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 #define UBLK_U_CMD_GET_FEATURES \
51 _IOR('u', 0x13, struct ublksrv_ctrl_cmd)
52 #define UBLK_U_CMD_DEL_DEV_ASYNC \
53 _IOR('u', 0x14, struct ublksrv_ctrl_cmd)
54
55 /*
56 * 64bits are enough now, and it should be easy to extend in case of
57 * running out of feature flags
58 */
59 #define UBLK_FEATURES_LEN 8
60
61 /*
62 * IO commands, issued by ublk server, and handled by ublk driver.
63 *
64 * FETCH_REQ: issued via sqe(URING_CMD) beforehand for fetching IO request
65 * from ublk driver, should be issued only when starting device. After
66 * the associated cqe is returned, request's tag can be retrieved via
67 * cqe->userdata.
68 *
69 * COMMIT_AND_FETCH_REQ: issued via sqe(URING_CMD) after ublkserver handled
70 * this IO request, request's handling result is committed to ublk
71 * driver, meantime FETCH_REQ is piggyback, and FETCH_REQ has to be
72 * handled before completing io request.
73 *
74 * NEED_GET_DATA: only used for write requests to set io addr and copy data
75 * When NEED_GET_DATA is set, ublksrv has to issue UBLK_IO_NEED_GET_DATA
76 * command after ublk driver returns UBLK_IO_RES_NEED_GET_DATA.
77 *
78 * It is only used if ublksrv set UBLK_F_NEED_GET_DATA flag
79 * while starting a ublk device.
80 */
81
82 /*
83 * Legacy IO command definition, don't use in new application, and don't
84 * add new such definition any more
85 */
86 #define UBLK_IO_FETCH_REQ 0x20
87 #define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21
88 #define UBLK_IO_NEED_GET_DATA 0x22
89
90 /* Any new IO command should encode by __IOWR() */
91 #define UBLK_U_IO_FETCH_REQ \
92 _IOWR('u', UBLK_IO_FETCH_REQ, struct ublksrv_io_cmd)
93 #define UBLK_U_IO_COMMIT_AND_FETCH_REQ \
94 _IOWR('u', UBLK_IO_COMMIT_AND_FETCH_REQ, struct ublksrv_io_cmd)
95 #define UBLK_U_IO_NEED_GET_DATA \
96 _IOWR('u', UBLK_IO_NEED_GET_DATA, struct ublksrv_io_cmd)
97
98 /* only ABORT means that no re-fetch */
99 #define UBLK_IO_RES_OK 0
100 #define UBLK_IO_RES_NEED_GET_DATA 1
101 #define UBLK_IO_RES_ABORT (-ENODEV)
102
103 #define UBLKSRV_CMD_BUF_OFFSET 0
104 #define UBLKSRV_IO_BUF_OFFSET 0x80000000
105
106 /* tag bit is 16bit, so far limit at most 4096 IOs for each queue */
107 #define UBLK_MAX_QUEUE_DEPTH 4096
108
109 /* single IO buffer max size is 32MB */
110 #define UBLK_IO_BUF_OFF 0
111 #define UBLK_IO_BUF_BITS 25
112 #define UBLK_IO_BUF_BITS_MASK ((1ULL << UBLK_IO_BUF_BITS) - 1)
113
114 /* so at most 64K IOs for each queue */
115 #define UBLK_TAG_OFF UBLK_IO_BUF_BITS
116 #define UBLK_TAG_BITS 16
117 #define UBLK_TAG_BITS_MASK ((1ULL << UBLK_TAG_BITS) - 1)
118
119 /* max 4096 queues */
120 #define UBLK_QID_OFF (UBLK_TAG_OFF + UBLK_TAG_BITS)
121 #define UBLK_QID_BITS 12
122 #define UBLK_QID_BITS_MASK ((1ULL << UBLK_QID_BITS) - 1)
123
124 #define UBLK_MAX_NR_QUEUES (1U << UBLK_QID_BITS)
125
126 #define UBLKSRV_IO_BUF_TOTAL_BITS (UBLK_QID_OFF + UBLK_QID_BITS)
127 #define UBLKSRV_IO_BUF_TOTAL_SIZE (1ULL << UBLKSRV_IO_BUF_TOTAL_BITS)
128
129 /*
130 * zero copy requires 4k block size, and can remap ublk driver's io
131 * request into ublksrv's vm space
132 */
133 #define UBLK_F_SUPPORT_ZERO_COPY (1ULL << 0)
134
135 /*
136 * Force to complete io cmd via io_uring_cmd_complete_in_task so that
137 * performance comparison is done easily with using task_work_add
138 */
139 #define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1)
140
141 /*
142 * User should issue io cmd again for write requests to
143 * set io buffer address and copy data from bio vectors
144 * to the userspace io buffer.
145 *
146 * In this mode, task_work is not used.
147 */
148 #define UBLK_F_NEED_GET_DATA (1UL << 2)
149
150 #define UBLK_F_USER_RECOVERY (1UL << 3)
151
152 #define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4)
153
154 /*
155 * Unprivileged user can create /dev/ublkcN and /dev/ublkbN.
156 *
157 * /dev/ublk-control needs to be available for unprivileged user, and it
158 * can be done via udev rule to make all control commands available to
159 * unprivileged user. Except for the command of UBLK_CMD_ADD_DEV, all
160 * other commands are only allowed for the owner of the specified device.
161 *
162 * When userspace sends UBLK_CMD_ADD_DEV, the device pair's owner_uid and
163 * owner_gid are stored to ublksrv_ctrl_dev_info by kernel, so far only
164 * the current user's uid/gid is stored, that said owner of the created
165 * device is always the current user.
166 *
167 * We still need udev rule to apply OWNER/GROUP with the stored owner_uid
168 * and owner_gid.
169 *
170 * Then ublk server can be run as unprivileged user, and /dev/ublkbN can
171 * be accessed and managed by its owner represented by owner_uid/owner_gid.
172 */
173 #define UBLK_F_UNPRIVILEGED_DEV (1UL << 5)
174
175 /* use ioctl encoding for uring command */
176 #define UBLK_F_CMD_IOCTL_ENCODE (1UL << 6)
177
178 /*
179 * Copy between request and user buffer by pread()/pwrite()
180 *
181 * Not available for UBLK_F_UNPRIVILEGED_DEV, otherwise userspace may
182 * deceive us by not filling request buffer, then kernel uninitialized
183 * data may be leaked.
184 */
185 #define UBLK_F_USER_COPY (1UL << 7)
186
187 /*
188 * User space sets this flag when setting up the device to request zoned storage support. Kernel may
189 * deny the request by returning an error.
190 */
191 #define UBLK_F_ZONED (1ULL << 8)
192
193 /* device state */
194 #define UBLK_S_DEV_DEAD 0
195 #define UBLK_S_DEV_LIVE 1
196 #define UBLK_S_DEV_QUIESCED 2
197
198 /* shipped via sqe->cmd of io_uring command */
199 struct ublksrv_ctrl_cmd {
200 /* sent to which device, must be valid */
201 __u32 dev_id;
202
203 /* sent to which queue, must be -1 if the cmd isn't for queue */
204 __u16 queue_id;
205 /*
206 * cmd specific buffer, can be IN or OUT.
207 */
208 __u16 len;
209 __u64 addr;
210
211 /* inline data */
212 __u64 data[1];
213
214 /*
215 * Used for UBLK_F_UNPRIVILEGED_DEV and UBLK_CMD_GET_DEV_INFO2
216 * only, include null char
217 */
218 __u16 dev_path_len;
219 __u16 pad;
220 __u32 reserved;
221 };
222
223 struct ublksrv_ctrl_dev_info {
224 __u16 nr_hw_queues;
225 __u16 queue_depth;
226 __u16 state;
227 __u16 pad0;
228
229 __u32 max_io_buf_bytes;
230 __u32 dev_id;
231
232 __s32 ublksrv_pid;
233 __u32 pad1;
234
235 __u64 flags;
236
237 /* For ublksrv internal use, invisible to ublk driver */
238 __u64 ublksrv_flags;
239
240 __u32 owner_uid; /* store by kernel */
241 __u32 owner_gid; /* store by kernel */
242 __u64 reserved1;
243 __u64 reserved2;
244 };
245
246 #define UBLK_IO_OP_READ 0
247 #define UBLK_IO_OP_WRITE 1
248 #define UBLK_IO_OP_FLUSH 2
249 #define UBLK_IO_OP_DISCARD 3
250 #define UBLK_IO_OP_WRITE_SAME 4
251 #define UBLK_IO_OP_WRITE_ZEROES 5
252 #define UBLK_IO_OP_ZONE_OPEN 10
253 #define UBLK_IO_OP_ZONE_CLOSE 11
254 #define UBLK_IO_OP_ZONE_FINISH 12
255 #define UBLK_IO_OP_ZONE_APPEND 13
256 #define UBLK_IO_OP_ZONE_RESET_ALL 14
257 #define UBLK_IO_OP_ZONE_RESET 15
258 /*
259 * Construct a zone report. The report request is carried in `struct
260 * ublksrv_io_desc`. The `start_sector` field must be the first sector of a zone
261 * and shall indicate the first zone of the report. The `nr_zones` shall
262 * indicate how many zones should be reported at most. The report shall be
263 * delivered as a `struct blk_zone` array. To report fewer zones than requested,
264 * zero the last entry of the returned array.
265 *
266 * Related definitions(blk_zone, blk_zone_cond, blk_zone_type, ...) in
267 * include/uapi/linux/blkzoned.h are part of ublk UAPI.
268 */
269 #define UBLK_IO_OP_REPORT_ZONES 18
270
271 #define UBLK_IO_F_FAILFAST_DEV (1U << 8)
272 #define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9)
273 #define UBLK_IO_F_FAILFAST_DRIVER (1U << 10)
274 #define UBLK_IO_F_META (1U << 11)
275 #define UBLK_IO_F_FUA (1U << 13)
276 #define UBLK_IO_F_NOUNMAP (1U << 15)
277 #define UBLK_IO_F_SWAP (1U << 16)
278
279 /*
280 * io cmd is described by this structure, and stored in share memory, indexed
281 * by request tag.
282 *
283 * The data is stored by ublk driver, and read by ublksrv after one fetch command
284 * returns.
285 */
286 struct ublksrv_io_desc {
287 /* op: bit 0-7, flags: bit 8-31 */
288 __u32 op_flags;
289
290 union {
291 __u32 nr_sectors;
292 __u32 nr_zones; /* for UBLK_IO_OP_REPORT_ZONES */
293 };
294
295 /* start sector for this io */
296 __u64 start_sector;
297
298 /* buffer address in ublksrv daemon vm space, from ublk driver */
299 __u64 addr;
300 };
301
ublksrv_get_op(const struct ublksrv_io_desc * iod)302 static inline __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod)
303 {
304 return iod->op_flags & 0xff;
305 }
306
ublksrv_get_flags(const struct ublksrv_io_desc * iod)307 static inline __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod)
308 {
309 return iod->op_flags >> 8;
310 }
311
312 /* issued to ublk driver via /dev/ublkcN */
313 struct ublksrv_io_cmd {
314 __u16 q_id;
315
316 /* for fetch/commit which result */
317 __u16 tag;
318
319 /* io result, it is valid for COMMIT* command only */
320 __s32 result;
321
322 union {
323 /*
324 * userspace buffer address in ublksrv daemon process, valid for
325 * FETCH* command only
326 *
327 * `addr` should not be used when UBLK_F_USER_COPY is enabled,
328 * because userspace handles data copy by pread()/pwrite() over
329 * /dev/ublkcN. But in case of UBLK_F_ZONED, this union is
330 * re-used to pass back the allocated LBA for
331 * UBLK_IO_OP_ZONE_APPEND which actually depends on
332 * UBLK_F_USER_COPY
333 */
334 __u64 addr;
335 __u64 zone_append_lba;
336 };
337 };
338
339 struct ublk_param_basic {
340 #define UBLK_ATTR_READ_ONLY (1 << 0)
341 #define UBLK_ATTR_ROTATIONAL (1 << 1)
342 #define UBLK_ATTR_VOLATILE_CACHE (1 << 2)
343 #define UBLK_ATTR_FUA (1 << 3)
344 __u32 attrs;
345 __u8 logical_bs_shift;
346 __u8 physical_bs_shift;
347 __u8 io_opt_shift;
348 __u8 io_min_shift;
349
350 __u32 max_sectors;
351 __u32 chunk_sectors;
352
353 __u64 dev_sectors;
354 __u64 virt_boundary_mask;
355 };
356
357 struct ublk_param_discard {
358 __u32 discard_alignment;
359
360 __u32 discard_granularity;
361 __u32 max_discard_sectors;
362
363 __u32 max_write_zeroes_sectors;
364 __u16 max_discard_segments;
365 __u16 reserved0;
366 };
367
368 /*
369 * read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available
370 * after device is started
371 */
372 struct ublk_param_devt {
373 __u32 char_major;
374 __u32 char_minor;
375 __u32 disk_major;
376 __u32 disk_minor;
377 };
378
379 struct ublk_param_zoned {
380 __u32 max_open_zones;
381 __u32 max_active_zones;
382 __u32 max_zone_append_sectors;
383 __u8 reserved[20];
384 };
385
386 struct ublk_params {
387 /*
388 * Total length of parameters, userspace has to set 'len' for both
389 * SET_PARAMS and GET_PARAMS command, and driver may update len
390 * if two sides use different version of 'ublk_params', same with
391 * 'types' fields.
392 */
393 __u32 len;
394 #define UBLK_PARAM_TYPE_BASIC (1 << 0)
395 #define UBLK_PARAM_TYPE_DISCARD (1 << 1)
396 #define UBLK_PARAM_TYPE_DEVT (1 << 2)
397 #define UBLK_PARAM_TYPE_ZONED (1 << 3)
398 __u32 types; /* types of parameter included */
399
400 struct ublk_param_basic basic;
401 struct ublk_param_discard discard;
402 struct ublk_param_devt devt;
403 struct ublk_param_zoned zoned;
404 };
405
406 #endif
407