/* 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) #define UBLK_U_CMD_UPDATE_SIZE \ _IOWR('u', 0x15, struct ublksrv_ctrl_cmd) #define UBLK_U_CMD_QUIESCE_DEV \ _IOWR('u', 0x16, struct ublksrv_ctrl_cmd) #define UBLK_U_CMD_TRY_STOP_DEV \ _IOWR('u', 0x17, 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) #define UBLK_U_IO_REGISTER_IO_BUF \ _IOWR('u', 0x23, struct ublksrv_io_cmd) #define UBLK_U_IO_UNREGISTER_IO_BUF \ _IOWR('u', 0x24, struct ublksrv_io_cmd) /* * return 0 if the command is run successfully, otherwise failure code * is returned */ #define UBLK_U_IO_PREP_IO_CMDS \ _IOWR('u', 0x25, struct ublk_batch_io) /* * If failure code is returned, nothing in the command buffer is handled. * Otherwise, the returned value means how many bytes in command buffer * are handled actually, then number of handled IOs can be calculated with * `elem_bytes` for each IO. IOs in the remained bytes are not committed, * userspace has to check return value for dealing with partial committing * correctly. */ #define UBLK_U_IO_COMMIT_IO_CMDS \ _IOWR('u', 0x26, struct ublk_batch_io) /* * Fetch io commands to provided buffer in multishot style, * `IORING_URING_CMD_MULTISHOT` is required for this command. */ #define UBLK_U_IO_FETCH_IO_CMDS \ _IOWR('u', 0x27, struct ublk_batch_io) /* 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) /* Copy to/from request integrity buffer instead of data buffer */ #define UBLK_INTEGRITY_FLAG_OFF 62 #define UBLKSRV_IO_INTEGRITY_FLAG (1ULL << UBLK_INTEGRITY_FLAG_OFF) /* * ublk server can register data buffers for incoming I/O requests with a sparse * io_uring buffer table. The request buffer can then be used as the data buffer * for io_uring operations via the fixed buffer index. * Note that the ublk server can never directly access the request data memory. * * To use this feature, the ublk server must first register a sparse buffer * table on an io_uring instance. * When an incoming ublk request is received, the ublk server submits a * UBLK_U_IO_REGISTER_IO_BUF command to that io_uring instance. The * ublksrv_io_cmd's q_id and tag specify the request whose buffer to register * and addr is the index in the io_uring's buffer table to install the buffer. * SQEs can now be submitted to the io_uring to read/write the request's buffer * by enabling fixed buffers (e.g. using IORING_OP_{READ,WRITE}_FIXED or * IORING_URING_CMD_FIXED) and passing the registered buffer index in buf_index. * Once the last io_uring operation using the request's buffer has completed, * the ublk server submits a UBLK_U_IO_UNREGISTER_IO_BUF command with q_id, tag, * and addr again specifying the request buffer to unregister. * The ublk request is completed when its buffer is unregistered from all * io_uring instances and the ublk server issues UBLK_U_IO_COMMIT_AND_FETCH_REQ. * * Not available for UBLK_F_UNPRIVILEGED_DEV, as a ublk server can leak * uninitialized kernel memory by not reading into the full request buffer. */ #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) /* * - Block devices are recoverable if ublk server exits and restarts * - Outstanding I/O when ublk server exits is met with errors * - I/O issued while there is no ublk server queues */ #define UBLK_F_USER_RECOVERY (1UL << 3) /* * - Block devices are recoverable if ublk server exits and restarts * - Outstanding I/O when ublk server exits is reissued * - I/O issued while there is no ublk server queues */ #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) /* * - Block devices are recoverable if ublk server exits and restarts * - Outstanding I/O when ublk server exits is met with errors * - I/O issued while there is no ublk server is met with errors */ #define UBLK_F_USER_RECOVERY_FAIL_IO (1ULL << 9) /* * Resizing a block device is possible with UBLK_U_CMD_UPDATE_SIZE * New size is passed in cmd->data[0] and is in units of sectors */ #define UBLK_F_UPDATE_SIZE (1ULL << 10) /* * request buffer is registered automatically to uring_cmd's io_uring * context before delivering this io command to ublk server, meantime * it is un-registered automatically when completing this io command. * * For using this feature: * * - ublk server has to create sparse buffer table on the same `io_ring_ctx` * for issuing `UBLK_IO_FETCH_REQ` and `UBLK_IO_COMMIT_AND_FETCH_REQ`. * If uring_cmd isn't issued on same `io_ring_ctx`, it is ublk server's * responsibility to unregister the buffer by issuing `IO_UNREGISTER_IO_BUF` * manually, otherwise this ublk request won't complete. * * - ublk server passes auto buf register data via uring_cmd's sqe->addr, * `struct ublk_auto_buf_reg` is populated from sqe->addr, please see * the definition of ublk_sqe_addr_to_auto_buf_reg() * * - pass buffer index from `ublk_auto_buf_reg.index` * * - all reserved fields in `ublk_auto_buf_reg` need to be zeroed * * - pass flags from `ublk_auto_buf_reg.flags` if needed * * This way avoids extra cost from two uring_cmd, but also simplifies backend * implementation, such as, the dependency on IO_REGISTER_IO_BUF and * IO_UNREGISTER_IO_BUF becomes not necessary. * * If wrong data or flags are provided, both IO_FETCH_REQ and * IO_COMMIT_AND_FETCH_REQ are failed, for the latter, the ublk IO request * won't be completed until new IO_COMMIT_AND_FETCH_REQ command is issued * successfully */ #define UBLK_F_AUTO_BUF_REG (1ULL << 11) /* * Control command `UBLK_U_CMD_QUIESCE_DEV` is added for quiescing device, * which state can be transitioned to `UBLK_S_DEV_QUIESCED` or * `UBLK_S_DEV_FAIL_IO` finally, and it needs ublk server cooperation for * handling `UBLK_IO_RES_ABORT` correctly. * * Typical use case is for supporting to upgrade ublk server application, * meantime keep ublk block device persistent during the period. * * This feature is only available when UBLK_F_USER_RECOVERY is enabled. * * Note, this command returns -EBUSY in case that all IO commands are being * handled by ublk server and not completed in specified time period which * is passed from the control command parameter. */ #define UBLK_F_QUIESCE (1ULL << 12) /* * If this feature is set, ublk_drv supports each (qid,tag) pair having * its own independent daemon task that is responsible for handling it. * If it is not set, daemons are per-queue instead, so for two pairs * (qid1,tag1) and (qid2,tag2), if qid1 == qid2, then the same task must * be responsible for handling (qid1,tag1) and (qid2,tag2). */ #define UBLK_F_PER_IO_DAEMON (1ULL << 13) /* * If this feature is set, UBLK_U_IO_REGISTER_IO_BUF/UBLK_U_IO_UNREGISTER_IO_BUF * can be issued for an I/O on any task. q_id and tag are also ignored in * UBLK_U_IO_UNREGISTER_IO_BUF's ublksrv_io_cmd. * If it is unset, zero-copy buffers can only be registered and unregistered by * the I/O's daemon task. The q_id and tag of the registered buffer are required * in UBLK_U_IO_UNREGISTER_IO_BUF's ublksrv_io_cmd. */ #define UBLK_F_BUF_REG_OFF_DAEMON (1ULL << 14) /* * Support the following commands for delivering & committing io command * in batch. * * - UBLK_U_IO_PREP_IO_CMDS * - UBLK_U_IO_COMMIT_IO_CMDS * - UBLK_U_IO_FETCH_IO_CMDS * - UBLK_U_IO_REGISTER_IO_BUF * - UBLK_U_IO_UNREGISTER_IO_BUF * * The existing UBLK_U_IO_FETCH_REQ, UBLK_U_IO_COMMIT_AND_FETCH_REQ and * UBLK_U_IO_NEED_GET_DATA uring_cmd are not supported for this feature. */ #define UBLK_F_BATCH_IO (1ULL << 15) /* * ublk device supports requests with integrity/metadata buffer. * Requires UBLK_F_USER_COPY. */ #define UBLK_F_INTEGRITY (1ULL << 16) /* * The device supports the UBLK_CMD_TRY_STOP_DEV command, which * allows stopping the device only if there are no openers. */ #define UBLK_F_SAFE_STOP_DEV (1ULL << 17) /* Disable automatic partition scanning when device is started */ #define UBLK_F_NO_AUTO_PART_SCAN (1ULL << 18) /* device state */ #define UBLK_S_DEV_DEAD 0 #define UBLK_S_DEV_LIVE 1 #define UBLK_S_DEV_QUIESCED 2 #define UBLK_S_DEV_FAIL_IO 3 /* 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) /* * For UBLK_F_AUTO_BUF_REG & UBLK_AUTO_BUF_REG_FALLBACK only. * * This flag is set if auto buffer register is failed & ublk server passes * UBLK_AUTO_BUF_REG_FALLBACK, and ublk server need to register buffer * manually for handling the delivered IO command if this flag is observed * * ublk server has to check this flag if UBLK_AUTO_BUF_REG_FALLBACK is * passed in. */ #define UBLK_IO_F_NEED_REG_BUF (1U << 17) /* Request has an integrity data buffer */ #define UBLK_IO_F_INTEGRITY (1UL << 18) /* * 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; } /* * If this flag is set, fallback by completing the uring_cmd and setting * `UBLK_IO_F_NEED_REG_BUF` in case of auto-buf-register failure; * otherwise the client ublk request is failed silently * * If ublk server passes this flag, it has to check if UBLK_IO_F_NEED_REG_BUF * is set in `ublksrv_io_desc.op_flags`. If UBLK_IO_F_NEED_REG_BUF is set, * ublk server needs to register io buffer manually for handling IO command. */ #define UBLK_AUTO_BUF_REG_FALLBACK (1 << 0) #define UBLK_AUTO_BUF_REG_F_MASK UBLK_AUTO_BUF_REG_FALLBACK struct ublk_auto_buf_reg { /* index for registering the delivered request buffer */ __u16 index; __u8 flags; __u8 reserved0; /* * io_ring FD can be passed via the reserve field in future for * supporting to register io buffer to external io_uring */ __u32 reserved1; }; /* * For UBLK_F_AUTO_BUF_REG, auto buffer register data is carried via * uring_cmd's sqe->addr: * * - bit0 ~ bit15: buffer index * - bit16 ~ bit23: flags * - bit24 ~ bit31: reserved0 * - bit32 ~ bit63: reserved1 */ static inline struct ublk_auto_buf_reg ublk_sqe_addr_to_auto_buf_reg( __u64 sqe_addr) { struct ublk_auto_buf_reg reg = { .index = (__u16)sqe_addr, .flags = (__u8)(sqe_addr >> 16), .reserved0 = (__u8)(sqe_addr >> 24), .reserved1 = (__u32)(sqe_addr >> 32), }; return reg; } static inline __u64 ublk_auto_buf_reg_to_sqe_addr(const struct ublk_auto_buf_reg *buf) { __u64 addr = buf->index | (__u64)buf->flags << 16 | (__u64)buf->reserved0 << 24 | (__u64)buf->reserved1 << 32; return addr; } /* 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_elem_header { __u16 tag; /* IO tag */ /* * Buffer index for incoming io command, only valid iff * UBLK_F_AUTO_BUF_REG is set */ __u16 buf_index; __s32 result; /* I/O completion result (commit only) */ }; /* * uring_cmd buffer structure for batch commands * * buffer includes multiple elements, which number is specified by * `nr_elem`. Each element buffer is organized in the following order: * * struct ublk_elem_buffer { * // Mandatory fields (8 bytes) * struct ublk_elem_header header; * * // Optional fields (8 bytes each, included based on flags) * * // Buffer address (if UBLK_BATCH_F_HAS_BUF_ADDR) for copying data * // between ublk request and ublk server buffer * __u64 buf_addr; * * // returned Zone append LBA (if UBLK_BATCH_F_HAS_ZONE_LBA) * __u64 zone_lba; * } * * Used for `UBLK_U_IO_PREP_IO_CMDS` and `UBLK_U_IO_COMMIT_IO_CMDS` */ struct ublk_batch_io { __u16 q_id; #define UBLK_BATCH_F_HAS_ZONE_LBA (1 << 0) #define UBLK_BATCH_F_HAS_BUF_ADDR (1 << 1) #define UBLK_BATCH_F_AUTO_BUF_REG_FALLBACK (1 << 2) __u16 flags; __u16 nr_elem; __u8 elem_bytes; __u8 reserved; __u64 reserved2; }; 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_param_dma_align { __u32 alignment; __u8 pad[4]; }; #define UBLK_MIN_SEGMENT_SIZE 4096 /* * If any one of the three segment parameter is set as 0, the behavior is * undefined. */ struct ublk_param_segment { /* * seg_boundary_mask + 1 needs to be power_of_2(), and the sum has * to be >= UBLK_MIN_SEGMENT_SIZE(4096) */ __u64 seg_boundary_mask; /* * max_segment_size could be override by virt_boundary_mask, so be * careful when setting both. * * max_segment_size has to be >= UBLK_MIN_SEGMENT_SIZE(4096) */ __u32 max_segment_size; __u16 max_segments; __u8 pad[2]; }; struct ublk_param_integrity { __u32 flags; /* LBMD_PI_CAP_* from linux/fs.h */ __u16 max_integrity_segments; /* 0 means no limit */ __u8 interval_exp; __u8 metadata_size; /* UBLK_PARAM_TYPE_INTEGRITY requires nonzero */ __u8 pi_offset; __u8 csum_type; /* LBMD_PI_CSUM_* from linux/fs.h */ __u8 tag_size; __u8 pad[5]; }; 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) #define UBLK_PARAM_TYPE_DMA_ALIGN (1 << 4) #define UBLK_PARAM_TYPE_SEGMENT (1 << 5) #define UBLK_PARAM_TYPE_INTEGRITY (1 << 6) /* requires UBLK_F_INTEGRITY */ __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; struct ublk_param_dma_align dma; struct ublk_param_segment seg; struct ublk_param_integrity integrity; }; #endif
