ublk_cmd.h (12046B)
- /* 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)
- #define UBLK_U_CMD_DEL_DEV_ASYNC \
- _IOR('u', 0x14, 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()
- *
- * Not available for UBLK_F_UNPRIVILEGED_DEV, otherwise userspace may
- * deceive us by not filling request buffer, then kernel uninitialized
- * data may be leaked.
- */
- #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