ublk_cmd.h (12706B) - Raw
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 #ifndef USER_BLK_DRV_CMD_INC_H 3 #define USER_BLK_DRV_CMD_INC_H 4 5 #include <linux/types.h> 6 7 /* ublk server command definition */ 8 9 /* 10 * Admin commands, issued by ublk server, and handled by ublk driver. 11 * 12 * Legacy command definition, don't use in new application, and don't 13 * add new such definition any more 14 */ 15 #define UBLK_CMD_GET_QUEUE_AFFINITY 0x01 16 #define UBLK_CMD_GET_DEV_INFO 0x02 17 #define UBLK_CMD_ADD_DEV 0x04 18 #define UBLK_CMD_DEL_DEV 0x05 19 #define UBLK_CMD_START_DEV 0x06 20 #define UBLK_CMD_STOP_DEV 0x07 21 #define UBLK_CMD_SET_PARAMS 0x08 22 #define UBLK_CMD_GET_PARAMS 0x09 23 #define UBLK_CMD_START_USER_RECOVERY 0x10 24 #define UBLK_CMD_END_USER_RECOVERY 0x11 25 #define UBLK_CMD_GET_DEV_INFO2 0x12 26 27 /* Any new ctrl command should encode by __IO*() */ 28 #define UBLK_U_CMD_GET_QUEUE_AFFINITY \ 29 _IOR('u', UBLK_CMD_GET_QUEUE_AFFINITY, struct ublksrv_ctrl_cmd) 30 #define UBLK_U_CMD_GET_DEV_INFO \ 31 _IOR('u', UBLK_CMD_GET_DEV_INFO, struct ublksrv_ctrl_cmd) 32 #define UBLK_U_CMD_ADD_DEV \ 33 _IOWR('u', UBLK_CMD_ADD_DEV, struct ublksrv_ctrl_cmd) 34 #define UBLK_U_CMD_DEL_DEV \ 35 _IOWR('u', UBLK_CMD_DEL_DEV, struct ublksrv_ctrl_cmd) 36 #define UBLK_U_CMD_START_DEV \ 37 _IOWR('u', UBLK_CMD_START_DEV, struct ublksrv_ctrl_cmd) 38 #define UBLK_U_CMD_STOP_DEV \ 39 _IOWR('u', UBLK_CMD_STOP_DEV, struct ublksrv_ctrl_cmd) 40 #define UBLK_U_CMD_SET_PARAMS \ 41 _IOWR('u', UBLK_CMD_SET_PARAMS, struct ublksrv_ctrl_cmd) 42 #define UBLK_U_CMD_GET_PARAMS \ 43 _IOR('u', UBLK_CMD_GET_PARAMS, struct ublksrv_ctrl_cmd) 44 #define UBLK_U_CMD_START_USER_RECOVERY \ 45 _IOWR('u', UBLK_CMD_START_USER_RECOVERY, struct ublksrv_ctrl_cmd) 46 #define UBLK_U_CMD_END_USER_RECOVERY \ 47 _IOWR('u', UBLK_CMD_END_USER_RECOVERY, struct ublksrv_ctrl_cmd) 48 #define UBLK_U_CMD_GET_DEV_INFO2 \ 49 _IOR('u', UBLK_CMD_GET_DEV_INFO2, struct ublksrv_ctrl_cmd) 50 #define UBLK_U_CMD_GET_FEATURES \ 51 _IOR('u', 0x13, struct ublksrv_ctrl_cmd) 52 #define UBLK_U_CMD_DEL_DEV_ASYNC \ 53 _IOR('u', 0x14, struct ublksrv_ctrl_cmd) 54 55 /* 56 * 64bits are enough now, and it should be easy to extend in case of 57 * running out of feature flags 58 */ 59 #define UBLK_FEATURES_LEN 8 60 61 /* 62 * IO commands, issued by ublk server, and handled by ublk driver. 63 * 64 * FETCH_REQ: issued via sqe(URING_CMD) beforehand for fetching IO request 65 * from ublk driver, should be issued only when starting device. After 66 * the associated cqe is returned, request's tag can be retrieved via 67 * cqe->userdata. 68 * 69 * COMMIT_AND_FETCH_REQ: issued via sqe(URING_CMD) after ublkserver handled 70 * this IO request, request's handling result is committed to ublk 71 * driver, meantime FETCH_REQ is piggyback, and FETCH_REQ has to be 72 * handled before completing io request. 73 * 74 * NEED_GET_DATA: only used for write requests to set io addr and copy data 75 * When NEED_GET_DATA is set, ublksrv has to issue UBLK_IO_NEED_GET_DATA 76 * command after ublk driver returns UBLK_IO_RES_NEED_GET_DATA. 77 * 78 * It is only used if ublksrv set UBLK_F_NEED_GET_DATA flag 79 * while starting a ublk device. 80 */ 81 82 /* 83 * Legacy IO command definition, don't use in new application, and don't 84 * add new such definition any more 85 */ 86 #define UBLK_IO_FETCH_REQ 0x20 87 #define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21 88 #define UBLK_IO_NEED_GET_DATA 0x22 89 90 /* Any new IO command should encode by __IOWR() */ 91 #define UBLK_U_IO_FETCH_REQ \ 92 _IOWR('u', UBLK_IO_FETCH_REQ, struct ublksrv_io_cmd) 93 #define UBLK_U_IO_COMMIT_AND_FETCH_REQ \ 94 _IOWR('u', UBLK_IO_COMMIT_AND_FETCH_REQ, struct ublksrv_io_cmd) 95 #define UBLK_U_IO_NEED_GET_DATA \ 96 _IOWR('u', UBLK_IO_NEED_GET_DATA, struct ublksrv_io_cmd) 97 98 /* only ABORT means that no re-fetch */ 99 #define UBLK_IO_RES_OK 0 100 #define UBLK_IO_RES_NEED_GET_DATA 1 101 #define UBLK_IO_RES_ABORT (-ENODEV) 102 103 #define UBLKSRV_CMD_BUF_OFFSET 0 104 #define UBLKSRV_IO_BUF_OFFSET 0x80000000 105 106 /* tag bit is 16bit, so far limit at most 4096 IOs for each queue */ 107 #define UBLK_MAX_QUEUE_DEPTH 4096 108 109 /* single IO buffer max size is 32MB */ 110 #define UBLK_IO_BUF_OFF 0 111 #define UBLK_IO_BUF_BITS 25 112 #define UBLK_IO_BUF_BITS_MASK ((1ULL << UBLK_IO_BUF_BITS) - 1) 113 114 /* so at most 64K IOs for each queue */ 115 #define UBLK_TAG_OFF UBLK_IO_BUF_BITS 116 #define UBLK_TAG_BITS 16 117 #define UBLK_TAG_BITS_MASK ((1ULL << UBLK_TAG_BITS) - 1) 118 119 /* max 4096 queues */ 120 #define UBLK_QID_OFF (UBLK_TAG_OFF + UBLK_TAG_BITS) 121 #define UBLK_QID_BITS 12 122 #define UBLK_QID_BITS_MASK ((1ULL << UBLK_QID_BITS) - 1) 123 124 #define UBLK_MAX_NR_QUEUES (1U << UBLK_QID_BITS) 125 126 #define UBLKSRV_IO_BUF_TOTAL_BITS (UBLK_QID_OFF + UBLK_QID_BITS) 127 #define UBLKSRV_IO_BUF_TOTAL_SIZE (1ULL << UBLKSRV_IO_BUF_TOTAL_BITS) 128 129 /* 130 * zero copy requires 4k block size, and can remap ublk driver's io 131 * request into ublksrv's vm space 132 */ 133 #define UBLK_F_SUPPORT_ZERO_COPY (1ULL << 0) 134 135 /* 136 * Force to complete io cmd via io_uring_cmd_complete_in_task so that 137 * performance comparison is done easily with using task_work_add 138 */ 139 #define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1) 140 141 /* 142 * User should issue io cmd again for write requests to 143 * set io buffer address and copy data from bio vectors 144 * to the userspace io buffer. 145 * 146 * In this mode, task_work is not used. 147 */ 148 #define UBLK_F_NEED_GET_DATA (1UL << 2) 149 150 /* 151 * - Block devices are recoverable if ublk server exits and restarts 152 * - Outstanding I/O when ublk server exits is met with errors 153 * - I/O issued while there is no ublk server queues 154 */ 155 #define UBLK_F_USER_RECOVERY (1UL << 3) 156 157 /* 158 * - Block devices are recoverable if ublk server exits and restarts 159 * - Outstanding I/O when ublk server exits is reissued 160 * - I/O issued while there is no ublk server queues 161 */ 162 #define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4) 163 164 /* 165 * Unprivileged user can create /dev/ublkcN and /dev/ublkbN. 166 * 167 * /dev/ublk-control needs to be available for unprivileged user, and it 168 * can be done via udev rule to make all control commands available to 169 * unprivileged user. Except for the command of UBLK_CMD_ADD_DEV, all 170 * other commands are only allowed for the owner of the specified device. 171 * 172 * When userspace sends UBLK_CMD_ADD_DEV, the device pair's owner_uid and 173 * owner_gid are stored to ublksrv_ctrl_dev_info by kernel, so far only 174 * the current user's uid/gid is stored, that said owner of the created 175 * device is always the current user. 176 * 177 * We still need udev rule to apply OWNER/GROUP with the stored owner_uid 178 * and owner_gid. 179 * 180 * Then ublk server can be run as unprivileged user, and /dev/ublkbN can 181 * be accessed and managed by its owner represented by owner_uid/owner_gid. 182 */ 183 #define UBLK_F_UNPRIVILEGED_DEV (1UL << 5) 184 185 /* use ioctl encoding for uring command */ 186 #define UBLK_F_CMD_IOCTL_ENCODE (1UL << 6) 187 188 /* 189 * Copy between request and user buffer by pread()/pwrite() 190 * 191 * Not available for UBLK_F_UNPRIVILEGED_DEV, otherwise userspace may 192 * deceive us by not filling request buffer, then kernel uninitialized 193 * data may be leaked. 194 */ 195 #define UBLK_F_USER_COPY (1UL << 7) 196 197 /* 198 * User space sets this flag when setting up the device to request zoned storage support. Kernel may 199 * deny the request by returning an error. 200 */ 201 #define UBLK_F_ZONED (1ULL << 8) 202 203 /* 204 * - Block devices are recoverable if ublk server exits and restarts 205 * - Outstanding I/O when ublk server exits is met with errors 206 * - I/O issued while there is no ublk server is met with errors 207 */ 208 #define UBLK_F_USER_RECOVERY_FAIL_IO (1ULL << 9) 209 210 /* device state */ 211 #define UBLK_S_DEV_DEAD 0 212 #define UBLK_S_DEV_LIVE 1 213 #define UBLK_S_DEV_QUIESCED 2 214 #define UBLK_S_DEV_FAIL_IO 3 215 216 /* shipped via sqe->cmd of io_uring command */ 217 struct ublksrv_ctrl_cmd { 218 /* sent to which device, must be valid */ 219 __u32 dev_id; 220 221 /* sent to which queue, must be -1 if the cmd isn't for queue */ 222 __u16 queue_id; 223 /* 224 * cmd specific buffer, can be IN or OUT. 225 */ 226 __u16 len; 227 __u64 addr; 228 229 /* __inline__ data */ 230 __u64 data[1]; 231 232 /* 233 * Used for UBLK_F_UNPRIVILEGED_DEV and UBLK_CMD_GET_DEV_INFO2 234 * only, include null char 235 */ 236 __u16 dev_path_len; 237 __u16 pad; 238 __u32 reserved; 239 }; 240 241 struct ublksrv_ctrl_dev_info { 242 __u16 nr_hw_queues; 243 __u16 queue_depth; 244 __u16 state; 245 __u16 pad0; 246 247 __u32 max_io_buf_bytes; 248 __u32 dev_id; 249 250 __s32 ublksrv_pid; 251 __u32 pad1; 252 253 __u64 flags; 254 255 /* For ublksrv internal use, invisible to ublk driver */ 256 __u64 ublksrv_flags; 257 258 __u32 owner_uid; /* store by kernel */ 259 __u32 owner_gid; /* store by kernel */ 260 __u64 reserved1; 261 __u64 reserved2; 262 }; 263 264 #define UBLK_IO_OP_READ 0 265 #define UBLK_IO_OP_WRITE 1 266 #define UBLK_IO_OP_FLUSH 2 267 #define UBLK_IO_OP_DISCARD 3 268 #define UBLK_IO_OP_WRITE_SAME 4 269 #define UBLK_IO_OP_WRITE_ZEROES 5 270 #define UBLK_IO_OP_ZONE_OPEN 10 271 #define UBLK_IO_OP_ZONE_CLOSE 11 272 #define UBLK_IO_OP_ZONE_FINISH 12 273 #define UBLK_IO_OP_ZONE_APPEND 13 274 #define UBLK_IO_OP_ZONE_RESET_ALL 14 275 #define UBLK_IO_OP_ZONE_RESET 15 276 /* 277 * Construct a zone report. The report request is carried in `struct 278 * ublksrv_io_desc`. The `start_sector` field must be the first sector of a zone 279 * and shall indicate the first zone of the report. The `nr_zones` shall 280 * indicate how many zones should be reported at most. The report shall be 281 * delivered as a `struct blk_zone` array. To report fewer zones than requested, 282 * zero the last entry of the returned array. 283 * 284 * Related definitions(blk_zone, blk_zone_cond, blk_zone_type, ...) in 285 * include/uapi/linux/blkzoned.h are part of ublk UAPI. 286 */ 287 #define UBLK_IO_OP_REPORT_ZONES 18 288 289 #define UBLK_IO_F_FAILFAST_DEV (1U << 8) 290 #define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9) 291 #define UBLK_IO_F_FAILFAST_DRIVER (1U << 10) 292 #define UBLK_IO_F_META (1U << 11) 293 #define UBLK_IO_F_FUA (1U << 13) 294 #define UBLK_IO_F_NOUNMAP (1U << 15) 295 #define UBLK_IO_F_SWAP (1U << 16) 296 297 /* 298 * io cmd is described by this structure, and stored in share memory, indexed 299 * by request tag. 300 * 301 * The data is stored by ublk driver, and read by ublksrv after one fetch command 302 * returns. 303 */ 304 struct ublksrv_io_desc { 305 /* op: bit 0-7, flags: bit 8-31 */ 306 __u32 op_flags; 307 308 union { 309 __u32 nr_sectors; 310 __u32 nr_zones; /* for UBLK_IO_OP_REPORT_ZONES */ 311 }; 312 313 /* start sector for this io */ 314 __u64 start_sector; 315 316 /* buffer address in ublksrv daemon vm space, from ublk driver */ 317 __u64 addr; 318 }; 319 320 static __inline__ __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod) 321 { 322 return iod->op_flags & 0xff; 323 } 324 325 static __inline__ __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod) 326 { 327 return iod->op_flags >> 8; 328 } 329 330 /* issued to ublk driver via /dev/ublkcN */ 331 struct ublksrv_io_cmd { 332 __u16 q_id; 333 334 /* for fetch/commit which result */ 335 __u16 tag; 336 337 /* io result, it is valid for COMMIT* command only */ 338 __s32 result; 339 340 union { 341 /* 342 * userspace buffer address in ublksrv daemon process, valid for 343 * FETCH* command only 344 * 345 * `addr` should not be used when UBLK_F_USER_COPY is enabled, 346 * because userspace handles data copy by pread()/pwrite() over 347 * /dev/ublkcN. But in case of UBLK_F_ZONED, this union is 348 * re-used to pass back the allocated LBA for 349 * UBLK_IO_OP_ZONE_APPEND which actually depends on 350 * UBLK_F_USER_COPY 351 */ 352 __u64 addr; 353 __u64 zone_append_lba; 354 }; 355 }; 356 357 struct ublk_param_basic { 358 #define UBLK_ATTR_READ_ONLY (1 << 0) 359 #define UBLK_ATTR_ROTATIONAL (1 << 1) 360 #define UBLK_ATTR_VOLATILE_CACHE (1 << 2) 361 #define UBLK_ATTR_FUA (1 << 3) 362 __u32 attrs; 363 __u8 logical_bs_shift; 364 __u8 physical_bs_shift; 365 __u8 io_opt_shift; 366 __u8 io_min_shift; 367 368 __u32 max_sectors; 369 __u32 chunk_sectors; 370 371 __u64 dev_sectors; 372 __u64 virt_boundary_mask; 373 }; 374 375 struct ublk_param_discard { 376 __u32 discard_alignment; 377 378 __u32 discard_granularity; 379 __u32 max_discard_sectors; 380 381 __u32 max_write_zeroes_sectors; 382 __u16 max_discard_segments; 383 __u16 reserved0; 384 }; 385 386 /* 387 * read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available 388 * after device is started 389 */ 390 struct ublk_param_devt { 391 __u32 char_major; 392 __u32 char_minor; 393 __u32 disk_major; 394 __u32 disk_minor; 395 }; 396 397 struct ublk_param_zoned { 398 __u32 max_open_zones; 399 __u32 max_active_zones; 400 __u32 max_zone_append_sectors; 401 __u8 reserved[20]; 402 }; 403 404 struct ublk_params { 405 /* 406 * Total length of parameters, userspace has to set 'len' for both 407 * SET_PARAMS and GET_PARAMS command, and driver may update len 408 * if two sides use different version of 'ublk_params', same with 409 * 'types' fields. 410 */ 411 __u32 len; 412 #define UBLK_PARAM_TYPE_BASIC (1 << 0) 413 #define UBLK_PARAM_TYPE_DISCARD (1 << 1) 414 #define UBLK_PARAM_TYPE_DEVT (1 << 2) 415 #define UBLK_PARAM_TYPE_ZONED (1 << 3) 416 __u32 types; /* types of parameter included */ 417 418 struct ublk_param_basic basic; 419 struct ublk_param_discard discard; 420 struct ublk_param_devt devt; 421 struct ublk_param_zoned zoned; 422 }; 423 424 #endif