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
31 #define VDPASIM_NET_VQ_NUM 2
32
vdpasim_net_work(struct work_struct * work)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
vdpasim_net_get_config(struct vdpasim * vdpasim,void * config)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
vdpasim_net_setup_config(struct vdpasim * vdpasim,const struct vdpa_dev_set_config * config)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
vdpasim_net_mgmtdev_release(struct device * dev)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
vdpasim_net_dev_add(struct vdpa_mgmt_dev * mdev,const char * name,const struct vdpa_dev_set_config * config)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
vdpasim_net_dev_del(struct vdpa_mgmt_dev * mdev,struct vdpa_device * dev)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 };
195
vdpasim_net_init(void)196 static int __init vdpasim_net_init(void)
197 {
198 int ret;
199
200 ret = device_register(&vdpasim_net_mgmtdev);
201 if (ret)
202 return ret;
203
204 ret = vdpa_mgmtdev_register(&mgmt_dev);
205 if (ret)
206 goto parent_err;
207 return 0;
208
209 parent_err:
210 device_unregister(&vdpasim_net_mgmtdev);
211 return ret;
212 }
213
vdpasim_net_exit(void)214 static void __exit vdpasim_net_exit(void)
215 {
216 vdpa_mgmtdev_unregister(&mgmt_dev);
217 device_unregister(&vdpasim_net_mgmtdev);
218 }
219
220 module_init(vdpasim_net_init);
221 module_exit(vdpasim_net_exit);
222
223 MODULE_VERSION(DRV_VERSION);
224 MODULE_LICENSE(DRV_LICENSE);
225 MODULE_AUTHOR(DRV_AUTHOR);
226 MODULE_DESCRIPTION(DRV_DESC);
227