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.
11 */
12 #define UBLK_CMD_GET_QUEUE_AFFINITY 0x01
13 #define UBLK_CMD_GET_DEV_INFO 0x02
14 #define UBLK_CMD_ADD_DEV 0x04
15 #define UBLK_CMD_DEL_DEV 0x05
16 #define UBLK_CMD_START_DEV 0x06
17 #define UBLK_CMD_STOP_DEV 0x07
18 #define UBLK_CMD_SET_PARAMS 0x08
19 #define UBLK_CMD_GET_PARAMS 0x09
20 #define UBLK_CMD_START_USER_RECOVERY 0x10
21 #define UBLK_CMD_END_USER_RECOVERY 0x11
22 /*
23 * IO commands, issued by ublk server, and handled by ublk driver.
24 *
25 * FETCH_REQ: issued via sqe(URING_CMD) beforehand for fetching IO request
26 * from ublk driver, should be issued only when starting device. After
27 * the associated cqe is returned, request's tag can be retrieved via
28 * cqe->userdata.
29 *
30 * COMMIT_AND_FETCH_REQ: issued via sqe(URING_CMD) after ublkserver handled
31 * this IO request, request's handling result is committed to ublk
32 * driver, meantime FETCH_REQ is piggyback, and FETCH_REQ has to be
33 * handled before completing io request.
34 *
35 * NEED_GET_DATA: only used for write requests to set io addr and copy data
36 * When NEED_GET_DATA is set, ublksrv has to issue UBLK_IO_NEED_GET_DATA
37 * command after ublk driver returns UBLK_IO_RES_NEED_GET_DATA.
38 *
39 * It is only used if ublksrv set UBLK_F_NEED_GET_DATA flag
40 * while starting a ublk device.
41 */
42 #define UBLK_IO_FETCH_REQ 0x20
43 #define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21
44 #define UBLK_IO_NEED_GET_DATA 0x22
45
46 /* only ABORT means that no re-fetch */
47 #define UBLK_IO_RES_OK 0
48 #define UBLK_IO_RES_NEED_GET_DATA 1
49 #define UBLK_IO_RES_ABORT (-ENODEV)
50
51 #define UBLKSRV_CMD_BUF_OFFSET 0
52 #define UBLKSRV_IO_BUF_OFFSET 0x80000000
53
54 /* tag bit is 12bit, so at most 4096 IOs for each queue */
55 #define UBLK_MAX_QUEUE_DEPTH 4096
56
57 /*
58 * zero copy requires 4k block size, and can remap ublk driver's io
59 * request into ublksrv's vm space
60 */
61 #define UBLK_F_SUPPORT_ZERO_COPY (1ULL << 0)
62
63 /*
64 * Force to complete io cmd via io_uring_cmd_complete_in_task so that
65 * performance comparison is done easily with using task_work_add
66 */
67 #define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1)
68
69 /*
70 * User should issue io cmd again for write requests to
71 * set io buffer address and copy data from bio vectors
72 * to the userspace io buffer.
73 *
74 * In this mode, task_work is not used.
75 */
76 #define UBLK_F_NEED_GET_DATA (1UL << 2)
77
78 #define UBLK_F_USER_RECOVERY (1UL << 3)
79
80 #define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4)
81
82 /* device state */
83 #define UBLK_S_DEV_DEAD 0
84 #define UBLK_S_DEV_LIVE 1
85 #define UBLK_S_DEV_QUIESCED 2
86
87 /* shipped via sqe->cmd of io_uring command */
88 struct ublksrv_ctrl_cmd {
89 /* sent to which device, must be valid */
90 __u32 dev_id;
91
92 /* sent to which queue, must be -1 if the cmd isn't for queue */
93 __u16 queue_id;
94 /*
95 * cmd specific buffer, can be IN or OUT.
96 */
97 __u16 len;
98 __u64 addr;
99
100 /* inline data */
101 __u64 data[2];
102 };
103
104 struct ublksrv_ctrl_dev_info {
105 __u16 nr_hw_queues;
106 __u16 queue_depth;
107 __u16 state;
108 __u16 pad0;
109
110 __u32 max_io_buf_bytes;
111 __u32 dev_id;
112
113 __s32 ublksrv_pid;
114 __u32 pad1;
115
116 __u64 flags;
117
118 /* For ublksrv internal use, invisible to ublk driver */
119 __u64 ublksrv_flags;
120
121 __u64 reserved0;
122 __u64 reserved1;
123 __u64 reserved2;
124 };
125
126 #define UBLK_IO_OP_READ 0
127 #define UBLK_IO_OP_WRITE 1
128 #define UBLK_IO_OP_FLUSH 2
129 #define UBLK_IO_OP_DISCARD 3
130 #define UBLK_IO_OP_WRITE_SAME 4
131 #define UBLK_IO_OP_WRITE_ZEROES 5
132
133 #define UBLK_IO_F_FAILFAST_DEV (1U << 8)
134 #define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9)
135 #define UBLK_IO_F_FAILFAST_DRIVER (1U << 10)
136 #define UBLK_IO_F_META (1U << 11)
137 #define UBLK_IO_F_FUA (1U << 13)
138 #define UBLK_IO_F_NOUNMAP (1U << 15)
139 #define UBLK_IO_F_SWAP (1U << 16)
140
141 /*
142 * io cmd is described by this structure, and stored in share memory, indexed
143 * by request tag.
144 *
145 * The data is stored by ublk driver, and read by ublksrv after one fetch command
146 * returns.
147 */
148 struct ublksrv_io_desc {
149 /* op: bit 0-7, flags: bit 8-31 */
150 __u32 op_flags;
151
152 __u32 nr_sectors;
153
154 /* start sector for this io */
155 __u64 start_sector;
156
157 /* buffer address in ublksrv daemon vm space, from ublk driver */
158 __u64 addr;
159 };
160
ublksrv_get_op(const struct ublksrv_io_desc * iod)161 static inline __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod)
162 {
163 return iod->op_flags & 0xff;
164 }
165
ublksrv_get_flags(const struct ublksrv_io_desc * iod)166 static inline __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod)
167 {
168 return iod->op_flags >> 8;
169 }
170
171 /* issued to ublk driver via /dev/ublkcN */
172 struct ublksrv_io_cmd {
173 __u16 q_id;
174
175 /* for fetch/commit which result */
176 __u16 tag;
177
178 /* io result, it is valid for COMMIT* command only */
179 __s32 result;
180
181 /*
182 * userspace buffer address in ublksrv daemon process, valid for
183 * FETCH* command only
184 */
185 __u64 addr;
186 };
187
188 struct ublk_param_basic {
189 #define UBLK_ATTR_READ_ONLY (1 << 0)
190 #define UBLK_ATTR_ROTATIONAL (1 << 1)
191 #define UBLK_ATTR_VOLATILE_CACHE (1 << 2)
192 #define UBLK_ATTR_FUA (1 << 3)
193 __u32 attrs;
194 __u8 logical_bs_shift;
195 __u8 physical_bs_shift;
196 __u8 io_opt_shift;
197 __u8 io_min_shift;
198
199 __u32 max_sectors;
200 __u32 chunk_sectors;
201
202 __u64 dev_sectors;
203 __u64 virt_boundary_mask;
204 };
205
206 struct ublk_param_discard {
207 __u32 discard_alignment;
208
209 __u32 discard_granularity;
210 __u32 max_discard_sectors;
211
212 __u32 max_write_zeroes_sectors;
213 __u16 max_discard_segments;
214 __u16 reserved0;
215 };
216
217 struct ublk_params {
218 /*
219 * Total length of parameters, userspace has to set 'len' for both
220 * SET_PARAMS and GET_PARAMS command, and driver may update len
221 * if two sides use different version of 'ublk_params', same with
222 * 'types' fields.
223 */
224 __u32 len;
225 #define UBLK_PARAM_TYPE_BASIC (1 << 0)
226 #define UBLK_PARAM_TYPE_DISCARD (1 << 1)
227 __u32 types; /* types of parameter included */
228
229 struct ublk_param_basic basic;
230 struct ublk_param_discard discard;
231 };
232
233 #endif
234
