diff options
Diffstat (limited to 'include/uapi/linux/ublk_cmd.h')
| -rw-r--r-- | include/uapi/linux/ublk_cmd.h | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h new file mode 100644 index 000000000000..4f0c16ec875e --- /dev/null +++ b/include/uapi/linux/ublk_cmd.h @@ -0,0 +1,156 @@ +/* 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. + */ +#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 + +/* + * 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. + */ +#define UBLK_IO_FETCH_REQ 0x20 +#define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21 + +/* only ABORT means that no re-fetch */ +#define UBLK_IO_RES_OK 0 +#define UBLK_IO_RES_ABORT (-ENODEV) + +#define UBLKSRV_CMD_BUF_OFFSET 0 +#define UBLKSRV_IO_BUF_OFFSET 0x80000000 + +/* tag bit is 12bit, so at most 4096 IOs for each queue */ +#define UBLK_MAX_QUEUE_DEPTH 4096 + +/* + * 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 (1UL << 0) + +/* device state */ +#define UBLK_S_DEV_DEAD 0 +#define UBLK_S_DEV_LIVE 1 + +/* 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[2]; +}; + +struct ublksrv_ctrl_dev_info { + __u16 nr_hw_queues; + __u16 queue_depth; + __u16 block_size; + __u16 state; + + __u32 rq_max_blocks; + __u32 dev_id; + + __u64 dev_blocks; + + __s32 ublksrv_pid; + __s32 reserved0; + __u64 flags[2]; + + /* For ublksrv internal use, invisible to ublk driver */ + __u64 ublksrv_flags; + __u64 reserved1[9]; +}; + +#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_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_INTEGRITY (1U << 12) +#define UBLK_IO_F_FUA (1U << 13) +#define UBLK_IO_F_PREFLUSH (1U << 14) +#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; + + __u32 nr_sectors; + + /* 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; + + /* + * userspace buffer address in ublksrv daemon process, valid for + * FETCH* command only + */ + __u64 addr; +}; + +#endif |