             BlockCompletionFunc *cb, void *opaque);
 183void blk_aio_cancel(BlockAIOCB *acb);
 184void blk_aio_cancel_async(BlockAIOCB *acb);
 185int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
 186BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
 187                          BlockCompletionFunc *cb, void *opaque);
 188int coroutine_fn blk_co_pdiscard(BlockBackend *blk, int64_t offset,
 189                                 int64_t bytes);
 190int coroutine_fn blk_co_flush(BlockBackend *blk);
 191int blk_flush(BlockBackend *blk);
 192int blk_commit_all(void);
 193void blk_inc_in_flight(BlockBackend *blk);
 194void blk_dec_in_flight(BlockBackend *blk);
 195void blk_drain(BlockBackend *blk);
 196void blk_drain_all(void);
 197void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
 198                      BlockdevOnError on_write_error);
 199BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read);
 200BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
 201                                      int error);
 202void blk_error_action(BlockBackend *blk, BlockErrorAction action,
 203                      bool is_read, int error);
 204bool blk_supports_write_perm(BlockBackend *blk);
 205bool blk_is_writable(BlockBackend *blk);
 206bool blk_is_sg(BlockBackend *blk);
 207bool blk_enable_write_cache(BlockBackend *blk);
 208void blk_set_enable_write_cache(BlockBackend *blk, bool wce);
 209void blk_invalidate_cache(BlockBackend *blk, Error **errp);
 210bool blk_is_inserted(BlockBackend *blk);
 211bool blk_is_available(BlockBackend *blk);
 212void blk_lock_medium(BlockBackend *blk, bool locked);
 213void blk_eject(BlockBackend *blk, bool eject_flag);
 214int blk_get_flags(BlockBackend *blk);
 215uint32_t blk_get_request_alignment(BlockBackend *blk);
 216uint32_t blk_get_max_transfer(BlockBackend *blk);
 217uint64_t blk_get_max_hw_transfer(BlockBackend *blk);
 218int blk_get_max_iov(BlockBackend *blk);
 219int blk_get_max_hw_iov(BlockBackend *blk);
 220void blk_set_guest_block_size(BlockBackend *blk, int align);
 221void *blk_try_blockalign(BlockBackend *blk, size_t size);
 222void *blk_blockalign(BlockBackend *blk, size_t size);
 223bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp);
 224void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason);
 225void blk_op_block_all(BlockBackend *blk, Error *reason);
 226void blk_op_unblock_all(BlockBackend *blk, Error *reason);
 227AioContext *blk_get_aio_context(BlockBackend *blk);
 228int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
 229                        Error **errp);
 230void blk_add_aio_context_notifier(BlockBackend *blk,
 231        void (*attached_aio_context)(AioContext *new_context, void *opaque),
 232        void (*detach_aio_context)(void *opaque), void *opaque);
 233void blk_remove_aio_context_notifier(BlockBackend *blk,
 234                                     void (*attached_aio_context)(AioContext *,
 235                                                                  void *),
 236                                     void (*detach_aio_context)(void *),
 237                                     void *opaque);
 238void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify);
 239void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify);
 240void blk_io_plug(BlockBackend *blk);
 241void blk_io_unplug(BlockBackend *blk);
 242BlockAcctStats *blk_get_stats(BlockBackend *blk);
 243BlockBackendRootState *blk_get_root_state(BlockBackend *blk);
 244void blk_update_root_state(BlockBackend *blk);
 245bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk);
 246int blk_get_open_flags_from_root_state(BlockBackend *blk);
 248void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
 249                  BlockCompletionFunc *cb, void *opaque);
 250int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 251                                      int64_t bytes, BdrvRequestFlags flags);
 252int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf,
 253                          int64_t bytes);
 254int blk_truncate(BlockBackend *blk, int64_t offset, bool exact,
 255                 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp);
 256int blk_pdiscard(BlockBackend *blk, int64_t offset, int64_t bytes);
 257int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
 258                     int64_t pos, int size);
 259int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size);
 260int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz);
 261int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo);
 262BlockAIOCB *blk_abort_aio_request(BlockBackend *blk,
 263                                  BlockCompletionFunc *cb,
 264                                  void *opaque, int ret);
 266void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg);
 267void blk_io_limits_disable(BlockBackend *blk);
 268void blk_io_limits_enable(BlockBackend *blk, const char *group);
 269void blk_io_limits_update_group(BlockBackend *blk, const char *group);
 270void blk_set_force_allow_inactivate(BlockBackend *blk);
 272void blk_register_buf(BlockBackend *blk, void *host, size_t size);
 273void blk_unregister_buf(BlockBackend *blk, void *host);
 275int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
 276                                   BlockBackend *blk_out, int64_t off_out,
 277                                   int64_t bytes, BdrvRequestFlags read_flags,
 278                                   BdrvRequestFlags write_flags);
 280const BdrvChild *blk_root(BlockBackend *blk);
 282int blk_make_empty(BlockBackend *blk, Error **errp);