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 51 /* 52 * IO commands, issued by ublk server, and handled by ublk driver. 53 * 54 * FETCH_REQ: issued via sqe(URING_CMD) beforehand for fetching IO request 55 * from ublk driver, should be issued only when starting device. After 56 * the associated cqe is returned, request's tag can be retrieved via 57 * cqe->userdata. 58 * 59 * COMMIT_AND_FETCH_REQ: issued via sqe(URING_CMD) after ublkserver handled 60 * this IO request, request's handling result is committed to ublk 61 * driver, meantime FETCH_REQ is piggyback, and FETCH_REQ has to be 62 * handled before completing io request. 63 * 64 * NEED_GET_DATA: only used for write requests to set io addr and copy data 65 * When NEED_GET_DATA is set, ublksrv has to issue UBLK_IO_NEED_GET_DATA 66 * command after ublk driver returns UBLK_IO_RES_NEED_GET_DATA. 67 * 68 * It is only used if ublksrv set UBLK_F_NEED_GET_DATA flag 69 * while starting a ublk device. 70 */ 71 72 /* 73 * Legacy IO command definition, don't use in new application, and don't 74 * add new such definition any more 75 */ 76 #define UBLK_IO_FETCH_REQ 0x20 77 #define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21 78 #define UBLK_IO_NEED_GET_DATA 0x22 79 80 /* Any new IO command should encode by __IOWR() */ 81 #define UBLK_U_IO_FETCH_REQ \ 82 _IOWR('u', UBLK_IO_FETCH_REQ, struct ublksrv_io_cmd) 83 #define UBLK_U_IO_COMMIT_AND_FETCH_REQ \ 84 _IOWR('u', UBLK_IO_COMMIT_AND_FETCH_REQ, struct ublksrv_io_cmd) 85 #define UBLK_U_IO_NEED_GET_DATA \ 86 _IOWR('u', UBLK_IO_NEED_GET_DATA, struct ublksrv_io_cmd) 87 88 /* only ABORT means that no re-fetch */ 89 #define UBLK_IO_RES_OK 0 90 #define UBLK_IO_RES_NEED_GET_DATA 1 91 #define UBLK_IO_RES_ABORT (-ENODEV) 92 93 #define UBLKSRV_CMD_BUF_OFFSET 0 94 #define UBLKSRV_IO_BUF_OFFSET 0x80000000 95 96 /* tag bit is 12bit, so at most 4096 IOs for each queue */ 97 #define UBLK_MAX_QUEUE_DEPTH 4096 98 99 /* 100 * zero copy requires 4k block size, and can remap ublk driver's io 101 * request into ublksrv's vm space 102 */ 103 #define UBLK_F_SUPPORT_ZERO_COPY (1ULL << 0) 104 105 /* 106 * Force to complete io cmd via io_uring_cmd_complete_in_task so that 107 * performance comparison is done easily with using task_work_add 108 */ 109 #define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1) 110 111 /* 112 * User should issue io cmd again for write requests to 113 * set io buffer address and copy data from bio vectors 114 * to the userspace io buffer. 115 * 116 * In this mode, task_work is not used. 117 */ 118 #define UBLK_F_NEED_GET_DATA (1UL << 2) 119 120 #define UBLK_F_USER_RECOVERY (1UL << 3) 121 122 #define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4) 123 124 /* 125 * Unprivileged user can create /dev/ublkcN and /dev/ublkbN. 126 * 127 * /dev/ublk-control needs to be available for unprivileged user, and it 128 * can be done via udev rule to make all control commands available to 129 * unprivileged user. Except for the command of UBLK_CMD_ADD_DEV, all 130 * other commands are only allowed for the owner of the specified device. 131 * 132 * When userspace sends UBLK_CMD_ADD_DEV, the device pair's owner_uid and 133 * owner_gid are stored to ublksrv_ctrl_dev_info by kernel, so far only 134 * the current user's uid/gid is stored, that said owner of the created 135 * device is always the current user. 136 * 137 * We still need udev rule to apply OWNER/GROUP with the stored owner_uid 138 * and owner_gid. 139 * 140 * Then ublk server can be run as unprivileged user, and /dev/ublkbN can 141 * be accessed and managed by its owner represented by owner_uid/owner_gid. 142 */ 143 #define UBLK_F_UNPRIVILEGED_DEV (1UL << 5) 144 145 /* use ioctl encoding for uring command */ 146 #define UBLK_F_CMD_IOCTL_ENCODE (1UL << 6) 147 148 /* device state */ 149 #define UBLK_S_DEV_DEAD 0 150 #define UBLK_S_DEV_LIVE 1 151 #define UBLK_S_DEV_QUIESCED 2 152 153 /* shipped via sqe->cmd of io_uring command */ 154 struct ublksrv_ctrl_cmd { 155 /* sent to which device, must be valid */ 156 __u32 dev_id; 157 158 /* sent to which queue, must be -1 if the cmd isn't for queue */ 159 __u16 queue_id; 160 /* 161 * cmd specific buffer, can be IN or OUT. 162 */ 163 __u16 len; 164 __u64 addr; 165 166 /* inline data */ 167 __u64 data[1]; 168 169 /* 170 * Used for UBLK_F_UNPRIVILEGED_DEV and UBLK_CMD_GET_DEV_INFO2 171 * only, include null char 172 */ 173 __u16 dev_path_len; 174 __u16 pad; 175 __u32 reserved; 176 }; 177 178 struct ublksrv_ctrl_dev_info { 179 __u16 nr_hw_queues; 180 __u16 queue_depth; 181 __u16 state; 182 __u16 pad0; 183 184 __u32 max_io_buf_bytes; 185 __u32 dev_id; 186 187 __s32 ublksrv_pid; 188 __u32 pad1; 189 190 __u64 flags; 191 192 /* For ublksrv internal use, invisible to ublk driver */ 193 __u64 ublksrv_flags; 194 195 __u32 owner_uid; /* store by kernel */ 196 __u32 owner_gid; /* store by kernel */ 197 __u64 reserved1; 198 __u64 reserved2; 199 }; 200 201 #define UBLK_IO_OP_READ 0 202 #define UBLK_IO_OP_WRITE 1 203 #define UBLK_IO_OP_FLUSH 2 204 #define UBLK_IO_OP_DISCARD 3 205 #define UBLK_IO_OP_WRITE_SAME 4 206 #define UBLK_IO_OP_WRITE_ZEROES 5 207 208 #define UBLK_IO_F_FAILFAST_DEV (1U << 8) 209 #define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9) 210 #define UBLK_IO_F_FAILFAST_DRIVER (1U << 10) 211 #define UBLK_IO_F_META (1U << 11) 212 #define UBLK_IO_F_FUA (1U << 13) 213 #define UBLK_IO_F_NOUNMAP (1U << 15) 214 #define UBLK_IO_F_SWAP (1U << 16) 215 216 /* 217 * io cmd is described by this structure, and stored in share memory, indexed 218 * by request tag. 219 * 220 * The data is stored by ublk driver, and read by ublksrv after one fetch command 221 * returns. 222 */ 223 struct ublksrv_io_desc { 224 /* op: bit 0-7, flags: bit 8-31 */ 225 __u32 op_flags; 226 227 __u32 nr_sectors; 228 229 /* start sector for this io */ 230 __u64 start_sector; 231 232 /* buffer address in ublksrv daemon vm space, from ublk driver */ 233 __u64 addr; 234 }; 235 236 static inline __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod) 237 { 238 return iod->op_flags & 0xff; 239 } 240 241 static inline __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod) 242 { 243 return iod->op_flags >> 8; 244 } 245 246 /* issued to ublk driver via /dev/ublkcN */ 247 struct ublksrv_io_cmd { 248 __u16 q_id; 249 250 /* for fetch/commit which result */ 251 __u16 tag; 252 253 /* io result, it is valid for COMMIT* command only */ 254 __s32 result; 255 256 /* 257 * userspace buffer address in ublksrv daemon process, valid for 258 * FETCH* command only 259 */ 260 __u64 addr; 261 }; 262 263 struct ublk_param_basic { 264 #define UBLK_ATTR_READ_ONLY (1 << 0) 265 #define UBLK_ATTR_ROTATIONAL (1 << 1) 266 #define UBLK_ATTR_VOLATILE_CACHE (1 << 2) 267 #define UBLK_ATTR_FUA (1 << 3) 268 __u32 attrs; 269 __u8 logical_bs_shift; 270 __u8 physical_bs_shift; 271 __u8 io_opt_shift; 272 __u8 io_min_shift; 273 274 __u32 max_sectors; 275 __u32 chunk_sectors; 276 277 __u64 dev_sectors; 278 __u64 virt_boundary_mask; 279 }; 280 281 struct ublk_param_discard { 282 __u32 discard_alignment; 283 284 __u32 discard_granularity; 285 __u32 max_discard_sectors; 286 287 __u32 max_write_zeroes_sectors; 288 __u16 max_discard_segments; 289 __u16 reserved0; 290 }; 291 292 /* 293 * read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available 294 * after device is started 295 */ 296 struct ublk_param_devt { 297 __u32 char_major; 298 __u32 char_minor; 299 __u32 disk_major; 300 __u32 disk_minor; 301 }; 302 303 struct ublk_params { 304 /* 305 * Total length of parameters, userspace has to set 'len' for both 306 * SET_PARAMS and GET_PARAMS command, and driver may update len 307 * if two sides use different version of 'ublk_params', same with 308 * 'types' fields. 309 */ 310 __u32 len; 311 #define UBLK_PARAM_TYPE_BASIC (1 << 0) 312 #define UBLK_PARAM_TYPE_DISCARD (1 << 1) 313 #define UBLK_PARAM_TYPE_DEVT (1 << 2) 314 __u32 types; /* types of parameter included */ 315 316 struct ublk_param_basic basic; 317 struct ublk_param_discard discard; 318 struct ublk_param_devt devt; 319 }; 320 321 #endif 322