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Diffstat (limited to 'include/uapi/linux/ublk_cmd.h')
| -rw-r--r-- | include/uapi/linux/ublk_cmd.h | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h new file mode 100644 index 000000000..b9cfc5c96 --- /dev/null +++ b/include/uapi/linux/ublk_cmd.h @@ -0,0 +1,398 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef USER_BLK_DRV_CMD_INC_H +#define USER_BLK_DRV_CMD_INC_H + +#include <linux/types.h> + +/* ublk server command definition */ + +/* + * Admin commands, issued by ublk server, and handled by ublk driver. + * + * Legacy command definition, don't use in new application, and don't + * add new such definition any more + */ +#define UBLK_CMD_GET_QUEUE_AFFINITY 0x01 +#define UBLK_CMD_GET_DEV_INFO 0x02 +#define UBLK_CMD_ADD_DEV 0x04 +#define UBLK_CMD_DEL_DEV 0x05 +#define UBLK_CMD_START_DEV 0x06 +#define UBLK_CMD_STOP_DEV 0x07 +#define UBLK_CMD_SET_PARAMS 0x08 +#define UBLK_CMD_GET_PARAMS 0x09 +#define UBLK_CMD_START_USER_RECOVERY 0x10 +#define UBLK_CMD_END_USER_RECOVERY 0x11 +#define UBLK_CMD_GET_DEV_INFO2 0x12 + +/* Any new ctrl command should encode by __IO*() */ +#define UBLK_U_CMD_GET_QUEUE_AFFINITY \ + _IOR('u', UBLK_CMD_GET_QUEUE_AFFINITY, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_GET_DEV_INFO \ + _IOR('u', UBLK_CMD_GET_DEV_INFO, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_ADD_DEV \ + _IOWR('u', UBLK_CMD_ADD_DEV, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_DEL_DEV \ + _IOWR('u', UBLK_CMD_DEL_DEV, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_START_DEV \ + _IOWR('u', UBLK_CMD_START_DEV, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_STOP_DEV \ + _IOWR('u', UBLK_CMD_STOP_DEV, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_SET_PARAMS \ + _IOWR('u', UBLK_CMD_SET_PARAMS, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_GET_PARAMS \ + _IOR('u', UBLK_CMD_GET_PARAMS, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_START_USER_RECOVERY \ + _IOWR('u', UBLK_CMD_START_USER_RECOVERY, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_END_USER_RECOVERY \ + _IOWR('u', UBLK_CMD_END_USER_RECOVERY, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_GET_DEV_INFO2 \ + _IOR('u', UBLK_CMD_GET_DEV_INFO2, struct ublksrv_ctrl_cmd) +#define UBLK_U_CMD_GET_FEATURES \ + _IOR('u', 0x13, struct ublksrv_ctrl_cmd) + +/* + * 64bits are enough now, and it should be easy to extend in case of + * running out of feature flags + */ +#define UBLK_FEATURES_LEN 8 + +/* + * IO commands, issued by ublk server, and handled by ublk driver. + * + * FETCH_REQ: issued via sqe(URING_CMD) beforehand for fetching IO request + * from ublk driver, should be issued only when starting device. After + * the associated cqe is returned, request's tag can be retrieved via + * cqe->userdata. + * + * COMMIT_AND_FETCH_REQ: issued via sqe(URING_CMD) after ublkserver handled + * this IO request, request's handling result is committed to ublk + * driver, meantime FETCH_REQ is piggyback, and FETCH_REQ has to be + * handled before completing io request. + * + * NEED_GET_DATA: only used for write requests to set io addr and copy data + * When NEED_GET_DATA is set, ublksrv has to issue UBLK_IO_NEED_GET_DATA + * command after ublk driver returns UBLK_IO_RES_NEED_GET_DATA. + * + * It is only used if ublksrv set UBLK_F_NEED_GET_DATA flag + * while starting a ublk device. + */ + +/* + * Legacy IO command definition, don't use in new application, and don't + * add new such definition any more + */ +#define UBLK_IO_FETCH_REQ 0x20 +#define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21 +#define UBLK_IO_NEED_GET_DATA 0x22 + +/* Any new IO command should encode by __IOWR() */ +#define UBLK_U_IO_FETCH_REQ \ + _IOWR('u', UBLK_IO_FETCH_REQ, struct ublksrv_io_cmd) +#define UBLK_U_IO_COMMIT_AND_FETCH_REQ \ + _IOWR('u', UBLK_IO_COMMIT_AND_FETCH_REQ, struct ublksrv_io_cmd) +#define UBLK_U_IO_NEED_GET_DATA \ + _IOWR('u', UBLK_IO_NEED_GET_DATA, struct ublksrv_io_cmd) + +/* only ABORT means that no re-fetch */ +#define UBLK_IO_RES_OK 0 +#define UBLK_IO_RES_NEED_GET_DATA 1 +#define UBLK_IO_RES_ABORT (-ENODEV) + +#define UBLKSRV_CMD_BUF_OFFSET 0 +#define UBLKSRV_IO_BUF_OFFSET 0x80000000 + +/* tag bit is 16bit, so far limit at most 4096 IOs for each queue */ +#define UBLK_MAX_QUEUE_DEPTH 4096 + +/* single IO buffer max size is 32MB */ +#define UBLK_IO_BUF_OFF 0 +#define UBLK_IO_BUF_BITS 25 +#define UBLK_IO_BUF_BITS_MASK ((1ULL << UBLK_IO_BUF_BITS) - 1) + +/* so at most 64K IOs for each queue */ +#define UBLK_TAG_OFF UBLK_IO_BUF_BITS +#define UBLK_TAG_BITS 16 +#define UBLK_TAG_BITS_MASK ((1ULL << UBLK_TAG_BITS) - 1) + +/* max 4096 queues */ +#define UBLK_QID_OFF (UBLK_TAG_OFF + UBLK_TAG_BITS) +#define UBLK_QID_BITS 12 +#define UBLK_QID_BITS_MASK ((1ULL << UBLK_QID_BITS) - 1) + +#define UBLK_MAX_NR_QUEUES (1U << UBLK_QID_BITS) + +#define UBLKSRV_IO_BUF_TOTAL_BITS (UBLK_QID_OFF + UBLK_QID_BITS) +#define UBLKSRV_IO_BUF_TOTAL_SIZE (1ULL << UBLKSRV_IO_BUF_TOTAL_BITS) + +/* + * zero copy requires 4k block size, and can remap ublk driver's io + * request into ublksrv's vm space + */ +#define UBLK_F_SUPPORT_ZERO_COPY (1ULL << 0) + +/* + * Force to complete io cmd via io_uring_cmd_complete_in_task so that + * performance comparison is done easily with using task_work_add + */ +#define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1) + +/* + * User should issue io cmd again for write requests to + * set io buffer address and copy data from bio vectors + * to the userspace io buffer. + * + * In this mode, task_work is not used. + */ +#define UBLK_F_NEED_GET_DATA (1UL << 2) + +#define UBLK_F_USER_RECOVERY (1UL << 3) + +#define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4) + +/* + * Unprivileged user can create /dev/ublkcN and /dev/ublkbN. + * + * /dev/ublk-control needs to be available for unprivileged user, and it + * can be done via udev rule to make all control commands available to + * unprivileged user. Except for the command of UBLK_CMD_ADD_DEV, all + * other commands are only allowed for the owner of the specified device. + * + * When userspace sends UBLK_CMD_ADD_DEV, the device pair's owner_uid and + * owner_gid are stored to ublksrv_ctrl_dev_info by kernel, so far only + * the current user's uid/gid is stored, that said owner of the created + * device is always the current user. + * + * We still need udev rule to apply OWNER/GROUP with the stored owner_uid + * and owner_gid. + * + * Then ublk server can be run as unprivileged user, and /dev/ublkbN can + * be accessed and managed by its owner represented by owner_uid/owner_gid. + */ +#define UBLK_F_UNPRIVILEGED_DEV (1UL << 5) + +/* use ioctl encoding for uring command */ +#define UBLK_F_CMD_IOCTL_ENCODE (1UL << 6) + +/* Copy between request and user buffer by pread()/pwrite() */ +#define UBLK_F_USER_COPY (1UL << 7) + +/* + * User space sets this flag when setting up the device to request zoned storage support. Kernel may + * deny the request by returning an error. + */ +#define UBLK_F_ZONED (1ULL << 8) + +/* device state */ +#define UBLK_S_DEV_DEAD 0 +#define UBLK_S_DEV_LIVE 1 +#define UBLK_S_DEV_QUIESCED 2 + +/* shipped via sqe->cmd of io_uring command */ +struct ublksrv_ctrl_cmd { + /* sent to which device, must be valid */ + __u32 dev_id; + + /* sent to which queue, must be -1 if the cmd isn't for queue */ + __u16 queue_id; + /* + * cmd specific buffer, can be IN or OUT. + */ + __u16 len; + __u64 addr; + + /* inline data */ + __u64 data[1]; + + /* + * Used for UBLK_F_UNPRIVILEGED_DEV and UBLK_CMD_GET_DEV_INFO2 + * only, include null char + */ + __u16 dev_path_len; + __u16 pad; + __u32 reserved; +}; + +struct ublksrv_ctrl_dev_info { + __u16 nr_hw_queues; + __u16 queue_depth; + __u16 state; + __u16 pad0; + + __u32 max_io_buf_bytes; + __u32 dev_id; + + __s32 ublksrv_pid; + __u32 pad1; + + __u64 flags; + + /* For ublksrv internal use, invisible to ublk driver */ + __u64 ublksrv_flags; + + __u32 owner_uid; /* store by kernel */ + __u32 owner_gid; /* store by kernel */ + __u64 reserved1; + __u64 reserved2; +}; + +#define UBLK_IO_OP_READ 0 +#define UBLK_IO_OP_WRITE 1 +#define UBLK_IO_OP_FLUSH 2 +#define UBLK_IO_OP_DISCARD 3 +#define UBLK_IO_OP_WRITE_SAME 4 +#define UBLK_IO_OP_WRITE_ZEROES 5 +#define UBLK_IO_OP_ZONE_OPEN 10 +#define UBLK_IO_OP_ZONE_CLOSE 11 +#define UBLK_IO_OP_ZONE_FINISH 12 +#define UBLK_IO_OP_ZONE_APPEND 13 +#define UBLK_IO_OP_ZONE_RESET_ALL 14 +#define UBLK_IO_OP_ZONE_RESET 15 +/* + * Construct a zone report. The report request is carried in `struct + * ublksrv_io_desc`. The `start_sector` field must be the first sector of a zone + * and shall indicate the first zone of the report. The `nr_zones` shall + * indicate how many zones should be reported at most. The report shall be + * delivered as a `struct blk_zone` array. To report fewer zones than requested, + * zero the last entry of the returned array. + * + * Related definitions(blk_zone, blk_zone_cond, blk_zone_type, ...) in + * include/uapi/linux/blkzoned.h are part of ublk UAPI. + */ +#define UBLK_IO_OP_REPORT_ZONES 18 + +#define UBLK_IO_F_FAILFAST_DEV (1U << 8) +#define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9) +#define UBLK_IO_F_FAILFAST_DRIVER (1U << 10) +#define UBLK_IO_F_META (1U << 11) +#define UBLK_IO_F_FUA (1U << 13) +#define UBLK_IO_F_NOUNMAP (1U << 15) +#define UBLK_IO_F_SWAP (1U << 16) + +/* + * io cmd is described by this structure, and stored in share memory, indexed + * by request tag. + * + * The data is stored by ublk driver, and read by ublksrv after one fetch command + * returns. + */ +struct ublksrv_io_desc { + /* op: bit 0-7, flags: bit 8-31 */ + __u32 op_flags; + + union { + __u32 nr_sectors; + __u32 nr_zones; /* for UBLK_IO_OP_REPORT_ZONES */ + }; + + /* start sector for this io */ + __u64 start_sector; + + /* buffer address in ublksrv daemon vm space, from ublk driver */ + __u64 addr; +}; + +static inline __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod) +{ + return iod->op_flags & 0xff; +} + +static inline __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod) +{ + return iod->op_flags >> 8; +} + +/* issued to ublk driver via /dev/ublkcN */ +struct ublksrv_io_cmd { + __u16 q_id; + + /* for fetch/commit which result */ + __u16 tag; + + /* io result, it is valid for COMMIT* command only */ + __s32 result; + + union { + /* + * userspace buffer address in ublksrv daemon process, valid for + * FETCH* command only + * + * `addr` should not be used when UBLK_F_USER_COPY is enabled, + * because userspace handles data copy by pread()/pwrite() over + * /dev/ublkcN. But in case of UBLK_F_ZONED, this union is + * re-used to pass back the allocated LBA for + * UBLK_IO_OP_ZONE_APPEND which actually depends on + * UBLK_F_USER_COPY + */ + __u64 addr; + __u64 zone_append_lba; + }; +}; + +struct ublk_param_basic { +#define UBLK_ATTR_READ_ONLY (1 << 0) +#define UBLK_ATTR_ROTATIONAL (1 << 1) +#define UBLK_ATTR_VOLATILE_CACHE (1 << 2) +#define UBLK_ATTR_FUA (1 << 3) + __u32 attrs; + __u8 logical_bs_shift; + __u8 physical_bs_shift; + __u8 io_opt_shift; + __u8 io_min_shift; + + __u32 max_sectors; + __u32 chunk_sectors; + + __u64 dev_sectors; + __u64 virt_boundary_mask; +}; + +struct ublk_param_discard { + __u32 discard_alignment; + + __u32 discard_granularity; + __u32 max_discard_sectors; + + __u32 max_write_zeroes_sectors; + __u16 max_discard_segments; + __u16 reserved0; +}; + +/* + * read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available + * after device is started + */ +struct ublk_param_devt { + __u32 char_major; + __u32 char_minor; + __u32 disk_major; + __u32 disk_minor; +}; + +struct ublk_param_zoned { + __u32 max_open_zones; + __u32 max_active_zones; + __u32 max_zone_append_sectors; + __u8 reserved[20]; +}; + +struct ublk_params { + /* + * Total length of parameters, userspace has to set 'len' for both + * SET_PARAMS and GET_PARAMS command, and driver may update len + * if two sides use different version of 'ublk_params', same with + * 'types' fields. + */ + __u32 len; +#define UBLK_PARAM_TYPE_BASIC (1 << 0) +#define UBLK_PARAM_TYPE_DISCARD (1 << 1) +#define UBLK_PARAM_TYPE_DEVT (1 << 2) +#define UBLK_PARAM_TYPE_ZONED (1 << 3) + __u32 types; /* types of parameter included */ + + struct ublk_param_basic basic; + struct ublk_param_discard discard; + struct ublk_param_devt devt; + struct ublk_param_zoned zoned; +}; + +#endif |