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 /* 70 * Is the device still busy? 71 */ 72 bool (*drained_poll)(void *opaque); 73 } BlockDevOps; 74 75 /* This struct is embedded in (the private) BlockBackend struct and contains 76 * fields that must be public. This is in particular for QLIST_ENTRY() and 77 * friends so that BlockBackends can be kept in lists outside block-backend.c 78 * */ 79 typedef struct BlockBackendPublic { 80 ThrottleGroupMember throttle_group_member; 81 } BlockBackendPublic; 82 83 BlockBackend *blk_new(AioContext *ctx, uint64_t perm, uint64_t shared_perm); 84 BlockBackend *blk_new_with_bs(BlockDriverState *bs, uint64_t perm, 85 uint64_t shared_perm, Error **errp); 86 BlockBackend *blk_new_open(const char *filename, const char *reference, 87 QDict *options, int flags, Error **errp); 88 int blk_get_refcnt(BlockBackend *blk); 89 void blk_ref(BlockBackend *blk); 90 void blk_unref(BlockBackend *blk); 91 void blk_remove_all_bs(void); 92 const char *blk_name(const BlockBackend *blk); 93 BlockBackend *blk_by_name(const char *name); 94 BlockBackend *blk_next(BlockBackend *blk); 95 BlockBackend *blk_all_next(BlockBackend *blk); 96 bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp); 97 void monitor_remove_blk(BlockBackend *blk); 98 99 BlockBackendPublic *blk_get_public(BlockBackend *blk); 100 BlockBackend *blk_by_public(BlockBackendPublic *public); 101 102 BlockDriverState *blk_bs(BlockBackend *blk); 103 void blk_remove_bs(BlockBackend *blk); 104 int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp); 105 bool bdrv_has_blk(BlockDriverState *bs); 106 bool bdrv_is_root_node(BlockDriverState *bs); 107 int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm, 108 Error **errp); 109 void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm); 110 111 void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow); 112 void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow); 113 void blk_set_disable_request_queuing(BlockBackend *blk, bool disable); 114 void blk_iostatus_enable(BlockBackend *blk); 115 bool blk_iostatus_is_enabled(const BlockBackend *blk); 116 BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk); 117 void blk_iostatus_disable(BlockBackend *blk); 118 void blk_iostatus_reset(BlockBackend *blk); 119 void blk_iostatus_set_err(BlockBackend *blk, int error); 120 int blk_attach_dev(BlockBackend *blk, DeviceState *dev); 121 void blk_detach_dev(BlockBackend *blk, DeviceState *dev); 122 DeviceState *blk_get_attached_dev(BlockBackend *blk); 123 char *blk_get_attached_dev_id(BlockBackend *blk); 124 BlockBackend *blk_by_dev(void *dev); 125 BlockBackend *blk_by_qdev_id(const char *id, Error **errp); 126 void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque); 127 int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset, 128 unsigned int bytes, QEMUIOVector *qiov, 129 BdrvRequestFlags flags); 130 int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset, 131 unsigned int bytes, 132 QEMUIOVector *qiov, size_t qiov_offset, 133 BdrvRequestFlags flags); 134 int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset, 135 unsigned int bytes, QEMUIOVector *qiov, 136 BdrvRequestFlags flags); 137 138 static inline int coroutine_fn blk_co_pread(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_preadv(blk, offset, bytes, &qiov, flags); 145 } 146 147 static inline int coroutine_fn blk_co_pwrite(BlockBackend *blk, int64_t offset, 148 unsigned int bytes, void *buf, 149 BdrvRequestFlags flags) 150 { 151 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes); 152 153 return blk_co_pwritev(blk, offset, bytes, &qiov, flags); 154 } 155 156 int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset, 157 int bytes, BdrvRequestFlags flags); 158 BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset, 159 int bytes, BdrvRequestFlags flags, 160 BlockCompletionFunc *cb, void *opaque); 161 int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags); 162 int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int bytes); 163 int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes, 164 BdrvRequestFlags flags); 165 int64_t blk_getlength(BlockBackend *blk); 166 void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr); 167 int64_t blk_nb_sectors(BlockBackend *blk); 168 BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset, 169 QEMUIOVector *qiov, BdrvRequestFlags flags, 170 BlockCompletionFunc *cb, void *opaque); 171 BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset, 172 QEMUIOVector *qiov, BdrvRequestFlags flags, 173 BlockCompletionFunc *cb, void *opaque); 174 BlockAIOCB *blk_aio_flush(BlockBackend *blk, 175 BlockCompletionFunc *cb, void *opaque); 176 BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int bytes, 177 BlockCompletionFunc *cb, void *opaque); 178 void blk_aio_cancel(BlockAIOCB *acb); 179 void blk_aio_cancel_async(BlockAIOCB *acb); 180 int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf); 181 BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf, 182 BlockCompletionFunc *cb, void *opaque); 183 int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int bytes); 184 int blk_co_flush(BlockBackend *blk); 185 int blk_flush(BlockBackend *blk); 186 int blk_commit_all(void); 187 void blk_inc_in_flight(BlockBackend *blk); 188 void blk_dec_in_flight(BlockBackend *blk); 189 void blk_drain(BlockBackend *blk); 190 void blk_drain_all(void); 191 void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error, 192 BlockdevOnError on_write_error); 193 BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read); 194 BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read, 195 int error); 196 void blk_error_action(BlockBackend *blk, BlockErrorAction action, 197 bool is_read, int error); 198 bool blk_supports_write_perm(BlockBackend *blk); 199 bool blk_is_writable(BlockBackend *blk); 200 bool blk_is_sg(BlockBackend *blk); 201 bool blk_enable_write_cache(BlockBackend *blk); 202 void blk_set_enable_write_cache(BlockBackend *blk, bool wce); 203 void blk_invalidate_cache(BlockBackend *blk, Error **errp); 204 bool blk_is_inserted(BlockBackend *blk); 205 bool blk_is_available(BlockBackend *blk); 206 void blk_lock_medium(BlockBackend *blk, bool locked); 207 void blk_eject(BlockBackend *blk, bool eject_flag); 208 int blk_get_flags(BlockBackend *blk); 209 uint32_t blk_get_request_alignment(BlockBackend *blk); 210 uint32_t blk_get_max_transfer(BlockBackend *blk); 211 uint64_t blk_get_max_hw_transfer(BlockBackend *blk); 212 int blk_get_max_iov(BlockBackend *blk); 213 void blk_set_guest_block_size(BlockBackend *blk, int align); 214 void *blk_try_blockalign(BlockBackend *blk, size_t size); 215 void *blk_blockalign(BlockBackend *blk, size_t size); 216 bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp); 217 void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason); 218 void blk_op_block_all(BlockBackend *blk, Error *reason); 219 void blk_op_unblock_all(BlockBackend *blk, Error *reason); 220 AioContext *blk_get_aio_context(BlockBackend *blk); 221 int blk_set_aio_context(BlockBackend *blk, AioContext *new_context, 222 Error **errp); 223 void blk_add_aio_context_notifier(BlockBackend *blk, 224 void (*attached_aio_context)(AioContext *new_context, void *opaque), 225 void (*detach_aio_context)(void *opaque), void *opaque); 226 void blk_remove_aio_context_notifier(BlockBackend *blk, 227 void (*attached_aio_context)(AioContext *, 228 void *), 229 void (*detach_aio_context)(void *), 230 void *opaque); 231 void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify); 232 void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify); 233 void blk_io_plug(BlockBackend *blk); 234 void blk_io_unplug(BlockBackend *blk); 235 BlockAcctStats *blk_get_stats(BlockBackend *blk); 236 BlockBackendRootState *blk_get_root_state(BlockBackend *blk); 237 void blk_update_root_state(BlockBackend *blk); 238 bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk); 239 int blk_get_open_flags_from_root_state(BlockBackend *blk); 240 241 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk, 242 BlockCompletionFunc *cb, void *opaque); 243 int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset, 244 int bytes, BdrvRequestFlags flags); 245 int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf, 246 int bytes); 247 int blk_truncate(BlockBackend *blk, int64_t offset, bool exact, 248 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp); 249 int blk_pdiscard(BlockBackend *blk, int64_t offset, int bytes); 250 int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf, 251 int64_t pos, int size); 252 int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size); 253 int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz); 254 int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo); 255 BlockAIOCB *blk_abort_aio_request(BlockBackend *blk, 256 BlockCompletionFunc *cb, 257 void *opaque, int ret); 258 259 void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg); 260 void blk_io_limits_disable(BlockBackend *blk); 261 void blk_io_limits_enable(BlockBackend *blk, const char *group); 262 void blk_io_limits_update_group(BlockBackend *blk, const char *group); 263 void blk_set_force_allow_inactivate(BlockBackend *blk); 264 265 void blk_register_buf(BlockBackend *blk, void *host, size_t size); 266 void blk_unregister_buf(BlockBackend *blk, void *host); 267 268 int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in, 269 BlockBackend *blk_out, int64_t off_out, 270 int bytes, BdrvRequestFlags read_flags, 271 BdrvRequestFlags write_flags); 272 273 const BdrvChild *blk_root(BlockBackend *blk); 274 275 int blk_make_empty(BlockBackend *blk, Error **errp); 276 277 #endif 278