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, 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} BlockDevOps;
  70
  71/* This struct is embedded in (the private) BlockBackend struct and contains
  72 * fields that must be public. This is in particular for QLIST_ENTRY() and
  73 * friends so that BlockBackends can be kept in lists outside block-backend.c
  74 * */
  75typedef struct BlockBackendPublic {
  76    ThrottleGroupMember throttle_group_member;
  77} BlockBackendPublic;
  78
  79BlockBackend *blk_new(AioContext *ctx, uint64_t perm, uint64_t shared_perm);
  80BlockBackend *blk_new_open(const char *filename, const char *reference,
  81                           QDict *options, int flags, Error **errp);
  82int blk_get_refcnt(BlockBackend *blk);
  83void blk_ref(BlockBackend *blk);
  84void blk_unref(BlockBackend *blk);
  85void blk_remove_all_bs(void);
  86const char *blk_name(const BlockBackend *blk);
  87BlockBackend *blk_by_name(const char *name);
  88BlockBackend *blk_next(BlockBackend *blk);
  89BlockBackend *blk_all_next(BlockBackend *blk);
  90bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp);
  91void monitor_remove_blk(BlockBackend *blk);
  92
  93BlockBackendPublic *blk_get_public(BlockBackend *blk);
  94BlockBackend *blk_by_public(BlockBackendPublic *public);
  95
  96BlockDriverState *blk_bs(BlockBackend *blk);
  97void blk_remove_bs(BlockBackend *blk);
  98int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp);
  99bool bdrv_has_blk(BlockDriverState *bs);
 100bool bdrv_is_root_node(BlockDriverState *bs);
 101int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm,
 102                 Error **errp);
 103void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm);
 104
 105void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow);
 106void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow);
 107void blk_iostatus_enable(BlockBackend *blk);
 108bool blk_iostatus_is_enabled(const BlockBackend *blk);
 109BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk);
 110void blk_iostatus_disable(BlockBackend *blk);
 111void blk_iostatus_reset(BlockBackend *blk);
 112void blk_iostatus_set_err(BlockBackend *blk, int error);
 113int blk_attach_dev(BlockBackend *blk, DeviceState *dev);
 114void blk_detach_dev(BlockBackend *blk, DeviceState *dev);
 115DeviceState *blk_get_attached_dev(BlockBackend *blk);
 116char *blk_get_attached_dev_id(BlockBackend *blk);
 117BlockBackend *blk_by_dev(void *dev);
 118BlockBackend *blk_by_qdev_id(const char *id, Error **errp);
 119void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque);
 120int blk_pread_unthrottled(BlockBackend *blk, int64_t offset, uint8_t *buf,
 121                          int bytes);
 122int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
 123                               unsigned int bytes, QEMUIOVector *qiov,
 124                               BdrvRequestFlags flags);
 125int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
 126                               unsigned int bytes, QEMUIOVector *qiov,
 127                               BdrvRequestFlags flags);
 128
 129static inline int coroutine_fn blk_co_pread(BlockBackend *blk, int64_t offset,
 130                                            unsigned int bytes, void *buf,
 131                                            BdrvRequestFlags flags)
 132{
 133    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
 134
 135    return blk_co_preadv(blk, offset, bytes, &qiov, flags);
 136}
 137
 138static inline int coroutine_fn blk_co_pwrite(BlockBackend *blk, int64_t offset,
 139                                             unsigned int bytes, void *buf,
 140                                             BdrvRequestFlags flags)
 141{
 142    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
 143
 144    return blk_co_pwritev(blk, offset, bytes, &qiov, flags);
 145}
 146
 147int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 148                      int bytes, BdrvRequestFlags flags);
 149BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 150                                  int bytes, BdrvRequestFlags flags,
 151                                  BlockCompletionFunc *cb, void *opaque);
 152int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags);
 153int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int bytes);
 154int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes,
 155               BdrvRequestFlags flags);
 156int64_t blk_getlength(BlockBackend *blk);
 157void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr);
 158int64_t blk_nb_sectors(BlockBackend *blk);
 159BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset,
 160                           QEMUIOVector *qiov, BdrvRequestFlags flags,
 161                           BlockCompletionFunc *cb, void *opaque);
 162BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
 163                            QEMUIOVector *qiov, BdrvRequestFlags flags,
 164                            BlockCompletionFunc *cb, void *opaque);
 165BlockAIOCB *blk_aio_flush(BlockBackend *blk,
 166                          BlockCompletionFunc *cb, void *opaque);
 167BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int bytes,
 168                             BlockCompletionFunc *cb, void *opaque);
 169void blk_aio_cancel(BlockAIOCB *acb);
 170void blk_aio_cancel_async(BlockAIOCB *acb);
 171int blk_co_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
 172int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
 173BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
 174                          BlockCompletionFunc *cb, void *opaque);
 175int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int bytes);
 176int blk_co_flush(BlockBackend *blk);
 177int blk_flush(BlockBackend *blk);
 178int blk_commit_all(void);
 179void blk_inc_in_flight(BlockBackend *blk);
 180void blk_dec_in_flight(BlockBackend *blk);
 181void blk_drain(BlockBackend *blk);
 182void blk_drain_all(void);
 183void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
 184                      BlockdevOnError on_write_error);
 185BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read);
 186BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
 187                                      int error);
 188void blk_error_action(BlockBackend *blk, BlockErrorAction action,
 189                      bool is_read, int error);
 190bool blk_is_read_only(BlockBackend *blk);
 191bool blk_is_sg(BlockBackend *blk);
 192bool blk_enable_write_cache(BlockBackend *blk);
 193void blk_set_enable_write_cache(BlockBackend *blk, bool wce);
 194void blk_invalidate_cache(BlockBackend *blk, Error **errp);
 195bool blk_is_inserted(BlockBackend *blk);
 196bool blk_is_available(BlockBackend *blk);
 197void blk_lock_medium(BlockBackend *blk, bool locked);
 198void blk_eject(BlockBackend *blk, bool eject_flag);
 199int blk_get_flags(BlockBackend *blk);
 200uint32_t blk_get_request_alignment(BlockBackend *blk);
 201uint32_t blk_get_max_transfer(BlockBackend *blk);
 202int blk_get_max_iov(BlockBackend *blk);
 203void blk_set_guest_block_size(BlockBackend *blk, int align);
 204void *blk_try_blockalign(BlockBackend *blk, size_t size);
 205void *blk_blockalign(BlockBackend *blk, size_t size);
 206bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp);
 207void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason);
 208void blk_op_block_all(BlockBackend *blk, Error *reason);
 209void blk_op_unblock_all(BlockBackend *blk, Error *reason);
 210AioContext *blk_get_aio_context(BlockBackend *blk);
 211int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
 212                        Error **errp);
 213void blk_add_aio_context_notifier(BlockBackend *blk,
 214        void (*attached_aio_context)(AioContext *new_context, void *opaque),
 215        void (*detach_aio_context)(void *opaque), void *opaque);
 216void blk_remove_aio_context_notifier(BlockBackend *blk,
 217                                     void (*attached_aio_context)(AioContext *,
 218                                                                  void *),
 219                                     void (*detach_aio_context)(void *),
 220                                     void *opaque);
 221void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify);
 222void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify);
 223void blk_io_plug(BlockBackend *blk);
 224void blk_io_unplug(BlockBackend *blk);
 225BlockAcctStats *blk_get_stats(BlockBackend *blk);
 226BlockBackendRootState *blk_get_root_state(BlockBackend *blk);
 227void blk_update_root_state(BlockBackend *blk);
 228bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk);
 229int blk_get_open_flags_from_root_state(BlockBackend *blk);
 230
 231void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
 232                  BlockCompletionFunc *cb, void *opaque);
 233int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 234                                      int bytes, BdrvRequestFlags flags);
 235int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf,
 236                          int bytes);
 237int blk_truncate(BlockBackend *blk, int64_t offset, PreallocMode prealloc,
 238                 Error **errp);
 239int blk_pdiscard(BlockBackend *blk, int64_t offset, int bytes);
 240int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
 241                     int64_t pos, int size);
 242int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size);
 243int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz);
 244int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo);
 245BlockAIOCB *blk_abort_aio_request(BlockBackend *blk,
 246                                  BlockCompletionFunc *cb,
 247                                  void *opaque, int ret);
 248
 249void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg);
 250void blk_io_limits_disable(BlockBackend *blk);
 251void blk_io_limits_enable(BlockBackend *blk, const char *group);
 252void blk_io_limits_update_group(BlockBackend *blk, const char *group);
 253void blk_set_force_allow_inactivate(BlockBackend *blk);
 254
 255void blk_register_buf(BlockBackend *blk, void *host, size_t size);
 256void blk_unregister_buf(BlockBackend *blk, void *host);
 257
 258int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
 259                                   BlockBackend *blk_out, int64_t off_out,
 260                                   int bytes, BdrvRequestFlags read_flags,
 261                                   BdrvRequestFlags write_flags);
 262
 263const BdrvChild *blk_root(BlockBackend *blk);
 264
 265#endif
 266