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
5 #include <linux/types.h>
7 /* ublk server command definition */
10 * Admin commands, issued by ublk server, and handled by ublk driver.
12 * Legacy command definition, don't use in new application, and don't
13 * add new such definition any more
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
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)
52 * IO commands, issued by ublk server, and handled by ublk driver.
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
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.
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.
68 * It is only used if ublksrv set UBLK_F_NEED_GET_DATA flag
69 * while starting a ublk device.
73 * Legacy IO command definition, don't use in new application, and don't
74 * add new such definition any more
76 #define UBLK_IO_FETCH_REQ 0x20
77 #define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21
78 #define UBLK_IO_NEED_GET_DATA 0x22
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)
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)
93 #define UBLKSRV_CMD_BUF_OFFSET 0
94 #define UBLKSRV_IO_BUF_OFFSET 0x80000000
96 /* tag bit is 16bit, so far limit at most 4096 IOs for each queue */
97 #define UBLK_MAX_QUEUE_DEPTH 4096
99 /* single IO buffer max size is 32MB */
100 #define UBLK_IO_BUF_OFF 0
101 #define UBLK_IO_BUF_BITS 25
102 #define UBLK_IO_BUF_BITS_MASK ((1ULL << UBLK_IO_BUF_BITS) - 1)
104 /* so at most 64K IOs for each queue */
105 #define UBLK_TAG_OFF UBLK_IO_BUF_BITS
106 #define UBLK_TAG_BITS 16
107 #define UBLK_TAG_BITS_MASK ((1ULL << UBLK_TAG_BITS) - 1)
109 /* max 4096 queues */
110 #define UBLK_QID_OFF (UBLK_TAG_OFF + UBLK_TAG_BITS)
111 #define UBLK_QID_BITS 12
112 #define UBLK_QID_BITS_MASK ((1ULL << UBLK_QID_BITS) - 1)
114 #define UBLK_MAX_NR_QUEUES (1U << UBLK_QID_BITS)
116 #define UBLKSRV_IO_BUF_TOTAL_BITS (UBLK_QID_OFF + UBLK_QID_BITS)
117 #define UBLKSRV_IO_BUF_TOTAL_SIZE (1ULL << UBLKSRV_IO_BUF_TOTAL_BITS)
120 * zero copy requires 4k block size, and can remap ublk driver's io
121 * request into ublksrv's vm space
123 #define UBLK_F_SUPPORT_ZERO_COPY (1ULL << 0)
126 * Force to complete io cmd via io_uring_cmd_complete_in_task so that
127 * performance comparison is done easily with using task_work_add
129 #define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1)
132 * User should issue io cmd again for write requests to
133 * set io buffer address and copy data from bio vectors
134 * to the userspace io buffer.
136 * In this mode, task_work is not used.
138 #define UBLK_F_NEED_GET_DATA (1UL << 2)
140 #define UBLK_F_USER_RECOVERY (1UL << 3)
142 #define UBLK_F_USER_RECOVERY_REISSUE (1UL << 4)
145 * Unprivileged user can create /dev/ublkcN and /dev/ublkbN.
147 * /dev/ublk-control needs to be available for unprivileged user, and it
148 * can be done via udev rule to make all control commands available to
149 * unprivileged user. Except for the command of UBLK_CMD_ADD_DEV, all
150 * other commands are only allowed for the owner of the specified device.
152 * When userspace sends UBLK_CMD_ADD_DEV, the device pair's owner_uid and
153 * owner_gid are stored to ublksrv_ctrl_dev_info by kernel, so far only
154 * the current user's uid/gid is stored, that said owner of the created
155 * device is always the current user.
157 * We still need udev rule to apply OWNER/GROUP with the stored owner_uid
160 * Then ublk server can be run as unprivileged user, and /dev/ublkbN can
161 * be accessed and managed by its owner represented by owner_uid/owner_gid.
163 #define UBLK_F_UNPRIVILEGED_DEV (1UL << 5)
165 /* use ioctl encoding for uring command */
166 #define UBLK_F_CMD_IOCTL_ENCODE (1UL << 6)
168 /* Copy between request and user buffer by pread()/pwrite() */
169 #define UBLK_F_USER_COPY (1UL << 7)
172 #define UBLK_S_DEV_DEAD 0
173 #define UBLK_S_DEV_LIVE 1
174 #define UBLK_S_DEV_QUIESCED 2
176 /* shipped via sqe->cmd of io_uring command */
177 struct ublksrv_ctrl_cmd {
178 /* sent to which device, must be valid */
181 /* sent to which queue, must be -1 if the cmd isn't for queue */
184 * cmd specific buffer, can be IN or OUT.
193 * Used for UBLK_F_UNPRIVILEGED_DEV and UBLK_CMD_GET_DEV_INFO2
194 * only, include null char
201 struct ublksrv_ctrl_dev_info {
207 __u32 max_io_buf_bytes;
215 /* For ublksrv internal use, invisible to ublk driver */
218 __u32 owner_uid; /* store by kernel */
219 __u32 owner_gid; /* store by kernel */
224 #define UBLK_IO_OP_READ 0
225 #define UBLK_IO_OP_WRITE 1
226 #define UBLK_IO_OP_FLUSH 2
227 #define UBLK_IO_OP_DISCARD 3
228 #define UBLK_IO_OP_WRITE_SAME 4
229 #define UBLK_IO_OP_WRITE_ZEROES 5
231 #define UBLK_IO_F_FAILFAST_DEV (1U << 8)
232 #define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9)
233 #define UBLK_IO_F_FAILFAST_DRIVER (1U << 10)
234 #define UBLK_IO_F_META (1U << 11)
235 #define UBLK_IO_F_FUA (1U << 13)
236 #define UBLK_IO_F_NOUNMAP (1U << 15)
237 #define UBLK_IO_F_SWAP (1U << 16)
240 * io cmd is described by this structure, and stored in share memory, indexed
243 * The data is stored by ublk driver, and read by ublksrv after one fetch command
246 struct ublksrv_io_desc {
247 /* op: bit 0-7, flags: bit 8-31 */
252 /* start sector for this io */
255 /* buffer address in ublksrv daemon vm space, from ublk driver */
259 static inline __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod)
261 return iod->op_flags & 0xff;
264 static inline __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod)
266 return iod->op_flags >> 8;
269 /* issued to ublk driver via /dev/ublkcN */
270 struct ublksrv_io_cmd {
273 /* for fetch/commit which result */
276 /* io result, it is valid for COMMIT* command only */
280 * userspace buffer address in ublksrv daemon process, valid for
281 * FETCH* command only
286 struct ublk_param_basic {
287 #define UBLK_ATTR_READ_ONLY (1 << 0)
288 #define UBLK_ATTR_ROTATIONAL (1 << 1)
289 #define UBLK_ATTR_VOLATILE_CACHE (1 << 2)
290 #define UBLK_ATTR_FUA (1 << 3)
292 __u8 logical_bs_shift;
293 __u8 physical_bs_shift;
301 __u64 virt_boundary_mask;
304 struct ublk_param_discard {
305 __u32 discard_alignment;
307 __u32 discard_granularity;
308 __u32 max_discard_sectors;
310 __u32 max_write_zeroes_sectors;
311 __u16 max_discard_segments;
316 * read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available
317 * after device is started
319 struct ublk_param_devt {
328 * Total length of parameters, userspace has to set 'len' for both
329 * SET_PARAMS and GET_PARAMS command, and driver may update len
330 * if two sides use different version of 'ublk_params', same with
334 #define UBLK_PARAM_TYPE_BASIC (1 << 0)
335 #define UBLK_PARAM_TYPE_DISCARD (1 << 1)
336 #define UBLK_PARAM_TYPE_DEVT (1 << 2)
337 __u32 types; /* types of parameter included */
339 struct ublk_param_basic basic;
340 struct ublk_param_discard discard;
341 struct ublk_param_devt devt;