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 #define UBLK_U_IO_REGISTER_IO_BUF \
98 _IOWR('u', 0x23, struct ublksrv_io_cmd)
99 #define UBLK_U_IO_UNREGISTER_IO_BUF \
100 _IOWR('u', 0x24, struct ublksrv_io_cmd)
101
102 /* only ABORT means that no re-fetch */
103 #define UBLK_IO_RES_OK 0
104 #define UBLK_IO_RES_NEED_GET_DATA 1
105 #define UBLK_IO_RES_ABORT (-ENODEV)
106
107 #define UBLKSRV_CMD_BUF_OFFSET 0
108 #define UBLKSRV_IO_BUF_OFFSET 0x80000000
109
110 /* tag bit is 16bit, so far limit at most 4096 IOs for each queue */
111 #define UBLK_MAX_QUEUE_DEPTH 4096
112
113 /* single IO buffer max size is 32MB */
114 #define UBLK_IO_BUF_OFF 0
115 #define UBLK_IO_BUF_BITS 25
116 #define UBLK_IO_BUF_BITS_MASK ((1ULL << UBLK_IO_BUF_BITS) - 1)
117
118 /* so at most 64K IOs for each queue */
119 #define UBLK_TAG_OFF UBLK_IO_BUF_BITS
120 #define UBLK_TAG_BITS 16
121 #define UBLK_TAG_BITS_MASK ((1ULL << UBLK_TAG_BITS) - 1)
122
123 /* max 4096 queues */
124 #define UBLK_QID_OFF (UBLK_TAG_OFF + UBLK_TAG_BITS)
125 #define UBLK_QID_BITS 12
126 #define UBLK_QID_BITS_MASK ((1ULL << UBLK_QID_BITS) - 1)
127
128 #define UBLK_MAX_NR_QUEUES (1U << UBLK_QID_BITS)
129
130 #define UBLKSRV_IO_BUF_TOTAL_BITS (UBLK_QID_OFF + UBLK_QID_BITS)
131 #define UBLKSRV_IO_BUF_TOTAL_SIZE (1ULL << UBLKSRV_IO_BUF_TOTAL_BITS)
132
133 /*
134 * zero copy requires 4k block size, and can remap ublk driver's io
135 * request into ublksrv's vm space
136 */
137 #define UBLK_F_SUPPORT_ZERO_COPY (1ULL << 0)
138
139 /*
140 * Force to complete io cmd via io_uring_cmd_complete_in_task so that
141 * performance comparison is done easily with using task_work_add
142 */
143 #define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1)
144
145 /*
146 * User should issue io cmd again for write requests to
147 * set io buffer address and copy data from bio vectors
148 * to the userspace io buffer.
149 *
150 * In this mode, task_work is not used.
151 */
152 #define UBLK_F_NEED_GET_DATA (1UL << 2)
153
154 /*
155 * - Block devices are recoverable if ublk server exits and restarts
156 * - Outstanding I/O when ublk server exits is met with errors
157 * - I/O issued while there is no ublk server queues
158 */
159 #define UBLK_F_USER_RECOVERY (1UL << 3)
160
161 /*
162 * - Block devices are recoverable if ublk server exits and restarts
163 * - Outstanding I/O when ublk server exits is reissued
164 * - I/O issued while there is no ublk server queues
165 */
166 #define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4)
167
168 /*
169 * Unprivileged user can create /dev/ublkcN and /dev/ublkbN.
170 *
171 * /dev/ublk-control needs to be available for unprivileged user, and it
172 * can be done via udev rule to make all control commands available to
173 * unprivileged user. Except for the command of UBLK_CMD_ADD_DEV, all
174 * other commands are only allowed for the owner of the specified device.
175 *
176 * When userspace sends UBLK_CMD_ADD_DEV, the device pair's owner_uid and
177 * owner_gid are stored to ublksrv_ctrl_dev_info by kernel, so far only
178 * the current user's uid/gid is stored, that said owner of the created
179 * device is always the current user.
180 *
181 * We still need udev rule to apply OWNER/GROUP with the stored owner_uid
182 * and owner_gid.
183 *
184 * Then ublk server can be run as unprivileged user, and /dev/ublkbN can
185 * be accessed and managed by its owner represented by owner_uid/owner_gid.
186 */
187 #define UBLK_F_UNPRIVILEGED_DEV (1UL << 5)
188
189 /* use ioctl encoding for uring command */
190 #define UBLK_F_CMD_IOCTL_ENCODE (1UL << 6)
191
192 /*
193 * Copy between request and user buffer by pread()/pwrite()
194 *
195 * Not available for UBLK_F_UNPRIVILEGED_DEV, otherwise userspace may
196 * deceive us by not filling request buffer, then kernel uninitialized
197 * data may be leaked.
198 */
199 #define UBLK_F_USER_COPY (1UL << 7)
200
201 /*
202 * User space sets this flag when setting up the device to request zoned storage support. Kernel may
203 * deny the request by returning an error.
204 */
205 #define UBLK_F_ZONED (1ULL << 8)
206
207 /*
208 * - Block devices are recoverable if ublk server exits and restarts
209 * - Outstanding I/O when ublk server exits is met with errors
210 * - I/O issued while there is no ublk server is met with errors
211 */
212 #define UBLK_F_USER_RECOVERY_FAIL_IO (1ULL << 9)
213
214 /* device state */
215 #define UBLK_S_DEV_DEAD 0
216 #define UBLK_S_DEV_LIVE 1
217 #define UBLK_S_DEV_QUIESCED 2
218 #define UBLK_S_DEV_FAIL_IO 3
219
220 /* shipped via sqe->cmd of io_uring command */
221 struct ublksrv_ctrl_cmd {
222 /* sent to which device, must be valid */
223 __u32 dev_id;
224
225 /* sent to which queue, must be -1 if the cmd isn't for queue */
226 __u16 queue_id;
227 /*
228 * cmd specific buffer, can be IN or OUT.
229 */
230 __u16 len;
231 __u64 addr;
232
233 /* inline data */
234 __u64 data[1];
235
236 /*
237 * Used for UBLK_F_UNPRIVILEGED_DEV and UBLK_CMD_GET_DEV_INFO2
238 * only, include null char
239 */
240 __u16 dev_path_len;
241 __u16 pad;
242 __u32 reserved;
243 };
244
245 struct ublksrv_ctrl_dev_info {
246 __u16 nr_hw_queues;
247 __u16 queue_depth;
248 __u16 state;
249 __u16 pad0;
250
251 __u32 max_io_buf_bytes;
252 __u32 dev_id;
253
254 __s32 ublksrv_pid;
255 __u32 pad1;
256
257 __u64 flags;
258
259 /* For ublksrv internal use, invisible to ublk driver */
260 __u64 ublksrv_flags;
261
262 __u32 owner_uid; /* store by kernel */
263 __u32 owner_gid; /* store by kernel */
264 __u64 reserved1;
265 __u64 reserved2;
266 };
267
268 #define UBLK_IO_OP_READ 0
269 #define UBLK_IO_OP_WRITE 1
270 #define UBLK_IO_OP_FLUSH 2
271 #define UBLK_IO_OP_DISCARD 3
272 #define UBLK_IO_OP_WRITE_SAME 4
273 #define UBLK_IO_OP_WRITE_ZEROES 5
274 #define UBLK_IO_OP_ZONE_OPEN 10
275 #define UBLK_IO_OP_ZONE_CLOSE 11
276 #define UBLK_IO_OP_ZONE_FINISH 12
277 #define UBLK_IO_OP_ZONE_APPEND 13
278 #define UBLK_IO_OP_ZONE_RESET_ALL 14
279 #define UBLK_IO_OP_ZONE_RESET 15
280 /*
281 * Construct a zone report. The report request is carried in `struct
282 * ublksrv_io_desc`. The `start_sector` field must be the first sector of a zone
283 * and shall indicate the first zone of the report. The `nr_zones` shall
284 * indicate how many zones should be reported at most. The report shall be
285 * delivered as a `struct blk_zone` array. To report fewer zones than requested,
286 * zero the last entry of the returned array.
287 *
288 * Related definitions(blk_zone, blk_zone_cond, blk_zone_type, ...) in
289 * include/uapi/linux/blkzoned.h are part of ublk UAPI.
290 */
291 #define UBLK_IO_OP_REPORT_ZONES 18
292
293 #define UBLK_IO_F_FAILFAST_DEV (1U << 8)
294 #define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9)
295 #define UBLK_IO_F_FAILFAST_DRIVER (1U << 10)
296 #define UBLK_IO_F_META (1U << 11)
297 #define UBLK_IO_F_FUA (1U << 13)
298 #define UBLK_IO_F_NOUNMAP (1U << 15)
299 #define UBLK_IO_F_SWAP (1U << 16)
300
301 /*
302 * io cmd is described by this structure, and stored in share memory, indexed
303 * by request tag.
304 *
305 * The data is stored by ublk driver, and read by ublksrv after one fetch command
306 * returns.
307 */
308 struct ublksrv_io_desc {
309 /* op: bit 0-7, flags: bit 8-31 */
310 __u32 op_flags;
311
312 union {
313 __u32 nr_sectors;
314 __u32 nr_zones; /* for UBLK_IO_OP_REPORT_ZONES */
315 };
316
317 /* start sector for this io */
318 __u64 start_sector;
319
320 /* buffer address in ublksrv daemon vm space, from ublk driver */
321 __u64 addr;
322 };
323
ublksrv_get_op(const struct ublksrv_io_desc * iod)324 static inline __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod)
325 {
326 return iod->op_flags & 0xff;
327 }
328
ublksrv_get_flags(const struct ublksrv_io_desc * iod)329 static inline __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod)
330 {
331 return iod->op_flags >> 8;
332 }
333
334 /* issued to ublk driver via /dev/ublkcN */
335 struct ublksrv_io_cmd {
336 __u16 q_id;
337
338 /* for fetch/commit which result */
339 __u16 tag;
340
341 /* io result, it is valid for COMMIT* command only */
342 __s32 result;
343
344 union {
345 /*
346 * userspace buffer address in ublksrv daemon process, valid for
347 * FETCH* command only
348 *
349 * `addr` should not be used when UBLK_F_USER_COPY is enabled,
350 * because userspace handles data copy by pread()/pwrite() over
351 * /dev/ublkcN. But in case of UBLK_F_ZONED, this union is
352 * re-used to pass back the allocated LBA for
353 * UBLK_IO_OP_ZONE_APPEND which actually depends on
354 * UBLK_F_USER_COPY
355 */
356 __u64 addr;
357 __u64 zone_append_lba;
358 };
359 };
360
361 struct ublk_param_basic {
362 #define UBLK_ATTR_READ_ONLY (1 << 0)
363 #define UBLK_ATTR_ROTATIONAL (1 << 1)
364 #define UBLK_ATTR_VOLATILE_CACHE (1 << 2)
365 #define UBLK_ATTR_FUA (1 << 3)
366 __u32 attrs;
367 __u8 logical_bs_shift;
368 __u8 physical_bs_shift;
369 __u8 io_opt_shift;
370 __u8 io_min_shift;
371
372 __u32 max_sectors;
373 __u32 chunk_sectors;
374
375 __u64 dev_sectors;
376 __u64 virt_boundary_mask;
377 };
378
379 struct ublk_param_discard {
380 __u32 discard_alignment;
381
382 __u32 discard_granularity;
383 __u32 max_discard_sectors;
384
385 __u32 max_write_zeroes_sectors;
386 __u16 max_discard_segments;
387 __u16 reserved0;
388 };
389
390 /*
391 * read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available
392 * after device is started
393 */
394 struct ublk_param_devt {
395 __u32 char_major;
396 __u32 char_minor;
397 __u32 disk_major;
398 __u32 disk_minor;
399 };
400
401 struct ublk_param_zoned {
402 __u32 max_open_zones;
403 __u32 max_active_zones;
404 __u32 max_zone_append_sectors;
405 __u8 reserved[20];
406 };
407
408 struct ublk_param_dma_align {
409 __u32 alignment;
410 __u8 pad[4];
411 };
412
413 struct ublk_params {
414 /*
415 * Total length of parameters, userspace has to set 'len' for both
416 * SET_PARAMS and GET_PARAMS command, and driver may update len
417 * if two sides use different version of 'ublk_params', same with
418 * 'types' fields.
419 */
420 __u32 len;
421 #define UBLK_PARAM_TYPE_BASIC (1 << 0)
422 #define UBLK_PARAM_TYPE_DISCARD (1 << 1)
423 #define UBLK_PARAM_TYPE_DEVT (1 << 2)
424 #define UBLK_PARAM_TYPE_ZONED (1 << 3)
425 #define UBLK_PARAM_TYPE_DMA_ALIGN (1 << 4)
426 __u32 types; /* types of parameter included */
427
428 struct ublk_param_basic basic;
429 struct ublk_param_discard discard;
430 struct ublk_param_devt devt;
431 struct ublk_param_zoned zoned;
432 struct ublk_param_dma_align dma;
433 };
434
435 #endif
436