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_with_bs(BlockDriverState *bs, uint64_t perm,
  81                              uint64_t shared_perm, Error **errp);
  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(const BlockBackend *blk);
  89BlockBackend *blk_by_name(const char *name);
  90BlockBackend *blk_next(BlockBackend *blk);
  91BlockBackend *blk_all_next(BlockBackend *blk);
  92bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp);
  93void monitor_remove_blk(BlockBackend *blk);
  94
  95BlockBackendPublic *blk_get_public(BlockBackend *blk);
  96BlockBackend *blk_by_public(BlockBackendPublic *public);
  97
  98BlockDriverState *blk_bs(BlockBackend *blk);
  99void blk_remove_bs(BlockBackend *blk);
 100int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp);
 101bool bdrv_has_blk(BlockDriverState *bs);
 102bool bdrv_is_root_node(BlockDriverState *bs);
 103int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm,
 104                 Error **errp);
 105void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm);
 106
 107void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow);
 108void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow);
 109void blk_set_disable_request_queuing(BlockBackend *blk, bool disable);
 110void blk_iostatus_enable(BlockBackend *blk);
 111bool blk_iostatus_is_enabled(const BlockBackend *blk);
 112BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk);
 113void blk_iostatus_disable(BlockBackend *blk);
 114void blk_iostatus_reset(BlockBackend *blk);
 115void blk_iostatus_set_err(BlockBackend *blk, int error);
 116int blk_attach_dev(BlockBackend *blk, DeviceState *dev);
 117void blk_detach_dev(BlockBackend *blk, DeviceState *dev);
 118DeviceState *blk_get_attached_dev(BlockBackend *blk);
 119char *blk_get_attached_dev_id(BlockBackend *blk);
 120BlockBackend *blk_by_dev(void *dev);
 121BlockBackend *blk_by_qdev_id(const char *id, Error **errp);
 122void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque);
 123int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
 124                               unsigned int bytes, QEMUIOVector *qiov,
 125                               BdrvRequestFlags flags);
 126int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
 127                                     unsigned int bytes,
 128                                     QEMUIOVector *qiov, size_t qiov_offset,
 129                                     BdrvRequestFlags flags);
 130int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
 131                               unsigned int bytes, QEMUIOVector *qiov,
 132                               BdrvRequestFlags flags);
 133
 134static inline int coroutine_fn blk_co_pread(BlockBackend *blk, int64_t offset,
 135                                            unsigned int bytes, void *buf,
 136                                            BdrvRequestFlags flags)
 137{
 138    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
 139
 140    return blk_co_preadv(blk, offset, bytes, &qiov, flags);
 141}
 142
 143static inline int coroutine_fn blk_co_pwrite(BlockBackend *blk, int64_t offset,
 144                                             unsigned int bytes, void *buf,
 145                                             BdrvRequestFlags flags)
 146{
 147    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
 148
 149    return blk_co_pwritev(blk, offset, bytes, &qiov, flags);
 150}
 151
 152int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 153                      int bytes, BdrvRequestFlags flags);
 154BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 155                                  int bytes, BdrvRequestFlags flags,
 156                                  BlockCompletionFunc *cb, void *opaque);
 157int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags);
 158int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int bytes);
 159int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes,
 160               BdrvRequestFlags flags);
 161int64_t blk_getlength(BlockBackend *blk);
 162void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr);
 163int64_t blk_nb_sectors(BlockBackend *blk);
 164BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset,
 165                           QEMUIOVector *qiov, BdrvRequestFlags flags,
 166                           BlockCompletionFunc *cb, void *opaque);
 167BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
 168                            QEMUIOVector *qiov, BdrvRequestFlags flags,
 169                            BlockCompletionFunc *cb, void *opaque);
 170BlockAIOCB *blk_aio_flush(BlockBackend *blk,
 171                          BlockCompletionFunc *cb, void *opaque);
 172BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int bytes,
 173                             BlockCompletionFunc *cb, void *opaque);
 174void blk_aio_cancel(BlockAIOCB *acb);
 175void blk_aio_cancel_async(BlockAIOCB *acb);
 176int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
 177BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
 178                          BlockCompletionFunc *cb, void *opaque);
 179int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int bytes);
 180int blk_co_flush(BlockBackend *blk);
 181int blk_flush(BlockBackend *blk);
 182int blk_commit_all(void);
 183void blk_inc_in_flight(BlockBackend *blk);
 184void blk_dec_in_flight(BlockBackend *blk);
 185void blk_drain(BlockBackend *blk);
 186void blk_drain_all(void);
 187void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
 188                      BlockdevOnError on_write_error);
 189BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read);
 190BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
 191                                      int error);
 192void blk_error_action(BlockBackend *blk, BlockErrorAction action,
 193                      bool is_read, int error);
 194bool blk_supports_write_perm(BlockBackend *blk);
 195bool blk_is_writable(BlockBackend *blk);
 196bool blk_is_sg(BlockBackend *blk);
 197bool blk_enable_write_cache(BlockBackend *blk);
 198void blk_set_enable_write_cache(BlockBackend *blk, bool wce);
 199void blk_invalidate_cache(BlockBackend *blk, Error **errp);
 200bool blk_is_inserted(BlockBackend *blk);
 201bool blk_is_available(BlockBackend *blk);
 202void blk_lock_medium(BlockBackend *blk, bool locked);
 203void blk_eject(BlockBackend *blk, bool eject_flag);
 204int blk_get_flags(BlockBackend *blk);
 205uint32_t blk_get_request_alignment(BlockBackend *blk);
 206uint32_t blk_get_max_transfer(BlockBackend *blk);
 207int blk_get_max_iov(BlockBackend *blk);
 208void blk_set_guest_block_size(BlockBackend *blk, int align);
 209void *blk_try_blockalign(BlockBackend *blk, size_t size);
 210void *blk_blockalign(BlockBackend *blk, size_t size);
 211bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp);
 212void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason);
 213void blk_op_block_all(BlockBackend *blk, Error *reason);
 214void blk_op_unblock_all(BlockBackend *blk, Error *reason);
 215AioContext *blk_get_aio_context(BlockBackend *blk);
 216int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
 217                        Error **errp);
 218void blk_add_aio_context_notifier(BlockBackend *blk,
 219        void (*attached_aio_context)(AioContext *new_context, void *opaque),
 220        void (*detach_aio_context)(void *opaque), void *opaque);
 221void blk_remove_aio_context_notifier(BlockBackend *blk,
 222                                     void (*attached_aio_context)(AioContext *,
 223                                                                  void *),
 224                                     void (*detach_aio_context)(void *),
 225                                     void *opaque);
 226void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify);
 227void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify);
 228void blk_io_plug(BlockBackend *blk);
 229void blk_io_unplug(BlockBackend *blk);
 230BlockAcctStats *blk_get_stats(BlockBackend *blk);
 231BlockBackendRootState *blk_get_root_state(BlockBackend *blk);
 232void blk_update_root_state(BlockBackend *blk);
 233bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk);
 234int blk_get_open_flags_from_root_state(BlockBackend *blk);
 235
 236void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
 237                  BlockCompletionFunc *cb, void *opaque);
 238int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 239                                      int bytes, BdrvRequestFlags flags);
 240int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf,
 241                          int bytes);
 242int blk_truncate(BlockBackend *blk, int64_t offset, bool exact,
 243                 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp);
 244int blk_pdiscard(BlockBackend *blk, int64_t offset, int bytes);
 245int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
 246                     int64_t pos, int size);
 247int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size);
 248int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz);
 249int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo);
 250BlockAIOCB *blk_abort_aio_request(BlockBackend *blk,
 251                                  BlockCompletionFunc *cb,
 252                                  void *opaque, int ret);
 253
 254void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg);
 255void blk_io_limits_disable(BlockBackend *blk);
 256void blk_io_limits_enable(BlockBackend *blk, const char *group);
 257void blk_io_limits_update_group(BlockBackend *blk, const char *group);
 258void blk_set_force_allow_inactivate(BlockBackend *blk);
 259
 260void blk_register_buf(BlockBackend *blk, void *host, size_t size);
 261void blk_unregister_buf(BlockBackend *blk, void *host);
 262
 263int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
 264                                   BlockBackend *blk_out, int64_t off_out,
 265                                   int bytes, BdrvRequestFlags read_flags,
 266                                   BdrvRequestFlags write_flags);
 267
 268const BdrvChild *blk_root(BlockBackend *blk);
 269
 270int blk_make_empty(BlockBackend *blk, Error **errp);
 271
 272#endif
 273