1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
|
/* 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
/*
* 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)
/* 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 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;
__u64 reserved0;
__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;
};
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)
__u32 types; /* types of parameter included */
struct ublk_param_basic basic;
struct ublk_param_discard discard;
};
#endif
|
