| 1 | /* |
| 2 | * VDUSE (vDPA Device in Userspace) library |
| 3 | * |
| 4 | * Copyright (C) 2022 Bytedance Inc. and/or its affiliates. All rights reserved. |
| 5 | * |
| 6 | * Author: |
| 7 | * Xie Yongji <xieyongji@bytedance.com> |
| 8 | * |
| 9 | * This work is licensed under the terms of the GNU GPL, version 2 or |
| 10 | * later. See the COPYING file in the top-level directory. |
| 11 | */ |
| 12 | |
| 13 | #ifndef LIBVDUSE_H |
| 14 | #define LIBVDUSE_H |
| 15 | |
| 16 | #include <stdint.h> |
| 17 | #include <sys/uio.h> |
| 18 | |
| 19 | #define VIRTQUEUE_MAX_SIZE 1024 |
| 20 | |
| 21 | /* VDUSE device structure */ |
| 22 | typedef struct VduseDev VduseDev; |
| 23 | |
| 24 | /* Virtqueue structure */ |
| 25 | typedef struct VduseVirtq VduseVirtq; |
| 26 | |
| 27 | /* Some operation of VDUSE backend */ |
| 28 | typedef struct VduseOps { |
| 29 | /* Called when virtqueue can be processed */ |
| 30 | void (*enable_queue)(VduseDev *dev, VduseVirtq *vq); |
| 31 | /* Called when virtqueue processing should be stopped */ |
| 32 | void (*disable_queue)(VduseDev *dev, VduseVirtq *vq); |
| 33 | } VduseOps; |
| 34 | |
| 35 | /* Describing elements of the I/O buffer */ |
| 36 | typedef struct VduseVirtqElement { |
| 37 | /* Descriptor table index */ |
| 38 | unsigned int index; |
| 39 | /* Number of physically-contiguous device-readable descriptors */ |
| 40 | unsigned int out_num; |
| 41 | /* Number of physically-contiguous device-writable descriptors */ |
| 42 | unsigned int in_num; |
| 43 | /* Array to store physically-contiguous device-writable descriptors */ |
| 44 | struct iovec *in_sg; |
| 45 | /* Array to store physically-contiguous device-readable descriptors */ |
| 46 | struct iovec *out_sg; |
| 47 | } VduseVirtqElement; |
| 48 | |
| 49 | |
| 50 | /** |
| 51 | * vduse_get_virtio_features: |
| 52 | * |
| 53 | * Get supported virtio features |
| 54 | * |
| 55 | * Returns: supported feature bits |
| 56 | */ |
| 57 | uint64_t vduse_get_virtio_features(void); |
| 58 | |
| 59 | /** |
| 60 | * vduse_queue_get_dev: |
| 61 | * @vq: specified virtqueue |
| 62 | * |
| 63 | * Get corresponding VDUSE device from the virtqueue. |
| 64 | * |
| 65 | * Returns: a pointer to VDUSE device on success, NULL on failure. |
| 66 | */ |
| 67 | VduseDev *vduse_queue_get_dev(VduseVirtq *vq); |
| 68 | |
| 69 | /** |
| 70 | * vduse_queue_get_fd: |
| 71 | * @vq: specified virtqueue |
| 72 | * |
| 73 | * Get the kick fd for the virtqueue. |
| 74 | * |
| 75 | * Returns: file descriptor on success, -1 on failure. |
| 76 | */ |
| 77 | int vduse_queue_get_fd(VduseVirtq *vq); |
| 78 | |
| 79 | /** |
| 80 | * vduse_queue_pop: |
| 81 | * @vq: specified virtqueue |
| 82 | * @sz: the size of struct to return (must be >= VduseVirtqElement) |
| 83 | * |
| 84 | * Pop an element from virtqueue available ring. |
| 85 | * |
| 86 | * Returns: a pointer to a structure containing VduseVirtqElement on success, |
| 87 | * NULL on failure. |
| 88 | */ |
| 89 | void *vduse_queue_pop(VduseVirtq *vq, size_t sz); |
| 90 | |
| 91 | /** |
| 92 | * vduse_queue_push: |
| 93 | * @vq: specified virtqueue |
| 94 | * @elem: pointer to VduseVirtqElement returned by vduse_queue_pop() |
| 95 | * @len: length in bytes to write |
| 96 | * |
| 97 | * Push an element to virtqueue used ring. |
| 98 | */ |
| 99 | void vduse_queue_push(VduseVirtq *vq, const VduseVirtqElement *elem, |
| 100 | unsigned int len); |
| 101 | /** |
| 102 | * vduse_queue_notify: |
| 103 | * @vq: specified virtqueue |
| 104 | * |
| 105 | * Request to notify the queue. |
| 106 | */ |
| 107 | void vduse_queue_notify(VduseVirtq *vq); |
| 108 | |
| 109 | /** |
| 110 | * vduse_dev_get_priv: |
| 111 | * @dev: VDUSE device |
| 112 | * |
| 113 | * Get the private pointer passed to vduse_dev_create(). |
| 114 | * |
| 115 | * Returns: private pointer on success, NULL on failure. |
| 116 | */ |
| 117 | void *vduse_dev_get_priv(VduseDev *dev); |
| 118 | |
| 119 | /** |
| 120 | * vduse_dev_get_queue: |
| 121 | * @dev: VDUSE device |
| 122 | * @index: virtqueue index |
| 123 | * |
| 124 | * Get the specified virtqueue. |
| 125 | * |
| 126 | * Returns: a pointer to the virtqueue on success, NULL on failure. |
| 127 | */ |
| 128 | VduseVirtq *vduse_dev_get_queue(VduseDev *dev, int index); |
| 129 | |
| 130 | /** |
| 131 | * vduse_dev_get_fd: |
| 132 | * @dev: VDUSE device |
| 133 | * |
| 134 | * Get the control message fd for the VDUSE device. |
| 135 | * |
| 136 | * Returns: file descriptor on success, -1 on failure. |
| 137 | */ |
| 138 | int vduse_dev_get_fd(VduseDev *dev); |
| 139 | |
| 140 | /** |
| 141 | * vduse_dev_handler: |
| 142 | * @dev: VDUSE device |
| 143 | * |
| 144 | * Used to process the control message. |
| 145 | * |
| 146 | * Returns: file descriptor on success, -errno on failure. |
| 147 | */ |
| 148 | int vduse_dev_handler(VduseDev *dev); |
| 149 | |
| 150 | /** |
| 151 | * vduse_dev_update_config: |
| 152 | * @dev: VDUSE device |
| 153 | * @size: the size to write to configuration space |
| 154 | * @offset: the offset from the beginning of configuration space |
| 155 | * @buffer: the buffer used to write from |
| 156 | * |
| 157 | * Update device configuration space and inject a config interrupt. |
| 158 | * |
| 159 | * Returns: 0 on success, -errno on failure. |
| 160 | */ |
| 161 | int vduse_dev_update_config(VduseDev *dev, uint32_t size, |
| 162 | uint32_t offset, char *buffer); |
| 163 | |
| 164 | /** |
| 165 | * vduse_dev_setup_queue: |
| 166 | * @dev: VDUSE device |
| 167 | * @index: virtqueue index |
| 168 | * @max_size: the max size of virtqueue |
| 169 | * |
| 170 | * Setup the specified virtqueue. |
| 171 | * |
| 172 | * Returns: 0 on success, -errno on failure. |
| 173 | */ |
| 174 | int vduse_dev_setup_queue(VduseDev *dev, int index, int max_size); |
| 175 | |
| 176 | /** |
| 177 | * vduse_set_reconnect_log_file: |
| 178 | * @dev: VDUSE device |
| 179 | * @file: filename of reconnect log |
| 180 | * |
| 181 | * Specify the file to store log for reconnecting. It should |
| 182 | * be called before vduse_dev_setup_queue(). |
| 183 | * |
| 184 | * Returns: 0 on success, -errno on failure. |
| 185 | */ |
| 186 | int vduse_set_reconnect_log_file(VduseDev *dev, const char *filename); |
| 187 | |
| 188 | /** |
| 189 | * vduse_dev_create_by_fd: |
| 190 | * @fd: passed file descriptor |
| 191 | * @num_queues: the number of virtqueues |
| 192 | * @ops: the operation of VDUSE backend |
| 193 | * @priv: private pointer |
| 194 | * |
| 195 | * Create VDUSE device from a passed file descriptor. |
| 196 | * |
| 197 | * Returns: pointer to VDUSE device on success, NULL on failure. |
| 198 | */ |
| 199 | VduseDev *vduse_dev_create_by_fd(int fd, uint16_t num_queues, |
| 200 | const VduseOps *ops, void *priv); |
| 201 | |
| 202 | /** |
| 203 | * vduse_dev_create_by_name: |
| 204 | * @name: VDUSE device name |
| 205 | * @num_queues: the number of virtqueues |
| 206 | * @ops: the operation of VDUSE backend |
| 207 | * @priv: private pointer |
| 208 | * |
| 209 | * Create VDUSE device on /dev/vduse/$NAME. |
| 210 | * |
| 211 | * Returns: pointer to VDUSE device on success, NULL on failure. |
| 212 | */ |
| 213 | VduseDev *vduse_dev_create_by_name(const char *name, uint16_t num_queues, |
| 214 | const VduseOps *ops, void *priv); |
| 215 | |
| 216 | /** |
| 217 | * vduse_dev_create: |
| 218 | * @name: VDUSE device name |
| 219 | * @device_id: virtio device id |
| 220 | * @vendor_id: virtio vendor id |
| 221 | * @features: virtio features |
| 222 | * @num_queues: the number of virtqueues |
| 223 | * @config_size: the size of the configuration space |
| 224 | * @config: the buffer of the configuration space |
| 225 | * @ops: the operation of VDUSE backend |
| 226 | * @priv: private pointer |
| 227 | * |
| 228 | * Create VDUSE device. |
| 229 | * |
| 230 | * Returns: pointer to VDUSE device on success, NULL on failure. |
| 231 | */ |
| 232 | VduseDev *vduse_dev_create(const char *name, uint32_t device_id, |
| 233 | uint32_t vendor_id, uint64_t features, |
| 234 | uint16_t num_queues, uint32_t config_size, |
| 235 | char *config, const VduseOps *ops, void *priv); |
| 236 | |
| 237 | /** |
| 238 | * vduse_dev_destroy: |
| 239 | * @dev: VDUSE device |
| 240 | * |
| 241 | * Destroy the VDUSE device. |
| 242 | * |
| 243 | * Returns: 0 on success, -errno on failure. |
| 244 | */ |
| 245 | int vduse_dev_destroy(VduseDev *dev); |
| 246 | |
| 247 | #endif |