include/vki/vki-linux-io_uring.h

   1 /*
   2    This file is part of Valgrind, a dynamic binary instrumentation framework.
   3
   4    Copyright (C) 2019 Bart Van Assche <bvanassche@acm.org>
   5
   6    This program is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful, but
  12    WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, see <http://www.gnu.org/licenses/>.
  18
  19    The GNU General Public License is contained in the file COPYING.
  20 */
  21
  22 #ifndef _VKI_IO_URING_H_
  23 #define _VKI_IO_URING_H_
  24
  25 // Derived from linux-5.2/include/uapi/linux/io_uring.h */
  26
  27 /*
  28  * IO submission data structure (Submission Queue Entry)
  29  */
  30 struct vki_io_uring_sqe {
  31         __vki_u8        opcode;         /* type of operation for this sqe */
  32         __vki_u8        flags;          /* IOSQE_ flags */
  33         __vki_u16       ioprio;         /* ioprio for the request */
  34         __vki_s32       fd;             /* file descriptor to do IO on */
  35         __vki_u64       off;            /* offset into file */
  36         __vki_u64       addr;           /* pointer to buffer or iovecs */
  37         __vki_u32       len;            /* buffer size or number of iovecs */
  38         union {
  39                 int             rw_flags;
  40                 __vki_u32       fsync_flags;
  41                 __vki_u16       poll_events;
  42                 __vki_u32       sync_range_flags;
  43                 __vki_u32       msg_flags;
  44         };
  45         __vki_u64       user_data;      /* data to be passed back at completion time */
  46         union {
  47                 __vki_u16       buf_index;      /* index into fixed buffers, if used */
  48                 __vki_u64       __pad2[3];
  49         };
  50 };
  51
  52 /*
  53  * sqe->flags
  54  */
  55 #define VKI_IOSQE_FIXED_FILE    (1U << 0)       /* use fixed fileset */
  56 #define VKI_IOSQE_IO_DRAIN      (1U << 1)       /* issue after inflight IO */
  57 #define VKI_IOSQE_IO_LINK       (1U << 2)       /* links next sqe */
  58
  59 /*
  60  * io_uring_setup() flags
  61  */
  62 #define VKI_IORING_SETUP_IOPOLL (1U << 0)       /* io_context is polled */
  63 #define VKI_IORING_SETUP_SQPOLL (1U << 1)       /* SQ poll thread */
  64 #define VKI_IORING_SETUP_SQ_AFF (1U << 2)       /* sq_thread_cpu is valid */
  65
  66 #define VKI_IORING_OP_NOP               0
  67 #define VKI_IORING_OP_READV             1
  68 #define VKI_IORING_OP_WRITEV    2
  69 #define VKI_IORING_OP_FSYNC             3
  70 #define VKI_IORING_OP_READ_FIXED        4
  71 #define VKI_IORING_OP_WRITE_FIXED       5
  72 #define VKI_IORING_OP_POLL_ADD  6
  73 #define VKI_IORING_OP_POLL_REMOVE       7
  74 #define VKI_IORING_OP_SYNC_FILE_RANGE   8
  75 #define VKI_IORING_OP_SENDMSG   9
  76 #define VKI_IORING_OP_RECVMSG   10
  77
  78 /*
  79  * sqe->fsync_flags
  80  */
  81 #define VKI_IORING_FSYNC_DATASYNC       (1U << 0)
  82
  83 /*
  84  * IO completion data structure (Completion Queue Entry)
  85  */
  86 struct vki_io_uring_cqe {
  87         __vki_u64       user_data;      /* sqe->data submission passed back */
  88         __vki_s32       res;            /* result code for this event */
  89         __vki_u32       flags;
  90 };
  91
  92 /*
  93  * Magic offsets for the application to mmap the data it needs
  94  */
  95 #define VKI_IORING_OFF_SQ_RING          0ULL
  96 #define VKI_IORING_OFF_CQ_RING          0x8000000ULL
  97 #define VKI_IORING_OFF_SQES             0x10000000ULL
  98
  99 /*
 100  * Filled with the offset for mmap(2)
 101  */
 102 struct vki_io_sqring_offsets {
 103         __vki_u32 head;
 104         __vki_u32 tail;
 105         __vki_u32 ring_mask;
 106         __vki_u32 ring_entries;
 107         __vki_u32 flags;
 108         __vki_u32 dropped;
 109         __vki_u32 array;
 110         __vki_u32 resv1;
 111         __vki_u64 resv2;
 112 };
 113
 114 /*
 115  * sq_ring->flags
 116  */
 117 #define VKI_IORING_SQ_NEED_WAKEUP       (1U << 0) /* needs io_uring_enter wakeup */
 118
 119 struct vki_io_cqring_offsets {
 120         __vki_u32 head;
 121         __vki_u32 tail;
 122         __vki_u32 ring_mask;
 123         __vki_u32 ring_entries;
 124         __vki_u32 overflow;
 125         __vki_u32 cqes;
 126         __vki_u64 resv[2];
 127 };
 128
 129 /*
 130  * io_uring_enter(2) flags
 131  */
 132 #define VKI_IORING_ENTER_GETEVENTS      (1U << 0)
 133 #define VKI_IORING_ENTER_SQ_WAKEUP      (1U << 1)
 134
 135 /*
 136  * Passed in for io_uring_setup(2). Copied back with updated info on success
 137  */
 138 struct vki_io_uring_params {
 139         __vki_u32 sq_entries;
 140         __vki_u32 cq_entries;
 141         __vki_u32 flags;
 142         __vki_u32 sq_thread_cpu;
 143         __vki_u32 sq_thread_idle;
 144         __vki_u32 resv[5];
 145         struct vki_io_sqring_offsets sq_off;
 146         struct vki_io_cqring_offsets cq_off;
 147 };
 148
 149 /*
 150  * io_uring_register(2) opcodes and arguments
 151  */
 152 #define VKI_IORING_REGISTER_BUFFERS     0
 153 #define VKI_IORING_UNREGISTER_BUFFERS   1
 154 #define VKI_IORING_REGISTER_FILES       2
 155 #define VKI_IORING_UNREGISTER_FILES     3
 156 #define VKI_IORING_REGISTER_EVENTFD     4
 157 #define VKI_IORING_UNREGISTER_EVENTFD   5
 158
 159 #endif