linux-headers (unknown)
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 * Legacy command definition, don't use in new application, and don't
13 * add new such definition any more
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
21 #define UBLK_CMD_SET_PARAMS 0x08
22 #define UBLK_CMD_GET_PARAMS 0x09
23 #define UBLK_CMD_START_USER_RECOVERY 0x10
24 #define UBLK_CMD_END_USER_RECOVERY 0x11
25 #define UBLK_CMD_GET_DEV_INFO2 0x12
26
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
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.
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.
70 */
71
72 /*
73 * Legacy IO command definition, don't use in new application, and don't
74 * add new such definition any more
75 */
76 #define UBLK_IO_FETCH_REQ 0x20
77 #define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21
78 #define UBLK_IO_NEED_GET_DATA 0x22
79
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
88 /* only ABORT means that no re-fetch */
89 #define UBLK_IO_RES_OK 0
90 #define UBLK_IO_RES_NEED_GET_DATA 1
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 */
103 #define UBLK_F_SUPPORT_ZERO_COPY (1ULL << 0)
104
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 */
109 #define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1)
110
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
120 #define UBLK_F_USER_RECOVERY (1UL << 3)
121
122 #define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4)
123
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
145 /* use ioctl encoding for uring command */
146 #define UBLK_F_CMD_IOCTL_ENCODE (1UL << 6)
147
148 /* device state */
149 #define UBLK_S_DEV_DEAD 0
150 #define UBLK_S_DEV_LIVE 1
151 #define UBLK_S_DEV_QUIESCED 2
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 */
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;
176 };
177
178 struct ublksrv_ctrl_dev_info {
179 __u16 nr_hw_queues;
180 __u16 queue_depth;
181 __u16 state;
182 __u16 pad0;
183
184 __u32 max_io_buf_bytes;
185 __u32 dev_id;
186
187 __s32 ublksrv_pid;
188 __u32 pad1;
189
190 __u64 flags;
191
192 /* For ublksrv internal use, invisible to ublk driver */
193 __u64 ublksrv_flags;
194
195 __u32 owner_uid; /* store by kernel */
196 __u32 owner_gid; /* store by kernel */
197 __u64 reserved1;
198 __u64 reserved2;
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)
212 #define UBLK_IO_F_FUA (1U << 13)
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
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
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
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)
313 #define UBLK_PARAM_TYPE_DEVT (1 << 2)
314 __u32 types; /* types of parameter included */
315
316 struct ublk_param_basic basic;
317 struct ublk_param_discard discard;
318 struct ublk_param_devt devt;
319 };
320
321 #endif
Browse
Usage
Versions