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