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;
77 __u64 user_data; /* data to be passed back at completion time */
78 /* pack this to avoid bogus arm OABI complaints */
80 /* index into fixed buffers, if used */
82 /* for grouped buffer selection */
84 } __attribute__((packed));
85 /* personality to use, if used */
103 * If the ring is initialized with IORING_SETUP_SQE128, then
104 * this field is used for 80 bytes of arbitrary command data
111 * If sqe->file_index is set to this for opcodes that instantiate a new
112 * direct descriptor (like openat/openat2/accept), then io_uring will allocate
113 * an available direct descriptor instead of having the application pass one
114 * in. The picked direct descriptor will be returned in cqe->res, or -ENFILE
115 * if the space is full.
117 #define IORING_FILE_INDEX_ALLOC (~0U)
119 enum io_uring_sqe_flags_bit {
120 IOSQE_FIXED_FILE_BIT,
123 IOSQE_IO_HARDLINK_BIT,
125 IOSQE_BUFFER_SELECT_BIT,
126 IOSQE_CQE_SKIP_SUCCESS_BIT,
132 /* use fixed fileset */
133 #define IOSQE_FIXED_FILE (1U << IOSQE_FIXED_FILE_BIT)
134 /* issue after inflight IO */
135 #define IOSQE_IO_DRAIN (1U << IOSQE_IO_DRAIN_BIT)
137 #define IOSQE_IO_LINK (1U << IOSQE_IO_LINK_BIT)
138 /* like LINK, but stronger */
139 #define IOSQE_IO_HARDLINK (1U << IOSQE_IO_HARDLINK_BIT)
140 /* always go async */
141 #define IOSQE_ASYNC (1U << IOSQE_ASYNC_BIT)
142 /* select buffer from sqe->buf_group */
143 #define IOSQE_BUFFER_SELECT (1U << IOSQE_BUFFER_SELECT_BIT)
144 /* don't post CQE if request succeeded */
145 #define IOSQE_CQE_SKIP_SUCCESS (1U << IOSQE_CQE_SKIP_SUCCESS_BIT)
148 * io_uring_setup() flags
150 #define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */
151 #define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */
152 #define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */
153 #define IORING_SETUP_CQSIZE (1U << 3) /* app defines CQ size */
154 #define IORING_SETUP_CLAMP (1U << 4) /* clamp SQ/CQ ring sizes */
155 #define IORING_SETUP_ATTACH_WQ (1U << 5) /* attach to existing wq */
156 #define IORING_SETUP_R_DISABLED (1U << 6) /* start with ring disabled */
157 #define IORING_SETUP_SUBMIT_ALL (1U << 7) /* continue submit on error */
159 * Cooperative task running. When requests complete, they often require
160 * forcing the submitter to transition to the kernel to complete. If this
161 * flag is set, work will be done when the task transitions anyway, rather
162 * than force an inter-processor interrupt reschedule. This avoids interrupting
163 * a task running in userspace, and saves an IPI.
165 #define IORING_SETUP_COOP_TASKRUN (1U << 8)
167 * If COOP_TASKRUN is set, get notified if task work is available for
168 * running and a kernel transition would be needed to run it. This sets
169 * IORING_SQ_TASKRUN in the sq ring flags. Not valid with COOP_TASKRUN.
171 #define IORING_SETUP_TASKRUN_FLAG (1U << 9)
172 #define IORING_SETUP_SQE128 (1U << 10) /* SQEs are 128 byte */
173 #define IORING_SETUP_CQE32 (1U << 11) /* CQEs are 32 byte */
175 * Only one task is allowed to submit requests
177 #define IORING_SETUP_SINGLE_ISSUER (1U << 12)
180 * Defer running task work to get events.
181 * Rather than running bits of task work whenever the task transitions
182 * try to do it just before it is needed.
184 #define IORING_SETUP_DEFER_TASKRUN (1U << 13)
187 * Application provides the memory for the rings
189 #define IORING_SETUP_NO_MMAP (1U << 14)
192 * Register the ring fd in itself for use with
193 * IORING_REGISTER_USE_REGISTERED_RING; return a registered fd index rather
196 #define IORING_SETUP_REGISTERED_FD_ONLY (1U << 15)
199 * Removes indirection through the SQ index array.
201 #define IORING_SETUP_NO_SQARRAY (1U << 16)
208 IORING_OP_READ_FIXED,
209 IORING_OP_WRITE_FIXED,
211 IORING_OP_POLL_REMOVE,
212 IORING_OP_SYNC_FILE_RANGE,
216 IORING_OP_TIMEOUT_REMOVE,
218 IORING_OP_ASYNC_CANCEL,
219 IORING_OP_LINK_TIMEOUT,
224 IORING_OP_FILES_UPDATE,
235 IORING_OP_PROVIDE_BUFFERS,
236 IORING_OP_REMOVE_BUFFERS,
252 IORING_OP_SENDMSG_ZC,
253 IORING_OP_READ_MULTISHOT,
255 IORING_OP_FUTEX_WAIT,
256 IORING_OP_FUTEX_WAKE,
257 IORING_OP_FUTEX_WAITV,
258 IORING_OP_FIXED_FD_INSTALL,
261 /* this goes last, obviously */
266 * sqe->uring_cmd_flags top 8bits aren't available for userspace
267 * IORING_URING_CMD_FIXED use registered buffer; pass this flag
268 * along with setting sqe->buf_index.
270 #define IORING_URING_CMD_FIXED (1U << 0)
271 #define IORING_URING_CMD_MASK IORING_URING_CMD_FIXED
277 #define IORING_FSYNC_DATASYNC (1U << 0)
282 #define IORING_TIMEOUT_ABS (1U << 0)
283 #define IORING_TIMEOUT_UPDATE (1U << 1)
284 #define IORING_TIMEOUT_BOOTTIME (1U << 2)
285 #define IORING_TIMEOUT_REALTIME (1U << 3)
286 #define IORING_LINK_TIMEOUT_UPDATE (1U << 4)
287 #define IORING_TIMEOUT_ETIME_SUCCESS (1U << 5)
288 #define IORING_TIMEOUT_MULTISHOT (1U << 6)
289 #define IORING_TIMEOUT_CLOCK_MASK (IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)
290 #define IORING_TIMEOUT_UPDATE_MASK (IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE)
293 * extends splice(2) flags
295 #define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
298 * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
299 * command flags for POLL_ADD are stored in sqe->len.
301 * IORING_POLL_ADD_MULTI Multishot poll. Sets IORING_CQE_F_MORE if
302 * the poll handler will continue to report
303 * CQEs on behalf of the same SQE.
305 * IORING_POLL_UPDATE Update existing poll request, matching
306 * sqe->addr as the old user_data field.
308 * IORING_POLL_LEVEL Level triggered poll.
310 #define IORING_POLL_ADD_MULTI (1U << 0)
311 #define IORING_POLL_UPDATE_EVENTS (1U << 1)
312 #define IORING_POLL_UPDATE_USER_DATA (1U << 2)
313 #define IORING_POLL_ADD_LEVEL (1U << 3)
316 * ASYNC_CANCEL flags.
318 * IORING_ASYNC_CANCEL_ALL Cancel all requests that match the given key
319 * IORING_ASYNC_CANCEL_FD Key off 'fd' for cancelation rather than the
320 * request 'user_data'
321 * IORING_ASYNC_CANCEL_ANY Match any request
322 * IORING_ASYNC_CANCEL_FD_FIXED 'fd' passed in is a fixed descriptor
323 * IORING_ASYNC_CANCEL_USERDATA Match on user_data, default for no other key
324 * IORING_ASYNC_CANCEL_OP Match request based on opcode
326 #define IORING_ASYNC_CANCEL_ALL (1U << 0)
327 #define IORING_ASYNC_CANCEL_FD (1U << 1)
328 #define IORING_ASYNC_CANCEL_ANY (1U << 2)
329 #define IORING_ASYNC_CANCEL_FD_FIXED (1U << 3)
330 #define IORING_ASYNC_CANCEL_USERDATA (1U << 4)
331 #define IORING_ASYNC_CANCEL_OP (1U << 5)
334 * send/sendmsg and recv/recvmsg flags (sqe->ioprio)
336 * IORING_RECVSEND_POLL_FIRST If set, instead of first attempting to send
337 * or receive and arm poll if that yields an
338 * -EAGAIN result, arm poll upfront and skip
339 * the initial transfer attempt.
341 * IORING_RECV_MULTISHOT Multishot recv. Sets IORING_CQE_F_MORE if
342 * the handler will continue to report
343 * CQEs on behalf of the same SQE.
345 * IORING_RECVSEND_FIXED_BUF Use registered buffers, the index is stored in
346 * the buf_index field.
348 * IORING_SEND_ZC_REPORT_USAGE
349 * If set, SEND[MSG]_ZC should report
350 * the zerocopy usage in cqe.res
351 * for the IORING_CQE_F_NOTIF cqe.
352 * 0 is reported if zerocopy was actually possible.
353 * IORING_NOTIF_USAGE_ZC_COPIED if data was copied
354 * (at least partially).
356 * IORING_RECVSEND_BUNDLE Used with IOSQE_BUFFER_SELECT. If set, send or
357 * recv will grab as many buffers from the buffer
358 * group ID given and send them all. The completion
359 * result will be the number of buffers send, with
360 * the starting buffer ID in cqe->flags as per
361 * usual for provided buffer usage. The buffers
362 * will be contigious from the starting buffer ID.
364 #define IORING_RECVSEND_POLL_FIRST (1U << 0)
365 #define IORING_RECV_MULTISHOT (1U << 1)
366 #define IORING_RECVSEND_FIXED_BUF (1U << 2)
367 #define IORING_SEND_ZC_REPORT_USAGE (1U << 3)
368 #define IORING_RECVSEND_BUNDLE (1U << 4)
371 * cqe.res for IORING_CQE_F_NOTIF if
372 * IORING_SEND_ZC_REPORT_USAGE was requested
374 * It should be treated as a flag, all other
375 * bits of cqe.res should be treated as reserved!
377 #define IORING_NOTIF_USAGE_ZC_COPIED (1U << 31)
380 * accept flags stored in sqe->ioprio
382 #define IORING_ACCEPT_MULTISHOT (1U << 0)
383 #define IORING_ACCEPT_DONTWAIT (1U << 1)
384 #define IORING_ACCEPT_POLL_FIRST (1U << 2)
387 * IORING_OP_MSG_RING command types, stored in sqe->addr
389 enum io_uring_msg_ring_flags {
390 IORING_MSG_DATA, /* pass sqe->len as 'res' and off as user_data */
391 IORING_MSG_SEND_FD, /* send a registered fd to another ring */
395 * IORING_OP_MSG_RING flags (sqe->msg_ring_flags)
397 * IORING_MSG_RING_CQE_SKIP Don't post a CQE to the target ring. Not
398 * applicable for IORING_MSG_DATA, obviously.
400 #define IORING_MSG_RING_CQE_SKIP (1U << 0)
401 /* Pass through the flags from sqe->file_index to cqe->flags */
402 #define IORING_MSG_RING_FLAGS_PASS (1U << 1)
405 * IORING_OP_FIXED_FD_INSTALL flags (sqe->install_fd_flags)
407 * IORING_FIXED_FD_NO_CLOEXEC Don't mark the fd as O_CLOEXEC
409 #define IORING_FIXED_FD_NO_CLOEXEC (1U << 0)
412 * IORING_OP_NOP flags (sqe->nop_flags)
414 * IORING_NOP_INJECT_RESULT Inject result from sqe->result
416 #define IORING_NOP_INJECT_RESULT (1U << 0)
419 * IO completion data structure (Completion Queue Entry)
421 struct io_uring_cqe {
422 __u64 user_data; /* sqe->data submission passed back */
423 __s32 res; /* result code for this event */
427 * If the ring is initialized with IORING_SETUP_CQE32, then this field
428 * contains 16-bytes of padding, doubling the size of the CQE.
436 * IORING_CQE_F_BUFFER If set, the upper 16 bits are the buffer ID
437 * IORING_CQE_F_MORE If set, parent SQE will generate more CQE entries
438 * IORING_CQE_F_SOCK_NONEMPTY If set, more data to read after socket recv
439 * IORING_CQE_F_NOTIF Set for notification CQEs. Can be used to distinct
442 #define IORING_CQE_F_BUFFER (1U << 0)
443 #define IORING_CQE_F_MORE (1U << 1)
444 #define IORING_CQE_F_SOCK_NONEMPTY (1U << 2)
445 #define IORING_CQE_F_NOTIF (1U << 3)
447 #define IORING_CQE_BUFFER_SHIFT 16
450 * Magic offsets for the application to mmap the data it needs
452 #define IORING_OFF_SQ_RING 0ULL
453 #define IORING_OFF_CQ_RING 0x8000000ULL
454 #define IORING_OFF_SQES 0x10000000ULL
455 #define IORING_OFF_PBUF_RING 0x80000000ULL
456 #define IORING_OFF_PBUF_SHIFT 16
457 #define IORING_OFF_MMAP_MASK 0xf8000000ULL
460 * Filled with the offset for mmap(2)
462 struct io_sqring_offsets {
477 #define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */
478 #define IORING_SQ_CQ_OVERFLOW (1U << 1) /* CQ ring is overflown */
479 #define IORING_SQ_TASKRUN (1U << 2) /* task should enter the kernel */
481 struct io_cqring_offsets {
497 /* disable eventfd notifications */
498 #define IORING_CQ_EVENTFD_DISABLED (1U << 0)
501 * io_uring_enter(2) flags
503 #define IORING_ENTER_GETEVENTS (1U << 0)
504 #define IORING_ENTER_SQ_WAKEUP (1U << 1)
505 #define IORING_ENTER_SQ_WAIT (1U << 2)
506 #define IORING_ENTER_EXT_ARG (1U << 3)
507 #define IORING_ENTER_REGISTERED_RING (1U << 4)
510 * Passed in for io_uring_setup(2). Copied back with updated info on success
512 struct io_uring_params {
517 __u32 sq_thread_idle;
521 struct io_sqring_offsets sq_off;
522 struct io_cqring_offsets cq_off;
526 * io_uring_params->features flags
528 #define IORING_FEAT_SINGLE_MMAP (1U << 0)
529 #define IORING_FEAT_NODROP (1U << 1)
530 #define IORING_FEAT_SUBMIT_STABLE (1U << 2)
531 #define IORING_FEAT_RW_CUR_POS (1U << 3)
532 #define IORING_FEAT_CUR_PERSONALITY (1U << 4)
533 #define IORING_FEAT_FAST_POLL (1U << 5)
534 #define IORING_FEAT_POLL_32BITS (1U << 6)
535 #define IORING_FEAT_SQPOLL_NONFIXED (1U << 7)
536 #define IORING_FEAT_EXT_ARG (1U << 8)
537 #define IORING_FEAT_NATIVE_WORKERS (1U << 9)
538 #define IORING_FEAT_RSRC_TAGS (1U << 10)
539 #define IORING_FEAT_CQE_SKIP (1U << 11)
540 #define IORING_FEAT_LINKED_FILE (1U << 12)
541 #define IORING_FEAT_REG_REG_RING (1U << 13)
542 #define IORING_FEAT_RECVSEND_BUNDLE (1U << 14)
545 * io_uring_register(2) opcodes and arguments
547 enum io_uring_register_op {
548 IORING_REGISTER_BUFFERS = 0,
549 IORING_UNREGISTER_BUFFERS = 1,
550 IORING_REGISTER_FILES = 2,
551 IORING_UNREGISTER_FILES = 3,
552 IORING_REGISTER_EVENTFD = 4,
553 IORING_UNREGISTER_EVENTFD = 5,
554 IORING_REGISTER_FILES_UPDATE = 6,
555 IORING_REGISTER_EVENTFD_ASYNC = 7,
556 IORING_REGISTER_PROBE = 8,
557 IORING_REGISTER_PERSONALITY = 9,
558 IORING_UNREGISTER_PERSONALITY = 10,
559 IORING_REGISTER_RESTRICTIONS = 11,
560 IORING_REGISTER_ENABLE_RINGS = 12,
562 /* extended with tagging */
563 IORING_REGISTER_FILES2 = 13,
564 IORING_REGISTER_FILES_UPDATE2 = 14,
565 IORING_REGISTER_BUFFERS2 = 15,
566 IORING_REGISTER_BUFFERS_UPDATE = 16,
568 /* set/clear io-wq thread affinities */
569 IORING_REGISTER_IOWQ_AFF = 17,
570 IORING_UNREGISTER_IOWQ_AFF = 18,
572 /* set/get max number of io-wq workers */
573 IORING_REGISTER_IOWQ_MAX_WORKERS = 19,
575 /* register/unregister io_uring fd with the ring */
576 IORING_REGISTER_RING_FDS = 20,
577 IORING_UNREGISTER_RING_FDS = 21,
579 /* register ring based provide buffer group */
580 IORING_REGISTER_PBUF_RING = 22,
581 IORING_UNREGISTER_PBUF_RING = 23,
583 /* sync cancelation API */
584 IORING_REGISTER_SYNC_CANCEL = 24,
586 /* register a range of fixed file slots for automatic slot allocation */
587 IORING_REGISTER_FILE_ALLOC_RANGE = 25,
589 /* return status information for a buffer group */
590 IORING_REGISTER_PBUF_STATUS = 26,
592 /* set/clear busy poll settings */
593 IORING_REGISTER_NAPI = 27,
594 IORING_UNREGISTER_NAPI = 28,
597 IORING_REGISTER_LAST,
599 /* flag added to the opcode to use a registered ring fd */
600 IORING_REGISTER_USE_REGISTERED_RING = 1U << 31
603 /* io-wq worker categories */
609 /* deprecated, see struct io_uring_rsrc_update */
610 struct io_uring_files_update {
613 __aligned_u64 /* __s32 * */ fds;
617 * Register a fully sparse file space, rather than pass in an array of all
618 * -1 file descriptors.
620 #define IORING_RSRC_REGISTER_SPARSE (1U << 0)
622 struct io_uring_rsrc_register {
630 struct io_uring_rsrc_update {
636 struct io_uring_rsrc_update2 {
645 /* Skip updating fd indexes set to this value in the fd table */
646 #define IORING_REGISTER_FILES_SKIP (-2)
648 #define IO_URING_OP_SUPPORTED (1U << 0)
650 struct io_uring_probe_op {
653 __u16 flags; /* IO_URING_OP_* flags */
657 struct io_uring_probe {
658 __u8 last_op; /* last opcode supported */
659 __u8 ops_len; /* length of ops[] array below */
662 struct io_uring_probe_op ops[];
665 struct io_uring_restriction {
668 __u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
669 __u8 sqe_op; /* IORING_RESTRICTION_SQE_OP */
670 __u8 sqe_flags; /* IORING_RESTRICTION_SQE_FLAGS_* */
676 struct io_uring_buf {
683 struct io_uring_buf_ring {
686 * To avoid spilling into more pages than we need to, the
687 * ring tail is overlaid with the io_uring_buf->resv field.
695 __DECLARE_FLEX_ARRAY(struct io_uring_buf, bufs);
700 * Flags for IORING_REGISTER_PBUF_RING.
702 * IOU_PBUF_RING_MMAP: If set, kernel will allocate the memory for the ring.
703 * The application must not set a ring_addr in struct
704 * io_uring_buf_reg, instead it must subsequently call
705 * mmap(2) with the offset set as:
706 * IORING_OFF_PBUF_RING | (bgid << IORING_OFF_PBUF_SHIFT)
707 * to get a virtual mapping for the ring.
709 enum io_uring_register_pbuf_ring_flags {
710 IOU_PBUF_RING_MMAP = 1,
713 /* argument for IORING_(UN)REGISTER_PBUF_RING */
714 struct io_uring_buf_reg {
722 /* argument for IORING_REGISTER_PBUF_STATUS */
723 struct io_uring_buf_status {
724 __u32 buf_group; /* input */
725 __u32 head; /* output */
729 /* argument for IORING_(UN)REGISTER_NAPI */
730 struct io_uring_napi {
732 __u8 prefer_busy_poll;
738 * io_uring_restriction->opcode values
740 enum io_uring_register_restriction_op {
741 /* Allow an io_uring_register(2) opcode */
742 IORING_RESTRICTION_REGISTER_OP = 0,
744 /* Allow an sqe opcode */
745 IORING_RESTRICTION_SQE_OP = 1,
747 /* Allow sqe flags */
748 IORING_RESTRICTION_SQE_FLAGS_ALLOWED = 2,
750 /* Require sqe flags (these flags must be set on each submission) */
751 IORING_RESTRICTION_SQE_FLAGS_REQUIRED = 3,
753 IORING_RESTRICTION_LAST
756 struct io_uring_getevents_arg {
764 * Argument for IORING_REGISTER_SYNC_CANCEL
766 struct io_uring_sync_cancel_reg {
770 struct __kernel_timespec timeout;
777 * Argument for IORING_REGISTER_FILE_ALLOC_RANGE
778 * The range is specified as [off, off + len)
780 struct io_uring_file_index_range {
786 struct io_uring_recvmsg_out {
794 * Argument for IORING_OP_URING_CMD when file is a socket
796 enum io_uring_socket_op {
797 SOCKET_URING_OP_SIOCINQ = 0,
798 SOCKET_URING_OP_SIOCOUTQ,
799 SOCKET_URING_OP_GETSOCKOPT,
800 SOCKET_URING_OP_SETSOCKOPT,