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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
32static char *macaddr;
33module_param(macaddr, charp, 0);
34MODULE_PARM_DESC(macaddr, "Ethernet MAC address");
35
36u8 macaddr_buf[ETH_ALEN];
37
38static struct vdpasim *vdpasim_net_dev;
39
40static void vdpasim_net_work(struct work_struct *work)
41{
42 struct vdpasim *vdpasim = container_of(work, struct vdpasim, work);
43 struct vdpasim_virtqueue *txq = &vdpasim->vqs[1];
44 struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0];
45 ssize_t read, write;
46 size_t total_write;
47 int pkts = 0;
48 int err;
49
50 spin_lock(&vdpasim->lock);
51
52 if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
53 goto out;
54
55 if (!txq->ready || !rxq->ready)
56 goto out;
57
58 while (true) {
59 total_write = 0;
60 err = vringh_getdesc_iotlb(&txq->vring, &txq->out_iov, NULL,
61 &txq->head, GFP_ATOMIC);
62 if (err <= 0)
63 break;
64
65 err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->in_iov,
66 &rxq->head, GFP_ATOMIC);
67 if (err <= 0) {
68 vringh_complete_iotlb(&txq->vring, txq->head, 0);
69 break;
70 }
71
72 while (true) {
73 read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov,
74 vdpasim->buffer,
75 PAGE_SIZE);
76 if (read <= 0)
77 break;
78
79 write = vringh_iov_push_iotlb(&rxq->vring, &rxq->in_iov,
80 vdpasim->buffer, read);
81 if (write <= 0)
82 break;
83
84 total_write += write;
85 }
86
87
88 smp_wmb();
89
90 vringh_complete_iotlb(&txq->vring, txq->head, 0);
91 vringh_complete_iotlb(&rxq->vring, rxq->head, total_write);
92
93
94 smp_wmb();
95
96 local_bh_disable();
97 if (vringh_need_notify_iotlb(&txq->vring) > 0)
98 vringh_notify(&txq->vring);
99 if (vringh_need_notify_iotlb(&rxq->vring) > 0)
100 vringh_notify(&rxq->vring);
101 local_bh_enable();
102
103 if (++pkts > 4) {
104 schedule_work(&vdpasim->work);
105 goto out;
106 }
107 }
108
109out:
110 spin_unlock(&vdpasim->lock);
111}
112
113static void vdpasim_net_get_config(struct vdpasim *vdpasim, void *config)
114{
115 struct virtio_net_config *net_config =
116 (struct virtio_net_config *)config;
117
118 net_config->mtu = cpu_to_vdpasim16(vdpasim, 1500);
119 net_config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP);
120 memcpy(net_config->mac, macaddr_buf, ETH_ALEN);
121}
122
123static int __init vdpasim_net_init(void)
124{
125 struct vdpasim_dev_attr dev_attr = {};
126 int ret;
127
128 if (macaddr) {
129 mac_pton(macaddr, macaddr_buf);
130 if (!is_valid_ether_addr(macaddr_buf)) {
131 ret = -EADDRNOTAVAIL;
132 goto out;
133 }
134 } else {
135 eth_random_addr(macaddr_buf);
136 }
137
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 vdpasim_net_dev = vdpasim_create(&dev_attr);
147 if (IS_ERR(vdpasim_net_dev)) {
148 ret = PTR_ERR(vdpasim_net_dev);
149 goto out;
150 }
151
152 ret = vdpa_register_device(&vdpasim_net_dev->vdpa);
153 if (ret)
154 goto put_dev;
155
156 return 0;
157
158put_dev:
159 put_device(&vdpasim_net_dev->vdpa.dev);
160out:
161 return ret;
162}
163
164static void __exit vdpasim_net_exit(void)
165{
166 struct vdpa_device *vdpa = &vdpasim_net_dev->vdpa;
167
168 vdpa_unregister_device(vdpa);
169}
170
171module_init(vdpasim_net_init);
172module_exit(vdpasim_net_exit);
173
174MODULE_VERSION(DRV_VERSION);
175MODULE_LICENSE(DRV_LICENSE);
176MODULE_AUTHOR(DRV_AUTHOR);
177MODULE_DESCRIPTION(DRV_DESC);
178
