1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * VDPA simulator for networking device. 4 * 5 * Copyright (c) 2020, Red Hat Inc. All rights reserved. 6 * Author: Jason Wang <jasowang@redhat.com> 7 * 8 */ 9 10 #include <linux/init.h> 11 #include <linux/module.h> 12 #include <linux/device.h> 13 #include <linux/kernel.h> 14 #include <linux/sched.h> 15 #include <linux/etherdevice.h> 16 #include <linux/vringh.h> 17 #include <linux/vdpa.h> 18 #include <uapi/linux/virtio_net.h> 19 #include <uapi/linux/vdpa.h> 20 21 #include "vdpa_sim.h" 22 23 #define DRV_VERSION "0.1" 24 #define DRV_AUTHOR "Jason Wang <jasowang@redhat.com>" 25 #define DRV_DESC "vDPA Device Simulator for networking device" 26 #define DRV_LICENSE "GPL v2" 27 28 #define VDPASIM_NET_FEATURES (VDPASIM_FEATURES | \ 29 (1ULL << VIRTIO_NET_F_MAC) | \ 30 (1ULL << VIRTIO_NET_F_MTU) | \ 31 (1ULL << VIRTIO_NET_F_CTRL_VQ) | \ 32 (1ULL << VIRTIO_NET_F_CTRL_MAC_ADDR)) 33 34 /* 3 virtqueues, 2 address spaces, 2 virtqueue groups */ 35 #define VDPASIM_NET_VQ_NUM 3 36 #define VDPASIM_NET_AS_NUM 2 37 #define VDPASIM_NET_GROUP_NUM 2 38 39 static void vdpasim_net_complete(struct vdpasim_virtqueue *vq, size_t len) 40 { 41 /* Make sure data is wrote before advancing index */ 42 smp_wmb(); 43 44 vringh_complete_iotlb(&vq->vring, vq->head, len); 45 46 /* Make sure used is visible before rasing the interrupt. */ 47 smp_wmb(); 48 49 local_bh_disable(); 50 if (vringh_need_notify_iotlb(&vq->vring) > 0) 51 vringh_notify(&vq->vring); 52 local_bh_enable(); 53 } 54 55 static bool receive_filter(struct vdpasim *vdpasim, size_t len) 56 { 57 bool modern = vdpasim->features & (1ULL << VIRTIO_F_VERSION_1); 58 size_t hdr_len = modern ? sizeof(struct virtio_net_hdr_v1) : 59 sizeof(struct virtio_net_hdr); 60 struct virtio_net_config *vio_config = vdpasim->config; 61 62 if (len < ETH_ALEN + hdr_len) 63 return false; 64 65 if (!strncmp(vdpasim->buffer + hdr_len, vio_config->mac, ETH_ALEN)) 66 return true; 67 68 return false; 69 } 70 71 static virtio_net_ctrl_ack vdpasim_handle_ctrl_mac(struct vdpasim *vdpasim, 72 u8 cmd) 73 { 74 struct virtio_net_config *vio_config = vdpasim->config; 75 struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2]; 76 virtio_net_ctrl_ack status = VIRTIO_NET_ERR; 77 size_t read; 78 79 switch (cmd) { 80 case VIRTIO_NET_CTRL_MAC_ADDR_SET: 81 read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov, 82 vio_config->mac, ETH_ALEN); 83 if (read == ETH_ALEN) 84 status = VIRTIO_NET_OK; 85 break; 86 default: 87 break; 88 } 89 90 return status; 91 } 92 93 static void vdpasim_handle_cvq(struct vdpasim *vdpasim) 94 { 95 struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2]; 96 virtio_net_ctrl_ack status = VIRTIO_NET_ERR; 97 struct virtio_net_ctrl_hdr ctrl; 98 size_t read, write; 99 int err; 100 101 if (!(vdpasim->features & (1ULL << VIRTIO_NET_F_CTRL_VQ))) 102 return; 103 104 if (!cvq->ready) 105 return; 106 107 while (true) { 108 err = vringh_getdesc_iotlb(&cvq->vring, &cvq->in_iov, 109 &cvq->out_iov, 110 &cvq->head, GFP_ATOMIC); 111 if (err <= 0) 112 break; 113 114 read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov, &ctrl, 115 sizeof(ctrl)); 116 if (read != sizeof(ctrl)) 117 break; 118 119 switch (ctrl.class) { 120 case VIRTIO_NET_CTRL_MAC: 121 status = vdpasim_handle_ctrl_mac(vdpasim, ctrl.cmd); 122 break; 123 default: 124 break; 125 } 126 127 /* Make sure data is wrote before advancing index */ 128 smp_wmb(); 129 130 write = vringh_iov_push_iotlb(&cvq->vring, &cvq->out_iov, 131 &status, sizeof(status)); 132 vringh_complete_iotlb(&cvq->vring, cvq->head, write); 133 vringh_kiov_cleanup(&cvq->in_iov); 134 vringh_kiov_cleanup(&cvq->out_iov); 135 136 /* Make sure used is visible before rasing the interrupt. */ 137 smp_wmb(); 138 139 local_bh_disable(); 140 if (cvq->cb) 141 cvq->cb(cvq->private); 142 local_bh_enable(); 143 } 144 } 145 146 static void vdpasim_net_work(struct work_struct *work) 147 { 148 struct vdpasim *vdpasim = container_of(work, struct vdpasim, work); 149 struct vdpasim_virtqueue *txq = &vdpasim->vqs[1]; 150 struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0]; 151 ssize_t read, write; 152 int pkts = 0; 153 int err; 154 155 spin_lock(&vdpasim->lock); 156 157 if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK)) 158 goto out; 159 160 vdpasim_handle_cvq(vdpasim); 161 162 if (!txq->ready || !rxq->ready) 163 goto out; 164 165 while (true) { 166 err = vringh_getdesc_iotlb(&txq->vring, &txq->out_iov, NULL, 167 &txq->head, GFP_ATOMIC); 168 if (err <= 0) 169 break; 170 171 read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov, 172 vdpasim->buffer, 173 PAGE_SIZE); 174 175 if (!receive_filter(vdpasim, read)) { 176 vdpasim_net_complete(txq, 0); 177 continue; 178 } 179 180 err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->in_iov, 181 &rxq->head, GFP_ATOMIC); 182 if (err <= 0) { 183 vdpasim_net_complete(txq, 0); 184 break; 185 } 186 187 write = vringh_iov_push_iotlb(&rxq->vring, &rxq->in_iov, 188 vdpasim->buffer, read); 189 if (write <= 0) 190 break; 191 192 vdpasim_net_complete(txq, 0); 193 vdpasim_net_complete(rxq, write); 194 195 if (++pkts > 4) { 196 schedule_work(&vdpasim->work); 197 goto out; 198 } 199 } 200 201 out: 202 spin_unlock(&vdpasim->lock); 203 } 204 205 static void vdpasim_net_get_config(struct vdpasim *vdpasim, void *config) 206 { 207 struct virtio_net_config *net_config = config; 208 209 net_config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP); 210 } 211 212 static void vdpasim_net_setup_config(struct vdpasim *vdpasim, 213 const struct vdpa_dev_set_config *config) 214 { 215 struct virtio_net_config *vio_config = vdpasim->config; 216 217 if (config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR)) 218 memcpy(vio_config->mac, config->net.mac, ETH_ALEN); 219 if (config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MTU)) 220 vio_config->mtu = cpu_to_vdpasim16(vdpasim, config->net.mtu); 221 else 222 /* Setup default MTU to be 1500 */ 223 vio_config->mtu = cpu_to_vdpasim16(vdpasim, 1500); 224 } 225 226 static void vdpasim_net_mgmtdev_release(struct device *dev) 227 { 228 } 229 230 static struct device vdpasim_net_mgmtdev = { 231 .init_name = "vdpasim_net", 232 .release = vdpasim_net_mgmtdev_release, 233 }; 234 235 static int vdpasim_net_dev_add(struct vdpa_mgmt_dev *mdev, const char *name, 236 const struct vdpa_dev_set_config *config) 237 { 238 struct vdpasim_dev_attr dev_attr = {}; 239 struct vdpasim *simdev; 240 int ret; 241 242 dev_attr.mgmt_dev = mdev; 243 dev_attr.name = name; 244 dev_attr.id = VIRTIO_ID_NET; 245 dev_attr.supported_features = VDPASIM_NET_FEATURES; 246 dev_attr.nvqs = VDPASIM_NET_VQ_NUM; 247 dev_attr.ngroups = VDPASIM_NET_GROUP_NUM; 248 dev_attr.nas = VDPASIM_NET_AS_NUM; 249 dev_attr.config_size = sizeof(struct virtio_net_config); 250 dev_attr.get_config = vdpasim_net_get_config; 251 dev_attr.work_fn = vdpasim_net_work; 252 dev_attr.buffer_size = PAGE_SIZE; 253 254 simdev = vdpasim_create(&dev_attr); 255 if (IS_ERR(simdev)) 256 return PTR_ERR(simdev); 257 258 vdpasim_net_setup_config(simdev, config); 259 260 ret = _vdpa_register_device(&simdev->vdpa, VDPASIM_NET_VQ_NUM); 261 if (ret) 262 goto reg_err; 263 264 return 0; 265 266 reg_err: 267 put_device(&simdev->vdpa.dev); 268 return ret; 269 } 270 271 static void vdpasim_net_dev_del(struct vdpa_mgmt_dev *mdev, 272 struct vdpa_device *dev) 273 { 274 struct vdpasim *simdev = container_of(dev, struct vdpasim, vdpa); 275 276 _vdpa_unregister_device(&simdev->vdpa); 277 } 278 279 static const struct vdpa_mgmtdev_ops vdpasim_net_mgmtdev_ops = { 280 .dev_add = vdpasim_net_dev_add, 281 .dev_del = vdpasim_net_dev_del 282 }; 283 284 static struct virtio_device_id id_table[] = { 285 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, 286 { 0 }, 287 }; 288 289 static struct vdpa_mgmt_dev mgmt_dev = { 290 .device = &vdpasim_net_mgmtdev, 291 .id_table = id_table, 292 .ops = &vdpasim_net_mgmtdev_ops, 293 .config_attr_mask = (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR | 294 1 << VDPA_ATTR_DEV_NET_CFG_MTU), 295 .max_supported_vqs = VDPASIM_NET_VQ_NUM, 296 .supported_features = VDPASIM_NET_FEATURES, 297 }; 298 299 static int __init vdpasim_net_init(void) 300 { 301 int ret; 302 303 ret = device_register(&vdpasim_net_mgmtdev); 304 if (ret) 305 return ret; 306 307 ret = vdpa_mgmtdev_register(&mgmt_dev); 308 if (ret) 309 goto parent_err; 310 return 0; 311 312 parent_err: 313 device_unregister(&vdpasim_net_mgmtdev); 314 return ret; 315 } 316 317 static void __exit vdpasim_net_exit(void) 318 { 319 vdpa_mgmtdev_unregister(&mgmt_dev); 320 device_unregister(&vdpasim_net_mgmtdev); 321 } 322 323 module_init(vdpasim_net_init); 324 module_exit(vdpasim_net_exit); 325 326 MODULE_VERSION(DRV_VERSION); 327 MODULE_LICENSE(DRV_LICENSE); 328 MODULE_AUTHOR(DRV_AUTHOR); 329 MODULE_DESCRIPTION(DRV_DESC); 330