1 /* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */
3 * Header file for the io_uring interface.
5 * Copyright (C) 2019 Jens Axboe
6 * Copyright (C) 2019 Christoph Hellwig
8 #ifndef LINUX_IO_URING_H
9 #define LINUX_IO_URING_H
12 #include <linux/types.h>
14 * this file is shared with liburing and that has to autodetect
15 * if linux/time_types.h is available or not, it can
16 * define UAPI_LINUX_IO_URING_H_SKIP_LINUX_TIME_TYPES_H
17 * if linux/time_types.h is not available
19 #ifndef UAPI_LINUX_IO_URING_H_SKIP_LINUX_TIME_TYPES_H
20 #include <linux/time_types.h>
28 * IO submission data structure (Submission Queue Entry)
31 __u8 opcode; /* type of operation for this sqe */
32 __u8 flags; /* IOSQE_ flags */
33 __u16 ioprio; /* ioprio for the request */
34 __s32 fd; /* file descriptor to do IO on */
36 __u64 off; /* offset into file */
44 __u64 addr; /* pointer to buffer or iovecs */
51 __u32 len; /* buffer size or number of iovecs */
53 __kernel_rwf_t rw_flags;
55 __u16 poll_events; /* compatibility */
56 __u32 poll32_events; /* word-reversed for BE */
57 __u32 sync_range_flags;
71 __u32 uring_cmd_flags;
74 __u32 install_fd_flags;
76 __u64 user_data; /* data to be passed back at completion time */
77 /* pack this to avoid bogus arm OABI complaints */
79 /* index into fixed buffers, if used */
81 /* for grouped buffer selection */
83 } __attribute__((packed));
84 /* personality to use, if used */
102 * If the ring is initialized with IORING_SETUP_SQE128, then
103 * this field is used for 80 bytes of arbitrary command data
110 * If sqe->file_index is set to this for opcodes that instantiate a new
111 * direct descriptor (like openat/openat2/accept), then io_uring will allocate
112 * an available direct descriptor instead of having the application pass one
113 * in. The picked direct descriptor will be returned in cqe->res, or -ENFILE
114 * if the space is full.
116 #define IORING_FILE_INDEX_ALLOC (~0U)
119 IOSQE_FIXED_FILE_BIT,
122 IOSQE_IO_HARDLINK_BIT,
124 IOSQE_BUFFER_SELECT_BIT,
125 IOSQE_CQE_SKIP_SUCCESS_BIT,
131 /* use fixed fileset */
132 #define IOSQE_FIXED_FILE (1U << IOSQE_FIXED_FILE_BIT)
133 /* issue after inflight IO */
134 #define IOSQE_IO_DRAIN (1U << IOSQE_IO_DRAIN_BIT)
136 #define IOSQE_IO_LINK (1U << IOSQE_IO_LINK_BIT)
137 /* like LINK, but stronger */
138 #define IOSQE_IO_HARDLINK (1U << IOSQE_IO_HARDLINK_BIT)
139 /* always go async */
140 #define IOSQE_ASYNC (1U << IOSQE_ASYNC_BIT)
141 /* select buffer from sqe->buf_group */
142 #define IOSQE_BUFFER_SELECT (1U << IOSQE_BUFFER_SELECT_BIT)
143 /* don't post CQE if request succeeded */
144 #define IOSQE_CQE_SKIP_SUCCESS (1U << IOSQE_CQE_SKIP_SUCCESS_BIT)
147 * io_uring_setup() flags
149 #define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */
150 #define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */
151 #define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */
152 #define IORING_SETUP_CQSIZE (1U << 3) /* app defines CQ size */
153 #define IORING_SETUP_CLAMP (1U << 4) /* clamp SQ/CQ ring sizes */
154 #define IORING_SETUP_ATTACH_WQ (1U << 5) /* attach to existing wq */
155 #define IORING_SETUP_R_DISABLED (1U << 6) /* start with ring disabled */
156 #define IORING_SETUP_SUBMIT_ALL (1U << 7) /* continue submit on error */
158 * Cooperative task running. When requests complete, they often require
159 * forcing the submitter to transition to the kernel to complete. If this
160 * flag is set, work will be done when the task transitions anyway, rather
161 * than force an inter-processor interrupt reschedule. This avoids interrupting
162 * a task running in userspace, and saves an IPI.
164 #define IORING_SETUP_COOP_TASKRUN (1U << 8)
166 * If COOP_TASKRUN is set, get notified if task work is available for
167 * running and a kernel transition would be needed to run it. This sets
168 * IORING_SQ_TASKRUN in the sq ring flags. Not valid with COOP_TASKRUN.
170 #define IORING_SETUP_TASKRUN_FLAG (1U << 9)
171 #define IORING_SETUP_SQE128 (1U << 10) /* SQEs are 128 byte */
172 #define IORING_SETUP_CQE32 (1U << 11) /* CQEs are 32 byte */
174 * Only one task is allowed to submit requests
176 #define IORING_SETUP_SINGLE_ISSUER (1U << 12)
179 * Defer running task work to get events.
180 * Rather than running bits of task work whenever the task transitions
181 * try to do it just before it is needed.
183 #define IORING_SETUP_DEFER_TASKRUN (1U << 13)
186 * Application provides the memory for the rings
188 #define IORING_SETUP_NO_MMAP (1U << 14)
191 * Register the ring fd in itself for use with
192 * IORING_REGISTER_USE_REGISTERED_RING; return a registered fd index rather
195 #define IORING_SETUP_REGISTERED_FD_ONLY (1U << 15)
198 * Removes indirection through the SQ index array.
200 #define IORING_SETUP_NO_SQARRAY (1U << 16)
207 IORING_OP_READ_FIXED,
208 IORING_OP_WRITE_FIXED,
210 IORING_OP_POLL_REMOVE,
211 IORING_OP_SYNC_FILE_RANGE,
215 IORING_OP_TIMEOUT_REMOVE,
217 IORING_OP_ASYNC_CANCEL,
218 IORING_OP_LINK_TIMEOUT,
223 IORING_OP_FILES_UPDATE,
234 IORING_OP_PROVIDE_BUFFERS,
235 IORING_OP_REMOVE_BUFFERS,
251 IORING_OP_SENDMSG_ZC,
252 IORING_OP_READ_MULTISHOT,
254 IORING_OP_FUTEX_WAIT,
255 IORING_OP_FUTEX_WAKE,
256 IORING_OP_FUTEX_WAITV,
257 IORING_OP_FIXED_FD_INSTALL,
260 /* this goes last, obviously */
265 * sqe->uring_cmd_flags top 8bits aren't available for userspace
266 * IORING_URING_CMD_FIXED use registered buffer; pass this flag
267 * along with setting sqe->buf_index.
269 #define IORING_URING_CMD_FIXED (1U << 0)
270 #define IORING_URING_CMD_MASK IORING_URING_CMD_FIXED
276 #define IORING_FSYNC_DATASYNC (1U << 0)
281 #define IORING_TIMEOUT_ABS (1U << 0)
282 #define IORING_TIMEOUT_UPDATE (1U << 1)
283 #define IORING_TIMEOUT_BOOTTIME (1U << 2)
284 #define IORING_TIMEOUT_REALTIME (1U << 3)
285 #define IORING_LINK_TIMEOUT_UPDATE (1U << 4)
286 #define IORING_TIMEOUT_ETIME_SUCCESS (1U << 5)
287 #define IORING_TIMEOUT_MULTISHOT (1U << 6)
288 #define IORING_TIMEOUT_CLOCK_MASK (IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)
289 #define IORING_TIMEOUT_UPDATE_MASK (IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE)
292 * extends splice(2) flags
294 #define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
297 * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
298 * command flags for POLL_ADD are stored in sqe->len.
300 * IORING_POLL_ADD_MULTI Multishot poll. Sets IORING_CQE_F_MORE if
301 * the poll handler will continue to report
302 * CQEs on behalf of the same SQE.
304 * IORING_POLL_UPDATE Update existing poll request, matching
305 * sqe->addr as the old user_data field.
307 * IORING_POLL_LEVEL Level triggered poll.
309 #define IORING_POLL_ADD_MULTI (1U << 0)
310 #define IORING_POLL_UPDATE_EVENTS (1U << 1)
311 #define IORING_POLL_UPDATE_USER_DATA (1U << 2)
312 #define IORING_POLL_ADD_LEVEL (1U << 3)
315 * ASYNC_CANCEL flags.
317 * IORING_ASYNC_CANCEL_ALL Cancel all requests that match the given key
318 * IORING_ASYNC_CANCEL_FD Key off 'fd' for cancelation rather than the
319 * request 'user_data'
320 * IORING_ASYNC_CANCEL_ANY Match any request
321 * IORING_ASYNC_CANCEL_FD_FIXED 'fd' passed in is a fixed descriptor
322 * IORING_ASYNC_CANCEL_USERDATA Match on user_data, default for no other key
323 * IORING_ASYNC_CANCEL_OP Match request based on opcode
325 #define IORING_ASYNC_CANCEL_ALL (1U << 0)
326 #define IORING_ASYNC_CANCEL_FD (1U << 1)
327 #define IORING_ASYNC_CANCEL_ANY (1U << 2)
328 #define IORING_ASYNC_CANCEL_FD_FIXED (1U << 3)
329 #define IORING_ASYNC_CANCEL_USERDATA (1U << 4)
330 #define IORING_ASYNC_CANCEL_OP (1U << 5)
333 * send/sendmsg and recv/recvmsg flags (sqe->ioprio)
335 * IORING_RECVSEND_POLL_FIRST If set, instead of first attempting to send
336 * or receive and arm poll if that yields an
337 * -EAGAIN result, arm poll upfront and skip
338 * the initial transfer attempt.
340 * IORING_RECV_MULTISHOT Multishot recv. Sets IORING_CQE_F_MORE if
341 * the handler will continue to report
342 * CQEs on behalf of the same SQE.
344 * IORING_RECVSEND_FIXED_BUF Use registered buffers, the index is stored in
345 * the buf_index field.
347 * IORING_SEND_ZC_REPORT_USAGE
348 * If set, SEND[MSG]_ZC should report
349 * the zerocopy usage in cqe.res
350 * for the IORING_CQE_F_NOTIF cqe.
351 * 0 is reported if zerocopy was actually possible.
352 * IORING_NOTIF_USAGE_ZC_COPIED if data was copied
353 * (at least partially).
355 #define IORING_RECVSEND_POLL_FIRST (1U << 0)
356 #define IORING_RECV_MULTISHOT (1U << 1)
357 #define IORING_RECVSEND_FIXED_BUF (1U << 2)
358 #define IORING_SEND_ZC_REPORT_USAGE (1U << 3)
361 * cqe.res for IORING_CQE_F_NOTIF if
362 * IORING_SEND_ZC_REPORT_USAGE was requested
364 * It should be treated as a flag, all other
365 * bits of cqe.res should be treated as reserved!
367 #define IORING_NOTIF_USAGE_ZC_COPIED (1U << 31)
370 * accept flags stored in sqe->ioprio
372 #define IORING_ACCEPT_MULTISHOT (1U << 0)
375 * IORING_OP_MSG_RING command types, stored in sqe->addr
378 IORING_MSG_DATA, /* pass sqe->len as 'res' and off as user_data */
379 IORING_MSG_SEND_FD, /* send a registered fd to another ring */
383 * IORING_OP_MSG_RING flags (sqe->msg_ring_flags)
385 * IORING_MSG_RING_CQE_SKIP Don't post a CQE to the target ring. Not
386 * applicable for IORING_MSG_DATA, obviously.
388 #define IORING_MSG_RING_CQE_SKIP (1U << 0)
389 /* Pass through the flags from sqe->file_index to cqe->flags */
390 #define IORING_MSG_RING_FLAGS_PASS (1U << 1)
393 * IORING_OP_FIXED_FD_INSTALL flags (sqe->install_fd_flags)
395 * IORING_FIXED_FD_NO_CLOEXEC Don't mark the fd as O_CLOEXEC
397 #define IORING_FIXED_FD_NO_CLOEXEC (1U << 0)
400 * IO completion data structure (Completion Queue Entry)
402 struct io_uring_cqe {
403 __u64 user_data; /* sqe->data submission passed back */
404 __s32 res; /* result code for this event */
408 * If the ring is initialized with IORING_SETUP_CQE32, then this field
409 * contains 16-bytes of padding, doubling the size of the CQE.
417 * IORING_CQE_F_BUFFER If set, the upper 16 bits are the buffer ID
418 * IORING_CQE_F_MORE If set, parent SQE will generate more CQE entries
419 * IORING_CQE_F_SOCK_NONEMPTY If set, more data to read after socket recv
420 * IORING_CQE_F_NOTIF Set for notification CQEs. Can be used to distinct
423 #define IORING_CQE_F_BUFFER (1U << 0)
424 #define IORING_CQE_F_MORE (1U << 1)
425 #define IORING_CQE_F_SOCK_NONEMPTY (1U << 2)
426 #define IORING_CQE_F_NOTIF (1U << 3)
429 IORING_CQE_BUFFER_SHIFT = 16,
433 * Magic offsets for the application to mmap the data it needs
435 #define IORING_OFF_SQ_RING 0ULL
436 #define IORING_OFF_CQ_RING 0x8000000ULL
437 #define IORING_OFF_SQES 0x10000000ULL
438 #define IORING_OFF_PBUF_RING 0x80000000ULL
439 #define IORING_OFF_PBUF_SHIFT 16
440 #define IORING_OFF_MMAP_MASK 0xf8000000ULL
443 * Filled with the offset for mmap(2)
445 struct io_sqring_offsets {
460 #define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */
461 #define IORING_SQ_CQ_OVERFLOW (1U << 1) /* CQ ring is overflown */
462 #define IORING_SQ_TASKRUN (1U << 2) /* task should enter the kernel */
464 struct io_cqring_offsets {
480 /* disable eventfd notifications */
481 #define IORING_CQ_EVENTFD_DISABLED (1U << 0)
484 * io_uring_enter(2) flags
486 #define IORING_ENTER_GETEVENTS (1U << 0)
487 #define IORING_ENTER_SQ_WAKEUP (1U << 1)
488 #define IORING_ENTER_SQ_WAIT (1U << 2)
489 #define IORING_ENTER_EXT_ARG (1U << 3)
490 #define IORING_ENTER_REGISTERED_RING (1U << 4)
493 * Passed in for io_uring_setup(2). Copied back with updated info on success
495 struct io_uring_params {
500 __u32 sq_thread_idle;
504 struct io_sqring_offsets sq_off;
505 struct io_cqring_offsets cq_off;
509 * io_uring_params->features flags
511 #define IORING_FEAT_SINGLE_MMAP (1U << 0)
512 #define IORING_FEAT_NODROP (1U << 1)
513 #define IORING_FEAT_SUBMIT_STABLE (1U << 2)
514 #define IORING_FEAT_RW_CUR_POS (1U << 3)
515 #define IORING_FEAT_CUR_PERSONALITY (1U << 4)
516 #define IORING_FEAT_FAST_POLL (1U << 5)
517 #define IORING_FEAT_POLL_32BITS (1U << 6)
518 #define IORING_FEAT_SQPOLL_NONFIXED (1U << 7)
519 #define IORING_FEAT_EXT_ARG (1U << 8)
520 #define IORING_FEAT_NATIVE_WORKERS (1U << 9)
521 #define IORING_FEAT_RSRC_TAGS (1U << 10)
522 #define IORING_FEAT_CQE_SKIP (1U << 11)
523 #define IORING_FEAT_LINKED_FILE (1U << 12)
524 #define IORING_FEAT_REG_REG_RING (1U << 13)
527 * io_uring_register(2) opcodes and arguments
530 IORING_REGISTER_BUFFERS = 0,
531 IORING_UNREGISTER_BUFFERS = 1,
532 IORING_REGISTER_FILES = 2,
533 IORING_UNREGISTER_FILES = 3,
534 IORING_REGISTER_EVENTFD = 4,
535 IORING_UNREGISTER_EVENTFD = 5,
536 IORING_REGISTER_FILES_UPDATE = 6,
537 IORING_REGISTER_EVENTFD_ASYNC = 7,
538 IORING_REGISTER_PROBE = 8,
539 IORING_REGISTER_PERSONALITY = 9,
540 IORING_UNREGISTER_PERSONALITY = 10,
541 IORING_REGISTER_RESTRICTIONS = 11,
542 IORING_REGISTER_ENABLE_RINGS = 12,
544 /* extended with tagging */
545 IORING_REGISTER_FILES2 = 13,
546 IORING_REGISTER_FILES_UPDATE2 = 14,
547 IORING_REGISTER_BUFFERS2 = 15,
548 IORING_REGISTER_BUFFERS_UPDATE = 16,
550 /* set/clear io-wq thread affinities */
551 IORING_REGISTER_IOWQ_AFF = 17,
552 IORING_UNREGISTER_IOWQ_AFF = 18,
554 /* set/get max number of io-wq workers */
555 IORING_REGISTER_IOWQ_MAX_WORKERS = 19,
557 /* register/unregister io_uring fd with the ring */
558 IORING_REGISTER_RING_FDS = 20,
559 IORING_UNREGISTER_RING_FDS = 21,
561 /* register ring based provide buffer group */
562 IORING_REGISTER_PBUF_RING = 22,
563 IORING_UNREGISTER_PBUF_RING = 23,
565 /* sync cancelation API */
566 IORING_REGISTER_SYNC_CANCEL = 24,
568 /* register a range of fixed file slots for automatic slot allocation */
569 IORING_REGISTER_FILE_ALLOC_RANGE = 25,
571 /* return status information for a buffer group */
572 IORING_REGISTER_PBUF_STATUS = 26,
574 /* set/clear busy poll settings */
575 IORING_REGISTER_NAPI = 27,
576 IORING_UNREGISTER_NAPI = 28,
579 IORING_REGISTER_LAST,
581 /* flag added to the opcode to use a registered ring fd */
582 IORING_REGISTER_USE_REGISTERED_RING = 1U << 31
585 /* io-wq worker categories */
591 /* deprecated, see struct io_uring_rsrc_update */
592 struct io_uring_files_update {
595 __aligned_u64 /* __s32 * */ fds;
599 * Register a fully sparse file space, rather than pass in an array of all
600 * -1 file descriptors.
602 #define IORING_RSRC_REGISTER_SPARSE (1U << 0)
604 struct io_uring_rsrc_register {
612 struct io_uring_rsrc_update {
618 struct io_uring_rsrc_update2 {
627 /* Skip updating fd indexes set to this value in the fd table */
628 #define IORING_REGISTER_FILES_SKIP (-2)
630 #define IO_URING_OP_SUPPORTED (1U << 0)
632 struct io_uring_probe_op {
635 __u16 flags; /* IO_URING_OP_* flags */
639 struct io_uring_probe {
640 __u8 last_op; /* last opcode supported */
641 __u8 ops_len; /* length of ops[] array below */
644 struct io_uring_probe_op ops[];
647 struct io_uring_restriction {
650 __u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
651 __u8 sqe_op; /* IORING_RESTRICTION_SQE_OP */
652 __u8 sqe_flags; /* IORING_RESTRICTION_SQE_FLAGS_* */
658 struct io_uring_buf {
665 struct io_uring_buf_ring {
668 * To avoid spilling into more pages than we need to, the
669 * ring tail is overlaid with the io_uring_buf->resv field.
677 __DECLARE_FLEX_ARRAY(struct io_uring_buf, bufs);
682 * Flags for IORING_REGISTER_PBUF_RING.
684 * IOU_PBUF_RING_MMAP: If set, kernel will allocate the memory for the ring.
685 * The application must not set a ring_addr in struct
686 * io_uring_buf_reg, instead it must subsequently call
687 * mmap(2) with the offset set as:
688 * IORING_OFF_PBUF_RING | (bgid << IORING_OFF_PBUF_SHIFT)
689 * to get a virtual mapping for the ring.
692 IOU_PBUF_RING_MMAP = 1,
695 /* argument for IORING_(UN)REGISTER_PBUF_RING */
696 struct io_uring_buf_reg {
704 /* argument for IORING_REGISTER_PBUF_STATUS */
705 struct io_uring_buf_status {
706 __u32 buf_group; /* input */
707 __u32 head; /* output */
711 /* argument for IORING_(UN)REGISTER_NAPI */
712 struct io_uring_napi {
714 __u8 prefer_busy_poll;
720 * io_uring_restriction->opcode values
723 /* Allow an io_uring_register(2) opcode */
724 IORING_RESTRICTION_REGISTER_OP = 0,
726 /* Allow an sqe opcode */
727 IORING_RESTRICTION_SQE_OP = 1,
729 /* Allow sqe flags */
730 IORING_RESTRICTION_SQE_FLAGS_ALLOWED = 2,
732 /* Require sqe flags (these flags must be set on each submission) */
733 IORING_RESTRICTION_SQE_FLAGS_REQUIRED = 3,
735 IORING_RESTRICTION_LAST
738 struct io_uring_getevents_arg {
746 * Argument for IORING_REGISTER_SYNC_CANCEL
748 struct io_uring_sync_cancel_reg {
752 struct __kernel_timespec timeout;
759 * Argument for IORING_REGISTER_FILE_ALLOC_RANGE
760 * The range is specified as [off, off + len)
762 struct io_uring_file_index_range {
768 struct io_uring_recvmsg_out {
776 * Argument for IORING_OP_URING_CMD when file is a socket
779 SOCKET_URING_OP_SIOCINQ = 0,
780 SOCKET_URING_OP_SIOCOUTQ,
781 SOCKET_URING_OP_GETSOCKOPT,
782 SOCKET_URING_OP_SETSOCKOPT,