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_with_bs(BlockDriverState *bs, uint64_t perm, 81 uint64_t shared_perm, Error **errp); 82 BlockBackend *blk_new_open(const char *filename, const char *reference, 83 QDict *options, int flags, Error **errp); 84 int blk_get_refcnt(BlockBackend *blk); 85 void blk_ref(BlockBackend *blk); 86 void blk_unref(BlockBackend *blk); 87 void blk_remove_all_bs(void); 88 const char *blk_name(const BlockBackend *blk); 89 BlockBackend *blk_by_name(const char *name); 90 BlockBackend *blk_next(BlockBackend *blk); 91 BlockBackend *blk_all_next(BlockBackend *blk); 92 bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp); 93 void monitor_remove_blk(BlockBackend *blk); 94 95 BlockBackendPublic *blk_get_public(BlockBackend *blk); 96 BlockBackend *blk_by_public(BlockBackendPublic *public); 97 98 BlockDriverState *blk_bs(BlockBackend *blk); 99 void blk_remove_bs(BlockBackend *blk); 100 int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp); 101 bool bdrv_has_blk(BlockDriverState *bs); 102 bool bdrv_is_root_node(BlockDriverState *bs); 103 int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm, 104 Error **errp); 105 void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm); 106 107 void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow); 108 void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow); 109 void blk_set_disable_request_queuing(BlockBackend *blk, bool disable); 110 void blk_iostatus_enable(BlockBackend *blk); 111 bool blk_iostatus_is_enabled(const BlockBackend *blk); 112 BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk); 113 void blk_iostatus_disable(BlockBackend *blk); 114 void blk_iostatus_reset(BlockBackend *blk); 115 void blk_iostatus_set_err(BlockBackend *blk, int error); 116 int blk_attach_dev(BlockBackend *blk, DeviceState *dev); 117 void blk_detach_dev(BlockBackend *blk, DeviceState *dev); 118 DeviceState *blk_get_attached_dev(BlockBackend *blk); 119 char *blk_get_attached_dev_id(BlockBackend *blk); 120 BlockBackend *blk_by_dev(void *dev); 121 BlockBackend *blk_by_qdev_id(const char *id, Error **errp); 122 void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque); 123 int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset, 124 unsigned int bytes, QEMUIOVector *qiov, 125 BdrvRequestFlags flags); 126 int 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); 130 int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset, 131 unsigned int bytes, QEMUIOVector *qiov, 132 BdrvRequestFlags flags); 133 134 static 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 } 142 143 static 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 } 151 152 int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset, 153 int bytes, BdrvRequestFlags flags); 154 BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset, 155 int bytes, BdrvRequestFlags flags, 156 BlockCompletionFunc *cb, void *opaque); 157 int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags); 158 int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int bytes); 159 int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes, 160 BdrvRequestFlags flags); 161 int64_t blk_getlength(BlockBackend *blk); 162 void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr); 163 int64_t blk_nb_sectors(BlockBackend *blk); 164 BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset, 165 QEMUIOVector *qiov, BdrvRequestFlags flags, 166 BlockCompletionFunc *cb, void *opaque); 167 BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset, 168 QEMUIOVector *qiov, BdrvRequestFlags flags, 169 BlockCompletionFunc *cb, void *opaque); 170 BlockAIOCB *blk_aio_flush(BlockBackend *blk, 171 BlockCompletionFunc *cb, void *opaque); 172 BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int bytes, 173 BlockCompletionFunc *cb, void *opaque); 174 void blk_aio_cancel(BlockAIOCB *acb); 175 void blk_aio_cancel_async(BlockAIOCB *acb); 176 int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf); 177 BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf, 178 BlockCompletionFunc *cb, void *opaque); 179 int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int bytes); 180 int blk_co_flush(BlockBackend *blk); 181 int blk_flush(BlockBackend *blk); 182 int blk_commit_all(void); 183 void blk_inc_in_flight(BlockBackend *blk); 184 void blk_dec_in_flight(BlockBackend *blk); 185 void blk_drain(BlockBackend *blk); 186 void blk_drain_all(void); 187 void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error, 188 BlockdevOnError on_write_error); 189 BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read); 190 BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read, 191 int error); 192 void blk_error_action(BlockBackend *blk, BlockErrorAction action, 193 bool is_read, int error); 194 bool blk_supports_write_perm(BlockBackend *blk); 195 bool blk_is_writable(BlockBackend *blk); 196 bool blk_is_sg(BlockBackend *blk); 197 bool blk_enable_write_cache(BlockBackend *blk); 198 void blk_set_enable_write_cache(BlockBackend *blk, bool wce); 199 void blk_invalidate_cache(BlockBackend *blk, Error **errp); 200 bool blk_is_inserted(BlockBackend *blk); 201 bool blk_is_available(BlockBackend *blk); 202 void blk_lock_medium(BlockBackend *blk, bool locked); 203 void blk_eject(BlockBackend *blk, bool eject_flag); 204 int blk_get_flags(BlockBackend *blk); 205 uint32_t blk_get_request_alignment(BlockBackend *blk); 206 uint32_t blk_get_max_transfer(BlockBackend *blk); 207 int blk_get_max_iov(BlockBackend *blk); 208 void blk_set_guest_block_size(BlockBackend *blk, int align); 209 void *blk_try_blockalign(BlockBackend *blk, size_t size); 210 void *blk_blockalign(BlockBackend *blk, size_t size); 211 bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp); 212 void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason); 213 void blk_op_block_all(BlockBackend *blk, Error *reason); 214 void blk_op_unblock_all(BlockBackend *blk, Error *reason); 215 AioContext *blk_get_aio_context(BlockBackend *blk); 216 int blk_set_aio_context(BlockBackend *blk, AioContext *new_context, 217 Error **errp); 218 void 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); 221 void blk_remove_aio_context_notifier(BlockBackend *blk, 222 void (*attached_aio_context)(AioContext *, 223 void *), 224 void (*detach_aio_context)(void *), 225 void *opaque); 226 void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify); 227 void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify); 228 void blk_io_plug(BlockBackend *blk); 229 void blk_io_unplug(BlockBackend *blk); 230 BlockAcctStats *blk_get_stats(BlockBackend *blk); 231 BlockBackendRootState *blk_get_root_state(BlockBackend *blk); 232 void blk_update_root_state(BlockBackend *blk); 233 bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk); 234 int blk_get_open_flags_from_root_state(BlockBackend *blk); 235 236 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk, 237 BlockCompletionFunc *cb, void *opaque); 238 int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset, 239 int bytes, BdrvRequestFlags flags); 240 int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf, 241 int bytes); 242 int blk_truncate(BlockBackend *blk, int64_t offset, bool exact, 243 PreallocMode prealloc, BdrvRequestFlags flags, Error **errp); 244 int blk_pdiscard(BlockBackend *blk, int64_t offset, int bytes); 245 int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf, 246 int64_t pos, int size); 247 int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size); 248 int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz); 249 int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo); 250 BlockAIOCB *blk_abort_aio_request(BlockBackend *blk, 251 BlockCompletionFunc *cb, 252 void *opaque, int ret); 253 254 void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg); 255 void blk_io_limits_disable(BlockBackend *blk); 256 void blk_io_limits_enable(BlockBackend *blk, const char *group); 257 void blk_io_limits_update_group(BlockBackend *blk, const char *group); 258 void blk_set_force_allow_inactivate(BlockBackend *blk); 259 260 void blk_register_buf(BlockBackend *blk, void *host, size_t size); 261 void blk_unregister_buf(BlockBackend *blk, void *host); 262 263 int 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); 267 268 const BdrvChild *blk_root(BlockBackend *blk); 269 270 int blk_make_empty(BlockBackend *blk, Error **errp); 271 272 #endif 273