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
vdpasim_net_complete(struct vdpasim_virtqueue * vq,size_t len)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
receive_filter(struct vdpasim * vdpasim,size_t len)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 (is_broadcast_ether_addr(vdpasim->buffer + hdr_len) ||
66 is_multicast_ether_addr(vdpasim->buffer + hdr_len))
67 return true;
68 if (!strncmp(vdpasim->buffer + hdr_len, vio_config->mac, ETH_ALEN))
69 return true;
70
71 return false;
72 }
73
vdpasim_handle_ctrl_mac(struct vdpasim * vdpasim,u8 cmd)74 static virtio_net_ctrl_ack vdpasim_handle_ctrl_mac(struct vdpasim *vdpasim,
75 u8 cmd)
76 {
77 struct virtio_net_config *vio_config = vdpasim->config;
78 struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
79 virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
80 size_t read;
81
82 switch (cmd) {
83 case VIRTIO_NET_CTRL_MAC_ADDR_SET:
84 read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov,
85 vio_config->mac, ETH_ALEN);
86 if (read == ETH_ALEN)
87 status = VIRTIO_NET_OK;
88 break;
89 default:
90 break;
91 }
92
93 return status;
94 }
95
vdpasim_handle_cvq(struct vdpasim * vdpasim)96 static void vdpasim_handle_cvq(struct vdpasim *vdpasim)
97 {
98 struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
99 virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
100 struct virtio_net_ctrl_hdr ctrl;
101 size_t read, write;
102 int err;
103
104 if (!(vdpasim->features & (1ULL << VIRTIO_NET_F_CTRL_VQ)))
105 return;
106
107 if (!cvq->ready)
108 return;
109
110 while (true) {
111 err = vringh_getdesc_iotlb(&cvq->vring, &cvq->in_iov,
112 &cvq->out_iov,
113 &cvq->head, GFP_ATOMIC);
114 if (err <= 0)
115 break;
116
117 read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov, &ctrl,
118 sizeof(ctrl));
119 if (read != sizeof(ctrl))
120 break;
121
122 switch (ctrl.class) {
123 case VIRTIO_NET_CTRL_MAC:
124 status = vdpasim_handle_ctrl_mac(vdpasim, ctrl.cmd);
125 break;
126 default:
127 break;
128 }
129
130 /* Make sure data is wrote before advancing index */
131 smp_wmb();
132
133 write = vringh_iov_push_iotlb(&cvq->vring, &cvq->out_iov,
134 &status, sizeof(status));
135 vringh_complete_iotlb(&cvq->vring, cvq->head, write);
136 vringh_kiov_cleanup(&cvq->in_iov);
137 vringh_kiov_cleanup(&cvq->out_iov);
138
139 /* Make sure used is visible before rasing the interrupt. */
140 smp_wmb();
141
142 local_bh_disable();
143 if (cvq->cb)
144 cvq->cb(cvq->private);
145 local_bh_enable();
146 }
147 }
148
vdpasim_net_work(struct work_struct * work)149 static void vdpasim_net_work(struct work_struct *work)
150 {
151 struct vdpasim *vdpasim = container_of(work, struct vdpasim, work);
152 struct vdpasim_virtqueue *txq = &vdpasim->vqs[1];
153 struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0];
154 ssize_t read, write;
155 int pkts = 0;
156 int err;
157
158 spin_lock(&vdpasim->lock);
159
160 if (!vdpasim->running)
161 goto out;
162
163 if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
164 goto out;
165
166 vdpasim_handle_cvq(vdpasim);
167
168 if (!txq->ready || !rxq->ready)
169 goto out;
170
171 while (true) {
172 err = vringh_getdesc_iotlb(&txq->vring, &txq->out_iov, NULL,
173 &txq->head, GFP_ATOMIC);
174 if (err <= 0)
175 break;
176
177 read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov,
178 vdpasim->buffer,
179 PAGE_SIZE);
180
181 if (!receive_filter(vdpasim, read)) {
182 vdpasim_net_complete(txq, 0);
183 continue;
184 }
185
186 err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->in_iov,
187 &rxq->head, GFP_ATOMIC);
188 if (err <= 0) {
189 vdpasim_net_complete(txq, 0);
190 break;
191 }
192
193 write = vringh_iov_push_iotlb(&rxq->vring, &rxq->in_iov,
194 vdpasim->buffer, read);
195 if (write <= 0)
196 break;
197
198 vdpasim_net_complete(txq, 0);
199 vdpasim_net_complete(rxq, write);
200
201 if (++pkts > 4) {
202 schedule_work(&vdpasim->work);
203 goto out;
204 }
205 }
206
207 out:
208 spin_unlock(&vdpasim->lock);
209 }
210
vdpasim_net_get_config(struct vdpasim * vdpasim,void * config)211 static void vdpasim_net_get_config(struct vdpasim *vdpasim, void *config)
212 {
213 struct virtio_net_config *net_config = config;
214
215 net_config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP);
216 }
217
vdpasim_net_setup_config(struct vdpasim * vdpasim,const struct vdpa_dev_set_config * config)218 static void vdpasim_net_setup_config(struct vdpasim *vdpasim,
219 const struct vdpa_dev_set_config *config)
220 {
221 struct virtio_net_config *vio_config = vdpasim->config;
222
223 if (config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR))
224 memcpy(vio_config->mac, config->net.mac, ETH_ALEN);
225 if (config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MTU))
226 vio_config->mtu = cpu_to_vdpasim16(vdpasim, config->net.mtu);
227 else
228 /* Setup default MTU to be 1500 */
229 vio_config->mtu = cpu_to_vdpasim16(vdpasim, 1500);
230 }
231
vdpasim_net_mgmtdev_release(struct device * dev)232 static void vdpasim_net_mgmtdev_release(struct device *dev)
233 {
234 }
235
236 static struct device vdpasim_net_mgmtdev = {
237 .init_name = "vdpasim_net",
238 .release = vdpasim_net_mgmtdev_release,
239 };
240
vdpasim_net_dev_add(struct vdpa_mgmt_dev * mdev,const char * name,const struct vdpa_dev_set_config * config)241 static int vdpasim_net_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
242 const struct vdpa_dev_set_config *config)
243 {
244 struct vdpasim_dev_attr dev_attr = {};
245 struct vdpasim *simdev;
246 int ret;
247
248 dev_attr.mgmt_dev = mdev;
249 dev_attr.name = name;
250 dev_attr.id = VIRTIO_ID_NET;
251 dev_attr.supported_features = VDPASIM_NET_FEATURES;
252 dev_attr.nvqs = VDPASIM_NET_VQ_NUM;
253 dev_attr.ngroups = VDPASIM_NET_GROUP_NUM;
254 dev_attr.nas = VDPASIM_NET_AS_NUM;
255 dev_attr.config_size = sizeof(struct virtio_net_config);
256 dev_attr.get_config = vdpasim_net_get_config;
257 dev_attr.work_fn = vdpasim_net_work;
258 dev_attr.buffer_size = PAGE_SIZE;
259
260 simdev = vdpasim_create(&dev_attr, config);
261 if (IS_ERR(simdev))
262 return PTR_ERR(simdev);
263
264 vdpasim_net_setup_config(simdev, config);
265
266 ret = _vdpa_register_device(&simdev->vdpa, VDPASIM_NET_VQ_NUM);
267 if (ret)
268 goto reg_err;
269
270 return 0;
271
272 reg_err:
273 put_device(&simdev->vdpa.dev);
274 return ret;
275 }
276
vdpasim_net_dev_del(struct vdpa_mgmt_dev * mdev,struct vdpa_device * dev)277 static void vdpasim_net_dev_del(struct vdpa_mgmt_dev *mdev,
278 struct vdpa_device *dev)
279 {
280 struct vdpasim *simdev = container_of(dev, struct vdpasim, vdpa);
281
282 _vdpa_unregister_device(&simdev->vdpa);
283 }
284
285 static const struct vdpa_mgmtdev_ops vdpasim_net_mgmtdev_ops = {
286 .dev_add = vdpasim_net_dev_add,
287 .dev_del = vdpasim_net_dev_del
288 };
289
290 static struct virtio_device_id id_table[] = {
291 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
292 { 0 },
293 };
294
295 static struct vdpa_mgmt_dev mgmt_dev = {
296 .device = &vdpasim_net_mgmtdev,
297 .id_table = id_table,
298 .ops = &vdpasim_net_mgmtdev_ops,
299 .config_attr_mask = (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR |
300 1 << VDPA_ATTR_DEV_NET_CFG_MTU |
301 1 << VDPA_ATTR_DEV_FEATURES),
302 .max_supported_vqs = VDPASIM_NET_VQ_NUM,
303 .supported_features = VDPASIM_NET_FEATURES,
304 };
305
vdpasim_net_init(void)306 static int __init vdpasim_net_init(void)
307 {
308 int ret;
309
310 ret = device_register(&vdpasim_net_mgmtdev);
311 if (ret) {
312 put_device(&vdpasim_net_mgmtdev);
313 return ret;
314 }
315
316 ret = vdpa_mgmtdev_register(&mgmt_dev);
317 if (ret)
318 goto parent_err;
319 return 0;
320
321 parent_err:
322 device_unregister(&vdpasim_net_mgmtdev);
323 return ret;
324 }
325
vdpasim_net_exit(void)326 static void __exit vdpasim_net_exit(void)
327 {
328 vdpa_mgmtdev_unregister(&mgmt_dev);
329 device_unregister(&vdpasim_net_mgmtdev);
330 }
331
332 module_init(vdpasim_net_init);
333 module_exit(vdpasim_net_exit);
334
335 MODULE_VERSION(DRV_VERSION);
336 MODULE_LICENSE(DRV_LICENSE);
337 MODULE_AUTHOR(DRV_AUTHOR);
338 MODULE_DESCRIPTION(DRV_DESC);
339