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 */ 29 typedef 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 * */ 75 typedef struct BlockBackendPublic { 76 ThrottleGroupMember throttle_group_member; 77 } BlockBackendPublic; 78 79 BlockBackend *blk_new(AioContext *ctx, uint64_t perm, uint64_t shared_perm); 80 BlockBackend *blk_new_open(const char *filename, const char *reference, 81 QDict *options, int flags, Error **errp); 82 int blk_get_refcnt(BlockBackend *blk); 83 void blk_ref(BlockBackend *blk); 84 void blk_unref(BlockBackend *blk); 85 void blk_remove_all_bs(void); 86 const char *blk_name(const BlockBackend *blk); 87 BlockBackend *blk_by_name(const char *name); 88 BlockBackend *blk_next(BlockBackend *blk); 89 BlockBackend *blk_all_next(BlockBackend *blk); 90 bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp); 91 void monitor_remove_blk(BlockBackend *blk); 92 93 BlockBackendPublic *blk_get_public(BlockBackend *blk); 94 BlockBackend *blk_by_public(BlockBackendPublic *public); 95 96 BlockDriverState *blk_bs(BlockBackend *blk); 97 void blk_remove_bs(BlockBackend *blk); 98 int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp); 99 bool bdrv_has_blk(BlockDriverState *bs); 100 bool bdrv_is_root_node(BlockDriverState *bs); 101 int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm, 102 Error **errp); 103 void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm); 104 105 void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow); 106 void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow); 107 void blk_set_disable_request_queuing(BlockBackend *blk, bool disable); 108 void blk_iostatus_enable(BlockBackend *blk); 109 bool blk_iostatus_is_enabled(const BlockBackend *blk); 110 BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk); 111 void blk_iostatus_disable(BlockBackend *blk); 112 void blk_iostatus_reset(BlockBackend *blk); 113 void blk_iostatus_set_err(BlockBackend *blk, int error); 114 int blk_attach_dev(BlockBackend *blk, DeviceState *dev); 115 void blk_detach_dev(BlockBackend *blk, DeviceState *dev); 116 DeviceState *blk_get_attached_dev(BlockBackend *blk); 117 char *blk_get_attached_dev_id(BlockBackend *blk); 118 BlockBackend *blk_by_dev(void *dev); 119 BlockBackend *blk_by_qdev_id(const char *id, Error **errp); 120 void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque); 121 int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset, 122 unsigned int bytes, QEMUIOVector *qiov, 123 BdrvRequestFlags flags); 124 int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset, 125 unsigned int bytes, 126 QEMUIOVector *qiov, size_t qiov_offset, 127 BdrvRequestFlags flags); 128 int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset, 129 unsigned int bytes, QEMUIOVector *qiov, 130 BdrvRequestFlags flags); 131 132 static inline int coroutine_fn blk_co_pread(BlockBackend *blk, int64_t offset, 133 unsigned int bytes, void *buf, 134 BdrvRequestFlags flags) 135 { 136 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes); 137 138 return blk_co_preadv(blk, offset, bytes, &qiov, flags); 139 } 140 141 static inline int coroutine_fn blk_co_pwrite(BlockBackend *blk, int64_t offset, 142 unsigned int bytes, void *buf, 143 BdrvRequestFlags flags) 144 { 145 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes); 146 147 return blk_co_pwritev(blk, offset, bytes, &qiov, flags); 148 } 149 150 int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset, 151 int bytes, BdrvRequestFlags flags); 152 BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset, 153 int bytes, BdrvRequestFlags flags, 154 BlockCompletionFunc *cb, void *opaque); 155 int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags); 156 int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int bytes); 157 int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes, 158 BdrvRequestFlags flags); 159 int64_t blk_getlength(BlockBackend *blk); 160 void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr); 161 int64_t blk_nb_sectors(BlockBackend *blk); 162 BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset, 163 QEMUIOVector *qiov, BdrvRequestFlags flags, 164 BlockCompletionFunc *cb, void *opaque); 165 BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset, 166 QEMUIOVector *qiov, BdrvRequestFlags flags, 167 BlockCompletionFunc *cb, void *opaque); 168 BlockAIOCB *blk_aio_flush(BlockBackend *blk, 169 BlockCompletionFunc *cb, void *opaque); 170 BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int bytes, 171 BlockCompletionFunc *cb, void *opaque); 172 void blk_aio_cancel(BlockAIOCB *acb); 173 void blk_aio_cancel_async(BlockAIOCB *acb); 174 int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf); 175 BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf, 176 BlockCompletionFunc *cb, void *opaque); 177 int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int bytes); 178 int blk_co_flush(BlockBackend *blk); 179 int blk_flush(BlockBackend *blk); 180 int blk_commit_all(void); 181 void blk_inc_in_flight(BlockBackend *blk); 182 void blk_dec_in_flight(BlockBackend *blk); 183 void blk_drain(BlockBackend *blk); 184 void blk_drain_all(void); 185 void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error, 186 BlockdevOnError on_write_error); 187 BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read); 188 BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read, 189 int error); 190 void blk_error_action(BlockBackend *blk, BlockErrorAction action, 191 bool is_read, int error); 192 bool blk_is_read_only(BlockBackend *blk); 193 bool blk_is_sg(BlockBackend *blk); 194 bool blk_enable_write_cache(BlockBackend *blk); 195 void blk_set_enable_write_cache(BlockBackend *blk, bool wce); 196 void blk_invalidate_cache(BlockBackend *blk, Error **errp); 197 bool blk_is_inserted(BlockBackend *blk); 198 bool blk_is_available(BlockBackend *blk); 199 void blk_lock_medium(BlockBackend *blk, bool locked); 200 void blk_eject(BlockBackend *blk, bool eject_flag); 201 int blk_get_flags(BlockBackend *blk); 202 uint32_t blk_get_request_alignment(BlockBackend *blk); 203 uint32_t blk_get_max_transfer(BlockBackend *blk); 204 int blk_get_max_iov(BlockBackend *blk); 205 void blk_set_guest_block_size(BlockBackend *blk, int align); 206 void *blk_try_blockalign(BlockBackend *blk, size_t size); 207 void *blk_blockalign(BlockBackend *blk, size_t size); 208 bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp); 209 void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason); 210 void blk_op_block_all(BlockBackend *blk, Error *reason); 211 void blk_op_unblock_all(BlockBackend *blk, Error *reason); 212 AioContext *blk_get_aio_context(BlockBackend *blk); 213 int blk_set_aio_context(BlockBackend *blk, AioContext *new_context, 214 Error **errp); 215 void blk_add_aio_context_notifier(BlockBackend *blk, 216 void (*attached_aio_context)(AioContext *new_context, void *opaque), 217 void (*detach_aio_context)(void *opaque), void *opaque); 218 void blk_remove_aio_context_notifier(BlockBackend *blk, 219 void (*attached_aio_context)(AioContext *, 220 void *), 221 void (*detach_aio_context)(void *), 222 void *opaque); 223 void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify); 224 void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify); 225 void blk_io_plug(BlockBackend *blk); 226 void blk_io_unplug(BlockBackend *blk); 227 BlockAcctStats *blk_get_stats(BlockBackend *blk); 228 BlockBackendRootState *blk_get_root_state(BlockBackend *blk); 229 void blk_update_root_state(BlockBackend *blk); 230 bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk); 231 int blk_get_open_flags_from_root_state(BlockBackend *blk); 232 233 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk, 234 BlockCompletionFunc *cb, void *opaque); 235 int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset, 236 int bytes, BdrvRequestFlags flags); 237 int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf, 238 int bytes); 239 int blk_truncate(BlockBackend *blk, int64_t offset, bool exact, 240 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp); 241 int blk_pdiscard(BlockBackend *blk, int64_t offset, int bytes); 242 int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf, 243 int64_t pos, int size); 244 int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size); 245 int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz); 246 int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo); 247 BlockAIOCB *blk_abort_aio_request(BlockBackend *blk, 248 BlockCompletionFunc *cb, 249 void *opaque, int ret); 250 251 void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg); 252 void blk_io_limits_disable(BlockBackend *blk); 253 void blk_io_limits_enable(BlockBackend *blk, const char *group); 254 void blk_io_limits_update_group(BlockBackend *blk, const char *group); 255 void blk_set_force_allow_inactivate(BlockBackend *blk); 256 257 void blk_register_buf(BlockBackend *blk, void *host, size_t size); 258 void blk_unregister_buf(BlockBackend *blk, void *host); 259 260 int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in, 261 BlockBackend *blk_out, int64_t off_out, 262 int bytes, BdrvRequestFlags read_flags, 263 BdrvRequestFlags write_flags); 264 265 const BdrvChild *blk_root(BlockBackend *blk); 266 267 #endif 268