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1
/*
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 * Virtio Network Device
3
 *
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 * Copyright IBM, Corp. 2007
5
 *
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 * Authors:
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 *  Anthony Liguori   <aliguori@us.ibm.com>
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 *
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 * This work is licensed under the terms of the GNU GPL, version 2.  See
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 * the COPYING file in the top-level directory.
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 *
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 */
13

    
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#include "qemu/iov.h"
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#include "virtio.h"
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#include "net/net.h"
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#include "net/checksum.h"
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#include "net/tap.h"
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#include "qemu/error-report.h"
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#include "qemu/timer.h"
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#include "virtio-net.h"
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#include "vhost_net.h"
23

    
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#define VIRTIO_NET_VM_VERSION    11
25

    
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#define MAC_TABLE_ENTRIES    64
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#define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
28

    
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typedef struct VirtIONet
30
{
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    VirtIODevice vdev;
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    uint8_t mac[ETH_ALEN];
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    uint16_t status;
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    VirtQueue *rx_vq;
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    VirtQueue *tx_vq;
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    VirtQueue *ctrl_vq;
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    NICState *nic;
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    QEMUTimer *tx_timer;
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    QEMUBH *tx_bh;
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    uint32_t tx_timeout;
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    int32_t tx_burst;
42
    int tx_waiting;
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    uint32_t has_vnet_hdr;
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    size_t host_hdr_len;
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    size_t guest_hdr_len;
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    uint8_t has_ufo;
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    struct {
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        VirtQueueElement elem;
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        ssize_t len;
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    } async_tx;
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    int mergeable_rx_bufs;
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    uint8_t promisc;
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    uint8_t allmulti;
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    uint8_t alluni;
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    uint8_t nomulti;
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    uint8_t nouni;
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    uint8_t nobcast;
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    uint8_t vhost_started;
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    struct {
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        int in_use;
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        int first_multi;
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        uint8_t multi_overflow;
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        uint8_t uni_overflow;
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        uint8_t *macs;
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    } mac_table;
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    uint32_t *vlans;
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    DeviceState *qdev;
68
} VirtIONet;
69

    
70
/* TODO
71
 * - we could suppress RX interrupt if we were so inclined.
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 */
73

    
74
static VirtIONet *to_virtio_net(VirtIODevice *vdev)
75
{
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    return (VirtIONet *)vdev;
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}
78

    
79
static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
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{
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    VirtIONet *n = to_virtio_net(vdev);
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    struct virtio_net_config netcfg;
83

    
84
    stw_p(&netcfg.status, n->status);
85
    memcpy(netcfg.mac, n->mac, ETH_ALEN);
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    memcpy(config, &netcfg, sizeof(netcfg));
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}
88

    
89
static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
90
{
91
    VirtIONet *n = to_virtio_net(vdev);
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    struct virtio_net_config netcfg;
93

    
94
    memcpy(&netcfg, config, sizeof(netcfg));
95

    
96
    if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
97
        memcpy(n->mac, netcfg.mac, ETH_ALEN);
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        qemu_format_nic_info_str(&n->nic->nc, n->mac);
99
    }
100
}
101

    
102
static bool virtio_net_started(VirtIONet *n, uint8_t status)
103
{
104
    return (status & VIRTIO_CONFIG_S_DRIVER_OK) &&
105
        (n->status & VIRTIO_NET_S_LINK_UP) && n->vdev.vm_running;
106
}
107

    
108
static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
109
{
110
    if (!n->nic->nc.peer) {
111
        return;
112
    }
113
    if (n->nic->nc.peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
114
        return;
115
    }
116

    
117
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
118
        return;
119
    }
120
    if (!!n->vhost_started == virtio_net_started(n, status) &&
121
                              !n->nic->nc.peer->link_down) {
122
        return;
123
    }
124
    if (!n->vhost_started) {
125
        int r;
126
        if (!vhost_net_query(tap_get_vhost_net(n->nic->nc.peer), &n->vdev)) {
127
            return;
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        }
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        r = vhost_net_start(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
130
        if (r < 0) {
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            error_report("unable to start vhost net: %d: "
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                         "falling back on userspace virtio", -r);
133
        } else {
134
            n->vhost_started = 1;
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        }
136
    } else {
137
        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
138
        n->vhost_started = 0;
139
    }
140
}
141

    
142
static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
143
{
144
    VirtIONet *n = to_virtio_net(vdev);
145

    
146
    virtio_net_vhost_status(n, status);
147

    
148
    if (!n->tx_waiting) {
149
        return;
150
    }
151

    
152
    if (virtio_net_started(n, status) && !n->vhost_started) {
153
        if (n->tx_timer) {
154
            qemu_mod_timer(n->tx_timer,
155
                           qemu_get_clock_ns(vm_clock) + n->tx_timeout);
156
        } else {
157
            qemu_bh_schedule(n->tx_bh);
158
        }
159
    } else {
160
        if (n->tx_timer) {
161
            qemu_del_timer(n->tx_timer);
162
        } else {
163
            qemu_bh_cancel(n->tx_bh);
164
        }
165
    }
166
}
167

    
168
static void virtio_net_set_link_status(NetClientState *nc)
169
{
170
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
171
    uint16_t old_status = n->status;
172

    
173
    if (nc->link_down)
174
        n->status &= ~VIRTIO_NET_S_LINK_UP;
175
    else
176
        n->status |= VIRTIO_NET_S_LINK_UP;
177

    
178
    if (n->status != old_status)
179
        virtio_notify_config(&n->vdev);
180

    
181
    virtio_net_set_status(&n->vdev, n->vdev.status);
182
}
183

    
184
static void virtio_net_reset(VirtIODevice *vdev)
185
{
186
    VirtIONet *n = to_virtio_net(vdev);
187

    
188
    /* Reset back to compatibility mode */
189
    n->promisc = 1;
190
    n->allmulti = 0;
191
    n->alluni = 0;
192
    n->nomulti = 0;
193
    n->nouni = 0;
194
    n->nobcast = 0;
195

    
196
    /* Flush any MAC and VLAN filter table state */
197
    n->mac_table.in_use = 0;
198
    n->mac_table.first_multi = 0;
199
    n->mac_table.multi_overflow = 0;
200
    n->mac_table.uni_overflow = 0;
201
    memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
202
    memset(n->vlans, 0, MAX_VLAN >> 3);
203
}
204

    
205
static void peer_test_vnet_hdr(VirtIONet *n)
206
{
207
    if (!n->nic->nc.peer)
208
        return;
209

    
210
    if (n->nic->nc.peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP)
211
        return;
212

    
213
    n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->nc.peer);
214
}
215

    
216
static int peer_has_vnet_hdr(VirtIONet *n)
217
{
218
    return n->has_vnet_hdr;
219
}
220

    
221
static int peer_has_ufo(VirtIONet *n)
222
{
223
    if (!peer_has_vnet_hdr(n))
224
        return 0;
225

    
226
    n->has_ufo = tap_has_ufo(n->nic->nc.peer);
227

    
228
    return n->has_ufo;
229
}
230

    
231
static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs)
232
{
233
    n->mergeable_rx_bufs = mergeable_rx_bufs;
234

    
235
    n->guest_hdr_len = n->mergeable_rx_bufs ?
236
        sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
237

    
238
    if (peer_has_vnet_hdr(n) &&
239
        tap_has_vnet_hdr_len(n->nic->nc.peer, n->guest_hdr_len)) {
240
        tap_set_vnet_hdr_len(n->nic->nc.peer, n->guest_hdr_len);
241
        n->host_hdr_len = n->guest_hdr_len;
242
    }
243
}
244

    
245
static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
246
{
247
    VirtIONet *n = to_virtio_net(vdev);
248

    
249
    features |= (1 << VIRTIO_NET_F_MAC);
250

    
251
    if (!peer_has_vnet_hdr(n)) {
252
        features &= ~(0x1 << VIRTIO_NET_F_CSUM);
253
        features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO4);
254
        features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO6);
255
        features &= ~(0x1 << VIRTIO_NET_F_HOST_ECN);
256

    
257
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_CSUM);
258
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO4);
259
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO6);
260
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_ECN);
261
    }
262

    
263
    if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
264
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_UFO);
265
        features &= ~(0x1 << VIRTIO_NET_F_HOST_UFO);
266
    }
267

    
268
    if (!n->nic->nc.peer ||
269
        n->nic->nc.peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
270
        return features;
271
    }
272
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
273
        return features;
274
    }
275
    return vhost_net_get_features(tap_get_vhost_net(n->nic->nc.peer), features);
276
}
277

    
278
static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
279
{
280
    uint32_t features = 0;
281

    
282
    /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
283
     * but also these: */
284
    features |= (1 << VIRTIO_NET_F_MAC);
285
    features |= (1 << VIRTIO_NET_F_CSUM);
286
    features |= (1 << VIRTIO_NET_F_HOST_TSO4);
287
    features |= (1 << VIRTIO_NET_F_HOST_TSO6);
288
    features |= (1 << VIRTIO_NET_F_HOST_ECN);
289

    
290
    return features;
291
}
292

    
293
static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
294
{
295
    VirtIONet *n = to_virtio_net(vdev);
296

    
297
    virtio_net_set_mrg_rx_bufs(n, !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF)));
298

    
299
    if (n->has_vnet_hdr) {
300
        tap_set_offload(n->nic->nc.peer,
301
                        (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
302
                        (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
303
                        (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
304
                        (features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
305
                        (features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
306
    }
307
    if (!n->nic->nc.peer ||
308
        n->nic->nc.peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
309
        return;
310
    }
311
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
312
        return;
313
    }
314
    vhost_net_ack_features(tap_get_vhost_net(n->nic->nc.peer), features);
315
}
316

    
317
static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
318
                                     VirtQueueElement *elem)
319
{
320
    uint8_t on;
321

    
322
    if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(on)) {
323
        error_report("virtio-net ctrl invalid rx mode command");
324
        exit(1);
325
    }
326

    
327
    on = ldub_p(elem->out_sg[1].iov_base);
328

    
329
    if (cmd == VIRTIO_NET_CTRL_RX_MODE_PROMISC)
330
        n->promisc = on;
331
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)
332
        n->allmulti = on;
333
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLUNI)
334
        n->alluni = on;
335
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOMULTI)
336
        n->nomulti = on;
337
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOUNI)
338
        n->nouni = on;
339
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOBCAST)
340
        n->nobcast = on;
341
    else
342
        return VIRTIO_NET_ERR;
343

    
344
    return VIRTIO_NET_OK;
345
}
346

    
347
static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
348
                                 VirtQueueElement *elem)
349
{
350
    struct virtio_net_ctrl_mac mac_data;
351

    
352
    if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET || elem->out_num != 3 ||
353
        elem->out_sg[1].iov_len < sizeof(mac_data) ||
354
        elem->out_sg[2].iov_len < sizeof(mac_data))
355
        return VIRTIO_NET_ERR;
356

    
357
    n->mac_table.in_use = 0;
358
    n->mac_table.first_multi = 0;
359
    n->mac_table.uni_overflow = 0;
360
    n->mac_table.multi_overflow = 0;
361
    memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
362

    
363
    mac_data.entries = ldl_p(elem->out_sg[1].iov_base);
364

    
365
    if (sizeof(mac_data.entries) +
366
        (mac_data.entries * ETH_ALEN) > elem->out_sg[1].iov_len)
367
        return VIRTIO_NET_ERR;
368

    
369
    if (mac_data.entries <= MAC_TABLE_ENTRIES) {
370
        memcpy(n->mac_table.macs, elem->out_sg[1].iov_base + sizeof(mac_data),
371
               mac_data.entries * ETH_ALEN);
372
        n->mac_table.in_use += mac_data.entries;
373
    } else {
374
        n->mac_table.uni_overflow = 1;
375
    }
376

    
377
    n->mac_table.first_multi = n->mac_table.in_use;
378

    
379
    mac_data.entries = ldl_p(elem->out_sg[2].iov_base);
380

    
381
    if (sizeof(mac_data.entries) +
382
        (mac_data.entries * ETH_ALEN) > elem->out_sg[2].iov_len)
383
        return VIRTIO_NET_ERR;
384

    
385
    if (mac_data.entries) {
386
        if (n->mac_table.in_use + mac_data.entries <= MAC_TABLE_ENTRIES) {
387
            memcpy(n->mac_table.macs + (n->mac_table.in_use * ETH_ALEN),
388
                   elem->out_sg[2].iov_base + sizeof(mac_data),
389
                   mac_data.entries * ETH_ALEN);
390
            n->mac_table.in_use += mac_data.entries;
391
        } else {
392
            n->mac_table.multi_overflow = 1;
393
        }
394
    }
395

    
396
    return VIRTIO_NET_OK;
397
}
398

    
399
static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
400
                                        VirtQueueElement *elem)
401
{
402
    uint16_t vid;
403

    
404
    if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(vid)) {
405
        error_report("virtio-net ctrl invalid vlan command");
406
        return VIRTIO_NET_ERR;
407
    }
408

    
409
    vid = lduw_p(elem->out_sg[1].iov_base);
410

    
411
    if (vid >= MAX_VLAN)
412
        return VIRTIO_NET_ERR;
413

    
414
    if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
415
        n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
416
    else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
417
        n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
418
    else
419
        return VIRTIO_NET_ERR;
420

    
421
    return VIRTIO_NET_OK;
422
}
423

    
424
static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
425
{
426
    VirtIONet *n = to_virtio_net(vdev);
427
    struct virtio_net_ctrl_hdr ctrl;
428
    virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
429
    VirtQueueElement elem;
430

    
431
    while (virtqueue_pop(vq, &elem)) {
432
        if ((elem.in_num < 1) || (elem.out_num < 1)) {
433
            error_report("virtio-net ctrl missing headers");
434
            exit(1);
435
        }
436

    
437
        if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
438
            elem.in_sg[elem.in_num - 1].iov_len < sizeof(status)) {
439
            error_report("virtio-net ctrl header not in correct element");
440
            exit(1);
441
        }
442

    
443
        ctrl.class = ldub_p(elem.out_sg[0].iov_base);
444
        ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
445

    
446
        if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE)
447
            status = virtio_net_handle_rx_mode(n, ctrl.cmd, &elem);
448
        else if (ctrl.class == VIRTIO_NET_CTRL_MAC)
449
            status = virtio_net_handle_mac(n, ctrl.cmd, &elem);
450
        else if (ctrl.class == VIRTIO_NET_CTRL_VLAN)
451
            status = virtio_net_handle_vlan_table(n, ctrl.cmd, &elem);
452

    
453
        stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
454

    
455
        virtqueue_push(vq, &elem, sizeof(status));
456
        virtio_notify(vdev, vq);
457
    }
458
}
459

    
460
/* RX */
461

    
462
static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
463
{
464
    VirtIONet *n = to_virtio_net(vdev);
465

    
466
    qemu_flush_queued_packets(&n->nic->nc);
467
}
468

    
469
static int virtio_net_can_receive(NetClientState *nc)
470
{
471
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
472
    if (!n->vdev.vm_running) {
473
        return 0;
474
    }
475

    
476
    if (!virtio_queue_ready(n->rx_vq) ||
477
        !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
478
        return 0;
479

    
480
    return 1;
481
}
482

    
483
static int virtio_net_has_buffers(VirtIONet *n, int bufsize)
484
{
485
    if (virtio_queue_empty(n->rx_vq) ||
486
        (n->mergeable_rx_bufs &&
487
         !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
488
        virtio_queue_set_notification(n->rx_vq, 1);
489

    
490
        /* To avoid a race condition where the guest has made some buffers
491
         * available after the above check but before notification was
492
         * enabled, check for available buffers again.
493
         */
494
        if (virtio_queue_empty(n->rx_vq) ||
495
            (n->mergeable_rx_bufs &&
496
             !virtqueue_avail_bytes(n->rx_vq, bufsize, 0)))
497
            return 0;
498
    }
499

    
500
    virtio_queue_set_notification(n->rx_vq, 0);
501
    return 1;
502
}
503

    
504
/* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
505
 * it never finds out that the packets don't have valid checksums.  This
506
 * causes dhclient to get upset.  Fedora's carried a patch for ages to
507
 * fix this with Xen but it hasn't appeared in an upstream release of
508
 * dhclient yet.
509
 *
510
 * To avoid breaking existing guests, we catch udp packets and add
511
 * checksums.  This is terrible but it's better than hacking the guest
512
 * kernels.
513
 *
514
 * N.B. if we introduce a zero-copy API, this operation is no longer free so
515
 * we should provide a mechanism to disable it to avoid polluting the host
516
 * cache.
517
 */
518
static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
519
                                        uint8_t *buf, size_t size)
520
{
521
    if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
522
        (size > 27 && size < 1500) && /* normal sized MTU */
523
        (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
524
        (buf[23] == 17) && /* ip.protocol == UDP */
525
        (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
526
        net_checksum_calculate(buf, size);
527
        hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
528
    }
529
}
530

    
531
static void receive_header(VirtIONet *n, const struct iovec *iov, int iov_cnt,
532
                           const void *buf, size_t size)
533
{
534
    if (n->has_vnet_hdr) {
535
        /* FIXME this cast is evil */
536
        void *wbuf = (void *)buf;
537
        work_around_broken_dhclient(wbuf, wbuf + n->host_hdr_len,
538
                                    size - n->host_hdr_len);
539
        iov_from_buf(iov, iov_cnt, 0, buf, sizeof(struct virtio_net_hdr));
540
    } else {
541
        struct virtio_net_hdr hdr = {
542
            .flags = 0,
543
            .gso_type = VIRTIO_NET_HDR_GSO_NONE
544
        };
545
        iov_from_buf(iov, iov_cnt, 0, &hdr, sizeof hdr);
546
    }
547
}
548

    
549
static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
550
{
551
    static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
552
    static const uint8_t vlan[] = {0x81, 0x00};
553
    uint8_t *ptr = (uint8_t *)buf;
554
    int i;
555

    
556
    if (n->promisc)
557
        return 1;
558

    
559
    ptr += n->host_hdr_len;
560

    
561
    if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
562
        int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff;
563
        if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
564
            return 0;
565
    }
566

    
567
    if (ptr[0] & 1) { // multicast
568
        if (!memcmp(ptr, bcast, sizeof(bcast))) {
569
            return !n->nobcast;
570
        } else if (n->nomulti) {
571
            return 0;
572
        } else if (n->allmulti || n->mac_table.multi_overflow) {
573
            return 1;
574
        }
575

    
576
        for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
577
            if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
578
                return 1;
579
            }
580
        }
581
    } else { // unicast
582
        if (n->nouni) {
583
            return 0;
584
        } else if (n->alluni || n->mac_table.uni_overflow) {
585
            return 1;
586
        } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
587
            return 1;
588
        }
589

    
590
        for (i = 0; i < n->mac_table.first_multi; i++) {
591
            if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
592
                return 1;
593
            }
594
        }
595
    }
596

    
597
    return 0;
598
}
599

    
600
static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t size)
601
{
602
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
603
    struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE];
604
    struct virtio_net_hdr_mrg_rxbuf mhdr;
605
    unsigned mhdr_cnt = 0;
606
    size_t offset, i, guest_offset;
607

    
608
    if (!virtio_net_can_receive(&n->nic->nc))
609
        return -1;
610

    
611
    /* hdr_len refers to the header we supply to the guest */
612
    if (!virtio_net_has_buffers(n, size + n->guest_hdr_len - n->host_hdr_len))
613
        return 0;
614

    
615
    if (!receive_filter(n, buf, size))
616
        return size;
617

    
618
    offset = i = 0;
619

    
620
    while (offset < size) {
621
        VirtQueueElement elem;
622
        int len, total;
623
        const struct iovec *sg = elem.in_sg;
624

    
625
        total = 0;
626

    
627
        if (virtqueue_pop(n->rx_vq, &elem) == 0) {
628
            if (i == 0)
629
                return -1;
630
            error_report("virtio-net unexpected empty queue: "
631
                    "i %zd mergeable %d offset %zd, size %zd, "
632
                    "guest hdr len %zd, host hdr len %zd guest features 0x%x",
633
                    i, n->mergeable_rx_bufs, offset, size,
634
                    n->guest_hdr_len, n->host_hdr_len, n->vdev.guest_features);
635
            exit(1);
636
        }
637

    
638
        if (elem.in_num < 1) {
639
            error_report("virtio-net receive queue contains no in buffers");
640
            exit(1);
641
        }
642

    
643
        if (i == 0) {
644
            assert(offset == 0);
645
            if (n->mergeable_rx_bufs) {
646
                mhdr_cnt = iov_copy(mhdr_sg, ARRAY_SIZE(mhdr_sg),
647
                                    sg, elem.in_num,
648
                                    offsetof(typeof(mhdr), num_buffers),
649
                                    sizeof(mhdr.num_buffers));
650
            }
651

    
652
            receive_header(n, sg, elem.in_num, buf, size);
653
            offset = n->host_hdr_len;
654
            total += n->guest_hdr_len;
655
            guest_offset = n->guest_hdr_len;
656
        } else {
657
            guest_offset = 0;
658
        }
659

    
660
        /* copy in packet.  ugh */
661
        len = iov_from_buf(sg, elem.in_num, guest_offset,
662
                           buf + offset, size - offset);
663
        total += len;
664
        offset += len;
665
        /* If buffers can't be merged, at this point we
666
         * must have consumed the complete packet.
667
         * Otherwise, drop it. */
668
        if (!n->mergeable_rx_bufs && offset < size) {
669
#if 0
670
            error_report("virtio-net truncated non-mergeable packet: "
671
                         "i %zd mergeable %d offset %zd, size %zd, "
672
                         "guest hdr len %zd, host hdr len %zd",
673
                         i, n->mergeable_rx_bufs,
674
                         offset, size, n->guest_hdr_len, n->host_hdr_len);
675
#endif
676
            return size;
677
        }
678

    
679
        /* signal other side */
680
        virtqueue_fill(n->rx_vq, &elem, total, i++);
681
    }
682

    
683
    if (mhdr_cnt) {
684
        stw_p(&mhdr.num_buffers, i);
685
        iov_from_buf(mhdr_sg, mhdr_cnt,
686
                     0,
687
                     &mhdr.num_buffers, sizeof mhdr.num_buffers);
688
    }
689

    
690
    virtqueue_flush(n->rx_vq, i);
691
    virtio_notify(&n->vdev, n->rx_vq);
692

    
693
    return size;
694
}
695

    
696
static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);
697

    
698
static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
699
{
700
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
701

    
702
    virtqueue_push(n->tx_vq, &n->async_tx.elem, 0);
703
    virtio_notify(&n->vdev, n->tx_vq);
704

    
705
    n->async_tx.elem.out_num = n->async_tx.len = 0;
706

    
707
    virtio_queue_set_notification(n->tx_vq, 1);
708
    virtio_net_flush_tx(n, n->tx_vq);
709
}
710

    
711
/* TX */
712
static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
713
{
714
    VirtQueueElement elem;
715
    int32_t num_packets = 0;
716
    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
717
        return num_packets;
718
    }
719

    
720
    assert(n->vdev.vm_running);
721

    
722
    if (n->async_tx.elem.out_num) {
723
        virtio_queue_set_notification(n->tx_vq, 0);
724
        return num_packets;
725
    }
726

    
727
    while (virtqueue_pop(vq, &elem)) {
728
        ssize_t ret, len;
729
        unsigned int out_num = elem.out_num;
730
        struct iovec *out_sg = &elem.out_sg[0];
731
        struct iovec sg[VIRTQUEUE_MAX_SIZE];
732

    
733
        if (out_num < 1) {
734
            error_report("virtio-net header not in first element");
735
            exit(1);
736
        }
737

    
738
        /*
739
         * If host wants to see the guest header as is, we can
740
         * pass it on unchanged. Otherwise, copy just the parts
741
         * that host is interested in.
742
         */
743
        assert(n->host_hdr_len <= n->guest_hdr_len);
744
        if (n->host_hdr_len != n->guest_hdr_len) {
745
            unsigned sg_num = iov_copy(sg, ARRAY_SIZE(sg),
746
                                       out_sg, out_num,
747
                                       0, n->host_hdr_len);
748
            sg_num += iov_copy(sg + sg_num, ARRAY_SIZE(sg) - sg_num,
749
                             out_sg, out_num,
750
                             n->guest_hdr_len, -1);
751
            out_num = sg_num;
752
            out_sg = sg;
753
        }
754

    
755
        len = n->guest_hdr_len;
756

    
757
        ret = qemu_sendv_packet_async(&n->nic->nc, out_sg, out_num,
758
                                      virtio_net_tx_complete);
759
        if (ret == 0) {
760
            virtio_queue_set_notification(n->tx_vq, 0);
761
            n->async_tx.elem = elem;
762
            n->async_tx.len  = len;
763
            return -EBUSY;
764
        }
765

    
766
        len += ret;
767

    
768
        virtqueue_push(vq, &elem, 0);
769
        virtio_notify(&n->vdev, vq);
770

    
771
        if (++num_packets >= n->tx_burst) {
772
            break;
773
        }
774
    }
775
    return num_packets;
776
}
777

    
778
static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
779
{
780
    VirtIONet *n = to_virtio_net(vdev);
781

    
782
    /* This happens when device was stopped but VCPU wasn't. */
783
    if (!n->vdev.vm_running) {
784
        n->tx_waiting = 1;
785
        return;
786
    }
787

    
788
    if (n->tx_waiting) {
789
        virtio_queue_set_notification(vq, 1);
790
        qemu_del_timer(n->tx_timer);
791
        n->tx_waiting = 0;
792
        virtio_net_flush_tx(n, vq);
793
    } else {
794
        qemu_mod_timer(n->tx_timer,
795
                       qemu_get_clock_ns(vm_clock) + n->tx_timeout);
796
        n->tx_waiting = 1;
797
        virtio_queue_set_notification(vq, 0);
798
    }
799
}
800

    
801
static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
802
{
803
    VirtIONet *n = to_virtio_net(vdev);
804

    
805
    if (unlikely(n->tx_waiting)) {
806
        return;
807
    }
808
    n->tx_waiting = 1;
809
    /* This happens when device was stopped but VCPU wasn't. */
810
    if (!n->vdev.vm_running) {
811
        return;
812
    }
813
    virtio_queue_set_notification(vq, 0);
814
    qemu_bh_schedule(n->tx_bh);
815
}
816

    
817
static void virtio_net_tx_timer(void *opaque)
818
{
819
    VirtIONet *n = opaque;
820
    assert(n->vdev.vm_running);
821

    
822
    n->tx_waiting = 0;
823

    
824
    /* Just in case the driver is not ready on more */
825
    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
826
        return;
827

    
828
    virtio_queue_set_notification(n->tx_vq, 1);
829
    virtio_net_flush_tx(n, n->tx_vq);
830
}
831

    
832
static void virtio_net_tx_bh(void *opaque)
833
{
834
    VirtIONet *n = opaque;
835
    int32_t ret;
836

    
837
    assert(n->vdev.vm_running);
838

    
839
    n->tx_waiting = 0;
840

    
841
    /* Just in case the driver is not ready on more */
842
    if (unlikely(!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)))
843
        return;
844

    
845
    ret = virtio_net_flush_tx(n, n->tx_vq);
846
    if (ret == -EBUSY) {
847
        return; /* Notification re-enable handled by tx_complete */
848
    }
849

    
850
    /* If we flush a full burst of packets, assume there are
851
     * more coming and immediately reschedule */
852
    if (ret >= n->tx_burst) {
853
        qemu_bh_schedule(n->tx_bh);
854
        n->tx_waiting = 1;
855
        return;
856
    }
857

    
858
    /* If less than a full burst, re-enable notification and flush
859
     * anything that may have come in while we weren't looking.  If
860
     * we find something, assume the guest is still active and reschedule */
861
    virtio_queue_set_notification(n->tx_vq, 1);
862
    if (virtio_net_flush_tx(n, n->tx_vq) > 0) {
863
        virtio_queue_set_notification(n->tx_vq, 0);
864
        qemu_bh_schedule(n->tx_bh);
865
        n->tx_waiting = 1;
866
    }
867
}
868

    
869
static void virtio_net_save(QEMUFile *f, void *opaque)
870
{
871
    VirtIONet *n = opaque;
872

    
873
    /* At this point, backend must be stopped, otherwise
874
     * it might keep writing to memory. */
875
    assert(!n->vhost_started);
876
    virtio_save(&n->vdev, f);
877

    
878
    qemu_put_buffer(f, n->mac, ETH_ALEN);
879
    qemu_put_be32(f, n->tx_waiting);
880
    qemu_put_be32(f, n->mergeable_rx_bufs);
881
    qemu_put_be16(f, n->status);
882
    qemu_put_byte(f, n->promisc);
883
    qemu_put_byte(f, n->allmulti);
884
    qemu_put_be32(f, n->mac_table.in_use);
885
    qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
886
    qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
887
    qemu_put_be32(f, n->has_vnet_hdr);
888
    qemu_put_byte(f, n->mac_table.multi_overflow);
889
    qemu_put_byte(f, n->mac_table.uni_overflow);
890
    qemu_put_byte(f, n->alluni);
891
    qemu_put_byte(f, n->nomulti);
892
    qemu_put_byte(f, n->nouni);
893
    qemu_put_byte(f, n->nobcast);
894
    qemu_put_byte(f, n->has_ufo);
895
}
896

    
897
static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
898
{
899
    VirtIONet *n = opaque;
900
    int i;
901
    int ret;
902

    
903
    if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
904
        return -EINVAL;
905

    
906
    ret = virtio_load(&n->vdev, f);
907
    if (ret) {
908
        return ret;
909
    }
910

    
911
    qemu_get_buffer(f, n->mac, ETH_ALEN);
912
    n->tx_waiting = qemu_get_be32(f);
913

    
914
    virtio_net_set_mrg_rx_bufs(n, qemu_get_be32(f));
915

    
916
    if (version_id >= 3)
917
        n->status = qemu_get_be16(f);
918

    
919
    if (version_id >= 4) {
920
        if (version_id < 8) {
921
            n->promisc = qemu_get_be32(f);
922
            n->allmulti = qemu_get_be32(f);
923
        } else {
924
            n->promisc = qemu_get_byte(f);
925
            n->allmulti = qemu_get_byte(f);
926
        }
927
    }
928

    
929
    if (version_id >= 5) {
930
        n->mac_table.in_use = qemu_get_be32(f);
931
        /* MAC_TABLE_ENTRIES may be different from the saved image */
932
        if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
933
            qemu_get_buffer(f, n->mac_table.macs,
934
                            n->mac_table.in_use * ETH_ALEN);
935
        } else if (n->mac_table.in_use) {
936
            uint8_t *buf = g_malloc0(n->mac_table.in_use);
937
            qemu_get_buffer(f, buf, n->mac_table.in_use * ETH_ALEN);
938
            g_free(buf);
939
            n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
940
            n->mac_table.in_use = 0;
941
        }
942
    }
943
 
944
    if (version_id >= 6)
945
        qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
946

    
947
    if (version_id >= 7) {
948
        if (qemu_get_be32(f) && !peer_has_vnet_hdr(n)) {
949
            error_report("virtio-net: saved image requires vnet_hdr=on");
950
            return -1;
951
        }
952

    
953
        if (n->has_vnet_hdr) {
954
            tap_set_offload(n->nic->nc.peer,
955
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
956
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
957
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
958
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
959
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
960
        }
961
    }
962

    
963
    if (version_id >= 9) {
964
        n->mac_table.multi_overflow = qemu_get_byte(f);
965
        n->mac_table.uni_overflow = qemu_get_byte(f);
966
    }
967

    
968
    if (version_id >= 10) {
969
        n->alluni = qemu_get_byte(f);
970
        n->nomulti = qemu_get_byte(f);
971
        n->nouni = qemu_get_byte(f);
972
        n->nobcast = qemu_get_byte(f);
973
    }
974

    
975
    if (version_id >= 11) {
976
        if (qemu_get_byte(f) && !peer_has_ufo(n)) {
977
            error_report("virtio-net: saved image requires TUN_F_UFO support");
978
            return -1;
979
        }
980
    }
981

    
982
    /* Find the first multicast entry in the saved MAC filter */
983
    for (i = 0; i < n->mac_table.in_use; i++) {
984
        if (n->mac_table.macs[i * ETH_ALEN] & 1) {
985
            break;
986
        }
987
    }
988
    n->mac_table.first_multi = i;
989

    
990
    /* nc.link_down can't be migrated, so infer link_down according
991
     * to link status bit in n->status */
992
    n->nic->nc.link_down = (n->status & VIRTIO_NET_S_LINK_UP) == 0;
993

    
994
    return 0;
995
}
996

    
997
static void virtio_net_cleanup(NetClientState *nc)
998
{
999
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
1000

    
1001
    n->nic = NULL;
1002
}
1003

    
1004
static NetClientInfo net_virtio_info = {
1005
    .type = NET_CLIENT_OPTIONS_KIND_NIC,
1006
    .size = sizeof(NICState),
1007
    .can_receive = virtio_net_can_receive,
1008
    .receive = virtio_net_receive,
1009
        .cleanup = virtio_net_cleanup,
1010
    .link_status_changed = virtio_net_set_link_status,
1011
};
1012

    
1013
VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
1014
                              virtio_net_conf *net)
1015
{
1016
    VirtIONet *n;
1017

    
1018
    n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
1019
                                        sizeof(struct virtio_net_config),
1020
                                        sizeof(VirtIONet));
1021

    
1022
    n->vdev.get_config = virtio_net_get_config;
1023
    n->vdev.set_config = virtio_net_set_config;
1024
    n->vdev.get_features = virtio_net_get_features;
1025
    n->vdev.set_features = virtio_net_set_features;
1026
    n->vdev.bad_features = virtio_net_bad_features;
1027
    n->vdev.reset = virtio_net_reset;
1028
    n->vdev.set_status = virtio_net_set_status;
1029
    n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
1030

    
1031
    if (net->tx && strcmp(net->tx, "timer") && strcmp(net->tx, "bh")) {
1032
        error_report("virtio-net: "
1033
                     "Unknown option tx=%s, valid options: \"timer\" \"bh\"",
1034
                     net->tx);
1035
        error_report("Defaulting to \"bh\"");
1036
    }
1037

    
1038
    if (net->tx && !strcmp(net->tx, "timer")) {
1039
        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_timer);
1040
        n->tx_timer = qemu_new_timer_ns(vm_clock, virtio_net_tx_timer, n);
1041
        n->tx_timeout = net->txtimer;
1042
    } else {
1043
        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_bh);
1044
        n->tx_bh = qemu_bh_new(virtio_net_tx_bh, n);
1045
    }
1046
    n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
1047
    qemu_macaddr_default_if_unset(&conf->macaddr);
1048
    memcpy(&n->mac[0], &conf->macaddr, sizeof(n->mac));
1049
    n->status = VIRTIO_NET_S_LINK_UP;
1050

    
1051
    n->nic = qemu_new_nic(&net_virtio_info, conf, object_get_typename(OBJECT(dev)), dev->id, n);
1052
    peer_test_vnet_hdr(n);
1053
    if (peer_has_vnet_hdr(n)) {
1054
        tap_using_vnet_hdr(n->nic->nc.peer, 1);
1055
        n->host_hdr_len = sizeof(struct virtio_net_hdr);
1056
    } else {
1057
        n->host_hdr_len = 0;
1058
    }
1059

    
1060
    qemu_format_nic_info_str(&n->nic->nc, conf->macaddr.a);
1061

    
1062
    n->tx_waiting = 0;
1063
    n->tx_burst = net->txburst;
1064
    virtio_net_set_mrg_rx_bufs(n, 0);
1065
    n->promisc = 1; /* for compatibility */
1066

    
1067
    n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
1068

    
1069
    n->vlans = g_malloc0(MAX_VLAN >> 3);
1070

    
1071
    n->qdev = dev;
1072
    register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
1073
                    virtio_net_save, virtio_net_load, n);
1074

    
1075
    add_boot_device_path(conf->bootindex, dev, "/ethernet-phy@0");
1076

    
1077
    return &n->vdev;
1078
}
1079

    
1080
void virtio_net_exit(VirtIODevice *vdev)
1081
{
1082
    VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
1083

    
1084
    /* This will stop vhost backend if appropriate. */
1085
    virtio_net_set_status(vdev, 0);
1086

    
1087
    qemu_purge_queued_packets(&n->nic->nc);
1088

    
1089
    unregister_savevm(n->qdev, "virtio-net", n);
1090

    
1091
    g_free(n->mac_table.macs);
1092
    g_free(n->vlans);
1093

    
1094
    if (n->tx_timer) {
1095
        qemu_del_timer(n->tx_timer);
1096
        qemu_free_timer(n->tx_timer);
1097
    } else {
1098
        qemu_bh_delete(n->tx_bh);
1099
    }
1100

    
1101
    qemu_del_net_client(&n->nic->nc);
1102
    virtio_cleanup(&n->vdev);
1103
}