/* * QEMU Block backends * * Copyright (C) 2014-2016 Red Hat, Inc. * * Authors: * Markus Armbruster <armbru@redhat.com>, * * This work is licensed under the terms of the GNU LGPL, version 2.1 * or later. See the COPYING.LIB file in the top-level directory. */ #ifndef BLOCK_BACKEND_H #define BLOCK_BACKEND_H #include "qemu/iov.h" #include "block/throttle-groups.h" /* * TODO Have to include block/block.h for a bunch of block layer * types. Unfortunately, this pulls in the whole BlockDriverState * API, which we don't want used by many BlockBackend users. Some of * the types belong here, and the rest should be split into a common * header and one for the BlockDriverState API. */ #include "block/block.h" /* Callbacks for block device models */ typedef struct BlockDevOps { /* * Runs when virtual media changed (monitor commands eject, change) * Argument load is true on load and false on eject. * Beware: doesn't run when a host device's physical media * changes. Sure would be useful if it did. * Device models with removable media must implement this callback. */ void (*change_media_cb)(void *opaque, bool load, Error **errp); /* * Runs when an eject request is issued from the monitor, the tray * is closed, and the medium is locked. * Device models that do not implement is_medium_locked will not need * this callback. Device models that can lock the medium or tray might * want to implement the callback and unlock the tray when "force" is * true, even if they do not support eject requests. */ void (*eject_request_cb)(void *opaque, bool force); /* * Is the virtual tray open? * Device models implement this only when the device has a tray. */ bool (*is_tray_open)(void *opaque); /* * Is the virtual medium locked into the device? * Device models implement this only when device has such a lock. */ bool (*is_medium_locked)(void *opaque); /* * Runs when the size changed (e.g. monitor command block_resize) */ void (*resize_cb)(void *opaque); /* * Runs when the backend receives a drain request. */ void (*drained_begin)(void *opaque); /* * Runs when the backend's last drain request ends. */ void (*drained_end)(void *opaque); } BlockDevOps; /* This struct is embedded in (the private) BlockBackend struct and contains * fields that must be public. This is in particular for QLIST_ENTRY() and * friends so that BlockBackends can be kept in lists outside block-backend.c */ typedef struct BlockBackendPublic { /* I/O throttling has its own locking, but also some fields are * protected by the AioContext lock. */ /* Protected by AioContext lock. */ CoQueue throttled_reqs[2]; /* Nonzero if the I/O limits are currently being ignored; generally * it is zero. */ unsigned int io_limits_disabled; /* The following fields are protected by the ThrottleGroup lock. * See the ThrottleGroup documentation for details. * throttle_state tells us if I/O limits are configured. */ ThrottleState *throttle_state; ThrottleTimers throttle_timers; unsigned pending_reqs[2]; QLIST_ENTRY(BlockBackendPublic) round_robin; } BlockBackendPublic; BlockBackend *blk_new(uint64_t perm, uint64_t shared_perm); BlockBackend *blk_new_open(const char *filename, const char *reference, QDict *options, int flags, Error **errp); int blk_get_refcnt(BlockBackend *blk); void blk_ref(BlockBackend *blk); void blk_unref(BlockBackend *blk); void blk_remove_all_bs(void); const char *blk_name(const BlockBackend *blk); BlockBackend *blk_by_name(const char *name); BlockBackend *blk_next(BlockBackend *blk); bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp); void monitor_remove_blk(BlockBackend *blk); BlockBackendPublic *blk_get_public(BlockBackend *blk); BlockBackend *blk_by_public(BlockBackendPublic *public); BlockDriverState *blk_bs(BlockBackend *blk); void blk_remove_bs(BlockBackend *blk); int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp); bool bdrv_has_blk(BlockDriverState *bs); bool bdrv_is_root_node(BlockDriverState *bs); int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm, Error **errp); void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm); void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow); void blk_iostatus_enable(BlockBackend *blk); bool blk_iostatus_is_enabled(const BlockBackend *blk); BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk); void blk_iostatus_disable(BlockBackend *blk); void blk_iostatus_reset(BlockBackend *blk); void blk_iostatus_set_err(BlockBackend *blk, int error); int blk_attach_dev(BlockBackend *blk, DeviceState *dev); void blk_attach_dev_legacy(BlockBackend *blk, void *dev); void blk_detach_dev(BlockBackend *blk, void *dev); void *blk_get_attached_dev(BlockBackend *blk); BlockBackend *blk_by_dev(void *dev); BlockBackend *blk_by_qdev_id(const char *id, Error **errp); void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque); int blk_pread_unthrottled(BlockBackend *blk, int64_t offset, uint8_t *buf, int count); int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset, unsigned int bytes, QEMUIOVector *qiov, BdrvRequestFlags flags); int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset, unsigned int bytes, QEMUIOVector *qiov, BdrvRequestFlags flags); int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset, int count, BdrvRequestFlags flags); BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset, int count, BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque); int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags); int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int count); int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int count, BdrvRequestFlags flags); int64_t blk_getlength(BlockBackend *blk); void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr); int64_t blk_nb_sectors(BlockBackend *blk); BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset, QEMUIOVector *qiov, BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque); BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset, QEMUIOVector *qiov, BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque); BlockAIOCB *blk_aio_flush(BlockBackend *blk, BlockCompletionFunc *cb, void *opaque); BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int count, BlockCompletionFunc *cb, void *opaque); void blk_aio_cancel(BlockAIOCB *acb); void blk_aio_cancel_async(BlockAIOCB *acb); int blk_co_ioctl(BlockBackend *blk, unsigned long int req, void *buf); int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf); BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf, BlockCompletionFunc *cb, void *opaque); int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int count); int blk_co_flush(BlockBackend *blk); int blk_flush(BlockBackend *blk); int blk_commit_all(void); void blk_drain(BlockBackend *blk); void blk_drain_all(void); void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error, BlockdevOnError on_write_error); BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read); BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read, int error); void blk_error_action(BlockBackend *blk, BlockErrorAction action, bool is_read, int error); int blk_is_read_only(BlockBackend *blk); int blk_is_sg(BlockBackend *blk); int blk_enable_write_cache(BlockBackend *blk); void blk_set_enable_write_cache(BlockBackend *blk, bool wce); void blk_invalidate_cache(BlockBackend *blk, Error **errp); bool blk_is_inserted(BlockBackend *blk); bool blk_is_available(BlockBackend *blk); void blk_lock_medium(BlockBackend *blk, bool locked); void blk_eject(BlockBackend *blk, bool eject_flag); int blk_get_flags(BlockBackend *blk); uint32_t blk_get_max_transfer(BlockBackend *blk); int blk_get_max_iov(BlockBackend *blk); void blk_set_guest_block_size(BlockBackend *blk, int align); void *blk_try_blockalign(BlockBackend *blk, size_t size); void *blk_blockalign(BlockBackend *blk, size_t size); bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp); void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason); void blk_op_block_all(BlockBackend *blk, Error *reason); void blk_op_unblock_all(BlockBackend *blk, Error *reason); AioContext *blk_get_aio_context(BlockBackend *blk); void blk_set_aio_context(BlockBackend *blk, AioContext *new_context); void blk_add_aio_context_notifier(BlockBackend *blk, void (*attached_aio_context)(AioContext *new_context, void *opaque), void (*detach_aio_context)(void *opaque), void *opaque); void blk_remove_aio_context_notifier(BlockBackend *blk, void (*attached_aio_context)(AioContext *, void *), void (*detach_aio_context)(void *), void *opaque); void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify); void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify); void blk_io_plug(BlockBackend *blk); void blk_io_unplug(BlockBackend *blk); BlockAcctStats *blk_get_stats(BlockBackend *blk); BlockBackendRootState *blk_get_root_state(BlockBackend *blk); void blk_update_root_state(BlockBackend *blk); bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk); int blk_get_open_flags_from_root_state(BlockBackend *blk); void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk, BlockCompletionFunc *cb, void *opaque); int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset, int count, BdrvRequestFlags flags); int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf, int count); int blk_truncate(BlockBackend *blk, int64_t offset, Error **errp); int blk_pdiscard(BlockBackend *blk, int64_t offset, int count); int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf, int64_t pos, int size); int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size); int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz); int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo); BlockAIOCB *blk_abort_aio_request(BlockBackend *blk, BlockCompletionFunc *cb, void *opaque, int ret); void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg); void blk_io_limits_disable(BlockBackend *blk); void blk_io_limits_enable(BlockBackend *blk, const char *group); void blk_io_limits_update_group(BlockBackend *blk, const char *group); #endif