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/* 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
#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
/*
* 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.
*/
#define UBLK_IO_FETCH_REQ 0x20
#define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21
#define UBLK_IO_NEED_GET_DATA 0x22
/* 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 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 (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)
/* 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_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;
__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;
};
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_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)
__u32 types; /* types of parameter included */
struct ublk_param_basic basic;
struct ublk_param_discard discard;
struct ublk_param_devt devt;
};
#endif
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