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 53 /* 54 * 64bits are enough now, and it should be easy to extend in case of 55 * running out of feature flags 56 */ 57 #define UBLK_FEATURES_LEN 8 58 59 /* 60 * IO commands, issued by ublk server, and handled by ublk driver. 61 * 62 * FETCH_REQ: issued via sqe(URING_CMD) beforehand for fetching IO request 63 * from ublk driver, should be issued only when starting device. After 64 * the associated cqe is returned, request's tag can be retrieved via 65 * cqe->userdata. 66 * 67 * COMMIT_AND_FETCH_REQ: issued via sqe(URING_CMD) after ublkserver handled 68 * this IO request, request's handling result is committed to ublk 69 * driver, meantime FETCH_REQ is piggyback, and FETCH_REQ has to be 70 * handled before completing io request. 71 * 72 * NEED_GET_DATA: only used for write requests to set io addr and copy data 73 * When NEED_GET_DATA is set, ublksrv has to issue UBLK_IO_NEED_GET_DATA 74 * command after ublk driver returns UBLK_IO_RES_NEED_GET_DATA. 75 * 76 * It is only used if ublksrv set UBLK_F_NEED_GET_DATA flag 77 * while starting a ublk device. 78 */ 79 80 /* 81 * Legacy IO command definition, don't use in new application, and don't 82 * add new such definition any more 83 */ 84 #define UBLK_IO_FETCH_REQ 0x20 85 #define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21 86 #define UBLK_IO_NEED_GET_DATA 0x22 87 88 /* Any new IO command should encode by __IOWR() */ 89 #define UBLK_U_IO_FETCH_REQ \ 90 _IOWR('u', UBLK_IO_FETCH_REQ, struct ublksrv_io_cmd) 91 #define UBLK_U_IO_COMMIT_AND_FETCH_REQ \ 92 _IOWR('u', UBLK_IO_COMMIT_AND_FETCH_REQ, struct ublksrv_io_cmd) 93 #define UBLK_U_IO_NEED_GET_DATA \ 94 _IOWR('u', UBLK_IO_NEED_GET_DATA, struct ublksrv_io_cmd) 95 96 /* only ABORT means that no re-fetch */ 97 #define UBLK_IO_RES_OK 0 98 #define UBLK_IO_RES_NEED_GET_DATA 1 99 #define UBLK_IO_RES_ABORT (-ENODEV) 100 101 #define UBLKSRV_CMD_BUF_OFFSET 0 102 #define UBLKSRV_IO_BUF_OFFSET 0x80000000 103 104 /* tag bit is 16bit, so far limit at most 4096 IOs for each queue */ 105 #define UBLK_MAX_QUEUE_DEPTH 4096 106 107 /* single IO buffer max size is 32MB */ 108 #define UBLK_IO_BUF_OFF 0 109 #define UBLK_IO_BUF_BITS 25 110 #define UBLK_IO_BUF_BITS_MASK ((1ULL << UBLK_IO_BUF_BITS) - 1) 111 112 /* so at most 64K IOs for each queue */ 113 #define UBLK_TAG_OFF UBLK_IO_BUF_BITS 114 #define UBLK_TAG_BITS 16 115 #define UBLK_TAG_BITS_MASK ((1ULL << UBLK_TAG_BITS) - 1) 116 117 /* max 4096 queues */ 118 #define UBLK_QID_OFF (UBLK_TAG_OFF + UBLK_TAG_BITS) 119 #define UBLK_QID_BITS 12 120 #define UBLK_QID_BITS_MASK ((1ULL << UBLK_QID_BITS) - 1) 121 122 #define UBLK_MAX_NR_QUEUES (1U << UBLK_QID_BITS) 123 124 #define UBLKSRV_IO_BUF_TOTAL_BITS (UBLK_QID_OFF + UBLK_QID_BITS) 125 #define UBLKSRV_IO_BUF_TOTAL_SIZE (1ULL << UBLKSRV_IO_BUF_TOTAL_BITS) 126 127 /* 128 * zero copy requires 4k block size, and can remap ublk driver's io 129 * request into ublksrv's vm space 130 */ 131 #define UBLK_F_SUPPORT_ZERO_COPY (1ULL << 0) 132 133 /* 134 * Force to complete io cmd via io_uring_cmd_complete_in_task so that 135 * performance comparison is done easily with using task_work_add 136 */ 137 #define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1) 138 139 /* 140 * User should issue io cmd again for write requests to 141 * set io buffer address and copy data from bio vectors 142 * to the userspace io buffer. 143 * 144 * In this mode, task_work is not used. 145 */ 146 #define UBLK_F_NEED_GET_DATA (1UL << 2) 147 148 #define UBLK_F_USER_RECOVERY (1UL << 3) 149 150 #define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4) 151 152 /* 153 * Unprivileged user can create /dev/ublkcN and /dev/ublkbN. 154 * 155 * /dev/ublk-control needs to be available for unprivileged user, and it 156 * can be done via udev rule to make all control commands available to 157 * unprivileged user. Except for the command of UBLK_CMD_ADD_DEV, all 158 * other commands are only allowed for the owner of the specified device. 159 * 160 * When userspace sends UBLK_CMD_ADD_DEV, the device pair's owner_uid and 161 * owner_gid are stored to ublksrv_ctrl_dev_info by kernel, so far only 162 * the current user's uid/gid is stored, that said owner of the created 163 * device is always the current user. 164 * 165 * We still need udev rule to apply OWNER/GROUP with the stored owner_uid 166 * and owner_gid. 167 * 168 * Then ublk server can be run as unprivileged user, and /dev/ublkbN can 169 * be accessed and managed by its owner represented by owner_uid/owner_gid. 170 */ 171 #define UBLK_F_UNPRIVILEGED_DEV (1UL << 5) 172 173 /* use ioctl encoding for uring command */ 174 #define UBLK_F_CMD_IOCTL_ENCODE (1UL << 6) 175 176 /* Copy between request and user buffer by pread()/pwrite() */ 177 #define UBLK_F_USER_COPY (1UL << 7) 178 179 /* device state */ 180 #define UBLK_S_DEV_DEAD 0 181 #define UBLK_S_DEV_LIVE 1 182 #define UBLK_S_DEV_QUIESCED 2 183 184 /* shipped via sqe->cmd of io_uring command */ 185 struct ublksrv_ctrl_cmd { 186 /* sent to which device, must be valid */ 187 __u32 dev_id; 188 189 /* sent to which queue, must be -1 if the cmd isn't for queue */ 190 __u16 queue_id; 191 /* 192 * cmd specific buffer, can be IN or OUT. 193 */ 194 __u16 len; 195 __u64 addr; 196 197 /* inline data */ 198 __u64 data[1]; 199 200 /* 201 * Used for UBLK_F_UNPRIVILEGED_DEV and UBLK_CMD_GET_DEV_INFO2 202 * only, include null char 203 */ 204 __u16 dev_path_len; 205 __u16 pad; 206 __u32 reserved; 207 }; 208 209 struct ublksrv_ctrl_dev_info { 210 __u16 nr_hw_queues; 211 __u16 queue_depth; 212 __u16 state; 213 __u16 pad0; 214 215 __u32 max_io_buf_bytes; 216 __u32 dev_id; 217 218 __s32 ublksrv_pid; 219 __u32 pad1; 220 221 __u64 flags; 222 223 /* For ublksrv internal use, invisible to ublk driver */ 224 __u64 ublksrv_flags; 225 226 __u32 owner_uid; /* store by kernel */ 227 __u32 owner_gid; /* store by kernel */ 228 __u64 reserved1; 229 __u64 reserved2; 230 }; 231 232 #define UBLK_IO_OP_READ 0 233 #define UBLK_IO_OP_WRITE 1 234 #define UBLK_IO_OP_FLUSH 2 235 #define UBLK_IO_OP_DISCARD 3 236 #define UBLK_IO_OP_WRITE_SAME 4 237 #define UBLK_IO_OP_WRITE_ZEROES 5 238 239 #define UBLK_IO_F_FAILFAST_DEV (1U << 8) 240 #define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9) 241 #define UBLK_IO_F_FAILFAST_DRIVER (1U << 10) 242 #define UBLK_IO_F_META (1U << 11) 243 #define UBLK_IO_F_FUA (1U << 13) 244 #define UBLK_IO_F_NOUNMAP (1U << 15) 245 #define UBLK_IO_F_SWAP (1U << 16) 246 247 /* 248 * io cmd is described by this structure, and stored in share memory, indexed 249 * by request tag. 250 * 251 * The data is stored by ublk driver, and read by ublksrv after one fetch command 252 * returns. 253 */ 254 struct ublksrv_io_desc { 255 /* op: bit 0-7, flags: bit 8-31 */ 256 __u32 op_flags; 257 258 __u32 nr_sectors; 259 260 /* start sector for this io */ 261 __u64 start_sector; 262 263 /* buffer address in ublksrv daemon vm space, from ublk driver */ 264 __u64 addr; 265 }; 266 267 static inline __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod) 268 { 269 return iod->op_flags & 0xff; 270 } 271 272 static inline __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod) 273 { 274 return iod->op_flags >> 8; 275 } 276 277 /* issued to ublk driver via /dev/ublkcN */ 278 struct ublksrv_io_cmd { 279 __u16 q_id; 280 281 /* for fetch/commit which result */ 282 __u16 tag; 283 284 /* io result, it is valid for COMMIT* command only */ 285 __s32 result; 286 287 /* 288 * userspace buffer address in ublksrv daemon process, valid for 289 * FETCH* command only 290 */ 291 __u64 addr; 292 }; 293 294 struct ublk_param_basic { 295 #define UBLK_ATTR_READ_ONLY (1 << 0) 296 #define UBLK_ATTR_ROTATIONAL (1 << 1) 297 #define UBLK_ATTR_VOLATILE_CACHE (1 << 2) 298 #define UBLK_ATTR_FUA (1 << 3) 299 __u32 attrs; 300 __u8 logical_bs_shift; 301 __u8 physical_bs_shift; 302 __u8 io_opt_shift; 303 __u8 io_min_shift; 304 305 __u32 max_sectors; 306 __u32 chunk_sectors; 307 308 __u64 dev_sectors; 309 __u64 virt_boundary_mask; 310 }; 311 312 struct ublk_param_discard { 313 __u32 discard_alignment; 314 315 __u32 discard_granularity; 316 __u32 max_discard_sectors; 317 318 __u32 max_write_zeroes_sectors; 319 __u16 max_discard_segments; 320 __u16 reserved0; 321 }; 322 323 /* 324 * read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available 325 * after device is started 326 */ 327 struct ublk_param_devt { 328 __u32 char_major; 329 __u32 char_minor; 330 __u32 disk_major; 331 __u32 disk_minor; 332 }; 333 334 struct ublk_params { 335 /* 336 * Total length of parameters, userspace has to set 'len' for both 337 * SET_PARAMS and GET_PARAMS command, and driver may update len 338 * if two sides use different version of 'ublk_params', same with 339 * 'types' fields. 340 */ 341 __u32 len; 342 #define UBLK_PARAM_TYPE_BASIC (1 << 0) 343 #define UBLK_PARAM_TYPE_DISCARD (1 << 1) 344 #define UBLK_PARAM_TYPE_DEVT (1 << 2) 345 __u32 types; /* types of parameter included */ 346 347 struct ublk_param_basic basic; 348 struct ublk_param_discard discard; 349 struct ublk_param_devt devt; 350 }; 351 352 #endif 353