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