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1
/*
2
 * Virtio Network Device
3
 *
4
 * Copyright IBM, Corp. 2007
5
 *
6
 * Authors:
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 *  Anthony Liguori   <aliguori@us.ibm.com>
8
 *
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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.
11
 *
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 */
13

    
14
#include "iov.h"
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#include "virtio.h"
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#include "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.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

    
24
#define VIRTIO_NET_VM_VERSION    11
25

    
26
#define MAC_TABLE_ENTRIES    64
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#define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
28

    
29
typedef struct VirtIONet
30
{
31
    VirtIODevice vdev;
32
    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;
36
    VirtQueue *ctrl_vq;
37
    NICState *nic;
38
    QEMUTimer *tx_timer;
39
    QEMUBH *tx_bh;
40
    uint32_t tx_timeout;
41
    int32_t tx_burst;
42
    int tx_waiting;
43
    uint32_t has_vnet_hdr;
44
    uint8_t has_ufo;
45
    struct {
46
        VirtQueueElement elem;
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        ssize_t len;
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    } async_tx;
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    int mergeable_rx_bufs;
50
    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;
56
    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;
66
} VirtIONet;
67

    
68
/* TODO
69
 * - we could suppress RX interrupt if we were so inclined.
70
 */
71

    
72
static VirtIONet *to_virtio_net(VirtIODevice *vdev)
73
{
74
    return (VirtIONet *)vdev;
75
}
76

    
77
static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
78
{
79
    VirtIONet *n = to_virtio_net(vdev);
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    struct virtio_net_config netcfg;
81

    
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    stw_p(&netcfg.status, n->status);
83
    memcpy(netcfg.mac, n->mac, ETH_ALEN);
84
    memcpy(config, &netcfg, sizeof(netcfg));
85
}
86

    
87
static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
88
{
89
    VirtIONet *n = to_virtio_net(vdev);
90
    struct virtio_net_config netcfg;
91

    
92
    memcpy(&netcfg, config, sizeof(netcfg));
93

    
94
    if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
95
        memcpy(n->mac, netcfg.mac, ETH_ALEN);
96
        qemu_format_nic_info_str(&n->nic->nc, n->mac);
97
    }
98
}
99

    
100
static bool virtio_net_started(VirtIONet *n, uint8_t status)
101
{
102
    return (status & VIRTIO_CONFIG_S_DRIVER_OK) &&
103
        (n->status & VIRTIO_NET_S_LINK_UP) && n->vdev.vm_running;
104
}
105

    
106
static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
107
{
108
    if (!n->nic->nc.peer) {
109
        return;
110
    }
111
    if (n->nic->nc.peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
112
        return;
113
    }
114

    
115
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
116
        return;
117
    }
118
    if (!!n->vhost_started == virtio_net_started(n, status) &&
119
                              !n->nic->nc.peer->link_down) {
120
        return;
121
    }
122
    if (!n->vhost_started) {
123
        int r;
124
        if (!vhost_net_query(tap_get_vhost_net(n->nic->nc.peer), &n->vdev)) {
125
            return;
126
        }
127
        r = vhost_net_start(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
128
        if (r < 0) {
129
            error_report("unable to start vhost net: %d: "
130
                         "falling back on userspace virtio", -r);
131
        } else {
132
            n->vhost_started = 1;
133
        }
134
    } else {
135
        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
136
        n->vhost_started = 0;
137
    }
138
}
139

    
140
static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
141
{
142
    VirtIONet *n = to_virtio_net(vdev);
143

    
144
    virtio_net_vhost_status(n, status);
145

    
146
    if (!n->tx_waiting) {
147
        return;
148
    }
149

    
150
    if (virtio_net_started(n, status) && !n->vhost_started) {
151
        if (n->tx_timer) {
152
            qemu_mod_timer(n->tx_timer,
153
                           qemu_get_clock_ns(vm_clock) + n->tx_timeout);
154
        } else {
155
            qemu_bh_schedule(n->tx_bh);
156
        }
157
    } else {
158
        if (n->tx_timer) {
159
            qemu_del_timer(n->tx_timer);
160
        } else {
161
            qemu_bh_cancel(n->tx_bh);
162
        }
163
    }
164
}
165

    
166
static void virtio_net_set_link_status(NetClientState *nc)
167
{
168
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
169
    uint16_t old_status = n->status;
170

    
171
    if (nc->link_down)
172
        n->status &= ~VIRTIO_NET_S_LINK_UP;
173
    else
174
        n->status |= VIRTIO_NET_S_LINK_UP;
175

    
176
    if (n->status != old_status)
177
        virtio_notify_config(&n->vdev);
178

    
179
    virtio_net_set_status(&n->vdev, n->vdev.status);
180
}
181

    
182
static void virtio_net_reset(VirtIODevice *vdev)
183
{
184
    VirtIONet *n = to_virtio_net(vdev);
185

    
186
    /* Reset back to compatibility mode */
187
    n->promisc = 1;
188
    n->allmulti = 0;
189
    n->alluni = 0;
190
    n->nomulti = 0;
191
    n->nouni = 0;
192
    n->nobcast = 0;
193

    
194
    /* Flush any MAC and VLAN filter table state */
195
    n->mac_table.in_use = 0;
196
    n->mac_table.first_multi = 0;
197
    n->mac_table.multi_overflow = 0;
198
    n->mac_table.uni_overflow = 0;
199
    memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
200
    memset(n->vlans, 0, MAX_VLAN >> 3);
201
}
202

    
203
static int peer_has_vnet_hdr(VirtIONet *n)
204
{
205
    if (!n->nic->nc.peer)
206
        return 0;
207

    
208
    if (n->nic->nc.peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP)
209
        return 0;
210

    
211
    n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->nc.peer);
212

    
213
    return n->has_vnet_hdr;
214
}
215

    
216
static int peer_has_ufo(VirtIONet *n)
217
{
218
    if (!peer_has_vnet_hdr(n))
219
        return 0;
220

    
221
    n->has_ufo = tap_has_ufo(n->nic->nc.peer);
222

    
223
    return n->has_ufo;
224
}
225

    
226
static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
227
{
228
    VirtIONet *n = to_virtio_net(vdev);
229

    
230
    features |= (1 << VIRTIO_NET_F_MAC);
231

    
232
    if (peer_has_vnet_hdr(n)) {
233
        tap_using_vnet_hdr(n->nic->nc.peer, 1);
234
    } else {
235
        features &= ~(0x1 << VIRTIO_NET_F_CSUM);
236
        features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO4);
237
        features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO6);
238
        features &= ~(0x1 << VIRTIO_NET_F_HOST_ECN);
239

    
240
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_CSUM);
241
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO4);
242
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO6);
243
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_ECN);
244
    }
245

    
246
    if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
247
        features &= ~(0x1 << VIRTIO_NET_F_GUEST_UFO);
248
        features &= ~(0x1 << VIRTIO_NET_F_HOST_UFO);
249
    }
250

    
251
    if (!n->nic->nc.peer ||
252
        n->nic->nc.peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
253
        return features;
254
    }
255
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
256
        return features;
257
    }
258
    return vhost_net_get_features(tap_get_vhost_net(n->nic->nc.peer), features);
259
}
260

    
261
static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
262
{
263
    uint32_t features = 0;
264

    
265
    /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
266
     * but also these: */
267
    features |= (1 << VIRTIO_NET_F_MAC);
268
    features |= (1 << VIRTIO_NET_F_CSUM);
269
    features |= (1 << VIRTIO_NET_F_HOST_TSO4);
270
    features |= (1 << VIRTIO_NET_F_HOST_TSO6);
271
    features |= (1 << VIRTIO_NET_F_HOST_ECN);
272

    
273
    return features;
274
}
275

    
276
static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
277
{
278
    VirtIONet *n = to_virtio_net(vdev);
279

    
280
    n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
281

    
282
    if (n->has_vnet_hdr) {
283
        tap_set_offload(n->nic->nc.peer,
284
                        (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
285
                        (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
286
                        (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
287
                        (features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
288
                        (features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
289
    }
290
    if (!n->nic->nc.peer ||
291
        n->nic->nc.peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
292
        return;
293
    }
294
    if (!tap_get_vhost_net(n->nic->nc.peer)) {
295
        return;
296
    }
297
    vhost_net_ack_features(tap_get_vhost_net(n->nic->nc.peer), features);
298
}
299

    
300
static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
301
                                     VirtQueueElement *elem)
302
{
303
    uint8_t on;
304

    
305
    if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(on)) {
306
        error_report("virtio-net ctrl invalid rx mode command");
307
        exit(1);
308
    }
309

    
310
    on = ldub_p(elem->out_sg[1].iov_base);
311

    
312
    if (cmd == VIRTIO_NET_CTRL_RX_MODE_PROMISC)
313
        n->promisc = on;
314
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)
315
        n->allmulti = on;
316
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLUNI)
317
        n->alluni = on;
318
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOMULTI)
319
        n->nomulti = on;
320
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOUNI)
321
        n->nouni = on;
322
    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOBCAST)
323
        n->nobcast = on;
324
    else
325
        return VIRTIO_NET_ERR;
326

    
327
    return VIRTIO_NET_OK;
328
}
329

    
330
static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
331
                                 VirtQueueElement *elem)
332
{
333
    struct virtio_net_ctrl_mac mac_data;
334

    
335
    if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET || elem->out_num != 3 ||
336
        elem->out_sg[1].iov_len < sizeof(mac_data) ||
337
        elem->out_sg[2].iov_len < sizeof(mac_data))
338
        return VIRTIO_NET_ERR;
339

    
340
    n->mac_table.in_use = 0;
341
    n->mac_table.first_multi = 0;
342
    n->mac_table.uni_overflow = 0;
343
    n->mac_table.multi_overflow = 0;
344
    memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
345

    
346
    mac_data.entries = ldl_p(elem->out_sg[1].iov_base);
347

    
348
    if (sizeof(mac_data.entries) +
349
        (mac_data.entries * ETH_ALEN) > elem->out_sg[1].iov_len)
350
        return VIRTIO_NET_ERR;
351

    
352
    if (mac_data.entries <= MAC_TABLE_ENTRIES) {
353
        memcpy(n->mac_table.macs, elem->out_sg[1].iov_base + sizeof(mac_data),
354
               mac_data.entries * ETH_ALEN);
355
        n->mac_table.in_use += mac_data.entries;
356
    } else {
357
        n->mac_table.uni_overflow = 1;
358
    }
359

    
360
    n->mac_table.first_multi = n->mac_table.in_use;
361

    
362
    mac_data.entries = ldl_p(elem->out_sg[2].iov_base);
363

    
364
    if (sizeof(mac_data.entries) +
365
        (mac_data.entries * ETH_ALEN) > elem->out_sg[2].iov_len)
366
        return VIRTIO_NET_ERR;
367

    
368
    if (mac_data.entries) {
369
        if (n->mac_table.in_use + mac_data.entries <= MAC_TABLE_ENTRIES) {
370
            memcpy(n->mac_table.macs + (n->mac_table.in_use * ETH_ALEN),
371
                   elem->out_sg[2].iov_base + sizeof(mac_data),
372
                   mac_data.entries * ETH_ALEN);
373
            n->mac_table.in_use += mac_data.entries;
374
        } else {
375
            n->mac_table.multi_overflow = 1;
376
        }
377
    }
378

    
379
    return VIRTIO_NET_OK;
380
}
381

    
382
static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
383
                                        VirtQueueElement *elem)
384
{
385
    uint16_t vid;
386

    
387
    if (elem->out_num != 2 || elem->out_sg[1].iov_len != sizeof(vid)) {
388
        error_report("virtio-net ctrl invalid vlan command");
389
        return VIRTIO_NET_ERR;
390
    }
391

    
392
    vid = lduw_p(elem->out_sg[1].iov_base);
393

    
394
    if (vid >= MAX_VLAN)
395
        return VIRTIO_NET_ERR;
396

    
397
    if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
398
        n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
399
    else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
400
        n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
401
    else
402
        return VIRTIO_NET_ERR;
403

    
404
    return VIRTIO_NET_OK;
405
}
406

    
407
static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
408
{
409
    VirtIONet *n = to_virtio_net(vdev);
410
    struct virtio_net_ctrl_hdr ctrl;
411
    virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
412
    VirtQueueElement elem;
413

    
414
    while (virtqueue_pop(vq, &elem)) {
415
        if ((elem.in_num < 1) || (elem.out_num < 1)) {
416
            error_report("virtio-net ctrl missing headers");
417
            exit(1);
418
        }
419

    
420
        if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
421
            elem.in_sg[elem.in_num - 1].iov_len < sizeof(status)) {
422
            error_report("virtio-net ctrl header not in correct element");
423
            exit(1);
424
        }
425

    
426
        ctrl.class = ldub_p(elem.out_sg[0].iov_base);
427
        ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
428

    
429
        if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE)
430
            status = virtio_net_handle_rx_mode(n, ctrl.cmd, &elem);
431
        else if (ctrl.class == VIRTIO_NET_CTRL_MAC)
432
            status = virtio_net_handle_mac(n, ctrl.cmd, &elem);
433
        else if (ctrl.class == VIRTIO_NET_CTRL_VLAN)
434
            status = virtio_net_handle_vlan_table(n, ctrl.cmd, &elem);
435

    
436
        stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
437

    
438
        virtqueue_push(vq, &elem, sizeof(status));
439
        virtio_notify(vdev, vq);
440
    }
441
}
442

    
443
/* RX */
444

    
445
static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
446
{
447
    VirtIONet *n = to_virtio_net(vdev);
448

    
449
    qemu_flush_queued_packets(&n->nic->nc);
450
}
451

    
452
static int virtio_net_can_receive(NetClientState *nc)
453
{
454
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
455
    if (!n->vdev.vm_running) {
456
        return 0;
457
    }
458

    
459
    if (!virtio_queue_ready(n->rx_vq) ||
460
        !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
461
        return 0;
462

    
463
    return 1;
464
}
465

    
466
static int virtio_net_has_buffers(VirtIONet *n, int bufsize)
467
{
468
    if (virtio_queue_empty(n->rx_vq) ||
469
        (n->mergeable_rx_bufs &&
470
         !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
471
        virtio_queue_set_notification(n->rx_vq, 1);
472

    
473
        /* To avoid a race condition where the guest has made some buffers
474
         * available after the above check but before notification was
475
         * enabled, check for available buffers again.
476
         */
477
        if (virtio_queue_empty(n->rx_vq) ||
478
            (n->mergeable_rx_bufs &&
479
             !virtqueue_avail_bytes(n->rx_vq, bufsize, 0)))
480
            return 0;
481
    }
482

    
483
    virtio_queue_set_notification(n->rx_vq, 0);
484
    return 1;
485
}
486

    
487
/* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
488
 * it never finds out that the packets don't have valid checksums.  This
489
 * causes dhclient to get upset.  Fedora's carried a patch for ages to
490
 * fix this with Xen but it hasn't appeared in an upstream release of
491
 * dhclient yet.
492
 *
493
 * To avoid breaking existing guests, we catch udp packets and add
494
 * checksums.  This is terrible but it's better than hacking the guest
495
 * kernels.
496
 *
497
 * N.B. if we introduce a zero-copy API, this operation is no longer free so
498
 * we should provide a mechanism to disable it to avoid polluting the host
499
 * cache.
500
 */
501
static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
502
                                        const uint8_t *buf, size_t size)
503
{
504
    if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
505
        (size > 27 && size < 1500) && /* normal sized MTU */
506
        (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
507
        (buf[23] == 17) && /* ip.protocol == UDP */
508
        (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
509
        /* FIXME this cast is evil */
510
        net_checksum_calculate((uint8_t *)buf, size);
511
        hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
512
    }
513
}
514

    
515
static int receive_header(VirtIONet *n, struct iovec *iov, int iovcnt,
516
                          const void *buf, size_t size, size_t hdr_len)
517
{
518
    struct virtio_net_hdr *hdr = (struct virtio_net_hdr *)iov[0].iov_base;
519
    int offset = 0;
520

    
521
    hdr->flags = 0;
522
    hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
523

    
524
    if (n->has_vnet_hdr) {
525
        memcpy(hdr, buf, sizeof(*hdr));
526
        offset = sizeof(*hdr);
527
        work_around_broken_dhclient(hdr, buf + offset, size - offset);
528
    }
529

    
530
    /* We only ever receive a struct virtio_net_hdr from the tapfd,
531
     * but we may be passing along a larger header to the guest.
532
     */
533
    iov[0].iov_base += hdr_len;
534
    iov[0].iov_len  -= hdr_len;
535

    
536
    return offset;
537
}
538

    
539
static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
540
{
541
    static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
542
    static const uint8_t vlan[] = {0x81, 0x00};
543
    uint8_t *ptr = (uint8_t *)buf;
544
    int i;
545

    
546
    if (n->promisc)
547
        return 1;
548

    
549
    if (n->has_vnet_hdr) {
550
        ptr += sizeof(struct virtio_net_hdr);
551
    }
552

    
553
    if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
554
        int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff;
555
        if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
556
            return 0;
557
    }
558

    
559
    if (ptr[0] & 1) { // multicast
560
        if (!memcmp(ptr, bcast, sizeof(bcast))) {
561
            return !n->nobcast;
562
        } else if (n->nomulti) {
563
            return 0;
564
        } else if (n->allmulti || n->mac_table.multi_overflow) {
565
            return 1;
566
        }
567

    
568
        for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
569
            if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
570
                return 1;
571
            }
572
        }
573
    } else { // unicast
574
        if (n->nouni) {
575
            return 0;
576
        } else if (n->alluni || n->mac_table.uni_overflow) {
577
            return 1;
578
        } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
579
            return 1;
580
        }
581

    
582
        for (i = 0; i < n->mac_table.first_multi; i++) {
583
            if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
584
                return 1;
585
            }
586
        }
587
    }
588

    
589
    return 0;
590
}
591

    
592
static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t size)
593
{
594
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
595
    struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
596
    size_t guest_hdr_len, offset, i, host_hdr_len;
597

    
598
    if (!virtio_net_can_receive(&n->nic->nc))
599
        return -1;
600

    
601
    /* hdr_len refers to the header we supply to the guest */
602
    guest_hdr_len = n->mergeable_rx_bufs ?
603
        sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
604

    
605

    
606
    host_hdr_len = n->has_vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
607
    if (!virtio_net_has_buffers(n, size + guest_hdr_len - host_hdr_len))
608
        return 0;
609

    
610
    if (!receive_filter(n, buf, size))
611
        return size;
612

    
613
    offset = i = 0;
614

    
615
    while (offset < size) {
616
        VirtQueueElement elem;
617
        int len, total;
618
        struct iovec sg[VIRTQUEUE_MAX_SIZE];
619

    
620
        total = 0;
621

    
622
        if (virtqueue_pop(n->rx_vq, &elem) == 0) {
623
            if (i == 0)
624
                return -1;
625
            error_report("virtio-net unexpected empty queue: "
626
                    "i %zd mergeable %d offset %zd, size %zd, "
627
                    "guest hdr len %zd, host hdr len %zd guest features 0x%x",
628
                    i, n->mergeable_rx_bufs, offset, size,
629
                    guest_hdr_len, host_hdr_len, n->vdev.guest_features);
630
            exit(1);
631
        }
632

    
633
        if (elem.in_num < 1) {
634
            error_report("virtio-net receive queue contains no in buffers");
635
            exit(1);
636
        }
637

    
638
        if (!n->mergeable_rx_bufs && elem.in_sg[0].iov_len != guest_hdr_len) {
639
            error_report("virtio-net header not in first element");
640
            exit(1);
641
        }
642

    
643
        memcpy(&sg, &elem.in_sg[0], sizeof(sg[0]) * elem.in_num);
644

    
645
        if (i == 0) {
646
            if (n->mergeable_rx_bufs)
647
                mhdr = (struct virtio_net_hdr_mrg_rxbuf *)sg[0].iov_base;
648

    
649
            offset += receive_header(n, sg, elem.in_num,
650
                                     buf + offset, size - offset, guest_hdr_len);
651
            total += guest_hdr_len;
652
        }
653

    
654
        /* copy in packet.  ugh */
655
        len = iov_from_buf(sg, elem.in_num, 0,
656
                           buf + offset, size - offset);
657
        total += len;
658
        offset += len;
659
        /* If buffers can't be merged, at this point we
660
         * must have consumed the complete packet.
661
         * Otherwise, drop it. */
662
        if (!n->mergeable_rx_bufs && offset < size) {
663
#if 0
664
            error_report("virtio-net truncated non-mergeable packet: "
665
                         "i %zd mergeable %d offset %zd, size %zd, "
666
                         "guest hdr len %zd, host hdr len %zd",
667
                         i, n->mergeable_rx_bufs,
668
                         offset, size, guest_hdr_len, host_hdr_len);
669
#endif
670
            return size;
671
        }
672

    
673
        /* signal other side */
674
        virtqueue_fill(n->rx_vq, &elem, total, i++);
675
    }
676

    
677
    if (mhdr) {
678
        stw_p(&mhdr->num_buffers, i);
679
    }
680

    
681
    virtqueue_flush(n->rx_vq, i);
682
    virtio_notify(&n->vdev, n->rx_vq);
683

    
684
    return size;
685
}
686

    
687
static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);
688

    
689
static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
690
{
691
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
692

    
693
    virtqueue_push(n->tx_vq, &n->async_tx.elem, 0);
694
    virtio_notify(&n->vdev, n->tx_vq);
695

    
696
    n->async_tx.elem.out_num = n->async_tx.len = 0;
697

    
698
    virtio_queue_set_notification(n->tx_vq, 1);
699
    virtio_net_flush_tx(n, n->tx_vq);
700
}
701

    
702
/* TX */
703
static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
704
{
705
    VirtQueueElement elem;
706
    int32_t num_packets = 0;
707
    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
708
        return num_packets;
709
    }
710

    
711
    assert(n->vdev.vm_running);
712

    
713
    if (n->async_tx.elem.out_num) {
714
        virtio_queue_set_notification(n->tx_vq, 0);
715
        return num_packets;
716
    }
717

    
718
    while (virtqueue_pop(vq, &elem)) {
719
        ssize_t ret, len = 0;
720
        unsigned int out_num = elem.out_num;
721
        struct iovec *out_sg = &elem.out_sg[0];
722
        unsigned hdr_len;
723

    
724
        /* hdr_len refers to the header received from the guest */
725
        hdr_len = n->mergeable_rx_bufs ?
726
            sizeof(struct virtio_net_hdr_mrg_rxbuf) :
727
            sizeof(struct virtio_net_hdr);
728

    
729
        if (out_num < 1 || out_sg->iov_len != hdr_len) {
730
            error_report("virtio-net header not in first element");
731
            exit(1);
732
        }
733

    
734
        /* ignore the header if GSO is not supported */
735
        if (!n->has_vnet_hdr) {
736
            out_num--;
737
            out_sg++;
738
            len += hdr_len;
739
        } else if (n->mergeable_rx_bufs) {
740
            /* tapfd expects a struct virtio_net_hdr */
741
            hdr_len -= sizeof(struct virtio_net_hdr);
742
            out_sg->iov_len -= hdr_len;
743
            len += hdr_len;
744
        }
745

    
746
        ret = qemu_sendv_packet_async(&n->nic->nc, out_sg, out_num,
747
                                      virtio_net_tx_complete);
748
        if (ret == 0) {
749
            virtio_queue_set_notification(n->tx_vq, 0);
750
            n->async_tx.elem = elem;
751
            n->async_tx.len  = len;
752
            return -EBUSY;
753
        }
754

    
755
        len += ret;
756

    
757
        virtqueue_push(vq, &elem, 0);
758
        virtio_notify(&n->vdev, vq);
759

    
760
        if (++num_packets >= n->tx_burst) {
761
            break;
762
        }
763
    }
764
    return num_packets;
765
}
766

    
767
static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
768
{
769
    VirtIONet *n = to_virtio_net(vdev);
770

    
771
    /* This happens when device was stopped but VCPU wasn't. */
772
    if (!n->vdev.vm_running) {
773
        n->tx_waiting = 1;
774
        return;
775
    }
776

    
777
    if (n->tx_waiting) {
778
        virtio_queue_set_notification(vq, 1);
779
        qemu_del_timer(n->tx_timer);
780
        n->tx_waiting = 0;
781
        virtio_net_flush_tx(n, vq);
782
    } else {
783
        qemu_mod_timer(n->tx_timer,
784
                       qemu_get_clock_ns(vm_clock) + n->tx_timeout);
785
        n->tx_waiting = 1;
786
        virtio_queue_set_notification(vq, 0);
787
    }
788
}
789

    
790
static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
791
{
792
    VirtIONet *n = to_virtio_net(vdev);
793

    
794
    if (unlikely(n->tx_waiting)) {
795
        return;
796
    }
797
    n->tx_waiting = 1;
798
    /* This happens when device was stopped but VCPU wasn't. */
799
    if (!n->vdev.vm_running) {
800
        return;
801
    }
802
    virtio_queue_set_notification(vq, 0);
803
    qemu_bh_schedule(n->tx_bh);
804
}
805

    
806
static void virtio_net_tx_timer(void *opaque)
807
{
808
    VirtIONet *n = opaque;
809
    assert(n->vdev.vm_running);
810

    
811
    n->tx_waiting = 0;
812

    
813
    /* Just in case the driver is not ready on more */
814
    if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
815
        return;
816

    
817
    virtio_queue_set_notification(n->tx_vq, 1);
818
    virtio_net_flush_tx(n, n->tx_vq);
819
}
820

    
821
static void virtio_net_tx_bh(void *opaque)
822
{
823
    VirtIONet *n = opaque;
824
    int32_t ret;
825

    
826
    assert(n->vdev.vm_running);
827

    
828
    n->tx_waiting = 0;
829

    
830
    /* Just in case the driver is not ready on more */
831
    if (unlikely(!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)))
832
        return;
833

    
834
    ret = virtio_net_flush_tx(n, n->tx_vq);
835
    if (ret == -EBUSY) {
836
        return; /* Notification re-enable handled by tx_complete */
837
    }
838

    
839
    /* If we flush a full burst of packets, assume there are
840
     * more coming and immediately reschedule */
841
    if (ret >= n->tx_burst) {
842
        qemu_bh_schedule(n->tx_bh);
843
        n->tx_waiting = 1;
844
        return;
845
    }
846

    
847
    /* If less than a full burst, re-enable notification and flush
848
     * anything that may have come in while we weren't looking.  If
849
     * we find something, assume the guest is still active and reschedule */
850
    virtio_queue_set_notification(n->tx_vq, 1);
851
    if (virtio_net_flush_tx(n, n->tx_vq) > 0) {
852
        virtio_queue_set_notification(n->tx_vq, 0);
853
        qemu_bh_schedule(n->tx_bh);
854
        n->tx_waiting = 1;
855
    }
856
}
857

    
858
static void virtio_net_save(QEMUFile *f, void *opaque)
859
{
860
    VirtIONet *n = opaque;
861

    
862
    /* At this point, backend must be stopped, otherwise
863
     * it might keep writing to memory. */
864
    assert(!n->vhost_started);
865
    virtio_save(&n->vdev, f);
866

    
867
    qemu_put_buffer(f, n->mac, ETH_ALEN);
868
    qemu_put_be32(f, n->tx_waiting);
869
    qemu_put_be32(f, n->mergeable_rx_bufs);
870
    qemu_put_be16(f, n->status);
871
    qemu_put_byte(f, n->promisc);
872
    qemu_put_byte(f, n->allmulti);
873
    qemu_put_be32(f, n->mac_table.in_use);
874
    qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
875
    qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
876
    qemu_put_be32(f, n->has_vnet_hdr);
877
    qemu_put_byte(f, n->mac_table.multi_overflow);
878
    qemu_put_byte(f, n->mac_table.uni_overflow);
879
    qemu_put_byte(f, n->alluni);
880
    qemu_put_byte(f, n->nomulti);
881
    qemu_put_byte(f, n->nouni);
882
    qemu_put_byte(f, n->nobcast);
883
    qemu_put_byte(f, n->has_ufo);
884
}
885

    
886
static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
887
{
888
    VirtIONet *n = opaque;
889
    int i;
890
    int ret;
891

    
892
    if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
893
        return -EINVAL;
894

    
895
    ret = virtio_load(&n->vdev, f);
896
    if (ret) {
897
        return ret;
898
    }
899

    
900
    qemu_get_buffer(f, n->mac, ETH_ALEN);
901
    n->tx_waiting = qemu_get_be32(f);
902
    n->mergeable_rx_bufs = qemu_get_be32(f);
903

    
904
    if (version_id >= 3)
905
        n->status = qemu_get_be16(f);
906

    
907
    if (version_id >= 4) {
908
        if (version_id < 8) {
909
            n->promisc = qemu_get_be32(f);
910
            n->allmulti = qemu_get_be32(f);
911
        } else {
912
            n->promisc = qemu_get_byte(f);
913
            n->allmulti = qemu_get_byte(f);
914
        }
915
    }
916

    
917
    if (version_id >= 5) {
918
        n->mac_table.in_use = qemu_get_be32(f);
919
        /* MAC_TABLE_ENTRIES may be different from the saved image */
920
        if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
921
            qemu_get_buffer(f, n->mac_table.macs,
922
                            n->mac_table.in_use * ETH_ALEN);
923
        } else if (n->mac_table.in_use) {
924
            uint8_t *buf = g_malloc0(n->mac_table.in_use);
925
            qemu_get_buffer(f, buf, n->mac_table.in_use * ETH_ALEN);
926
            g_free(buf);
927
            n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
928
            n->mac_table.in_use = 0;
929
        }
930
    }
931
 
932
    if (version_id >= 6)
933
        qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
934

    
935
    if (version_id >= 7) {
936
        if (qemu_get_be32(f) && !peer_has_vnet_hdr(n)) {
937
            error_report("virtio-net: saved image requires vnet_hdr=on");
938
            return -1;
939
        }
940

    
941
        if (n->has_vnet_hdr) {
942
            tap_using_vnet_hdr(n->nic->nc.peer, 1);
943
            tap_set_offload(n->nic->nc.peer,
944
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
945
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
946
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
947
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
948
                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
949
        }
950
    }
951

    
952
    if (version_id >= 9) {
953
        n->mac_table.multi_overflow = qemu_get_byte(f);
954
        n->mac_table.uni_overflow = qemu_get_byte(f);
955
    }
956

    
957
    if (version_id >= 10) {
958
        n->alluni = qemu_get_byte(f);
959
        n->nomulti = qemu_get_byte(f);
960
        n->nouni = qemu_get_byte(f);
961
        n->nobcast = qemu_get_byte(f);
962
    }
963

    
964
    if (version_id >= 11) {
965
        if (qemu_get_byte(f) && !peer_has_ufo(n)) {
966
            error_report("virtio-net: saved image requires TUN_F_UFO support");
967
            return -1;
968
        }
969
    }
970

    
971
    /* Find the first multicast entry in the saved MAC filter */
972
    for (i = 0; i < n->mac_table.in_use; i++) {
973
        if (n->mac_table.macs[i * ETH_ALEN] & 1) {
974
            break;
975
        }
976
    }
977
    n->mac_table.first_multi = i;
978

    
979
    /* nc.link_down can't be migrated, so infer link_down according
980
     * to link status bit in n->status */
981
    n->nic->nc.link_down = (n->status & VIRTIO_NET_S_LINK_UP) == 0;
982

    
983
    return 0;
984
}
985

    
986
static void virtio_net_cleanup(NetClientState *nc)
987
{
988
    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
989

    
990
    n->nic = NULL;
991
}
992

    
993
static NetClientInfo net_virtio_info = {
994
    .type = NET_CLIENT_OPTIONS_KIND_NIC,
995
    .size = sizeof(NICState),
996
    .can_receive = virtio_net_can_receive,
997
    .receive = virtio_net_receive,
998
        .cleanup = virtio_net_cleanup,
999
    .link_status_changed = virtio_net_set_link_status,
1000
};
1001

    
1002
VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
1003
                              virtio_net_conf *net)
1004
{
1005
    VirtIONet *n;
1006

    
1007
    n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
1008
                                        sizeof(struct virtio_net_config),
1009
                                        sizeof(VirtIONet));
1010

    
1011
    n->vdev.get_config = virtio_net_get_config;
1012
    n->vdev.set_config = virtio_net_set_config;
1013
    n->vdev.get_features = virtio_net_get_features;
1014
    n->vdev.set_features = virtio_net_set_features;
1015
    n->vdev.bad_features = virtio_net_bad_features;
1016
    n->vdev.reset = virtio_net_reset;
1017
    n->vdev.set_status = virtio_net_set_status;
1018
    n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
1019

    
1020
    if (net->tx && strcmp(net->tx, "timer") && strcmp(net->tx, "bh")) {
1021
        error_report("virtio-net: "
1022
                     "Unknown option tx=%s, valid options: \"timer\" \"bh\"",
1023
                     net->tx);
1024
        error_report("Defaulting to \"bh\"");
1025
    }
1026

    
1027
    if (net->tx && !strcmp(net->tx, "timer")) {
1028
        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_timer);
1029
        n->tx_timer = qemu_new_timer_ns(vm_clock, virtio_net_tx_timer, n);
1030
        n->tx_timeout = net->txtimer;
1031
    } else {
1032
        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_bh);
1033
        n->tx_bh = qemu_bh_new(virtio_net_tx_bh, n);
1034
    }
1035
    n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
1036
    qemu_macaddr_default_if_unset(&conf->macaddr);
1037
    memcpy(&n->mac[0], &conf->macaddr, sizeof(n->mac));
1038
    n->status = VIRTIO_NET_S_LINK_UP;
1039

    
1040
    n->nic = qemu_new_nic(&net_virtio_info, conf, object_get_typename(OBJECT(dev)), dev->id, n);
1041

    
1042
    qemu_format_nic_info_str(&n->nic->nc, conf->macaddr.a);
1043

    
1044
    n->tx_waiting = 0;
1045
    n->tx_burst = net->txburst;
1046
    n->mergeable_rx_bufs = 0;
1047
    n->promisc = 1; /* for compatibility */
1048

    
1049
    n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
1050

    
1051
    n->vlans = g_malloc0(MAX_VLAN >> 3);
1052

    
1053
    n->qdev = dev;
1054
    register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
1055
                    virtio_net_save, virtio_net_load, n);
1056

    
1057
    add_boot_device_path(conf->bootindex, dev, "/ethernet-phy@0");
1058

    
1059
    return &n->vdev;
1060
}
1061

    
1062
void virtio_net_exit(VirtIODevice *vdev)
1063
{
1064
    VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
1065

    
1066
    /* This will stop vhost backend if appropriate. */
1067
    virtio_net_set_status(vdev, 0);
1068

    
1069
    qemu_purge_queued_packets(&n->nic->nc);
1070

    
1071
    unregister_savevm(n->qdev, "virtio-net", n);
1072

    
1073
    g_free(n->mac_table.macs);
1074
    g_free(n->vlans);
1075

    
1076
    if (n->tx_timer) {
1077
        qemu_del_timer(n->tx_timer);
1078
        qemu_free_timer(n->tx_timer);
1079
    } else {
1080
        qemu_bh_delete(n->tx_bh);
1081
    }
1082

    
1083
    qemu_del_net_client(&n->nic->nc);
1084
    virtio_cleanup(&n->vdev);
1085
}