[thirdparty/linux.git] / include / uapi / linux / ublk_cmd.h

/* 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)

/*
 * 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 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)

/* use ioctl encoding for uring command */
#define UBLK_F_CMD_IOCTL_ENCODE	(1UL << 6)

/* 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
Commit	Line	Data
71f28f31 ML	1	/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
	2	#ifndef USER_BLK_DRV_CMD_INC_H
	3	#define USER_BLK_DRV_CMD_INC_H
	4
	5	#include <linux/types.h>
	6
	7	/* ublk server command definition */
	8
	9	/*
	10	* Admin commands, issued by ublk server, and handled by ublk driver.
2d786e66 ML	11	*
	12	* Legacy command definition, don't use in new application, and don't
	13	* add new such definition any more
71f28f31 ML	14	*/
	15	#define UBLK_CMD_GET_QUEUE_AFFINITY 0x01
	16	#define UBLK_CMD_GET_DEV_INFO 0x02
	17	#define UBLK_CMD_ADD_DEV 0x04
	18	#define UBLK_CMD_DEL_DEV 0x05
	19	#define UBLK_CMD_START_DEV 0x06
	20	#define UBLK_CMD_STOP_DEV 0x07
0aa73170 ML	21	#define UBLK_CMD_SET_PARAMS 0x08
0aa73170 ML	22	#define UBLK_CMD_GET_PARAMS 0x09
c732a852 Z	23	#define UBLK_CMD_START_USER_RECOVERY 0x10
c732a852 Z	24	#define UBLK_CMD_END_USER_RECOVERY 0x11
4093cb5a ML	25	#define UBLK_CMD_GET_DEV_INFO2 0x12
4093cb5a ML	26
2d786e66 ML	27	/* Any new ctrl command should encode by __IO() /
	28	#define UBLK_U_CMD_GET_QUEUE_AFFINITY \
	29	_IOR('u', UBLK_CMD_GET_QUEUE_AFFINITY, struct ublksrv_ctrl_cmd)
	30	#define UBLK_U_CMD_GET_DEV_INFO \
	31	_IOR('u', UBLK_CMD_GET_DEV_INFO, struct ublksrv_ctrl_cmd)
	32	#define UBLK_U_CMD_ADD_DEV \
	33	_IOWR('u', UBLK_CMD_ADD_DEV, struct ublksrv_ctrl_cmd)
	34	#define UBLK_U_CMD_DEL_DEV \
	35	_IOWR('u', UBLK_CMD_DEL_DEV, struct ublksrv_ctrl_cmd)
	36	#define UBLK_U_CMD_START_DEV \
	37	_IOWR('u', UBLK_CMD_START_DEV, struct ublksrv_ctrl_cmd)
	38	#define UBLK_U_CMD_STOP_DEV \
	39	_IOWR('u', UBLK_CMD_STOP_DEV, struct ublksrv_ctrl_cmd)
	40	#define UBLK_U_CMD_SET_PARAMS \
	41	_IOWR('u', UBLK_CMD_SET_PARAMS, struct ublksrv_ctrl_cmd)
	42	#define UBLK_U_CMD_GET_PARAMS \
	43	_IOR('u', UBLK_CMD_GET_PARAMS, struct ublksrv_ctrl_cmd)
	44	#define UBLK_U_CMD_START_USER_RECOVERY \
	45	_IOWR('u', UBLK_CMD_START_USER_RECOVERY, struct ublksrv_ctrl_cmd)
	46	#define UBLK_U_CMD_END_USER_RECOVERY \
	47	_IOWR('u', UBLK_CMD_END_USER_RECOVERY, struct ublksrv_ctrl_cmd)
	48	#define UBLK_U_CMD_GET_DEV_INFO2 \
	49	_IOR('u', UBLK_CMD_GET_DEV_INFO2, struct ublksrv_ctrl_cmd)
	50
71f28f31 ML	51	/*
	52	* IO commands, issued by ublk server, and handled by ublk driver.
	53	*
	54	* FETCH_REQ: issued via sqe(URING_CMD) beforehand for fetching IO request
	55	* from ublk driver, should be issued only when starting device. After
	56	* the associated cqe is returned, request's tag can be retrieved via
	57	* cqe->userdata.
	58	*
	59	* COMMIT_AND_FETCH_REQ: issued via sqe(URING_CMD) after ublkserver handled
	60	* this IO request, request's handling result is committed to ublk
	61	* driver, meantime FETCH_REQ is piggyback, and FETCH_REQ has to be
	62	* handled before completing io request.
4e18403d Z	63	*
	64	* NEED_GET_DATA: only used for write requests to set io addr and copy data
	65	* When NEED_GET_DATA is set, ublksrv has to issue UBLK_IO_NEED_GET_DATA
	66	* command after ublk driver returns UBLK_IO_RES_NEED_GET_DATA.
	67	*
	68	* It is only used if ublksrv set UBLK_F_NEED_GET_DATA flag
	69	* while starting a ublk device.
71f28f31	70	*/
2d786e66 ML	71
	72	/*
	73	* Legacy IO command definition, don't use in new application, and don't
	74	* add new such definition any more
	75	*/
71f28f31 ML	76	#define UBLK_IO_FETCH_REQ 0x20
71f28f31 ML	77	#define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21
4e18403d	78	#define UBLK_IO_NEED_GET_DATA 0x22
71f28f31	79
2d786e66 ML	80	/* Any new IO command should encode by __IOWR() */
	81	#define UBLK_U_IO_FETCH_REQ \
	82	_IOWR('u', UBLK_IO_FETCH_REQ, struct ublksrv_io_cmd)
	83	#define UBLK_U_IO_COMMIT_AND_FETCH_REQ \
	84	_IOWR('u', UBLK_IO_COMMIT_AND_FETCH_REQ, struct ublksrv_io_cmd)
	85	#define UBLK_U_IO_NEED_GET_DATA \
	86	_IOWR('u', UBLK_IO_NEED_GET_DATA, struct ublksrv_io_cmd)
	87
71f28f31 ML	88	/* only ABORT means that no re-fetch */
71f28f31 ML	89	#define UBLK_IO_RES_OK 0
4e18403d	90	#define UBLK_IO_RES_NEED_GET_DATA 1
71f28f31 ML	91	#define UBLK_IO_RES_ABORT (-ENODEV)
	92
	93	#define UBLKSRV_CMD_BUF_OFFSET 0
	94	#define UBLKSRV_IO_BUF_OFFSET 0x80000000
	95
	96	/* tag bit is 12bit, so at most 4096 IOs for each queue */
	97	#define UBLK_MAX_QUEUE_DEPTH 4096
	98
	99	/*
	100	* zero copy requires 4k block size, and can remap ublk driver's io
	101	* request into ublksrv's vm space
	102	*/
6d8c5afc	103	#define UBLK_F_SUPPORT_ZERO_COPY (1ULL << 0)
71f28f31	104
0edb3696 ML	105	/*
	106	* Force to complete io cmd via io_uring_cmd_complete_in_task so that
	107	* performance comparison is done easily with using task_work_add
	108	*/
6d8c5afc	109	#define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1)
0edb3696	110
4e18403d Z	111	/*
	112	* User should issue io cmd again for write requests to
	113	* set io buffer address and copy data from bio vectors
	114	* to the userspace io buffer.
	115	*
	116	* In this mode, task_work is not used.
	117	*/
	118	#define UBLK_F_NEED_GET_DATA (1UL << 2)
	119
77a440e2 Z	120	#define UBLK_F_USER_RECOVERY (1UL << 3)
77a440e2 Z	121
a0d41dc1 Z	122	#define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4)
a0d41dc1 Z	123
4093cb5a ML	124	/*
	125	* Unprivileged user can create /dev/ublkcN and /dev/ublkbN.
	126	*
	127	* /dev/ublk-control needs to be available for unprivileged user, and it
	128	* can be done via udev rule to make all control commands available to
	129	* unprivileged user. Except for the command of UBLK_CMD_ADD_DEV, all
	130	* other commands are only allowed for the owner of the specified device.
	131	*
	132	* When userspace sends UBLK_CMD_ADD_DEV, the device pair's owner_uid and
	133	* owner_gid are stored to ublksrv_ctrl_dev_info by kernel, so far only
	134	* the current user's uid/gid is stored, that said owner of the created
	135	* device is always the current user.
	136	*
	137	* We still need udev rule to apply OWNER/GROUP with the stored owner_uid
	138	* and owner_gid.
	139	*
	140	* Then ublk server can be run as unprivileged user, and /dev/ublkbN can
	141	* be accessed and managed by its owner represented by owner_uid/owner_gid.
	142	*/
	143	#define UBLK_F_UNPRIVILEGED_DEV (1UL << 5)
	144
2d786e66 ML	145	/* use ioctl encoding for uring command */
	146	#define UBLK_F_CMD_IOCTL_ENCODE (1UL << 6)
	147
71f28f31 ML	148	/* device state */
	149	#define UBLK_S_DEV_DEAD 0
	150	#define UBLK_S_DEV_LIVE 1
77a440e2	151	#define UBLK_S_DEV_QUIESCED 2
71f28f31 ML	152
	153	/* shipped via sqe->cmd of io_uring command */
	154	struct ublksrv_ctrl_cmd {
	155	/* sent to which device, must be valid */
	156	__u32 dev_id;
	157
	158	/* sent to which queue, must be -1 if the cmd isn't for queue */
	159	__u16 queue_id;
	160	/*
	161	* cmd specific buffer, can be IN or OUT.
	162	*/
	163	__u16 len;
	164	__u64 addr;
	165
	166	/* inline data */
4093cb5a ML	167	__u64 data[1];
	168
	169	/*
	170	* Used for UBLK_F_UNPRIVILEGED_DEV and UBLK_CMD_GET_DEV_INFO2
	171	* only, include null char
	172	*/
	173	__u16 dev_path_len;
	174	__u16 pad;
	175	__u32 reserved;
71f28f31 ML	176	};
	177
	178	struct ublksrv_ctrl_dev_info {
	179	__u16 nr_hw_queues;
	180	__u16 queue_depth;
71f28f31	181	__u16 state;
4bf9cbf3	182	__u16 pad0;
71f28f31	183
4bf9cbf3	184	__u32 max_io_buf_bytes;
71f28f31 ML	185	__u32 dev_id;
71f28f31 ML	186
71f28f31	187	__s32 ublksrv_pid;
4bf9cbf3 ML	188	__u32 pad1;
4bf9cbf3 ML	189
6d8c5afc	190	__u64 flags;
71f28f31 ML	191
	192	/* For ublksrv internal use, invisible to ublk driver */
	193	__u64 ublksrv_flags;
4bf9cbf3	194
4093cb5a ML	195	__u32 owner_uid; /* store by kernel */
4093cb5a ML	196	__u32 owner_gid; /* store by kernel */
4bf9cbf3 ML	197	__u64 reserved1;
4bf9cbf3 ML	198	__u64 reserved2;
71f28f31 ML	199	};
	200
	201	#define UBLK_IO_OP_READ 0
	202	#define UBLK_IO_OP_WRITE 1
	203	#define UBLK_IO_OP_FLUSH 2
	204	#define UBLK_IO_OP_DISCARD 3
	205	#define UBLK_IO_OP_WRITE_SAME 4
	206	#define UBLK_IO_OP_WRITE_ZEROES 5
	207
	208	#define UBLK_IO_F_FAILFAST_DEV (1U << 8)
	209	#define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9)
	210	#define UBLK_IO_F_FAILFAST_DRIVER (1U << 10)
	211	#define UBLK_IO_F_META (1U << 11)
71f28f31	212	#define UBLK_IO_F_FUA (1U << 13)
71f28f31 ML	213	#define UBLK_IO_F_NOUNMAP (1U << 15)
	214	#define UBLK_IO_F_SWAP (1U << 16)
	215
	216	/*
	217	* io cmd is described by this structure, and stored in share memory, indexed
	218	* by request tag.
	219	*
	220	* The data is stored by ublk driver, and read by ublksrv after one fetch command
	221	* returns.
	222	*/
	223	struct ublksrv_io_desc {
	224	/* op: bit 0-7, flags: bit 8-31 */
	225	__u32 op_flags;
	226
	227	__u32 nr_sectors;
	228
	229	/* start sector for this io */
	230	__u64 start_sector;
	231
	232	/* buffer address in ublksrv daemon vm space, from ublk driver */
	233	__u64 addr;
	234	};
	235
	236	static inline __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod)
	237	{
	238	return iod->op_flags & 0xff;
	239	}
	240
	241	static inline __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod)
	242	{
	243	return iod->op_flags >> 8;
	244	}
	245
	246	/* issued to ublk driver via /dev/ublkcN */
	247	struct ublksrv_io_cmd {
	248	__u16 q_id;
	249
	250	/* for fetch/commit which result */
	251	__u16 tag;
	252
	253	/* io result, it is valid for COMMIT* command only */
	254	__s32 result;
	255
	256	/*
	257	* userspace buffer address in ublksrv daemon process, valid for
	258	* FETCH* command only
	259	*/
	260	__u64 addr;
	261	};
	262
0aa73170 ML	263	struct ublk_param_basic {
	264	#define UBLK_ATTR_READ_ONLY (1 << 0)
	265	#define UBLK_ATTR_ROTATIONAL (1 << 1)
	266	#define UBLK_ATTR_VOLATILE_CACHE (1 << 2)
	267	#define UBLK_ATTR_FUA (1 << 3)
	268	__u32 attrs;
	269	__u8 logical_bs_shift;
	270	__u8 physical_bs_shift;
	271	__u8 io_opt_shift;
	272	__u8 io_min_shift;
	273
	274	__u32 max_sectors;
	275	__u32 chunk_sectors;
	276
	277	__u64 dev_sectors;
	278	__u64 virt_boundary_mask;
	279	};
	280
	281	struct ublk_param_discard {
	282	__u32 discard_alignment;
	283
	284	__u32 discard_granularity;
	285	__u32 max_discard_sectors;
	286
	287	__u32 max_write_zeroes_sectors;
	288	__u16 max_discard_segments;
	289	__u16 reserved0;
	290	};
	291
abb864d3 ML	292	/*
	293	* read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available
	294	* after device is started
	295	*/
	296	struct ublk_param_devt {
	297	__u32 char_major;
	298	__u32 char_minor;
	299	__u32 disk_major;
	300	__u32 disk_minor;
	301	};
	302
0aa73170 ML	303	struct ublk_params {
	304	/*
	305	* Total length of parameters, userspace has to set 'len' for both
	306	* SET_PARAMS and GET_PARAMS command, and driver may update len
	307	* if two sides use different version of 'ublk_params', same with
	308	* 'types' fields.
	309	*/
	310	__u32 len;
	311	#define UBLK_PARAM_TYPE_BASIC (1 << 0)
	312	#define UBLK_PARAM_TYPE_DISCARD (1 << 1)
abb864d3	313	#define UBLK_PARAM_TYPE_DEVT (1 << 2)
0aa73170 ML	314	__u32 types; /* types of parameter included */
	315
	316	struct ublk_param_basic basic;
	317	struct ublk_param_discard discard;
abb864d3	318	struct ublk_param_devt devt;
0aa73170 ML	319	};
0aa73170 ML	320
71f28f31	321	#endif