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 <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
  20 #include "vdpa_sim.h"
  21
  22 #define DRV_VERSION  "0.1"
  23 #define DRV_AUTHOR   "Jason Wang <jasowang@redhat.com>"
  24 #define DRV_DESC     "vDPA Device Simulator for networking device"
  25 #define DRV_LICENSE  "GPL v2"
  26
  27 #define VDPASIM_NET_FEATURES    (VDPASIM_FEATURES | \
  28                                  (1ULL << VIRTIO_NET_F_MAC))
  29
  30 #define VDPASIM_NET_VQ_NUM      2
  31
  32 static char *macaddr;
  33 module_param(macaddr, charp, 0);
  34 MODULE_PARM_DESC(macaddr, "Ethernet MAC address");
  35
  36 static u8 macaddr_buf[ETH_ALEN];
  37
  38 static void vdpasim_net_work(struct work_struct *work)
  39 {
  40         struct vdpasim *vdpasim = container_of(work, struct vdpasim, work);
  41         struct vdpasim_virtqueue *txq = &vdpasim->vqs[1];
  42         struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0];
  43         ssize_t read, write;
  44         size_t total_write;
  45         int pkts = 0;
  46         int err;
  47
  48         spin_lock(&vdpasim->lock);
  49
  50         if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
  51                 goto out;
  52
  53         if (!txq->ready || !rxq->ready)
  54                 goto out;
  55
  56         while (true) {
  57                 total_write = 0;
  58                 err = vringh_getdesc_iotlb(&txq->vring, &txq->out_iov, NULL,
  59                                            &txq->head, GFP_ATOMIC);
  60                 if (err <= 0)
  61                         break;
  62
  63                 err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->in_iov,
  64                                            &rxq->head, GFP_ATOMIC);
  65                 if (err <= 0) {
  66                         vringh_complete_iotlb(&txq->vring, txq->head, 0);
  67                         break;
  68                 }
  69
  70                 while (true) {
  71                         read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov,
  72                                                      vdpasim->buffer,
  73                                                      PAGE_SIZE);
  74                         if (read <= 0)
  75                                 break;
  76
  77                         write = vringh_iov_push_iotlb(&rxq->vring, &rxq->in_iov,
  78                                                       vdpasim->buffer, read);
  79                         if (write <= 0)
  80                                 break;
  81
  82                         total_write += write;
  83                 }
  84
  85                 /* Make sure data is wrote before advancing index */
  86                 smp_wmb();
  87
  88                 vringh_complete_iotlb(&txq->vring, txq->head, 0);
  89                 vringh_complete_iotlb(&rxq->vring, rxq->head, total_write);
  90
  91                 /* Make sure used is visible before rasing the interrupt. */
  92                 smp_wmb();
  93
  94                 local_bh_disable();
  95                 if (vringh_need_notify_iotlb(&txq->vring) > 0)
  96                         vringh_notify(&txq->vring);
  97                 if (vringh_need_notify_iotlb(&rxq->vring) > 0)
  98                         vringh_notify(&rxq->vring);
  99                 local_bh_enable();
 100
 101                 if (++pkts > 4) {
 102                         schedule_work(&vdpasim->work);
 103                         goto out;
 104                 }
 105         }
 106
 107 out:
 108         spin_unlock(&vdpasim->lock);
 109 }
 110
 111 static void vdpasim_net_get_config(struct vdpasim *vdpasim, void *config)
 112 {
 113         struct virtio_net_config *net_config =
 114                 (struct virtio_net_config *)config;
 115
 116         net_config->mtu = cpu_to_vdpasim16(vdpasim, 1500);
 117         net_config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP);
 118         memcpy(net_config->mac, macaddr_buf, ETH_ALEN);
 119 }
 120
 121 static void vdpasim_net_mgmtdev_release(struct device *dev)
 122 {
 123 }
 124
 125 static struct device vdpasim_net_mgmtdev = {
 126         .init_name = "vdpasim_net",
 127         .release = vdpasim_net_mgmtdev_release,
 128 };
 129
 130 static int vdpasim_net_dev_add(struct vdpa_mgmt_dev *mdev, const char *name)
 131 {
 132         struct vdpasim_dev_attr dev_attr = {};
 133         struct vdpasim *simdev;
 134         int ret;
 135
 136         dev_attr.mgmt_dev = mdev;
 137         dev_attr.name = name;
 138         dev_attr.id = VIRTIO_ID_NET;
 139         dev_attr.supported_features = VDPASIM_NET_FEATURES;
 140         dev_attr.nvqs = VDPASIM_NET_VQ_NUM;
 141         dev_attr.config_size = sizeof(struct virtio_net_config);
 142         dev_attr.get_config = vdpasim_net_get_config;
 143         dev_attr.work_fn = vdpasim_net_work;
 144         dev_attr.buffer_size = PAGE_SIZE;
 145
 146         simdev = vdpasim_create(&dev_attr);
 147         if (IS_ERR(simdev))
 148                 return PTR_ERR(simdev);
 149
 150         ret = _vdpa_register_device(&simdev->vdpa);
 151         if (ret)
 152                 goto reg_err;
 153
 154         return 0;
 155
 156 reg_err:
 157         put_device(&simdev->vdpa.dev);
 158         return ret;
 159 }
 160
 161 static void vdpasim_net_dev_del(struct vdpa_mgmt_dev *mdev,
 162                                 struct vdpa_device *dev)
 163 {
 164         struct vdpasim *simdev = container_of(dev, struct vdpasim, vdpa);
 165
 166         _vdpa_unregister_device(&simdev->vdpa);
 167 }
 168
 169 static const struct vdpa_mgmtdev_ops vdpasim_net_mgmtdev_ops = {
 170         .dev_add = vdpasim_net_dev_add,
 171         .dev_del = vdpasim_net_dev_del
 172 };
 173
 174 static struct virtio_device_id id_table[] = {
 175         { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
 176         { 0 },
 177 };
 178
 179 static struct vdpa_mgmt_dev mgmt_dev = {
 180         .device = &vdpasim_net_mgmtdev,
 181         .id_table = id_table,
 182         .ops = &vdpasim_net_mgmtdev_ops,
 183 };
 184
 185 static int __init vdpasim_net_init(void)
 186 {
 187         int ret;
 188
 189         if (macaddr) {
 190                 mac_pton(macaddr, macaddr_buf);
 191                 if (!is_valid_ether_addr(macaddr_buf))
 192                         return -EADDRNOTAVAIL;
 193         } else {
 194                 eth_random_addr(macaddr_buf);
 195         }
 196
 197         ret = device_register(&vdpasim_net_mgmtdev);
 198         if (ret)
 199                 return ret;
 200
 201         ret = vdpa_mgmtdev_register(&mgmt_dev);
 202         if (ret)
 203                 goto parent_err;
 204         return 0;
 205
 206 parent_err:
 207         device_unregister(&vdpasim_net_mgmtdev);
 208         return ret;
 209 }
 210
 211 static void __exit vdpasim_net_exit(void)
 212 {
 213         vdpa_mgmtdev_unregister(&mgmt_dev);
 214         device_unregister(&vdpasim_net_mgmtdev);
 215 }
 216
 217 module_init(vdpasim_net_init);
 218 module_exit(vdpasim_net_exit);
 219
 220 MODULE_VERSION(DRV_VERSION);
 221 MODULE_LICENSE(DRV_LICENSE);
 222 MODULE_AUTHOR(DRV_AUTHOR);
 223 MODULE_DESCRIPTION(DRV_DESC);