github.com/metacubex/gvisor@v0.0.0-20240320004321-933faba989ec/pkg/abi/linux/iouring.go (about) 1 // Copyright 2022 The gVisor Authors. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package linux 16 17 // Constants for io_uring_setup(2). See include/uapi/linux/io_uring.h. 18 const ( 19 IORING_SETUP_IOPOLL = (1 << 0) 20 IORING_SETUP_SQPOLL = (1 << 1) 21 IORING_SETUP_SQ_AFF = (1 << 2) 22 IORING_SETUP_CQSIZE = (1 << 3) 23 IORING_SETUP_CLAMP = (1 << 4) 24 IORING_SETUP_ATTACH_WQ = (1 << 5) 25 IORING_SETUP_R_DISABLED = (1 << 6) 26 IORING_SETUP_SUBMIT_ALL = (1 << 7) 27 ) 28 29 // Constants for io_uring_enter(2). See include/uapi/linux/io_uring.h. 30 const ( 31 IORING_ENTER_GETEVENTS = (1 << 0) 32 ) 33 34 // Constants for IoUringParams.Features. See include/uapi/linux/io_uring.h. 35 const ( 36 IORING_FEAT_SINGLE_MMAP = (1 << 0) 37 ) 38 39 // Constants for IO_URING. See include/uapi/linux/io_uring.h. 40 const ( 41 IORING_SETUP_COOP_TASKRUN = (1 << 8) 42 IORING_SETUP_TASKRUN_FLAG = (1 << 9) 43 IORING_SETUP_SQE128 = (1 << 10) 44 IORING_SETUP_CQE32 = (1 << 11) 45 ) 46 47 // Constants for IO_URING. See io_uring/io_uring.c. 48 const ( 49 IORING_MAX_ENTRIES = (1 << 15) // 32768 50 IORING_MAX_CQ_ENTRIES = (2 * IORING_MAX_ENTRIES) 51 ) 52 53 // Constants for the offsets for the application to mmap the data it needs. 54 // See include/uapi/linux/io_uring.h. 55 const ( 56 IORING_OFF_SQ_RING = 0 57 IORING_OFF_CQ_RING = 0x8000000 58 IORING_OFF_SQES = 0x10000000 59 ) 60 61 // Constants for the IO_URING opcodes. See include/uapi/linux/io_uring.h. 62 const ( 63 IORING_OP_NOP = 0 64 IORING_OP_READV = 1 65 ) 66 67 // IORingIndex represents SQE array indexes. 68 // 69 // +marshal 70 type IORingIndex uint32 71 72 // IOSqRingOffsets implements io_sqring_offsets struct. 73 // IOSqRingOffsets represents offsets into IORings. 74 // See struct io_sqring_offsets in include/uapi/linux/io_uring.h. 75 // 76 // +marshal 77 type IOSqRingOffsets struct { 78 Head uint32 // Offset to io_rings.sq.head 79 Tail uint32 // Offset to io_rings.sq.tail 80 RingMask uint32 // Offset to io_rings.sq_ring_mask 81 RingEntries uint32 // Offset to io_rings.sq_ring_entries 82 Flags uint32 // Offset to io_rings.sq_flags 83 Dropped uint32 // Offset to io_rings.sq_dropped 84 Array uint32 // Offset to an array of SQE indices 85 Resv1 uint32 // Currently reserved and expected to be zero 86 Resv2 uint64 // Currently reserved and expected to be zero 87 } 88 89 // IOCqRingOffsets implements io_cqring_offsets struct. 90 // IOCqRingOffsets represents offsets into IORings. 91 // See struct io_cqring_offsets in include/uapi/linux/io_uring.h. 92 // 93 // +marshal 94 type IOCqRingOffsets struct { 95 Head uint32 // Offset to io_rings.cq.head 96 Tail uint32 // Offset to io_rings.cq.tail 97 RingMask uint32 // Offset to io_rings.cq_ring_mask 98 RingEntries uint32 // Offset to io_rings.cq_ring_entries 99 Overflow uint32 // Offset to io_rings.cq_overflow 100 Cqes uint32 // Offset to io_rings.cqes 101 Flags uint32 // Offset to io_rings.cq_flags 102 Resv1 uint32 // Currently reserved and expected to be zero 103 Resv2 uint64 // Currently reserved and expected to be zero 104 } 105 106 // IOUringParams implements io_uring_params struct. 107 // See struct io_uring_params in include/uapi/linux/io_uring.h. 108 // 109 // +marshal 110 type IOUringParams struct { 111 SqEntries uint32 112 CqEntries uint32 113 Flags uint32 114 SqThreadCPU uint32 115 SqThreadIdle uint32 116 Features uint32 117 WqFd uint32 118 Resv [3]uint32 119 SqOff IOSqRingOffsets 120 CqOff IOCqRingOffsets 121 } 122 123 // IOUringCqe implements IO completion data structure (Completion Queue Entry) 124 // io_uring_cqe struct. As we don't currently support IORING_SETUP_CQE32 flag 125 // its size is 16 bytes. 126 // See struct io_uring_cqe in include/uapi/linux/io_uring.h. 127 // 128 // +marshal 129 // +stateify savable 130 type IOUringCqe struct { 131 UserData uint64 132 Res int32 133 Flags uint32 134 } 135 136 // IOUring implements io_uring struct. 137 // See struct io_uring in io_uring/io_uring.c. 138 // 139 // +marshal 140 // +stateify savable 141 type IOUring struct { 142 // Both head and tail should be cacheline aligned. And we assume that 143 // cacheline size is 64 bytes. 144 Head uint32 145 _ [60]byte 146 Tail uint32 147 _ [60]byte 148 } 149 150 // IORings implements io_rings struct. 151 // This struct describes layout of the mapped region backed by the ringBuffersFile. 152 // See struct io_rings in io_uring/io_uring.c. 153 // 154 // +marshal 155 // +stateify savable 156 type IORings struct { 157 Sq IOUring 158 Cq IOUring 159 SqRingMask uint32 160 CqRingMask uint32 161 SqRingEntries uint32 162 CqRingEntries uint32 163 sqDropped uint32 164 sqFlags int32 165 cqFlags uint32 166 CqOverflow uint32 167 _ [32]byte // Padding so cqes is cacheline aligned 168 // Linux has an additional field struct io_uring_cqe cqes[], which represents 169 // a dynamic array. We don't include it here in order to enable marshalling. 170 } 171 172 // IOUringSqe implements io_uring_sqe struct. 173 // This struct represents IO submission data structure (Submission Queue Entry). As we don't yet 174 // support IORING_SETUP_SQE128 flag, its size is 64 bytes with no extra padding at the end. 175 // See include/uapi/linux/io_uring.h. 176 // 177 // +marshal 178 // +stateify savable 179 type IOUringSqe struct { 180 Opcode uint8 181 Flags uint8 182 IoPrio uint16 183 Fd int32 184 OffOrAddrOrCmdOp uint64 185 AddrOrSpliceOff uint64 186 Len uint32 187 specialFlags uint32 188 UserData uint64 189 BufIndexOrGroup uint16 190 personality uint16 191 spliceFDOrFileIndex int32 192 addr3 uint64 193 _ uint64 194 } 195 196 const ( 197 _IOSqRingOffset = 0 // +checkoffset . IORings.Sq 198 _IOSqRingOffsetHead = 0 // +checkoffset . IOUring.Head 199 _IOSqRingOffsetTail = 64 // +checkoffset . IOUring.Tail 200 _IOSqRingOffsetMask = 256 // +checkoffset . IORings.SqRingMask 201 _IOSqRingOffsetEntries = 264 // +checkoffset . IORings.SqRingEntries 202 _IOSqRingOffsetFlags = 276 // +checkoffset . IORings.sqFlags 203 _IOSqRingOffsetDropped = 272 // +checkoffset . IORings.sqDropped 204 ) 205 206 // PreComputedIOSqRingOffsets returns precomputed values for IOSqRingOffsets. 207 func PreComputedIOSqRingOffsets() IOSqRingOffsets { 208 return IOSqRingOffsets{ 209 Head: _IOSqRingOffset + _IOSqRingOffsetHead, 210 Tail: _IOSqRingOffset + _IOSqRingOffsetTail, 211 RingMask: _IOSqRingOffsetMask, 212 RingEntries: _IOSqRingOffsetEntries, 213 Flags: _IOSqRingOffsetFlags, 214 Dropped: _IOSqRingOffsetDropped, 215 } 216 } 217 218 const ( 219 _IOCqRingOffset = 128 // +checkoffset . IORings.Cq 220 _IOCqRingOffsetHead = 0 // +checkoffset . IOUring.Head 221 _IOCqRingOffsetTail = 64 // +checkoffset . IOUring.Tail 222 _IOCqRingOffsetMask = 260 // +checkoffset . IORings.CqRingMask 223 _IOCqRingOffsetEntries = 268 // +checkoffset . IORings.CqRingEntries 224 _IOCqRingOffsetFlags = 280 // +checkoffset . IORings.cqFlags 225 _IOCqRingOffsetOverflow = 284 // +checkoffset . IORings.CqOverflow 226 ) 227 228 // PreComputedIOCqRingOffsets returns precomputed values for IOCqRingOffsets. 229 func PreComputedIOCqRingOffsets() IOCqRingOffsets { 230 return IOCqRingOffsets{ 231 Head: _IOCqRingOffset + _IOCqRingOffsetHead, 232 Tail: _IOCqRingOffset + _IOCqRingOffsetTail, 233 RingMask: _IOCqRingOffsetMask, 234 RingEntries: _IOCqRingOffsetEntries, 235 Overflow: _IOCqRingOffsetOverflow, 236 Flags: _IOCqRingOffsetFlags, 237 } 238 }