drivers/vdpa/vdpa_sim/vdpa_sim_net.c

   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 <[email protected]>
   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 <[email protected]>"
  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
  31 #define VDPASIM_NET_VQ_NUM      2
  32
  33 static void vdpasim_net_work(struct work_struct *work)
  34 {
  35         struct vdpasim *vdpasim = container_of(work, struct vdpasim, work);
  36         struct vdpasim_virtqueue *txq = &vdpasim->vqs[1];
  37         struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0];
  38         ssize_t read, write;
  39         size_t total_write;
  40         int pkts = 0;
  41         int err;
  42
  43         spin_lock(&vdpasim->lock);
  44
  45         if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
  46                 goto out;
  47
  48         if (!txq->ready || !rxq->ready)
  49                 goto out;
  50
  51         while (true) {
  52                 total_write = 0;
  53                 err = vringh_getdesc_iotlb(&txq->vring, &txq->out_iov, NULL,
  54                                            &txq->head, GFP_ATOMIC);
  55                 if (err <= 0)
  56                         break;
  57
  58                 err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->in_iov,
  59                                            &rxq->head, GFP_ATOMIC);
  60                 if (err <= 0) {
  61                         vringh_complete_iotlb(&txq->vring, txq->head, 0);
  62                         break;
  63                 }
  64
  65                 while (true) {
  66                         read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov,
  67                                                      vdpasim->buffer,
  68                                                      PAGE_SIZE);
  69                         if (read <= 0)
  70                                 break;
  71
  72                         write = vringh_iov_push_iotlb(&rxq->vring, &rxq->in_iov,
  73                                                       vdpasim->buffer, read);
  74                         if (write <= 0)
  75                                 break;
  76
  77                         total_write += write;
  78                 }
  79
  80                 /* Make sure data is wrote before advancing index */
  81                 smp_wmb();
  82
  83                 vringh_complete_iotlb(&txq->vring, txq->head, 0);
  84                 vringh_complete_iotlb(&rxq->vring, rxq->head, total_write);
  85
  86                 /* Make sure used is visible before rasing the interrupt. */
  87                 smp_wmb();
  88
  89                 local_bh_disable();
  90                 if (vringh_need_notify_iotlb(&txq->vring) > 0)
  91                         vringh_notify(&txq->vring);
  92                 if (vringh_need_notify_iotlb(&rxq->vring) > 0)
  93                         vringh_notify(&rxq->vring);
  94                 local_bh_enable();
  95
  96                 if (++pkts > 4) {
  97                         schedule_work(&vdpasim->work);
  98                         goto out;
  99                 }
 100         }
 101
 102 out:
 103         spin_unlock(&vdpasim->lock);
 104 }
 105
 106 static void vdpasim_net_get_config(struct vdpasim *vdpasim, void *config)
 107 {
 108         struct virtio_net_config *net_config = config;
 109
 110         net_config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP);
 111 }
 112
 113 static void vdpasim_net_setup_config(struct vdpasim *vdpasim,
 114                                      const struct vdpa_dev_set_config *config)
 115 {
 116         struct virtio_net_config *vio_config = vdpasim->config;
 117
 118         if (config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR))
 119                 memcpy(vio_config->mac, config->net.mac, ETH_ALEN);
 120         if (config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MTU))
 121                 vio_config->mtu = cpu_to_vdpasim16(vdpasim, config->net.mtu);
 122         else
 123                 /* Setup default MTU to be 1500 */
 124                 vio_config->mtu = cpu_to_vdpasim16(vdpasim, 1500);
 125 }
 126
 127 static void vdpasim_net_mgmtdev_release(struct device *dev)
 128 {
 129 }
 130
 131 static struct device vdpasim_net_mgmtdev = {
 132         .init_name = "vdpasim_net",
 133         .release = vdpasim_net_mgmtdev_release,
 134 };
 135
 136 static int vdpasim_net_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
 137                                const struct vdpa_dev_set_config *config)
 138 {
 139         struct vdpasim_dev_attr dev_attr = {};
 140         struct vdpasim *simdev;
 141         int ret;
 142
 143         dev_attr.mgmt_dev = mdev;
 144         dev_attr.name = name;
 145         dev_attr.id = VIRTIO_ID_NET;
 146         dev_attr.supported_features = VDPASIM_NET_FEATURES;
 147         dev_attr.nvqs = VDPASIM_NET_VQ_NUM;
 148         dev_attr.config_size = sizeof(struct virtio_net_config);
 149         dev_attr.get_config = vdpasim_net_get_config;
 150         dev_attr.work_fn = vdpasim_net_work;
 151         dev_attr.buffer_size = PAGE_SIZE;
 152
 153         simdev = vdpasim_create(&dev_attr);
 154         if (IS_ERR(simdev))
 155                 return PTR_ERR(simdev);
 156
 157         vdpasim_net_setup_config(simdev, config);
 158
 159         ret = _vdpa_register_device(&simdev->vdpa, VDPASIM_NET_VQ_NUM);
 160         if (ret)
 161                 goto reg_err;
 162
 163         return 0;
 164
 165 reg_err:
 166         put_device(&simdev->vdpa.dev);
 167         return ret;
 168 }
 169
 170 static void vdpasim_net_dev_del(struct vdpa_mgmt_dev *mdev,
 171                                 struct vdpa_device *dev)
 172 {
 173         struct vdpasim *simdev = container_of(dev, struct vdpasim, vdpa);
 174
 175         _vdpa_unregister_device(&simdev->vdpa);
 176 }
 177
 178 static const struct vdpa_mgmtdev_ops vdpasim_net_mgmtdev_ops = {
 179         .dev_add = vdpasim_net_dev_add,
 180         .dev_del = vdpasim_net_dev_del
 181 };
 182
 183 static struct virtio_device_id id_table[] = {
 184         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
 185         { 0 },
 186 };
 187
 188 static struct vdpa_mgmt_dev mgmt_dev = {
 189         .device = &vdpasim_net_mgmtdev,
 190         .id_table = id_table,
 191         .ops = &vdpasim_net_mgmtdev_ops,
 192         .config_attr_mask = (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR |
 193                              1 << VDPA_ATTR_DEV_NET_CFG_MTU),
 194         .max_supported_vqs = VDPASIM_NET_VQ_NUM,
 195         .supported_features = VDPASIM_NET_FEATURES,
 196 };
 197
 198 static int __init vdpasim_net_init(void)
 199 {
 200         int ret;
 201
 202         ret = device_register(&vdpasim_net_mgmtdev);
 203         if (ret)
 204                 return ret;
 205
 206         ret = vdpa_mgmtdev_register(&mgmt_dev);
 207         if (ret)
 208                 goto parent_err;
 209         return 0;
 210
 211 parent_err:
 212         device_unregister(&vdpasim_net_mgmtdev);
 213         return ret;
 214 }
 215
 216 static void __exit vdpasim_net_exit(void)
 217 {
 218         vdpa_mgmtdev_unregister(&mgmt_dev);
 219         device_unregister(&vdpasim_net_mgmtdev);
 220 }
 221
 222 module_init(vdpasim_net_init);
 223 module_exit(vdpasim_net_exit);
 224
 225 MODULE_VERSION(DRV_VERSION);
 226 MODULE_LICENSE(DRV_LICENSE);
 227 MODULE_AUTHOR(DRV_AUTHOR);
 228 MODULE_DESCRIPTION(DRV_DESC);