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 #define UBLK_U_IO_REGISTER_IO_BUF \ 98 _IOWR('u', 0x23, struct ublksrv_io_cmd) 99 #define UBLK_U_IO_UNREGISTER_IO_BUF \ 100 _IOWR('u', 0x24, struct ublksrv_io_cmd) 101 102 /* only ABORT means that no re-fetch */ 103 #define UBLK_IO_RES_OK 0 104 #define UBLK_IO_RES_NEED_GET_DATA 1 105 #define UBLK_IO_RES_ABORT (-ENODEV) 106 107 #define UBLKSRV_CMD_BUF_OFFSET 0 108 #define UBLKSRV_IO_BUF_OFFSET 0x80000000 109 110 /* tag bit is 16bit, so far limit at most 4096 IOs for each queue */ 111 #define UBLK_MAX_QUEUE_DEPTH 4096 112 113 /* single IO buffer max size is 32MB */ 114 #define UBLK_IO_BUF_OFF 0 115 #define UBLK_IO_BUF_BITS 25 116 #define UBLK_IO_BUF_BITS_MASK ((1ULL << UBLK_IO_BUF_BITS) - 1) 117 118 /* so at most 64K IOs for each queue */ 119 #define UBLK_TAG_OFF UBLK_IO_BUF_BITS 120 #define UBLK_TAG_BITS 16 121 #define UBLK_TAG_BITS_MASK ((1ULL << UBLK_TAG_BITS) - 1) 122 123 /* max 4096 queues */ 124 #define UBLK_QID_OFF (UBLK_TAG_OFF + UBLK_TAG_BITS) 125 #define UBLK_QID_BITS 12 126 #define UBLK_QID_BITS_MASK ((1ULL << UBLK_QID_BITS) - 1) 127 128 #define UBLK_MAX_NR_QUEUES (1U << UBLK_QID_BITS) 129 130 #define UBLKSRV_IO_BUF_TOTAL_BITS (UBLK_QID_OFF + UBLK_QID_BITS) 131 #define UBLKSRV_IO_BUF_TOTAL_SIZE (1ULL << UBLKSRV_IO_BUF_TOTAL_BITS) 132 133 /* 134 * zero copy requires 4k block size, and can remap ublk driver's io 135 * request into ublksrv's vm space 136 */ 137 #define UBLK_F_SUPPORT_ZERO_COPY (1ULL << 0) 138 139 /* 140 * Force to complete io cmd via io_uring_cmd_complete_in_task so that 141 * performance comparison is done easily with using task_work_add 142 */ 143 #define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1) 144 145 /* 146 * User should issue io cmd again for write requests to 147 * set io buffer address and copy data from bio vectors 148 * to the userspace io buffer. 149 * 150 * In this mode, task_work is not used. 151 */ 152 #define UBLK_F_NEED_GET_DATA (1UL << 2) 153 154 /* 155 * - Block devices are recoverable if ublk server exits and restarts 156 * - Outstanding I/O when ublk server exits is met with errors 157 * - I/O issued while there is no ublk server queues 158 */ 159 #define UBLK_F_USER_RECOVERY (1UL << 3) 160 161 /* 162 * - Block devices are recoverable if ublk server exits and restarts 163 * - Outstanding I/O when ublk server exits is reissued 164 * - I/O issued while there is no ublk server queues 165 */ 166 #define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4) 167 168 /* 169 * Unprivileged user can create /dev/ublkcN and /dev/ublkbN. 170 * 171 * /dev/ublk-control needs to be available for unprivileged user, and it 172 * can be done via udev rule to make all control commands available to 173 * unprivileged user. Except for the command of UBLK_CMD_ADD_DEV, all 174 * other commands are only allowed for the owner of the specified device. 175 * 176 * When userspace sends UBLK_CMD_ADD_DEV, the device pair's owner_uid and 177 * owner_gid are stored to ublksrv_ctrl_dev_info by kernel, so far only 178 * the current user's uid/gid is stored, that said owner of the created 179 * device is always the current user. 180 * 181 * We still need udev rule to apply OWNER/GROUP with the stored owner_uid 182 * and owner_gid. 183 * 184 * Then ublk server can be run as unprivileged user, and /dev/ublkbN can 185 * be accessed and managed by its owner represented by owner_uid/owner_gid. 186 */ 187 #define UBLK_F_UNPRIVILEGED_DEV (1UL << 5) 188 189 /* use ioctl encoding for uring command */ 190 #define UBLK_F_CMD_IOCTL_ENCODE (1UL << 6) 191 192 /* 193 * Copy between request and user buffer by pread()/pwrite() 194 * 195 * Not available for UBLK_F_UNPRIVILEGED_DEV, otherwise userspace may 196 * deceive us by not filling request buffer, then kernel uninitialized 197 * data may be leaked. 198 */ 199 #define UBLK_F_USER_COPY (1UL << 7) 200 201 /* 202 * User space sets this flag when setting up the device to request zoned storage support. Kernel may 203 * deny the request by returning an error. 204 */ 205 #define UBLK_F_ZONED (1ULL << 8) 206 207 /* 208 * - Block devices are recoverable if ublk server exits and restarts 209 * - Outstanding I/O when ublk server exits is met with errors 210 * - I/O issued while there is no ublk server is met with errors 211 */ 212 #define UBLK_F_USER_RECOVERY_FAIL_IO (1ULL << 9) 213 214 /* device state */ 215 #define UBLK_S_DEV_DEAD 0 216 #define UBLK_S_DEV_LIVE 1 217 #define UBLK_S_DEV_QUIESCED 2 218 #define UBLK_S_DEV_FAIL_IO 3 219 220 /* shipped via sqe->cmd of io_uring command */ 221 struct ublksrv_ctrl_cmd { 222 /* sent to which device, must be valid */ 223 __u32 dev_id; 224 225 /* sent to which queue, must be -1 if the cmd isn't for queue */ 226 __u16 queue_id; 227 /* 228 * cmd specific buffer, can be IN or OUT. 229 */ 230 __u16 len; 231 __u64 addr; 232 233 /* inline data */ 234 __u64 data[1]; 235 236 /* 237 * Used for UBLK_F_UNPRIVILEGED_DEV and UBLK_CMD_GET_DEV_INFO2 238 * only, include null char 239 */ 240 __u16 dev_path_len; 241 __u16 pad; 242 __u32 reserved; 243 }; 244 245 struct ublksrv_ctrl_dev_info { 246 __u16 nr_hw_queues; 247 __u16 queue_depth; 248 __u16 state; 249 __u16 pad0; 250 251 __u32 max_io_buf_bytes; 252 __u32 dev_id; 253 254 __s32 ublksrv_pid; 255 __u32 pad1; 256 257 __u64 flags; 258 259 /* For ublksrv internal use, invisible to ublk driver */ 260 __u64 ublksrv_flags; 261 262 __u32 owner_uid; /* store by kernel */ 263 __u32 owner_gid; /* store by kernel */ 264 __u64 reserved1; 265 __u64 reserved2; 266 }; 267 268 #define UBLK_IO_OP_READ 0 269 #define UBLK_IO_OP_WRITE 1 270 #define UBLK_IO_OP_FLUSH 2 271 #define UBLK_IO_OP_DISCARD 3 272 #define UBLK_IO_OP_WRITE_SAME 4 273 #define UBLK_IO_OP_WRITE_ZEROES 5 274 #define UBLK_IO_OP_ZONE_OPEN 10 275 #define UBLK_IO_OP_ZONE_CLOSE 11 276 #define UBLK_IO_OP_ZONE_FINISH 12 277 #define UBLK_IO_OP_ZONE_APPEND 13 278 #define UBLK_IO_OP_ZONE_RESET_ALL 14 279 #define UBLK_IO_OP_ZONE_RESET 15 280 /* 281 * Construct a zone report. The report request is carried in `struct 282 * ublksrv_io_desc`. The `start_sector` field must be the first sector of a zone 283 * and shall indicate the first zone of the report. The `nr_zones` shall 284 * indicate how many zones should be reported at most. The report shall be 285 * delivered as a `struct blk_zone` array. To report fewer zones than requested, 286 * zero the last entry of the returned array. 287 * 288 * Related definitions(blk_zone, blk_zone_cond, blk_zone_type, ...) in 289 * include/uapi/linux/blkzoned.h are part of ublk UAPI. 290 */ 291 #define UBLK_IO_OP_REPORT_ZONES 18 292 293 #define UBLK_IO_F_FAILFAST_DEV (1U << 8) 294 #define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9) 295 #define UBLK_IO_F_FAILFAST_DRIVER (1U << 10) 296 #define UBLK_IO_F_META (1U << 11) 297 #define UBLK_IO_F_FUA (1U << 13) 298 #define UBLK_IO_F_NOUNMAP (1U << 15) 299 #define UBLK_IO_F_SWAP (1U << 16) 300 301 /* 302 * io cmd is described by this structure, and stored in share memory, indexed 303 * by request tag. 304 * 305 * The data is stored by ublk driver, and read by ublksrv after one fetch command 306 * returns. 307 */ 308 struct ublksrv_io_desc { 309 /* op: bit 0-7, flags: bit 8-31 */ 310 __u32 op_flags; 311 312 union { 313 __u32 nr_sectors; 314 __u32 nr_zones; /* for UBLK_IO_OP_REPORT_ZONES */ 315 }; 316 317 /* start sector for this io */ 318 __u64 start_sector; 319 320 /* buffer address in ublksrv daemon vm space, from ublk driver */ 321 __u64 addr; 322 }; 323 324 static inline __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod) 325 { 326 return iod->op_flags & 0xff; 327 } 328 329 static inline __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod) 330 { 331 return iod->op_flags >> 8; 332 } 333 334 /* issued to ublk driver via /dev/ublkcN */ 335 struct ublksrv_io_cmd { 336 __u16 q_id; 337 338 /* for fetch/commit which result */ 339 __u16 tag; 340 341 /* io result, it is valid for COMMIT* command only */ 342 __s32 result; 343 344 union { 345 /* 346 * userspace buffer address in ublksrv daemon process, valid for 347 * FETCH* command only 348 * 349 * `addr` should not be used when UBLK_F_USER_COPY is enabled, 350 * because userspace handles data copy by pread()/pwrite() over 351 * /dev/ublkcN. But in case of UBLK_F_ZONED, this union is 352 * re-used to pass back the allocated LBA for 353 * UBLK_IO_OP_ZONE_APPEND which actually depends on 354 * UBLK_F_USER_COPY 355 */ 356 __u64 addr; 357 __u64 zone_append_lba; 358 }; 359 }; 360 361 struct ublk_param_basic { 362 #define UBLK_ATTR_READ_ONLY (1 << 0) 363 #define UBLK_ATTR_ROTATIONAL (1 << 1) 364 #define UBLK_ATTR_VOLATILE_CACHE (1 << 2) 365 #define UBLK_ATTR_FUA (1 << 3) 366 __u32 attrs; 367 __u8 logical_bs_shift; 368 __u8 physical_bs_shift; 369 __u8 io_opt_shift; 370 __u8 io_min_shift; 371 372 __u32 max_sectors; 373 __u32 chunk_sectors; 374 375 __u64 dev_sectors; 376 __u64 virt_boundary_mask; 377 }; 378 379 struct ublk_param_discard { 380 __u32 discard_alignment; 381 382 __u32 discard_granularity; 383 __u32 max_discard_sectors; 384 385 __u32 max_write_zeroes_sectors; 386 __u16 max_discard_segments; 387 __u16 reserved0; 388 }; 389 390 /* 391 * read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available 392 * after device is started 393 */ 394 struct ublk_param_devt { 395 __u32 char_major; 396 __u32 char_minor; 397 __u32 disk_major; 398 __u32 disk_minor; 399 }; 400 401 struct ublk_param_zoned { 402 __u32 max_open_zones; 403 __u32 max_active_zones; 404 __u32 max_zone_append_sectors; 405 __u8 reserved[20]; 406 }; 407 408 struct ublk_param_dma_align { 409 __u32 alignment; 410 __u8 pad[4]; 411 }; 412 413 #define UBLK_MIN_SEGMENT_SIZE 4096 414 /* 415 * If any one of the three segment parameter is set as 0, the behavior is 416 * undefined. 417 */ 418 struct ublk_param_segment { 419 /* 420 * seg_boundary_mask + 1 needs to be power_of_2(), and the sum has 421 * to be >= UBLK_MIN_SEGMENT_SIZE(4096) 422 */ 423 __u64 seg_boundary_mask; 424 425 /* 426 * max_segment_size could be override by virt_boundary_mask, so be 427 * careful when setting both. 428 * 429 * max_segment_size has to be >= UBLK_MIN_SEGMENT_SIZE(4096) 430 */ 431 __u32 max_segment_size; 432 __u16 max_segments; 433 __u8 pad[2]; 434 }; 435 436 struct ublk_params { 437 /* 438 * Total length of parameters, userspace has to set 'len' for both 439 * SET_PARAMS and GET_PARAMS command, and driver may update len 440 * if two sides use different version of 'ublk_params', same with 441 * 'types' fields. 442 */ 443 __u32 len; 444 #define UBLK_PARAM_TYPE_BASIC (1 << 0) 445 #define UBLK_PARAM_TYPE_DISCARD (1 << 1) 446 #define UBLK_PARAM_TYPE_DEVT (1 << 2) 447 #define UBLK_PARAM_TYPE_ZONED (1 << 3) 448 #define UBLK_PARAM_TYPE_DMA_ALIGN (1 << 4) 449 #define UBLK_PARAM_TYPE_SEGMENT (1 << 5) 450 __u32 types; /* types of parameter included */ 451 452 struct ublk_param_basic basic; 453 struct ublk_param_discard discard; 454 struct ublk_param_devt devt; 455 struct ublk_param_zoned zoned; 456 struct ublk_param_dma_align dma; 457 struct ublk_param_segment seg; 458 }; 459 460 #endif 461