1 /* $NetBSD: virtioreg.h,v 1.13 2023/11/19 19:47:03 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 2010 Minoura Makoto. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 /* 29 * Part of the file derived from `Virtio PCI Card Specification v0.8.6 DRAFT' 30 * Appendix A. 31 */ 32 /* An interface for efficient virtio implementation. 33 * 34 * This header is BSD licensed so anyone can use the definitions 35 * to implement compatible drivers/servers. 36 * 37 * Copyright 2007, 2009, IBM Corporation 38 * All rights reserved. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. Neither the name of IBM nor the names of its contributors 49 * may be used to endorse or promote products derived from this software 50 * without specific prior written permission. 51 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND 52 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 53 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 54 * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE 55 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 56 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 57 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 58 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 59 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 60 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 61 * SUCH DAMAGE. 62 */ 63 64 65 #ifndef _DEV_PCI_VIRTIOREG_H_ 66 #define _DEV_PCI_VIRTIOREG_H_ 67 68 #include <sys/types.h> 69 70 /* Virtio product id (all subsystems) */ 71 #define VIRTIO_DEVICE_ID_NETWORK 1 72 #define VIRTIO_DEVICE_ID_BLOCK 2 73 #define VIRTIO_DEVICE_ID_CONSOLE 3 74 #define VIRTIO_DEVICE_ID_ENTROPY 4 75 #define VIRTIO_DEVICE_ID_BALLOON 5 76 #define VIRTIO_DEVICE_ID_IOMEM 6 77 #define VIRTIO_DEVICE_ID_RPMSG 7 78 #define VIRTIO_DEVICE_ID_SCSI 8 79 #define VIRTIO_DEVICE_ID_9P 9 80 81 /* common device/guest features */ 82 #define VIRTIO_F_NOTIFY_ON_EMPTY __BIT(24) 83 #define VIRTIO_F_RING_INDIRECT_DESC __BIT(28) 84 #define VIRTIO_F_RING_EVENT_IDX __BIT(29) 85 #define VIRTIO_F_BAD_FEATURE __BIT(30) 86 #define VIRTIO_F_VERSION_1 __BIT(32) 87 #define VIRTIO_F_ACCESS_PLATFORM __BIT(33) 88 #define VIRTIO_F_RING_PACKED __BIT(34) 89 #define VIRTIO_F_ORDER_PLATFORM __BIT(36) 90 #define VIRTIO_F_SR_IOV __BIT(37) 91 92 /* common device status flags */ 93 #define VIRTIO_CONFIG_DEVICE_STATUS_RESET 0 94 #define VIRTIO_CONFIG_DEVICE_STATUS_ACK 1 95 #define VIRTIO_CONFIG_DEVICE_STATUS_DRIVER 2 96 #define VIRTIO_CONFIG_DEVICE_STATUS_DRIVER_OK 4 97 #define VIRTIO_CONFIG_DEVICE_STATUS_FEATURES_OK 8 98 #define VIRTIO_CONFIG_DEVICE_STATUS_DEVICE_NEEDS_RESET 64 99 #define VIRTIO_CONFIG_DEVICE_STATUS_FAILED 128 100 101 /* common ISR status flags */ 102 #define VIRTIO_CONFIG_ISR_QUEUE_INTERRUPT 1 103 #define VIRTIO_CONFIG_ISR_CONFIG_CHANGE 2 104 105 /* common device/guest features */ 106 #define VIRTIO_COMMON_FLAG_BITS \ 107 "\177\020" \ 108 "b\x24" "SR_IOV\0" \ 109 "b\x23" "ORDER_PLATFORM\0" \ 110 "b\x22" "RING_PACKED\0" \ 111 "b\x21" "ACCESS_PLATFORM\0" \ 112 "b\x20" "V1\0" \ 113 "b\x1e" "BAD_FEATURE\0" \ 114 "b\x1d" "EVENT_IDX\0" \ 115 "b\x1c" "INDIRECT_DESC\0" \ 116 "b\x18" "NOTIFY_ON_EMPTY\0" 117 118 119 /* 120 * Virtqueue 121 */ 122 123 /* marks a buffer as continuing via the next field. */ 124 #define VRING_DESC_F_NEXT 1 125 126 /* marks a buffer as write-only (otherwise read-only). */ 127 #define VRING_DESC_F_WRITE 2 128 129 /* the buffer contains a list of buffer descriptors. */ 130 #define VRING_DESC_F_INDIRECT 4 131 132 133 /* 134 * The Host uses this in used->flags to advise the Guest: don't kick me when 135 * you add a buffer. It's unreliable, so it's simply an optimization. Guest 136 * will still kick if it's out of buffers. 137 */ 138 #define VRING_USED_F_NO_NOTIFY 1 139 140 /* 141 * The Guest uses this in avail->flags to advise the Host: don't interrupt me 142 * when you consume a buffer. It's unreliable, so it's simply an 143 * optimization. 144 */ 145 #define VRING_AVAIL_F_NO_INTERRUPT 1 146 147 148 /* Virtio ring descriptors: 16 bytes. 149 * These can chain together via "next". */ 150 struct vring_desc { 151 /* Address (guest-physical). */ 152 uint64_t addr; 153 /* Length. */ 154 uint32_t len; 155 /* The flags as indicated above. */ 156 uint16_t flags; 157 /* We chain unused descriptors via this, too */ 158 uint16_t next; 159 } __packed; 160 161 struct vring_avail { 162 uint16_t flags; 163 uint16_t idx; 164 uint16_t ring[]; 165 /* trailed by uint16_t used_event when VIRTIO_F_RING_EVENT_IDX */ 166 } __packed; 167 168 /* u32 is used here for ids for padding reasons. */ 169 struct vring_used_elem { 170 /* Index of start of used descriptor chain. */ 171 uint32_t id; 172 /* Total length of the descriptor chain which was written to. */ 173 uint32_t len; 174 } __packed; 175 176 struct vring_used { 177 uint16_t flags; 178 uint16_t idx; 179 struct vring_used_elem ring[]; 180 /* trailed by uint16_t avail_event when VIRTIO_F_RING_EVENT_IDX */ 181 } __packed; 182 183 /* The standard layout for the ring is a continuous chunk of memory which 184 * looks like this. We assume num is a power of 2. 185 * 186 * struct vring { 187 * // The actual descriptors (16 bytes each) 188 * struct vring_desc desc[num]; 189 * 190 * // A ring of available descriptor heads with free-running index. 191 * __u16 avail_flags; 192 * __u16 avail_idx; 193 * __u16 available[num]; 194 * 195 * // Padding to the next align boundary. 196 * char pad[]; 197 * 198 * // A ring of used descriptor heads with free-running index. 199 * __u16 used_flags; 200 * __u16 used_idx; 201 * struct vring_used_elem used[num]; 202 * }; 203 * Note: for virtio PCI, align is 4096. 204 */ 205 206 #define VIRTIO_PAGE_SIZE (4096) 207 208 #endif /* _DEV_PCI_VIRTIOREG_H_ */ 209