xref: /openbmc/qemu/hw/net/virtio-net.c (revision 6e790746)
1 /*
2  * Virtio Network Device
3  *
4  * Copyright IBM, Corp. 2007
5  *
6  * Authors:
7  *  Anthony Liguori   <aliguori@us.ibm.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2.  See
10  * the COPYING file in the top-level directory.
11  *
12  */
13 
14 #include "qemu/iov.h"
15 #include "hw/virtio/virtio.h"
16 #include "net/net.h"
17 #include "net/checksum.h"
18 #include "net/tap.h"
19 #include "qemu/error-report.h"
20 #include "qemu/timer.h"
21 #include "hw/virtio/virtio-net.h"
22 #include "net/vhost_net.h"
23 
24 #define VIRTIO_NET_VM_VERSION    11
25 
26 #define MAC_TABLE_ENTRIES    64
27 #define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
28 
29 /*
30  * Calculate the number of bytes up to and including the given 'field' of
31  * 'container'.
32  */
33 #define endof(container, field) \
34     (offsetof(container, field) + sizeof(((container *)0)->field))
35 
36 typedef struct VirtIOFeature {
37     uint32_t flags;
38     size_t end;
39 } VirtIOFeature;
40 
41 static VirtIOFeature feature_sizes[] = {
42     {.flags = 1 << VIRTIO_NET_F_MAC,
43      .end = endof(struct virtio_net_config, mac)},
44     {.flags = 1 << VIRTIO_NET_F_STATUS,
45      .end = endof(struct virtio_net_config, status)},
46     {.flags = 1 << VIRTIO_NET_F_MQ,
47      .end = endof(struct virtio_net_config, max_virtqueue_pairs)},
48     {}
49 };
50 
51 static VirtIONetQueue *virtio_net_get_subqueue(NetClientState *nc)
52 {
53     VirtIONet *n = qemu_get_nic_opaque(nc);
54 
55     return &n->vqs[nc->queue_index];
56 }
57 
58 static int vq2q(int queue_index)
59 {
60     return queue_index / 2;
61 }
62 
63 /* TODO
64  * - we could suppress RX interrupt if we were so inclined.
65  */
66 
67 static VirtIONet *to_virtio_net(VirtIODevice *vdev)
68 {
69     return (VirtIONet *)vdev;
70 }
71 
72 static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
73 {
74     VirtIONet *n = to_virtio_net(vdev);
75     struct virtio_net_config netcfg;
76 
77     stw_p(&netcfg.status, n->status);
78     stw_p(&netcfg.max_virtqueue_pairs, n->max_queues);
79     memcpy(netcfg.mac, n->mac, ETH_ALEN);
80     memcpy(config, &netcfg, n->config_size);
81 }
82 
83 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
84 {
85     VirtIONet *n = to_virtio_net(vdev);
86     struct virtio_net_config netcfg = {};
87 
88     memcpy(&netcfg, config, n->config_size);
89 
90     if (!(n->vdev.guest_features >> VIRTIO_NET_F_CTRL_MAC_ADDR & 1) &&
91         memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
92         memcpy(n->mac, netcfg.mac, ETH_ALEN);
93         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
94     }
95 }
96 
97 static bool virtio_net_started(VirtIONet *n, uint8_t status)
98 {
99     return (status & VIRTIO_CONFIG_S_DRIVER_OK) &&
100         (n->status & VIRTIO_NET_S_LINK_UP) && n->vdev.vm_running;
101 }
102 
103 static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
104 {
105     NetClientState *nc = qemu_get_queue(n->nic);
106     int queues = n->multiqueue ? n->max_queues : 1;
107 
108     if (!nc->peer) {
109         return;
110     }
111     if (nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
112         return;
113     }
114 
115     if (!tap_get_vhost_net(nc->peer)) {
116         return;
117     }
118 
119     if (!!n->vhost_started == virtio_net_started(n, status) &&
120                               !nc->peer->link_down) {
121         return;
122     }
123     if (!n->vhost_started) {
124         int r;
125         if (!vhost_net_query(tap_get_vhost_net(nc->peer), &n->vdev)) {
126             return;
127         }
128         n->vhost_started = 1;
129         r = vhost_net_start(&n->vdev, n->nic->ncs, queues);
130         if (r < 0) {
131             error_report("unable to start vhost net: %d: "
132                          "falling back on userspace virtio", -r);
133             n->vhost_started = 0;
134         }
135     } else {
136         vhost_net_stop(&n->vdev, n->nic->ncs, queues);
137         n->vhost_started = 0;
138     }
139 }
140 
141 static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
142 {
143     VirtIONet *n = to_virtio_net(vdev);
144     VirtIONetQueue *q;
145     int i;
146     uint8_t queue_status;
147 
148     virtio_net_vhost_status(n, status);
149 
150     for (i = 0; i < n->max_queues; i++) {
151         q = &n->vqs[i];
152 
153         if ((!n->multiqueue && i != 0) || i >= n->curr_queues) {
154             queue_status = 0;
155         } else {
156             queue_status = status;
157         }
158 
159         if (!q->tx_waiting) {
160             continue;
161         }
162 
163         if (virtio_net_started(n, queue_status) && !n->vhost_started) {
164             if (q->tx_timer) {
165                 qemu_mod_timer(q->tx_timer,
166                                qemu_get_clock_ns(vm_clock) + n->tx_timeout);
167             } else {
168                 qemu_bh_schedule(q->tx_bh);
169             }
170         } else {
171             if (q->tx_timer) {
172                 qemu_del_timer(q->tx_timer);
173             } else {
174                 qemu_bh_cancel(q->tx_bh);
175             }
176         }
177     }
178 }
179 
180 static void virtio_net_set_link_status(NetClientState *nc)
181 {
182     VirtIONet *n = qemu_get_nic_opaque(nc);
183     uint16_t old_status = n->status;
184 
185     if (nc->link_down)
186         n->status &= ~VIRTIO_NET_S_LINK_UP;
187     else
188         n->status |= VIRTIO_NET_S_LINK_UP;
189 
190     if (n->status != old_status)
191         virtio_notify_config(&n->vdev);
192 
193     virtio_net_set_status(&n->vdev, n->vdev.status);
194 }
195 
196 static void virtio_net_reset(VirtIODevice *vdev)
197 {
198     VirtIONet *n = to_virtio_net(vdev);
199 
200     /* Reset back to compatibility mode */
201     n->promisc = 1;
202     n->allmulti = 0;
203     n->alluni = 0;
204     n->nomulti = 0;
205     n->nouni = 0;
206     n->nobcast = 0;
207     /* multiqueue is disabled by default */
208     n->curr_queues = 1;
209 
210     /* Flush any MAC and VLAN filter table state */
211     n->mac_table.in_use = 0;
212     n->mac_table.first_multi = 0;
213     n->mac_table.multi_overflow = 0;
214     n->mac_table.uni_overflow = 0;
215     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
216     memcpy(&n->mac[0], &n->nic->conf->macaddr, sizeof(n->mac));
217     memset(n->vlans, 0, MAX_VLAN >> 3);
218 }
219 
220 static void peer_test_vnet_hdr(VirtIONet *n)
221 {
222     NetClientState *nc = qemu_get_queue(n->nic);
223     if (!nc->peer) {
224         return;
225     }
226 
227     if (nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
228         return;
229     }
230 
231     n->has_vnet_hdr = tap_has_vnet_hdr(nc->peer);
232 }
233 
234 static int peer_has_vnet_hdr(VirtIONet *n)
235 {
236     return n->has_vnet_hdr;
237 }
238 
239 static int peer_has_ufo(VirtIONet *n)
240 {
241     if (!peer_has_vnet_hdr(n))
242         return 0;
243 
244     n->has_ufo = tap_has_ufo(qemu_get_queue(n->nic)->peer);
245 
246     return n->has_ufo;
247 }
248 
249 static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs)
250 {
251     int i;
252     NetClientState *nc;
253 
254     n->mergeable_rx_bufs = mergeable_rx_bufs;
255 
256     n->guest_hdr_len = n->mergeable_rx_bufs ?
257         sizeof(struct virtio_net_hdr_mrg_rxbuf) : sizeof(struct virtio_net_hdr);
258 
259     for (i = 0; i < n->max_queues; i++) {
260         nc = qemu_get_subqueue(n->nic, i);
261 
262         if (peer_has_vnet_hdr(n) &&
263             tap_has_vnet_hdr_len(nc->peer, n->guest_hdr_len)) {
264             tap_set_vnet_hdr_len(nc->peer, n->guest_hdr_len);
265             n->host_hdr_len = n->guest_hdr_len;
266         }
267     }
268 }
269 
270 static int peer_attach(VirtIONet *n, int index)
271 {
272     NetClientState *nc = qemu_get_subqueue(n->nic, index);
273 
274     if (!nc->peer) {
275         return 0;
276     }
277 
278     if (nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
279         return 0;
280     }
281 
282     return tap_enable(nc->peer);
283 }
284 
285 static int peer_detach(VirtIONet *n, int index)
286 {
287     NetClientState *nc = qemu_get_subqueue(n->nic, index);
288 
289     if (!nc->peer) {
290         return 0;
291     }
292 
293     if (nc->peer->info->type !=  NET_CLIENT_OPTIONS_KIND_TAP) {
294         return 0;
295     }
296 
297     return tap_disable(nc->peer);
298 }
299 
300 static void virtio_net_set_queues(VirtIONet *n)
301 {
302     int i;
303 
304     for (i = 0; i < n->max_queues; i++) {
305         if (i < n->curr_queues) {
306             assert(!peer_attach(n, i));
307         } else {
308             assert(!peer_detach(n, i));
309         }
310     }
311 }
312 
313 static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue, int ctrl);
314 
315 static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
316 {
317     VirtIONet *n = to_virtio_net(vdev);
318     NetClientState *nc = qemu_get_queue(n->nic);
319 
320     features |= (1 << VIRTIO_NET_F_MAC);
321 
322     if (!peer_has_vnet_hdr(n)) {
323         features &= ~(0x1 << VIRTIO_NET_F_CSUM);
324         features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO4);
325         features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO6);
326         features &= ~(0x1 << VIRTIO_NET_F_HOST_ECN);
327 
328         features &= ~(0x1 << VIRTIO_NET_F_GUEST_CSUM);
329         features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO4);
330         features &= ~(0x1 << VIRTIO_NET_F_GUEST_TSO6);
331         features &= ~(0x1 << VIRTIO_NET_F_GUEST_ECN);
332     }
333 
334     if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
335         features &= ~(0x1 << VIRTIO_NET_F_GUEST_UFO);
336         features &= ~(0x1 << VIRTIO_NET_F_HOST_UFO);
337     }
338 
339     if (!nc->peer || nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
340         return features;
341     }
342     if (!tap_get_vhost_net(nc->peer)) {
343         return features;
344     }
345     return vhost_net_get_features(tap_get_vhost_net(nc->peer), features);
346 }
347 
348 static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
349 {
350     uint32_t features = 0;
351 
352     /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
353      * but also these: */
354     features |= (1 << VIRTIO_NET_F_MAC);
355     features |= (1 << VIRTIO_NET_F_CSUM);
356     features |= (1 << VIRTIO_NET_F_HOST_TSO4);
357     features |= (1 << VIRTIO_NET_F_HOST_TSO6);
358     features |= (1 << VIRTIO_NET_F_HOST_ECN);
359 
360     return features;
361 }
362 
363 static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
364 {
365     VirtIONet *n = to_virtio_net(vdev);
366     int i;
367 
368     virtio_net_set_multiqueue(n, !!(features & (1 << VIRTIO_NET_F_MQ)),
369                               !!(features & (1 << VIRTIO_NET_F_CTRL_VQ)));
370 
371     virtio_net_set_mrg_rx_bufs(n, !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF)));
372 
373     if (n->has_vnet_hdr) {
374         tap_set_offload(qemu_get_subqueue(n->nic, 0)->peer,
375                         (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
376                         (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
377                         (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
378                         (features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
379                         (features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
380     }
381 
382     for (i = 0;  i < n->max_queues; i++) {
383         NetClientState *nc = qemu_get_subqueue(n->nic, i);
384 
385         if (!nc->peer || nc->peer->info->type != NET_CLIENT_OPTIONS_KIND_TAP) {
386             continue;
387         }
388         if (!tap_get_vhost_net(nc->peer)) {
389             continue;
390         }
391         vhost_net_ack_features(tap_get_vhost_net(nc->peer), features);
392     }
393 }
394 
395 static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
396                                      struct iovec *iov, unsigned int iov_cnt)
397 {
398     uint8_t on;
399     size_t s;
400 
401     s = iov_to_buf(iov, iov_cnt, 0, &on, sizeof(on));
402     if (s != sizeof(on)) {
403         return VIRTIO_NET_ERR;
404     }
405 
406     if (cmd == VIRTIO_NET_CTRL_RX_PROMISC) {
407         n->promisc = on;
408     } else if (cmd == VIRTIO_NET_CTRL_RX_ALLMULTI) {
409         n->allmulti = on;
410     } else if (cmd == VIRTIO_NET_CTRL_RX_ALLUNI) {
411         n->alluni = on;
412     } else if (cmd == VIRTIO_NET_CTRL_RX_NOMULTI) {
413         n->nomulti = on;
414     } else if (cmd == VIRTIO_NET_CTRL_RX_NOUNI) {
415         n->nouni = on;
416     } else if (cmd == VIRTIO_NET_CTRL_RX_NOBCAST) {
417         n->nobcast = on;
418     } else {
419         return VIRTIO_NET_ERR;
420     }
421 
422     return VIRTIO_NET_OK;
423 }
424 
425 static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
426                                  struct iovec *iov, unsigned int iov_cnt)
427 {
428     struct virtio_net_ctrl_mac mac_data;
429     size_t s;
430 
431     if (cmd == VIRTIO_NET_CTRL_MAC_ADDR_SET) {
432         if (iov_size(iov, iov_cnt) != sizeof(n->mac)) {
433             return VIRTIO_NET_ERR;
434         }
435         s = iov_to_buf(iov, iov_cnt, 0, &n->mac, sizeof(n->mac));
436         assert(s == sizeof(n->mac));
437         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
438         return VIRTIO_NET_OK;
439     }
440 
441     if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET) {
442         return VIRTIO_NET_ERR;
443     }
444 
445     n->mac_table.in_use = 0;
446     n->mac_table.first_multi = 0;
447     n->mac_table.uni_overflow = 0;
448     n->mac_table.multi_overflow = 0;
449     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
450 
451     s = iov_to_buf(iov, iov_cnt, 0, &mac_data.entries,
452                    sizeof(mac_data.entries));
453     mac_data.entries = ldl_p(&mac_data.entries);
454     if (s != sizeof(mac_data.entries)) {
455         return VIRTIO_NET_ERR;
456     }
457     iov_discard_front(&iov, &iov_cnt, s);
458 
459     if (mac_data.entries * ETH_ALEN > iov_size(iov, iov_cnt)) {
460         return VIRTIO_NET_ERR;
461     }
462 
463     if (mac_data.entries <= MAC_TABLE_ENTRIES) {
464         s = iov_to_buf(iov, iov_cnt, 0, n->mac_table.macs,
465                        mac_data.entries * ETH_ALEN);
466         if (s != mac_data.entries * ETH_ALEN) {
467             return VIRTIO_NET_ERR;
468         }
469         n->mac_table.in_use += mac_data.entries;
470     } else {
471         n->mac_table.uni_overflow = 1;
472     }
473 
474     iov_discard_front(&iov, &iov_cnt, mac_data.entries * ETH_ALEN);
475 
476     n->mac_table.first_multi = n->mac_table.in_use;
477 
478     s = iov_to_buf(iov, iov_cnt, 0, &mac_data.entries,
479                    sizeof(mac_data.entries));
480     mac_data.entries = ldl_p(&mac_data.entries);
481     if (s != sizeof(mac_data.entries)) {
482         return VIRTIO_NET_ERR;
483     }
484 
485     iov_discard_front(&iov, &iov_cnt, s);
486 
487     if (mac_data.entries * ETH_ALEN != iov_size(iov, iov_cnt)) {
488         return VIRTIO_NET_ERR;
489     }
490 
491     if (n->mac_table.in_use + mac_data.entries <= MAC_TABLE_ENTRIES) {
492         s = iov_to_buf(iov, iov_cnt, 0, n->mac_table.macs,
493                        mac_data.entries * ETH_ALEN);
494         if (s != mac_data.entries * ETH_ALEN) {
495             return VIRTIO_NET_ERR;
496         }
497         n->mac_table.in_use += mac_data.entries;
498     } else {
499         n->mac_table.multi_overflow = 1;
500     }
501 
502     return VIRTIO_NET_OK;
503 }
504 
505 static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
506                                         struct iovec *iov, unsigned int iov_cnt)
507 {
508     uint16_t vid;
509     size_t s;
510 
511     s = iov_to_buf(iov, iov_cnt, 0, &vid, sizeof(vid));
512     vid = lduw_p(&vid);
513     if (s != sizeof(vid)) {
514         return VIRTIO_NET_ERR;
515     }
516 
517     if (vid >= MAX_VLAN)
518         return VIRTIO_NET_ERR;
519 
520     if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
521         n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
522     else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
523         n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
524     else
525         return VIRTIO_NET_ERR;
526 
527     return VIRTIO_NET_OK;
528 }
529 
530 static int virtio_net_handle_mq(VirtIONet *n, uint8_t cmd,
531                                 struct iovec *iov, unsigned int iov_cnt)
532 {
533     struct virtio_net_ctrl_mq mq;
534     size_t s;
535     uint16_t queues;
536 
537     s = iov_to_buf(iov, iov_cnt, 0, &mq, sizeof(mq));
538     if (s != sizeof(mq)) {
539         return VIRTIO_NET_ERR;
540     }
541 
542     if (cmd != VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
543         return VIRTIO_NET_ERR;
544     }
545 
546     queues = lduw_p(&mq.virtqueue_pairs);
547 
548     if (queues < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
549         queues > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
550         queues > n->max_queues ||
551         !n->multiqueue) {
552         return VIRTIO_NET_ERR;
553     }
554 
555     n->curr_queues = queues;
556     /* stop the backend before changing the number of queues to avoid handling a
557      * disabled queue */
558     virtio_net_set_status(&n->vdev, n->vdev.status);
559     virtio_net_set_queues(n);
560 
561     return VIRTIO_NET_OK;
562 }
563 static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
564 {
565     VirtIONet *n = to_virtio_net(vdev);
566     struct virtio_net_ctrl_hdr ctrl;
567     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
568     VirtQueueElement elem;
569     size_t s;
570     struct iovec *iov;
571     unsigned int iov_cnt;
572 
573     while (virtqueue_pop(vq, &elem)) {
574         if (iov_size(elem.in_sg, elem.in_num) < sizeof(status) ||
575             iov_size(elem.out_sg, elem.out_num) < sizeof(ctrl)) {
576             error_report("virtio-net ctrl missing headers");
577             exit(1);
578         }
579 
580         iov = elem.out_sg;
581         iov_cnt = elem.out_num;
582         s = iov_to_buf(iov, iov_cnt, 0, &ctrl, sizeof(ctrl));
583         iov_discard_front(&iov, &iov_cnt, sizeof(ctrl));
584         if (s != sizeof(ctrl)) {
585             status = VIRTIO_NET_ERR;
586         } else if (ctrl.class == VIRTIO_NET_CTRL_RX) {
587             status = virtio_net_handle_rx_mode(n, ctrl.cmd, iov, iov_cnt);
588         } else if (ctrl.class == VIRTIO_NET_CTRL_MAC) {
589             status = virtio_net_handle_mac(n, ctrl.cmd, iov, iov_cnt);
590         } else if (ctrl.class == VIRTIO_NET_CTRL_VLAN) {
591             status = virtio_net_handle_vlan_table(n, ctrl.cmd, iov, iov_cnt);
592         } else if (ctrl.class == VIRTIO_NET_CTRL_MQ) {
593             status = virtio_net_handle_mq(n, ctrl.cmd, iov, iov_cnt);
594         }
595 
596         s = iov_from_buf(elem.in_sg, elem.in_num, 0, &status, sizeof(status));
597         assert(s == sizeof(status));
598 
599         virtqueue_push(vq, &elem, sizeof(status));
600         virtio_notify(vdev, vq);
601     }
602 }
603 
604 /* RX */
605 
606 static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
607 {
608     VirtIONet *n = to_virtio_net(vdev);
609     int queue_index = vq2q(virtio_get_queue_index(vq));
610 
611     qemu_flush_queued_packets(qemu_get_subqueue(n->nic, queue_index));
612 }
613 
614 static int virtio_net_can_receive(NetClientState *nc)
615 {
616     VirtIONet *n = qemu_get_nic_opaque(nc);
617     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
618 
619     if (!n->vdev.vm_running) {
620         return 0;
621     }
622 
623     if (nc->queue_index >= n->curr_queues) {
624         return 0;
625     }
626 
627     if (!virtio_queue_ready(q->rx_vq) ||
628         !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
629         return 0;
630     }
631 
632     return 1;
633 }
634 
635 static int virtio_net_has_buffers(VirtIONetQueue *q, int bufsize)
636 {
637     VirtIONet *n = q->n;
638     if (virtio_queue_empty(q->rx_vq) ||
639         (n->mergeable_rx_bufs &&
640          !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
641         virtio_queue_set_notification(q->rx_vq, 1);
642 
643         /* To avoid a race condition where the guest has made some buffers
644          * available after the above check but before notification was
645          * enabled, check for available buffers again.
646          */
647         if (virtio_queue_empty(q->rx_vq) ||
648             (n->mergeable_rx_bufs &&
649              !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
650             return 0;
651         }
652     }
653 
654     virtio_queue_set_notification(q->rx_vq, 0);
655     return 1;
656 }
657 
658 /* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
659  * it never finds out that the packets don't have valid checksums.  This
660  * causes dhclient to get upset.  Fedora's carried a patch for ages to
661  * fix this with Xen but it hasn't appeared in an upstream release of
662  * dhclient yet.
663  *
664  * To avoid breaking existing guests, we catch udp packets and add
665  * checksums.  This is terrible but it's better than hacking the guest
666  * kernels.
667  *
668  * N.B. if we introduce a zero-copy API, this operation is no longer free so
669  * we should provide a mechanism to disable it to avoid polluting the host
670  * cache.
671  */
672 static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
673                                         uint8_t *buf, size_t size)
674 {
675     if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
676         (size > 27 && size < 1500) && /* normal sized MTU */
677         (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
678         (buf[23] == 17) && /* ip.protocol == UDP */
679         (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
680         net_checksum_calculate(buf, size);
681         hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
682     }
683 }
684 
685 static void receive_header(VirtIONet *n, const struct iovec *iov, int iov_cnt,
686                            const void *buf, size_t size)
687 {
688     if (n->has_vnet_hdr) {
689         /* FIXME this cast is evil */
690         void *wbuf = (void *)buf;
691         work_around_broken_dhclient(wbuf, wbuf + n->host_hdr_len,
692                                     size - n->host_hdr_len);
693         iov_from_buf(iov, iov_cnt, 0, buf, sizeof(struct virtio_net_hdr));
694     } else {
695         struct virtio_net_hdr hdr = {
696             .flags = 0,
697             .gso_type = VIRTIO_NET_HDR_GSO_NONE
698         };
699         iov_from_buf(iov, iov_cnt, 0, &hdr, sizeof hdr);
700     }
701 }
702 
703 static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
704 {
705     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
706     static const uint8_t vlan[] = {0x81, 0x00};
707     uint8_t *ptr = (uint8_t *)buf;
708     int i;
709 
710     if (n->promisc)
711         return 1;
712 
713     ptr += n->host_hdr_len;
714 
715     if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
716         int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff;
717         if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
718             return 0;
719     }
720 
721     if (ptr[0] & 1) { // multicast
722         if (!memcmp(ptr, bcast, sizeof(bcast))) {
723             return !n->nobcast;
724         } else if (n->nomulti) {
725             return 0;
726         } else if (n->allmulti || n->mac_table.multi_overflow) {
727             return 1;
728         }
729 
730         for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
731             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
732                 return 1;
733             }
734         }
735     } else { // unicast
736         if (n->nouni) {
737             return 0;
738         } else if (n->alluni || n->mac_table.uni_overflow) {
739             return 1;
740         } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
741             return 1;
742         }
743 
744         for (i = 0; i < n->mac_table.first_multi; i++) {
745             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
746                 return 1;
747             }
748         }
749     }
750 
751     return 0;
752 }
753 
754 static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t size)
755 {
756     VirtIONet *n = qemu_get_nic_opaque(nc);
757     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
758     struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE];
759     struct virtio_net_hdr_mrg_rxbuf mhdr;
760     unsigned mhdr_cnt = 0;
761     size_t offset, i, guest_offset;
762 
763     if (!virtio_net_can_receive(nc)) {
764         return -1;
765     }
766 
767     /* hdr_len refers to the header we supply to the guest */
768     if (!virtio_net_has_buffers(q, size + n->guest_hdr_len - n->host_hdr_len)) {
769         return 0;
770     }
771 
772     if (!receive_filter(n, buf, size))
773         return size;
774 
775     offset = i = 0;
776 
777     while (offset < size) {
778         VirtQueueElement elem;
779         int len, total;
780         const struct iovec *sg = elem.in_sg;
781 
782         total = 0;
783 
784         if (virtqueue_pop(q->rx_vq, &elem) == 0) {
785             if (i == 0)
786                 return -1;
787             error_report("virtio-net unexpected empty queue: "
788                     "i %zd mergeable %d offset %zd, size %zd, "
789                     "guest hdr len %zd, host hdr len %zd guest features 0x%x",
790                     i, n->mergeable_rx_bufs, offset, size,
791                     n->guest_hdr_len, n->host_hdr_len, n->vdev.guest_features);
792             exit(1);
793         }
794 
795         if (elem.in_num < 1) {
796             error_report("virtio-net receive queue contains no in buffers");
797             exit(1);
798         }
799 
800         if (i == 0) {
801             assert(offset == 0);
802             if (n->mergeable_rx_bufs) {
803                 mhdr_cnt = iov_copy(mhdr_sg, ARRAY_SIZE(mhdr_sg),
804                                     sg, elem.in_num,
805                                     offsetof(typeof(mhdr), num_buffers),
806                                     sizeof(mhdr.num_buffers));
807             }
808 
809             receive_header(n, sg, elem.in_num, buf, size);
810             offset = n->host_hdr_len;
811             total += n->guest_hdr_len;
812             guest_offset = n->guest_hdr_len;
813         } else {
814             guest_offset = 0;
815         }
816 
817         /* copy in packet.  ugh */
818         len = iov_from_buf(sg, elem.in_num, guest_offset,
819                            buf + offset, size - offset);
820         total += len;
821         offset += len;
822         /* If buffers can't be merged, at this point we
823          * must have consumed the complete packet.
824          * Otherwise, drop it. */
825         if (!n->mergeable_rx_bufs && offset < size) {
826 #if 0
827             error_report("virtio-net truncated non-mergeable packet: "
828                          "i %zd mergeable %d offset %zd, size %zd, "
829                          "guest hdr len %zd, host hdr len %zd",
830                          i, n->mergeable_rx_bufs,
831                          offset, size, n->guest_hdr_len, n->host_hdr_len);
832 #endif
833             return size;
834         }
835 
836         /* signal other side */
837         virtqueue_fill(q->rx_vq, &elem, total, i++);
838     }
839 
840     if (mhdr_cnt) {
841         stw_p(&mhdr.num_buffers, i);
842         iov_from_buf(mhdr_sg, mhdr_cnt,
843                      0,
844                      &mhdr.num_buffers, sizeof mhdr.num_buffers);
845     }
846 
847     virtqueue_flush(q->rx_vq, i);
848     virtio_notify(&n->vdev, q->rx_vq);
849 
850     return size;
851 }
852 
853 static int32_t virtio_net_flush_tx(VirtIONetQueue *q);
854 
855 static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
856 {
857     VirtIONet *n = qemu_get_nic_opaque(nc);
858     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
859 
860     virtqueue_push(q->tx_vq, &q->async_tx.elem, 0);
861     virtio_notify(&n->vdev, q->tx_vq);
862 
863     q->async_tx.elem.out_num = q->async_tx.len = 0;
864 
865     virtio_queue_set_notification(q->tx_vq, 1);
866     virtio_net_flush_tx(q);
867 }
868 
869 /* TX */
870 static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
871 {
872     VirtIONet *n = q->n;
873     VirtQueueElement elem;
874     int32_t num_packets = 0;
875     int queue_index = vq2q(virtio_get_queue_index(q->tx_vq));
876     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
877         return num_packets;
878     }
879 
880     assert(n->vdev.vm_running);
881 
882     if (q->async_tx.elem.out_num) {
883         virtio_queue_set_notification(q->tx_vq, 0);
884         return num_packets;
885     }
886 
887     while (virtqueue_pop(q->tx_vq, &elem)) {
888         ssize_t ret, len;
889         unsigned int out_num = elem.out_num;
890         struct iovec *out_sg = &elem.out_sg[0];
891         struct iovec sg[VIRTQUEUE_MAX_SIZE];
892 
893         if (out_num < 1) {
894             error_report("virtio-net header not in first element");
895             exit(1);
896         }
897 
898         /*
899          * If host wants to see the guest header as is, we can
900          * pass it on unchanged. Otherwise, copy just the parts
901          * that host is interested in.
902          */
903         assert(n->host_hdr_len <= n->guest_hdr_len);
904         if (n->host_hdr_len != n->guest_hdr_len) {
905             unsigned sg_num = iov_copy(sg, ARRAY_SIZE(sg),
906                                        out_sg, out_num,
907                                        0, n->host_hdr_len);
908             sg_num += iov_copy(sg + sg_num, ARRAY_SIZE(sg) - sg_num,
909                              out_sg, out_num,
910                              n->guest_hdr_len, -1);
911             out_num = sg_num;
912             out_sg = sg;
913         }
914 
915         len = n->guest_hdr_len;
916 
917         ret = qemu_sendv_packet_async(qemu_get_subqueue(n->nic, queue_index),
918                                       out_sg, out_num, virtio_net_tx_complete);
919         if (ret == 0) {
920             virtio_queue_set_notification(q->tx_vq, 0);
921             q->async_tx.elem = elem;
922             q->async_tx.len  = len;
923             return -EBUSY;
924         }
925 
926         len += ret;
927 
928         virtqueue_push(q->tx_vq, &elem, 0);
929         virtio_notify(&n->vdev, q->tx_vq);
930 
931         if (++num_packets >= n->tx_burst) {
932             break;
933         }
934     }
935     return num_packets;
936 }
937 
938 static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
939 {
940     VirtIONet *n = to_virtio_net(vdev);
941     VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
942 
943     /* This happens when device was stopped but VCPU wasn't. */
944     if (!n->vdev.vm_running) {
945         q->tx_waiting = 1;
946         return;
947     }
948 
949     if (q->tx_waiting) {
950         virtio_queue_set_notification(vq, 1);
951         qemu_del_timer(q->tx_timer);
952         q->tx_waiting = 0;
953         virtio_net_flush_tx(q);
954     } else {
955         qemu_mod_timer(q->tx_timer,
956                        qemu_get_clock_ns(vm_clock) + n->tx_timeout);
957         q->tx_waiting = 1;
958         virtio_queue_set_notification(vq, 0);
959     }
960 }
961 
962 static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
963 {
964     VirtIONet *n = to_virtio_net(vdev);
965     VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
966 
967     if (unlikely(q->tx_waiting)) {
968         return;
969     }
970     q->tx_waiting = 1;
971     /* This happens when device was stopped but VCPU wasn't. */
972     if (!n->vdev.vm_running) {
973         return;
974     }
975     virtio_queue_set_notification(vq, 0);
976     qemu_bh_schedule(q->tx_bh);
977 }
978 
979 static void virtio_net_tx_timer(void *opaque)
980 {
981     VirtIONetQueue *q = opaque;
982     VirtIONet *n = q->n;
983     assert(n->vdev.vm_running);
984 
985     q->tx_waiting = 0;
986 
987     /* Just in case the driver is not ready on more */
988     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
989         return;
990 
991     virtio_queue_set_notification(q->tx_vq, 1);
992     virtio_net_flush_tx(q);
993 }
994 
995 static void virtio_net_tx_bh(void *opaque)
996 {
997     VirtIONetQueue *q = opaque;
998     VirtIONet *n = q->n;
999     int32_t ret;
1000 
1001     assert(n->vdev.vm_running);
1002 
1003     q->tx_waiting = 0;
1004 
1005     /* Just in case the driver is not ready on more */
1006     if (unlikely(!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)))
1007         return;
1008 
1009     ret = virtio_net_flush_tx(q);
1010     if (ret == -EBUSY) {
1011         return; /* Notification re-enable handled by tx_complete */
1012     }
1013 
1014     /* If we flush a full burst of packets, assume there are
1015      * more coming and immediately reschedule */
1016     if (ret >= n->tx_burst) {
1017         qemu_bh_schedule(q->tx_bh);
1018         q->tx_waiting = 1;
1019         return;
1020     }
1021 
1022     /* If less than a full burst, re-enable notification and flush
1023      * anything that may have come in while we weren't looking.  If
1024      * we find something, assume the guest is still active and reschedule */
1025     virtio_queue_set_notification(q->tx_vq, 1);
1026     if (virtio_net_flush_tx(q) > 0) {
1027         virtio_queue_set_notification(q->tx_vq, 0);
1028         qemu_bh_schedule(q->tx_bh);
1029         q->tx_waiting = 1;
1030     }
1031 }
1032 
1033 static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue, int ctrl)
1034 {
1035     VirtIODevice *vdev = &n->vdev;
1036     int i, max = multiqueue ? n->max_queues : 1;
1037 
1038     n->multiqueue = multiqueue;
1039 
1040     for (i = 2; i <= n->max_queues * 2 + 1; i++) {
1041         virtio_del_queue(vdev, i);
1042     }
1043 
1044     for (i = 1; i < max; i++) {
1045         n->vqs[i].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
1046         if (n->vqs[i].tx_timer) {
1047             n->vqs[i].tx_vq =
1048                 virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer);
1049             n->vqs[i].tx_timer = qemu_new_timer_ns(vm_clock,
1050                                                    virtio_net_tx_timer,
1051                                                    &n->vqs[i]);
1052         } else {
1053             n->vqs[i].tx_vq =
1054                 virtio_add_queue(vdev, 256, virtio_net_handle_tx_bh);
1055             n->vqs[i].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[i]);
1056         }
1057 
1058         n->vqs[i].tx_waiting = 0;
1059         n->vqs[i].n = n;
1060     }
1061 
1062     if (ctrl) {
1063         n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
1064     }
1065 
1066     virtio_net_set_queues(n);
1067 }
1068 
1069 static void virtio_net_save(QEMUFile *f, void *opaque)
1070 {
1071     int i;
1072     VirtIONet *n = opaque;
1073 
1074     /* At this point, backend must be stopped, otherwise
1075      * it might keep writing to memory. */
1076     assert(!n->vhost_started);
1077     virtio_save(&n->vdev, f);
1078 
1079     qemu_put_buffer(f, n->mac, ETH_ALEN);
1080     qemu_put_be32(f, n->vqs[0].tx_waiting);
1081     qemu_put_be32(f, n->mergeable_rx_bufs);
1082     qemu_put_be16(f, n->status);
1083     qemu_put_byte(f, n->promisc);
1084     qemu_put_byte(f, n->allmulti);
1085     qemu_put_be32(f, n->mac_table.in_use);
1086     qemu_put_buffer(f, n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
1087     qemu_put_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
1088     qemu_put_be32(f, n->has_vnet_hdr);
1089     qemu_put_byte(f, n->mac_table.multi_overflow);
1090     qemu_put_byte(f, n->mac_table.uni_overflow);
1091     qemu_put_byte(f, n->alluni);
1092     qemu_put_byte(f, n->nomulti);
1093     qemu_put_byte(f, n->nouni);
1094     qemu_put_byte(f, n->nobcast);
1095     qemu_put_byte(f, n->has_ufo);
1096     if (n->max_queues > 1) {
1097         qemu_put_be16(f, n->max_queues);
1098         qemu_put_be16(f, n->curr_queues);
1099         for (i = 1; i < n->curr_queues; i++) {
1100             qemu_put_be32(f, n->vqs[i].tx_waiting);
1101         }
1102     }
1103 }
1104 
1105 static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
1106 {
1107     VirtIONet *n = opaque;
1108     int ret, i, link_down;
1109 
1110     if (version_id < 2 || version_id > VIRTIO_NET_VM_VERSION)
1111         return -EINVAL;
1112 
1113     ret = virtio_load(&n->vdev, f);
1114     if (ret) {
1115         return ret;
1116     }
1117 
1118     qemu_get_buffer(f, n->mac, ETH_ALEN);
1119     n->vqs[0].tx_waiting = qemu_get_be32(f);
1120 
1121     virtio_net_set_mrg_rx_bufs(n, qemu_get_be32(f));
1122 
1123     if (version_id >= 3)
1124         n->status = qemu_get_be16(f);
1125 
1126     if (version_id >= 4) {
1127         if (version_id < 8) {
1128             n->promisc = qemu_get_be32(f);
1129             n->allmulti = qemu_get_be32(f);
1130         } else {
1131             n->promisc = qemu_get_byte(f);
1132             n->allmulti = qemu_get_byte(f);
1133         }
1134     }
1135 
1136     if (version_id >= 5) {
1137         n->mac_table.in_use = qemu_get_be32(f);
1138         /* MAC_TABLE_ENTRIES may be different from the saved image */
1139         if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
1140             qemu_get_buffer(f, n->mac_table.macs,
1141                             n->mac_table.in_use * ETH_ALEN);
1142         } else if (n->mac_table.in_use) {
1143             uint8_t *buf = g_malloc0(n->mac_table.in_use);
1144             qemu_get_buffer(f, buf, n->mac_table.in_use * ETH_ALEN);
1145             g_free(buf);
1146             n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
1147             n->mac_table.in_use = 0;
1148         }
1149     }
1150 
1151     if (version_id >= 6)
1152         qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
1153 
1154     if (version_id >= 7) {
1155         if (qemu_get_be32(f) && !peer_has_vnet_hdr(n)) {
1156             error_report("virtio-net: saved image requires vnet_hdr=on");
1157             return -1;
1158         }
1159 
1160         if (n->has_vnet_hdr) {
1161             tap_set_offload(qemu_get_queue(n->nic)->peer,
1162                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
1163                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
1164                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
1165                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
1166                     (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
1167         }
1168     }
1169 
1170     if (version_id >= 9) {
1171         n->mac_table.multi_overflow = qemu_get_byte(f);
1172         n->mac_table.uni_overflow = qemu_get_byte(f);
1173     }
1174 
1175     if (version_id >= 10) {
1176         n->alluni = qemu_get_byte(f);
1177         n->nomulti = qemu_get_byte(f);
1178         n->nouni = qemu_get_byte(f);
1179         n->nobcast = qemu_get_byte(f);
1180     }
1181 
1182     if (version_id >= 11) {
1183         if (qemu_get_byte(f) && !peer_has_ufo(n)) {
1184             error_report("virtio-net: saved image requires TUN_F_UFO support");
1185             return -1;
1186         }
1187     }
1188 
1189     if (n->max_queues > 1) {
1190         if (n->max_queues != qemu_get_be16(f)) {
1191             error_report("virtio-net: different max_queues ");
1192             return -1;
1193         }
1194 
1195         n->curr_queues = qemu_get_be16(f);
1196         for (i = 1; i < n->curr_queues; i++) {
1197             n->vqs[i].tx_waiting = qemu_get_be32(f);
1198         }
1199     }
1200 
1201     virtio_net_set_queues(n);
1202 
1203     /* Find the first multicast entry in the saved MAC filter */
1204     for (i = 0; i < n->mac_table.in_use; i++) {
1205         if (n->mac_table.macs[i * ETH_ALEN] & 1) {
1206             break;
1207         }
1208     }
1209     n->mac_table.first_multi = i;
1210 
1211     /* nc.link_down can't be migrated, so infer link_down according
1212      * to link status bit in n->status */
1213     link_down = (n->status & VIRTIO_NET_S_LINK_UP) == 0;
1214     for (i = 0; i < n->max_queues; i++) {
1215         qemu_get_subqueue(n->nic, i)->link_down = link_down;
1216     }
1217 
1218     return 0;
1219 }
1220 
1221 static void virtio_net_cleanup(NetClientState *nc)
1222 {
1223     VirtIONet *n = qemu_get_nic_opaque(nc);
1224 
1225     n->nic = NULL;
1226 }
1227 
1228 static NetClientInfo net_virtio_info = {
1229     .type = NET_CLIENT_OPTIONS_KIND_NIC,
1230     .size = sizeof(NICState),
1231     .can_receive = virtio_net_can_receive,
1232     .receive = virtio_net_receive,
1233         .cleanup = virtio_net_cleanup,
1234     .link_status_changed = virtio_net_set_link_status,
1235 };
1236 
1237 static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
1238 {
1239     VirtIONet *n = to_virtio_net(vdev);
1240     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
1241     assert(n->vhost_started);
1242     return vhost_net_virtqueue_pending(tap_get_vhost_net(nc->peer), idx);
1243 }
1244 
1245 static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
1246                                            bool mask)
1247 {
1248     VirtIONet *n = to_virtio_net(vdev);
1249     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
1250     assert(n->vhost_started);
1251     vhost_net_virtqueue_mask(tap_get_vhost_net(nc->peer),
1252                              vdev, idx, mask);
1253 }
1254 
1255 VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
1256                               virtio_net_conf *net, uint32_t host_features)
1257 {
1258     VirtIONet *n;
1259     int i, config_size = 0;
1260 
1261     for (i = 0; feature_sizes[i].flags != 0; i++) {
1262         if (host_features & feature_sizes[i].flags) {
1263             config_size = MAX(feature_sizes[i].end, config_size);
1264         }
1265     }
1266 
1267     n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
1268                                         config_size, sizeof(VirtIONet));
1269 
1270     n->config_size = config_size;
1271     n->vdev.get_config = virtio_net_get_config;
1272     n->vdev.set_config = virtio_net_set_config;
1273     n->vdev.get_features = virtio_net_get_features;
1274     n->vdev.set_features = virtio_net_set_features;
1275     n->vdev.bad_features = virtio_net_bad_features;
1276     n->vdev.reset = virtio_net_reset;
1277     n->vdev.set_status = virtio_net_set_status;
1278     n->vdev.guest_notifier_mask = virtio_net_guest_notifier_mask;
1279     n->vdev.guest_notifier_pending = virtio_net_guest_notifier_pending;
1280     n->max_queues = MAX(conf->queues, 1);
1281     n->vqs = g_malloc0(sizeof(VirtIONetQueue) * n->max_queues);
1282     n->vqs[0].rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
1283     n->curr_queues = 1;
1284     n->vqs[0].n = n;
1285     n->tx_timeout = net->txtimer;
1286 
1287     if (net->tx && strcmp(net->tx, "timer") && strcmp(net->tx, "bh")) {
1288         error_report("virtio-net: "
1289                      "Unknown option tx=%s, valid options: \"timer\" \"bh\"",
1290                      net->tx);
1291         error_report("Defaulting to \"bh\"");
1292     }
1293 
1294     if (net->tx && !strcmp(net->tx, "timer")) {
1295         n->vqs[0].tx_vq = virtio_add_queue(&n->vdev, 256,
1296                                            virtio_net_handle_tx_timer);
1297         n->vqs[0].tx_timer = qemu_new_timer_ns(vm_clock, virtio_net_tx_timer,
1298                                                &n->vqs[0]);
1299     } else {
1300         n->vqs[0].tx_vq = virtio_add_queue(&n->vdev, 256,
1301                                            virtio_net_handle_tx_bh);
1302         n->vqs[0].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[0]);
1303     }
1304     n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
1305     qemu_macaddr_default_if_unset(&conf->macaddr);
1306     memcpy(&n->mac[0], &conf->macaddr, sizeof(n->mac));
1307     n->status = VIRTIO_NET_S_LINK_UP;
1308 
1309     n->nic = qemu_new_nic(&net_virtio_info, conf, object_get_typename(OBJECT(dev)), dev->id, n);
1310     peer_test_vnet_hdr(n);
1311     if (peer_has_vnet_hdr(n)) {
1312         for (i = 0; i < n->max_queues; i++) {
1313             tap_using_vnet_hdr(qemu_get_subqueue(n->nic, i)->peer, true);
1314         }
1315         n->host_hdr_len = sizeof(struct virtio_net_hdr);
1316     } else {
1317         n->host_hdr_len = 0;
1318     }
1319 
1320     qemu_format_nic_info_str(qemu_get_queue(n->nic), conf->macaddr.a);
1321 
1322     n->vqs[0].tx_waiting = 0;
1323     n->tx_burst = net->txburst;
1324     virtio_net_set_mrg_rx_bufs(n, 0);
1325     n->promisc = 1; /* for compatibility */
1326 
1327     n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
1328 
1329     n->vlans = g_malloc0(MAX_VLAN >> 3);
1330 
1331     n->qdev = dev;
1332     register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
1333                     virtio_net_save, virtio_net_load, n);
1334 
1335     add_boot_device_path(conf->bootindex, dev, "/ethernet-phy@0");
1336 
1337     return &n->vdev;
1338 }
1339 
1340 void virtio_net_exit(VirtIODevice *vdev)
1341 {
1342     VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
1343     int i;
1344 
1345     /* This will stop vhost backend if appropriate. */
1346     virtio_net_set_status(vdev, 0);
1347 
1348     unregister_savevm(n->qdev, "virtio-net", n);
1349 
1350     g_free(n->mac_table.macs);
1351     g_free(n->vlans);
1352 
1353     for (i = 0; i < n->max_queues; i++) {
1354         VirtIONetQueue *q = &n->vqs[i];
1355         NetClientState *nc = qemu_get_subqueue(n->nic, i);
1356 
1357         qemu_purge_queued_packets(nc);
1358 
1359         if (q->tx_timer) {
1360             qemu_del_timer(q->tx_timer);
1361             qemu_free_timer(q->tx_timer);
1362         } else {
1363             qemu_bh_delete(q->tx_bh);
1364         }
1365     }
1366 
1367     g_free(n->vqs);
1368     qemu_del_nic(n->nic);
1369     virtio_cleanup(&n->vdev);
1370 }
1371