xref: /openbmc/qemu/hw/net/virtio-net.c (revision f764718d)
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/osdep.h"
15 #include "qemu/iov.h"
16 #include "hw/virtio/virtio.h"
17 #include "net/net.h"
18 #include "net/checksum.h"
19 #include "net/tap.h"
20 #include "qemu/error-report.h"
21 #include "qemu/timer.h"
22 #include "hw/virtio/virtio-net.h"
23 #include "net/vhost_net.h"
24 #include "hw/virtio/virtio-bus.h"
25 #include "qapi/qmp/qjson.h"
26 #include "qapi-event.h"
27 #include "hw/virtio/virtio-access.h"
28 #include "migration/misc.h"
29 
30 #define VIRTIO_NET_VM_VERSION    11
31 
32 #define MAC_TABLE_ENTRIES    64
33 #define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
34 
35 /* previously fixed value */
36 #define VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE 256
37 #define VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE 256
38 
39 /* for now, only allow larger queues; with virtio-1, guest can downsize */
40 #define VIRTIO_NET_RX_QUEUE_MIN_SIZE VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE
41 #define VIRTIO_NET_TX_QUEUE_MIN_SIZE VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE
42 
43 /*
44  * Calculate the number of bytes up to and including the given 'field' of
45  * 'container'.
46  */
47 #define endof(container, field) \
48     (offsetof(container, field) + sizeof(((container *)0)->field))
49 
50 typedef struct VirtIOFeature {
51     uint32_t flags;
52     size_t end;
53 } VirtIOFeature;
54 
55 static VirtIOFeature feature_sizes[] = {
56     {.flags = 1 << VIRTIO_NET_F_MAC,
57      .end = endof(struct virtio_net_config, mac)},
58     {.flags = 1 << VIRTIO_NET_F_STATUS,
59      .end = endof(struct virtio_net_config, status)},
60     {.flags = 1 << VIRTIO_NET_F_MQ,
61      .end = endof(struct virtio_net_config, max_virtqueue_pairs)},
62     {.flags = 1 << VIRTIO_NET_F_MTU,
63      .end = endof(struct virtio_net_config, mtu)},
64     {}
65 };
66 
67 static VirtIONetQueue *virtio_net_get_subqueue(NetClientState *nc)
68 {
69     VirtIONet *n = qemu_get_nic_opaque(nc);
70 
71     return &n->vqs[nc->queue_index];
72 }
73 
74 static int vq2q(int queue_index)
75 {
76     return queue_index / 2;
77 }
78 
79 /* TODO
80  * - we could suppress RX interrupt if we were so inclined.
81  */
82 
83 static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
84 {
85     VirtIONet *n = VIRTIO_NET(vdev);
86     struct virtio_net_config netcfg;
87 
88     virtio_stw_p(vdev, &netcfg.status, n->status);
89     virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queues);
90     virtio_stw_p(vdev, &netcfg.mtu, n->net_conf.mtu);
91     memcpy(netcfg.mac, n->mac, ETH_ALEN);
92     memcpy(config, &netcfg, n->config_size);
93 }
94 
95 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
96 {
97     VirtIONet *n = VIRTIO_NET(vdev);
98     struct virtio_net_config netcfg = {};
99 
100     memcpy(&netcfg, config, n->config_size);
101 
102     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR) &&
103         !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1) &&
104         memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
105         memcpy(n->mac, netcfg.mac, ETH_ALEN);
106         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
107     }
108 }
109 
110 static bool virtio_net_started(VirtIONet *n, uint8_t status)
111 {
112     VirtIODevice *vdev = VIRTIO_DEVICE(n);
113     return (status & VIRTIO_CONFIG_S_DRIVER_OK) &&
114         (n->status & VIRTIO_NET_S_LINK_UP) && vdev->vm_running;
115 }
116 
117 static void virtio_net_announce_timer(void *opaque)
118 {
119     VirtIONet *n = opaque;
120     VirtIODevice *vdev = VIRTIO_DEVICE(n);
121 
122     n->announce_counter--;
123     n->status |= VIRTIO_NET_S_ANNOUNCE;
124     virtio_notify_config(vdev);
125 }
126 
127 static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
128 {
129     VirtIODevice *vdev = VIRTIO_DEVICE(n);
130     NetClientState *nc = qemu_get_queue(n->nic);
131     int queues = n->multiqueue ? n->max_queues : 1;
132 
133     if (!get_vhost_net(nc->peer)) {
134         return;
135     }
136 
137     if ((virtio_net_started(n, status) && !nc->peer->link_down) ==
138         !!n->vhost_started) {
139         return;
140     }
141     if (!n->vhost_started) {
142         int r, i;
143 
144         if (n->needs_vnet_hdr_swap) {
145             error_report("backend does not support %s vnet headers; "
146                          "falling back on userspace virtio",
147                          virtio_is_big_endian(vdev) ? "BE" : "LE");
148             return;
149         }
150 
151         /* Any packets outstanding? Purge them to avoid touching rings
152          * when vhost is running.
153          */
154         for (i = 0;  i < queues; i++) {
155             NetClientState *qnc = qemu_get_subqueue(n->nic, i);
156 
157             /* Purge both directions: TX and RX. */
158             qemu_net_queue_purge(qnc->peer->incoming_queue, qnc);
159             qemu_net_queue_purge(qnc->incoming_queue, qnc->peer);
160         }
161 
162         if (virtio_has_feature(vdev->guest_features, VIRTIO_NET_F_MTU)) {
163             r = vhost_net_set_mtu(get_vhost_net(nc->peer), n->net_conf.mtu);
164             if (r < 0) {
165                 error_report("%uBytes MTU not supported by the backend",
166                              n->net_conf.mtu);
167 
168                 return;
169             }
170         }
171 
172         n->vhost_started = 1;
173         r = vhost_net_start(vdev, n->nic->ncs, queues);
174         if (r < 0) {
175             error_report("unable to start vhost net: %d: "
176                          "falling back on userspace virtio", -r);
177             n->vhost_started = 0;
178         }
179     } else {
180         vhost_net_stop(vdev, n->nic->ncs, queues);
181         n->vhost_started = 0;
182     }
183 }
184 
185 static int virtio_net_set_vnet_endian_one(VirtIODevice *vdev,
186                                           NetClientState *peer,
187                                           bool enable)
188 {
189     if (virtio_is_big_endian(vdev)) {
190         return qemu_set_vnet_be(peer, enable);
191     } else {
192         return qemu_set_vnet_le(peer, enable);
193     }
194 }
195 
196 static bool virtio_net_set_vnet_endian(VirtIODevice *vdev, NetClientState *ncs,
197                                        int queues, bool enable)
198 {
199     int i;
200 
201     for (i = 0; i < queues; i++) {
202         if (virtio_net_set_vnet_endian_one(vdev, ncs[i].peer, enable) < 0 &&
203             enable) {
204             while (--i >= 0) {
205                 virtio_net_set_vnet_endian_one(vdev, ncs[i].peer, false);
206             }
207 
208             return true;
209         }
210     }
211 
212     return false;
213 }
214 
215 static void virtio_net_vnet_endian_status(VirtIONet *n, uint8_t status)
216 {
217     VirtIODevice *vdev = VIRTIO_DEVICE(n);
218     int queues = n->multiqueue ? n->max_queues : 1;
219 
220     if (virtio_net_started(n, status)) {
221         /* Before using the device, we tell the network backend about the
222          * endianness to use when parsing vnet headers. If the backend
223          * can't do it, we fallback onto fixing the headers in the core
224          * virtio-net code.
225          */
226         n->needs_vnet_hdr_swap = virtio_net_set_vnet_endian(vdev, n->nic->ncs,
227                                                             queues, true);
228     } else if (virtio_net_started(n, vdev->status)) {
229         /* After using the device, we need to reset the network backend to
230          * the default (guest native endianness), otherwise the guest may
231          * lose network connectivity if it is rebooted into a different
232          * endianness.
233          */
234         virtio_net_set_vnet_endian(vdev, n->nic->ncs, queues, false);
235     }
236 }
237 
238 static void virtio_net_drop_tx_queue_data(VirtIODevice *vdev, VirtQueue *vq)
239 {
240     unsigned int dropped = virtqueue_drop_all(vq);
241     if (dropped) {
242         virtio_notify(vdev, vq);
243     }
244 }
245 
246 static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
247 {
248     VirtIONet *n = VIRTIO_NET(vdev);
249     VirtIONetQueue *q;
250     int i;
251     uint8_t queue_status;
252 
253     virtio_net_vnet_endian_status(n, status);
254     virtio_net_vhost_status(n, status);
255 
256     for (i = 0; i < n->max_queues; i++) {
257         NetClientState *ncs = qemu_get_subqueue(n->nic, i);
258         bool queue_started;
259         q = &n->vqs[i];
260 
261         if ((!n->multiqueue && i != 0) || i >= n->curr_queues) {
262             queue_status = 0;
263         } else {
264             queue_status = status;
265         }
266         queue_started =
267             virtio_net_started(n, queue_status) && !n->vhost_started;
268 
269         if (queue_started) {
270             qemu_flush_queued_packets(ncs);
271         }
272 
273         if (!q->tx_waiting) {
274             continue;
275         }
276 
277         if (queue_started) {
278             if (q->tx_timer) {
279                 timer_mod(q->tx_timer,
280                                qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
281             } else {
282                 qemu_bh_schedule(q->tx_bh);
283             }
284         } else {
285             if (q->tx_timer) {
286                 timer_del(q->tx_timer);
287             } else {
288                 qemu_bh_cancel(q->tx_bh);
289             }
290             if ((n->status & VIRTIO_NET_S_LINK_UP) == 0 &&
291                 (queue_status & VIRTIO_CONFIG_S_DRIVER_OK) &&
292                 vdev->vm_running) {
293                 /* if tx is waiting we are likely have some packets in tx queue
294                  * and disabled notification */
295                 q->tx_waiting = 0;
296                 virtio_queue_set_notification(q->tx_vq, 1);
297                 virtio_net_drop_tx_queue_data(vdev, q->tx_vq);
298             }
299         }
300     }
301 }
302 
303 static void virtio_net_set_link_status(NetClientState *nc)
304 {
305     VirtIONet *n = qemu_get_nic_opaque(nc);
306     VirtIODevice *vdev = VIRTIO_DEVICE(n);
307     uint16_t old_status = n->status;
308 
309     if (nc->link_down)
310         n->status &= ~VIRTIO_NET_S_LINK_UP;
311     else
312         n->status |= VIRTIO_NET_S_LINK_UP;
313 
314     if (n->status != old_status)
315         virtio_notify_config(vdev);
316 
317     virtio_net_set_status(vdev, vdev->status);
318 }
319 
320 static void rxfilter_notify(NetClientState *nc)
321 {
322     VirtIONet *n = qemu_get_nic_opaque(nc);
323 
324     if (nc->rxfilter_notify_enabled) {
325         gchar *path = object_get_canonical_path(OBJECT(n->qdev));
326         qapi_event_send_nic_rx_filter_changed(!!n->netclient_name,
327                                               n->netclient_name, path, &error_abort);
328         g_free(path);
329 
330         /* disable event notification to avoid events flooding */
331         nc->rxfilter_notify_enabled = 0;
332     }
333 }
334 
335 static intList *get_vlan_table(VirtIONet *n)
336 {
337     intList *list, *entry;
338     int i, j;
339 
340     list = NULL;
341     for (i = 0; i < MAX_VLAN >> 5; i++) {
342         for (j = 0; n->vlans[i] && j <= 0x1f; j++) {
343             if (n->vlans[i] & (1U << j)) {
344                 entry = g_malloc0(sizeof(*entry));
345                 entry->value = (i << 5) + j;
346                 entry->next = list;
347                 list = entry;
348             }
349         }
350     }
351 
352     return list;
353 }
354 
355 static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
356 {
357     VirtIONet *n = qemu_get_nic_opaque(nc);
358     VirtIODevice *vdev = VIRTIO_DEVICE(n);
359     RxFilterInfo *info;
360     strList *str_list, *entry;
361     int i;
362 
363     info = g_malloc0(sizeof(*info));
364     info->name = g_strdup(nc->name);
365     info->promiscuous = n->promisc;
366 
367     if (n->nouni) {
368         info->unicast = RX_STATE_NONE;
369     } else if (n->alluni) {
370         info->unicast = RX_STATE_ALL;
371     } else {
372         info->unicast = RX_STATE_NORMAL;
373     }
374 
375     if (n->nomulti) {
376         info->multicast = RX_STATE_NONE;
377     } else if (n->allmulti) {
378         info->multicast = RX_STATE_ALL;
379     } else {
380         info->multicast = RX_STATE_NORMAL;
381     }
382 
383     info->broadcast_allowed = n->nobcast;
384     info->multicast_overflow = n->mac_table.multi_overflow;
385     info->unicast_overflow = n->mac_table.uni_overflow;
386 
387     info->main_mac = qemu_mac_strdup_printf(n->mac);
388 
389     str_list = NULL;
390     for (i = 0; i < n->mac_table.first_multi; i++) {
391         entry = g_malloc0(sizeof(*entry));
392         entry->value = qemu_mac_strdup_printf(n->mac_table.macs + i * ETH_ALEN);
393         entry->next = str_list;
394         str_list = entry;
395     }
396     info->unicast_table = str_list;
397 
398     str_list = NULL;
399     for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
400         entry = g_malloc0(sizeof(*entry));
401         entry->value = qemu_mac_strdup_printf(n->mac_table.macs + i * ETH_ALEN);
402         entry->next = str_list;
403         str_list = entry;
404     }
405     info->multicast_table = str_list;
406     info->vlan_table = get_vlan_table(n);
407 
408     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VLAN)) {
409         info->vlan = RX_STATE_ALL;
410     } else if (!info->vlan_table) {
411         info->vlan = RX_STATE_NONE;
412     } else {
413         info->vlan = RX_STATE_NORMAL;
414     }
415 
416     /* enable event notification after query */
417     nc->rxfilter_notify_enabled = 1;
418 
419     return info;
420 }
421 
422 static void virtio_net_reset(VirtIODevice *vdev)
423 {
424     VirtIONet *n = VIRTIO_NET(vdev);
425 
426     /* Reset back to compatibility mode */
427     n->promisc = 1;
428     n->allmulti = 0;
429     n->alluni = 0;
430     n->nomulti = 0;
431     n->nouni = 0;
432     n->nobcast = 0;
433     /* multiqueue is disabled by default */
434     n->curr_queues = 1;
435     timer_del(n->announce_timer);
436     n->announce_counter = 0;
437     n->status &= ~VIRTIO_NET_S_ANNOUNCE;
438 
439     /* Flush any MAC and VLAN filter table state */
440     n->mac_table.in_use = 0;
441     n->mac_table.first_multi = 0;
442     n->mac_table.multi_overflow = 0;
443     n->mac_table.uni_overflow = 0;
444     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
445     memcpy(&n->mac[0], &n->nic->conf->macaddr, sizeof(n->mac));
446     qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
447     memset(n->vlans, 0, MAX_VLAN >> 3);
448 }
449 
450 static void peer_test_vnet_hdr(VirtIONet *n)
451 {
452     NetClientState *nc = qemu_get_queue(n->nic);
453     if (!nc->peer) {
454         return;
455     }
456 
457     n->has_vnet_hdr = qemu_has_vnet_hdr(nc->peer);
458 }
459 
460 static int peer_has_vnet_hdr(VirtIONet *n)
461 {
462     return n->has_vnet_hdr;
463 }
464 
465 static int peer_has_ufo(VirtIONet *n)
466 {
467     if (!peer_has_vnet_hdr(n))
468         return 0;
469 
470     n->has_ufo = qemu_has_ufo(qemu_get_queue(n->nic)->peer);
471 
472     return n->has_ufo;
473 }
474 
475 static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs,
476                                        int version_1)
477 {
478     int i;
479     NetClientState *nc;
480 
481     n->mergeable_rx_bufs = mergeable_rx_bufs;
482 
483     if (version_1) {
484         n->guest_hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
485     } else {
486         n->guest_hdr_len = n->mergeable_rx_bufs ?
487             sizeof(struct virtio_net_hdr_mrg_rxbuf) :
488             sizeof(struct virtio_net_hdr);
489     }
490 
491     for (i = 0; i < n->max_queues; i++) {
492         nc = qemu_get_subqueue(n->nic, i);
493 
494         if (peer_has_vnet_hdr(n) &&
495             qemu_has_vnet_hdr_len(nc->peer, n->guest_hdr_len)) {
496             qemu_set_vnet_hdr_len(nc->peer, n->guest_hdr_len);
497             n->host_hdr_len = n->guest_hdr_len;
498         }
499     }
500 }
501 
502 static int virtio_net_max_tx_queue_size(VirtIONet *n)
503 {
504     NetClientState *peer = n->nic_conf.peers.ncs[0];
505 
506     /*
507      * Backends other than vhost-user don't support max queue size.
508      */
509     if (!peer) {
510         return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE;
511     }
512 
513     if (peer->info->type != NET_CLIENT_DRIVER_VHOST_USER) {
514         return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE;
515     }
516 
517     return VIRTQUEUE_MAX_SIZE;
518 }
519 
520 static int peer_attach(VirtIONet *n, int index)
521 {
522     NetClientState *nc = qemu_get_subqueue(n->nic, index);
523 
524     if (!nc->peer) {
525         return 0;
526     }
527 
528     if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
529         vhost_set_vring_enable(nc->peer, 1);
530     }
531 
532     if (nc->peer->info->type != NET_CLIENT_DRIVER_TAP) {
533         return 0;
534     }
535 
536     if (n->max_queues == 1) {
537         return 0;
538     }
539 
540     return tap_enable(nc->peer);
541 }
542 
543 static int peer_detach(VirtIONet *n, int index)
544 {
545     NetClientState *nc = qemu_get_subqueue(n->nic, index);
546 
547     if (!nc->peer) {
548         return 0;
549     }
550 
551     if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
552         vhost_set_vring_enable(nc->peer, 0);
553     }
554 
555     if (nc->peer->info->type !=  NET_CLIENT_DRIVER_TAP) {
556         return 0;
557     }
558 
559     return tap_disable(nc->peer);
560 }
561 
562 static void virtio_net_set_queues(VirtIONet *n)
563 {
564     int i;
565     int r;
566 
567     if (n->nic->peer_deleted) {
568         return;
569     }
570 
571     for (i = 0; i < n->max_queues; i++) {
572         if (i < n->curr_queues) {
573             r = peer_attach(n, i);
574             assert(!r);
575         } else {
576             r = peer_detach(n, i);
577             assert(!r);
578         }
579     }
580 }
581 
582 static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue);
583 
584 static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
585                                         Error **errp)
586 {
587     VirtIONet *n = VIRTIO_NET(vdev);
588     NetClientState *nc = qemu_get_queue(n->nic);
589 
590     /* Firstly sync all virtio-net possible supported features */
591     features |= n->host_features;
592 
593     virtio_add_feature(&features, VIRTIO_NET_F_MAC);
594 
595     if (!peer_has_vnet_hdr(n)) {
596         virtio_clear_feature(&features, VIRTIO_NET_F_CSUM);
597         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_TSO4);
598         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_TSO6);
599         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_ECN);
600 
601         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_CSUM);
602         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO4);
603         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO6);
604         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ECN);
605     }
606 
607     if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
608         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_UFO);
609         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO);
610     }
611 
612     if (!get_vhost_net(nc->peer)) {
613         return features;
614     }
615     features = vhost_net_get_features(get_vhost_net(nc->peer), features);
616     vdev->backend_features = features;
617 
618     if (n->mtu_bypass_backend &&
619             (n->host_features & 1ULL << VIRTIO_NET_F_MTU)) {
620         features |= (1ULL << VIRTIO_NET_F_MTU);
621     }
622 
623     return features;
624 }
625 
626 static uint64_t virtio_net_bad_features(VirtIODevice *vdev)
627 {
628     uint64_t features = 0;
629 
630     /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
631      * but also these: */
632     virtio_add_feature(&features, VIRTIO_NET_F_MAC);
633     virtio_add_feature(&features, VIRTIO_NET_F_CSUM);
634     virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO4);
635     virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO6);
636     virtio_add_feature(&features, VIRTIO_NET_F_HOST_ECN);
637 
638     return features;
639 }
640 
641 static void virtio_net_apply_guest_offloads(VirtIONet *n)
642 {
643     qemu_set_offload(qemu_get_queue(n->nic)->peer,
644             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_CSUM)),
645             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO4)),
646             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO6)),
647             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_ECN)),
648             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_UFO)));
649 }
650 
651 static uint64_t virtio_net_guest_offloads_by_features(uint32_t features)
652 {
653     static const uint64_t guest_offloads_mask =
654         (1ULL << VIRTIO_NET_F_GUEST_CSUM) |
655         (1ULL << VIRTIO_NET_F_GUEST_TSO4) |
656         (1ULL << VIRTIO_NET_F_GUEST_TSO6) |
657         (1ULL << VIRTIO_NET_F_GUEST_ECN)  |
658         (1ULL << VIRTIO_NET_F_GUEST_UFO);
659 
660     return guest_offloads_mask & features;
661 }
662 
663 static inline uint64_t virtio_net_supported_guest_offloads(VirtIONet *n)
664 {
665     VirtIODevice *vdev = VIRTIO_DEVICE(n);
666     return virtio_net_guest_offloads_by_features(vdev->guest_features);
667 }
668 
669 static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features)
670 {
671     VirtIONet *n = VIRTIO_NET(vdev);
672     int i;
673 
674     if (n->mtu_bypass_backend &&
675             !virtio_has_feature(vdev->backend_features, VIRTIO_NET_F_MTU)) {
676         features &= ~(1ULL << VIRTIO_NET_F_MTU);
677     }
678 
679     virtio_net_set_multiqueue(n,
680                               virtio_has_feature(features, VIRTIO_NET_F_MQ));
681 
682     virtio_net_set_mrg_rx_bufs(n,
683                                virtio_has_feature(features,
684                                                   VIRTIO_NET_F_MRG_RXBUF),
685                                virtio_has_feature(features,
686                                                   VIRTIO_F_VERSION_1));
687 
688     if (n->has_vnet_hdr) {
689         n->curr_guest_offloads =
690             virtio_net_guest_offloads_by_features(features);
691         virtio_net_apply_guest_offloads(n);
692     }
693 
694     for (i = 0;  i < n->max_queues; i++) {
695         NetClientState *nc = qemu_get_subqueue(n->nic, i);
696 
697         if (!get_vhost_net(nc->peer)) {
698             continue;
699         }
700         vhost_net_ack_features(get_vhost_net(nc->peer), features);
701     }
702 
703     if (virtio_has_feature(features, VIRTIO_NET_F_CTRL_VLAN)) {
704         memset(n->vlans, 0, MAX_VLAN >> 3);
705     } else {
706         memset(n->vlans, 0xff, MAX_VLAN >> 3);
707     }
708 }
709 
710 static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
711                                      struct iovec *iov, unsigned int iov_cnt)
712 {
713     uint8_t on;
714     size_t s;
715     NetClientState *nc = qemu_get_queue(n->nic);
716 
717     s = iov_to_buf(iov, iov_cnt, 0, &on, sizeof(on));
718     if (s != sizeof(on)) {
719         return VIRTIO_NET_ERR;
720     }
721 
722     if (cmd == VIRTIO_NET_CTRL_RX_PROMISC) {
723         n->promisc = on;
724     } else if (cmd == VIRTIO_NET_CTRL_RX_ALLMULTI) {
725         n->allmulti = on;
726     } else if (cmd == VIRTIO_NET_CTRL_RX_ALLUNI) {
727         n->alluni = on;
728     } else if (cmd == VIRTIO_NET_CTRL_RX_NOMULTI) {
729         n->nomulti = on;
730     } else if (cmd == VIRTIO_NET_CTRL_RX_NOUNI) {
731         n->nouni = on;
732     } else if (cmd == VIRTIO_NET_CTRL_RX_NOBCAST) {
733         n->nobcast = on;
734     } else {
735         return VIRTIO_NET_ERR;
736     }
737 
738     rxfilter_notify(nc);
739 
740     return VIRTIO_NET_OK;
741 }
742 
743 static int virtio_net_handle_offloads(VirtIONet *n, uint8_t cmd,
744                                      struct iovec *iov, unsigned int iov_cnt)
745 {
746     VirtIODevice *vdev = VIRTIO_DEVICE(n);
747     uint64_t offloads;
748     size_t s;
749 
750     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
751         return VIRTIO_NET_ERR;
752     }
753 
754     s = iov_to_buf(iov, iov_cnt, 0, &offloads, sizeof(offloads));
755     if (s != sizeof(offloads)) {
756         return VIRTIO_NET_ERR;
757     }
758 
759     if (cmd == VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET) {
760         uint64_t supported_offloads;
761 
762         offloads = virtio_ldq_p(vdev, &offloads);
763 
764         if (!n->has_vnet_hdr) {
765             return VIRTIO_NET_ERR;
766         }
767 
768         supported_offloads = virtio_net_supported_guest_offloads(n);
769         if (offloads & ~supported_offloads) {
770             return VIRTIO_NET_ERR;
771         }
772 
773         n->curr_guest_offloads = offloads;
774         virtio_net_apply_guest_offloads(n);
775 
776         return VIRTIO_NET_OK;
777     } else {
778         return VIRTIO_NET_ERR;
779     }
780 }
781 
782 static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
783                                  struct iovec *iov, unsigned int iov_cnt)
784 {
785     VirtIODevice *vdev = VIRTIO_DEVICE(n);
786     struct virtio_net_ctrl_mac mac_data;
787     size_t s;
788     NetClientState *nc = qemu_get_queue(n->nic);
789 
790     if (cmd == VIRTIO_NET_CTRL_MAC_ADDR_SET) {
791         if (iov_size(iov, iov_cnt) != sizeof(n->mac)) {
792             return VIRTIO_NET_ERR;
793         }
794         s = iov_to_buf(iov, iov_cnt, 0, &n->mac, sizeof(n->mac));
795         assert(s == sizeof(n->mac));
796         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
797         rxfilter_notify(nc);
798 
799         return VIRTIO_NET_OK;
800     }
801 
802     if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET) {
803         return VIRTIO_NET_ERR;
804     }
805 
806     int in_use = 0;
807     int first_multi = 0;
808     uint8_t uni_overflow = 0;
809     uint8_t multi_overflow = 0;
810     uint8_t *macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
811 
812     s = iov_to_buf(iov, iov_cnt, 0, &mac_data.entries,
813                    sizeof(mac_data.entries));
814     mac_data.entries = virtio_ldl_p(vdev, &mac_data.entries);
815     if (s != sizeof(mac_data.entries)) {
816         goto error;
817     }
818     iov_discard_front(&iov, &iov_cnt, s);
819 
820     if (mac_data.entries * ETH_ALEN > iov_size(iov, iov_cnt)) {
821         goto error;
822     }
823 
824     if (mac_data.entries <= MAC_TABLE_ENTRIES) {
825         s = iov_to_buf(iov, iov_cnt, 0, macs,
826                        mac_data.entries * ETH_ALEN);
827         if (s != mac_data.entries * ETH_ALEN) {
828             goto error;
829         }
830         in_use += mac_data.entries;
831     } else {
832         uni_overflow = 1;
833     }
834 
835     iov_discard_front(&iov, &iov_cnt, mac_data.entries * ETH_ALEN);
836 
837     first_multi = in_use;
838 
839     s = iov_to_buf(iov, iov_cnt, 0, &mac_data.entries,
840                    sizeof(mac_data.entries));
841     mac_data.entries = virtio_ldl_p(vdev, &mac_data.entries);
842     if (s != sizeof(mac_data.entries)) {
843         goto error;
844     }
845 
846     iov_discard_front(&iov, &iov_cnt, s);
847 
848     if (mac_data.entries * ETH_ALEN != iov_size(iov, iov_cnt)) {
849         goto error;
850     }
851 
852     if (mac_data.entries <= MAC_TABLE_ENTRIES - in_use) {
853         s = iov_to_buf(iov, iov_cnt, 0, &macs[in_use * ETH_ALEN],
854                        mac_data.entries * ETH_ALEN);
855         if (s != mac_data.entries * ETH_ALEN) {
856             goto error;
857         }
858         in_use += mac_data.entries;
859     } else {
860         multi_overflow = 1;
861     }
862 
863     n->mac_table.in_use = in_use;
864     n->mac_table.first_multi = first_multi;
865     n->mac_table.uni_overflow = uni_overflow;
866     n->mac_table.multi_overflow = multi_overflow;
867     memcpy(n->mac_table.macs, macs, MAC_TABLE_ENTRIES * ETH_ALEN);
868     g_free(macs);
869     rxfilter_notify(nc);
870 
871     return VIRTIO_NET_OK;
872 
873 error:
874     g_free(macs);
875     return VIRTIO_NET_ERR;
876 }
877 
878 static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
879                                         struct iovec *iov, unsigned int iov_cnt)
880 {
881     VirtIODevice *vdev = VIRTIO_DEVICE(n);
882     uint16_t vid;
883     size_t s;
884     NetClientState *nc = qemu_get_queue(n->nic);
885 
886     s = iov_to_buf(iov, iov_cnt, 0, &vid, sizeof(vid));
887     vid = virtio_lduw_p(vdev, &vid);
888     if (s != sizeof(vid)) {
889         return VIRTIO_NET_ERR;
890     }
891 
892     if (vid >= MAX_VLAN)
893         return VIRTIO_NET_ERR;
894 
895     if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
896         n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
897     else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
898         n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
899     else
900         return VIRTIO_NET_ERR;
901 
902     rxfilter_notify(nc);
903 
904     return VIRTIO_NET_OK;
905 }
906 
907 static int virtio_net_handle_announce(VirtIONet *n, uint8_t cmd,
908                                       struct iovec *iov, unsigned int iov_cnt)
909 {
910     if (cmd == VIRTIO_NET_CTRL_ANNOUNCE_ACK &&
911         n->status & VIRTIO_NET_S_ANNOUNCE) {
912         n->status &= ~VIRTIO_NET_S_ANNOUNCE;
913         if (n->announce_counter) {
914             timer_mod(n->announce_timer,
915                       qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
916                       self_announce_delay(n->announce_counter));
917         }
918         return VIRTIO_NET_OK;
919     } else {
920         return VIRTIO_NET_ERR;
921     }
922 }
923 
924 static int virtio_net_handle_mq(VirtIONet *n, uint8_t cmd,
925                                 struct iovec *iov, unsigned int iov_cnt)
926 {
927     VirtIODevice *vdev = VIRTIO_DEVICE(n);
928     struct virtio_net_ctrl_mq mq;
929     size_t s;
930     uint16_t queues;
931 
932     s = iov_to_buf(iov, iov_cnt, 0, &mq, sizeof(mq));
933     if (s != sizeof(mq)) {
934         return VIRTIO_NET_ERR;
935     }
936 
937     if (cmd != VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
938         return VIRTIO_NET_ERR;
939     }
940 
941     queues = virtio_lduw_p(vdev, &mq.virtqueue_pairs);
942 
943     if (queues < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
944         queues > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
945         queues > n->max_queues ||
946         !n->multiqueue) {
947         return VIRTIO_NET_ERR;
948     }
949 
950     n->curr_queues = queues;
951     /* stop the backend before changing the number of queues to avoid handling a
952      * disabled queue */
953     virtio_net_set_status(vdev, vdev->status);
954     virtio_net_set_queues(n);
955 
956     return VIRTIO_NET_OK;
957 }
958 
959 static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
960 {
961     VirtIONet *n = VIRTIO_NET(vdev);
962     struct virtio_net_ctrl_hdr ctrl;
963     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
964     VirtQueueElement *elem;
965     size_t s;
966     struct iovec *iov, *iov2;
967     unsigned int iov_cnt;
968 
969     for (;;) {
970         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
971         if (!elem) {
972             break;
973         }
974         if (iov_size(elem->in_sg, elem->in_num) < sizeof(status) ||
975             iov_size(elem->out_sg, elem->out_num) < sizeof(ctrl)) {
976             virtio_error(vdev, "virtio-net ctrl missing headers");
977             virtqueue_detach_element(vq, elem, 0);
978             g_free(elem);
979             break;
980         }
981 
982         iov_cnt = elem->out_num;
983         iov2 = iov = g_memdup(elem->out_sg, sizeof(struct iovec) * elem->out_num);
984         s = iov_to_buf(iov, iov_cnt, 0, &ctrl, sizeof(ctrl));
985         iov_discard_front(&iov, &iov_cnt, sizeof(ctrl));
986         if (s != sizeof(ctrl)) {
987             status = VIRTIO_NET_ERR;
988         } else if (ctrl.class == VIRTIO_NET_CTRL_RX) {
989             status = virtio_net_handle_rx_mode(n, ctrl.cmd, iov, iov_cnt);
990         } else if (ctrl.class == VIRTIO_NET_CTRL_MAC) {
991             status = virtio_net_handle_mac(n, ctrl.cmd, iov, iov_cnt);
992         } else if (ctrl.class == VIRTIO_NET_CTRL_VLAN) {
993             status = virtio_net_handle_vlan_table(n, ctrl.cmd, iov, iov_cnt);
994         } else if (ctrl.class == VIRTIO_NET_CTRL_ANNOUNCE) {
995             status = virtio_net_handle_announce(n, ctrl.cmd, iov, iov_cnt);
996         } else if (ctrl.class == VIRTIO_NET_CTRL_MQ) {
997             status = virtio_net_handle_mq(n, ctrl.cmd, iov, iov_cnt);
998         } else if (ctrl.class == VIRTIO_NET_CTRL_GUEST_OFFLOADS) {
999             status = virtio_net_handle_offloads(n, ctrl.cmd, iov, iov_cnt);
1000         }
1001 
1002         s = iov_from_buf(elem->in_sg, elem->in_num, 0, &status, sizeof(status));
1003         assert(s == sizeof(status));
1004 
1005         virtqueue_push(vq, elem, sizeof(status));
1006         virtio_notify(vdev, vq);
1007         g_free(iov2);
1008         g_free(elem);
1009     }
1010 }
1011 
1012 /* RX */
1013 
1014 static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
1015 {
1016     VirtIONet *n = VIRTIO_NET(vdev);
1017     int queue_index = vq2q(virtio_get_queue_index(vq));
1018 
1019     qemu_flush_queued_packets(qemu_get_subqueue(n->nic, queue_index));
1020 }
1021 
1022 static int virtio_net_can_receive(NetClientState *nc)
1023 {
1024     VirtIONet *n = qemu_get_nic_opaque(nc);
1025     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1026     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
1027 
1028     if (!vdev->vm_running) {
1029         return 0;
1030     }
1031 
1032     if (nc->queue_index >= n->curr_queues) {
1033         return 0;
1034     }
1035 
1036     if (!virtio_queue_ready(q->rx_vq) ||
1037         !(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
1038         return 0;
1039     }
1040 
1041     return 1;
1042 }
1043 
1044 static int virtio_net_has_buffers(VirtIONetQueue *q, int bufsize)
1045 {
1046     VirtIONet *n = q->n;
1047     if (virtio_queue_empty(q->rx_vq) ||
1048         (n->mergeable_rx_bufs &&
1049          !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
1050         virtio_queue_set_notification(q->rx_vq, 1);
1051 
1052         /* To avoid a race condition where the guest has made some buffers
1053          * available after the above check but before notification was
1054          * enabled, check for available buffers again.
1055          */
1056         if (virtio_queue_empty(q->rx_vq) ||
1057             (n->mergeable_rx_bufs &&
1058              !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
1059             return 0;
1060         }
1061     }
1062 
1063     virtio_queue_set_notification(q->rx_vq, 0);
1064     return 1;
1065 }
1066 
1067 static void virtio_net_hdr_swap(VirtIODevice *vdev, struct virtio_net_hdr *hdr)
1068 {
1069     virtio_tswap16s(vdev, &hdr->hdr_len);
1070     virtio_tswap16s(vdev, &hdr->gso_size);
1071     virtio_tswap16s(vdev, &hdr->csum_start);
1072     virtio_tswap16s(vdev, &hdr->csum_offset);
1073 }
1074 
1075 /* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
1076  * it never finds out that the packets don't have valid checksums.  This
1077  * causes dhclient to get upset.  Fedora's carried a patch for ages to
1078  * fix this with Xen but it hasn't appeared in an upstream release of
1079  * dhclient yet.
1080  *
1081  * To avoid breaking existing guests, we catch udp packets and add
1082  * checksums.  This is terrible but it's better than hacking the guest
1083  * kernels.
1084  *
1085  * N.B. if we introduce a zero-copy API, this operation is no longer free so
1086  * we should provide a mechanism to disable it to avoid polluting the host
1087  * cache.
1088  */
1089 static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
1090                                         uint8_t *buf, size_t size)
1091 {
1092     if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
1093         (size > 27 && size < 1500) && /* normal sized MTU */
1094         (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
1095         (buf[23] == 17) && /* ip.protocol == UDP */
1096         (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
1097         net_checksum_calculate(buf, size);
1098         hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
1099     }
1100 }
1101 
1102 static void receive_header(VirtIONet *n, const struct iovec *iov, int iov_cnt,
1103                            const void *buf, size_t size)
1104 {
1105     if (n->has_vnet_hdr) {
1106         /* FIXME this cast is evil */
1107         void *wbuf = (void *)buf;
1108         work_around_broken_dhclient(wbuf, wbuf + n->host_hdr_len,
1109                                     size - n->host_hdr_len);
1110 
1111         if (n->needs_vnet_hdr_swap) {
1112             virtio_net_hdr_swap(VIRTIO_DEVICE(n), wbuf);
1113         }
1114         iov_from_buf(iov, iov_cnt, 0, buf, sizeof(struct virtio_net_hdr));
1115     } else {
1116         struct virtio_net_hdr hdr = {
1117             .flags = 0,
1118             .gso_type = VIRTIO_NET_HDR_GSO_NONE
1119         };
1120         iov_from_buf(iov, iov_cnt, 0, &hdr, sizeof hdr);
1121     }
1122 }
1123 
1124 static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
1125 {
1126     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1127     static const uint8_t vlan[] = {0x81, 0x00};
1128     uint8_t *ptr = (uint8_t *)buf;
1129     int i;
1130 
1131     if (n->promisc)
1132         return 1;
1133 
1134     ptr += n->host_hdr_len;
1135 
1136     if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
1137         int vid = lduw_be_p(ptr + 14) & 0xfff;
1138         if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
1139             return 0;
1140     }
1141 
1142     if (ptr[0] & 1) { // multicast
1143         if (!memcmp(ptr, bcast, sizeof(bcast))) {
1144             return !n->nobcast;
1145         } else if (n->nomulti) {
1146             return 0;
1147         } else if (n->allmulti || n->mac_table.multi_overflow) {
1148             return 1;
1149         }
1150 
1151         for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
1152             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
1153                 return 1;
1154             }
1155         }
1156     } else { // unicast
1157         if (n->nouni) {
1158             return 0;
1159         } else if (n->alluni || n->mac_table.uni_overflow) {
1160             return 1;
1161         } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
1162             return 1;
1163         }
1164 
1165         for (i = 0; i < n->mac_table.first_multi; i++) {
1166             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
1167                 return 1;
1168             }
1169         }
1170     }
1171 
1172     return 0;
1173 }
1174 
1175 static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
1176                                       size_t size)
1177 {
1178     VirtIONet *n = qemu_get_nic_opaque(nc);
1179     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
1180     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1181     struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE];
1182     struct virtio_net_hdr_mrg_rxbuf mhdr;
1183     unsigned mhdr_cnt = 0;
1184     size_t offset, i, guest_offset;
1185 
1186     if (!virtio_net_can_receive(nc)) {
1187         return -1;
1188     }
1189 
1190     /* hdr_len refers to the header we supply to the guest */
1191     if (!virtio_net_has_buffers(q, size + n->guest_hdr_len - n->host_hdr_len)) {
1192         return 0;
1193     }
1194 
1195     if (!receive_filter(n, buf, size))
1196         return size;
1197 
1198     offset = i = 0;
1199 
1200     while (offset < size) {
1201         VirtQueueElement *elem;
1202         int len, total;
1203         const struct iovec *sg;
1204 
1205         total = 0;
1206 
1207         elem = virtqueue_pop(q->rx_vq, sizeof(VirtQueueElement));
1208         if (!elem) {
1209             if (i) {
1210                 virtio_error(vdev, "virtio-net unexpected empty queue: "
1211                              "i %zd mergeable %d offset %zd, size %zd, "
1212                              "guest hdr len %zd, host hdr len %zd "
1213                              "guest features 0x%" PRIx64,
1214                              i, n->mergeable_rx_bufs, offset, size,
1215                              n->guest_hdr_len, n->host_hdr_len,
1216                              vdev->guest_features);
1217             }
1218             return -1;
1219         }
1220 
1221         if (elem->in_num < 1) {
1222             virtio_error(vdev,
1223                          "virtio-net receive queue contains no in buffers");
1224             virtqueue_detach_element(q->rx_vq, elem, 0);
1225             g_free(elem);
1226             return -1;
1227         }
1228 
1229         sg = elem->in_sg;
1230         if (i == 0) {
1231             assert(offset == 0);
1232             if (n->mergeable_rx_bufs) {
1233                 mhdr_cnt = iov_copy(mhdr_sg, ARRAY_SIZE(mhdr_sg),
1234                                     sg, elem->in_num,
1235                                     offsetof(typeof(mhdr), num_buffers),
1236                                     sizeof(mhdr.num_buffers));
1237             }
1238 
1239             receive_header(n, sg, elem->in_num, buf, size);
1240             offset = n->host_hdr_len;
1241             total += n->guest_hdr_len;
1242             guest_offset = n->guest_hdr_len;
1243         } else {
1244             guest_offset = 0;
1245         }
1246 
1247         /* copy in packet.  ugh */
1248         len = iov_from_buf(sg, elem->in_num, guest_offset,
1249                            buf + offset, size - offset);
1250         total += len;
1251         offset += len;
1252         /* If buffers can't be merged, at this point we
1253          * must have consumed the complete packet.
1254          * Otherwise, drop it. */
1255         if (!n->mergeable_rx_bufs && offset < size) {
1256             virtqueue_unpop(q->rx_vq, elem, total);
1257             g_free(elem);
1258             return size;
1259         }
1260 
1261         /* signal other side */
1262         virtqueue_fill(q->rx_vq, elem, total, i++);
1263         g_free(elem);
1264     }
1265 
1266     if (mhdr_cnt) {
1267         virtio_stw_p(vdev, &mhdr.num_buffers, i);
1268         iov_from_buf(mhdr_sg, mhdr_cnt,
1269                      0,
1270                      &mhdr.num_buffers, sizeof mhdr.num_buffers);
1271     }
1272 
1273     virtqueue_flush(q->rx_vq, i);
1274     virtio_notify(vdev, q->rx_vq);
1275 
1276     return size;
1277 }
1278 
1279 static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf,
1280                                   size_t size)
1281 {
1282     ssize_t r;
1283 
1284     rcu_read_lock();
1285     r = virtio_net_receive_rcu(nc, buf, size);
1286     rcu_read_unlock();
1287     return r;
1288 }
1289 
1290 static int32_t virtio_net_flush_tx(VirtIONetQueue *q);
1291 
1292 static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
1293 {
1294     VirtIONet *n = qemu_get_nic_opaque(nc);
1295     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
1296     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1297 
1298     virtqueue_push(q->tx_vq, q->async_tx.elem, 0);
1299     virtio_notify(vdev, q->tx_vq);
1300 
1301     g_free(q->async_tx.elem);
1302     q->async_tx.elem = NULL;
1303 
1304     virtio_queue_set_notification(q->tx_vq, 1);
1305     virtio_net_flush_tx(q);
1306 }
1307 
1308 /* TX */
1309 static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
1310 {
1311     VirtIONet *n = q->n;
1312     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1313     VirtQueueElement *elem;
1314     int32_t num_packets = 0;
1315     int queue_index = vq2q(virtio_get_queue_index(q->tx_vq));
1316     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
1317         return num_packets;
1318     }
1319 
1320     if (q->async_tx.elem) {
1321         virtio_queue_set_notification(q->tx_vq, 0);
1322         return num_packets;
1323     }
1324 
1325     for (;;) {
1326         ssize_t ret;
1327         unsigned int out_num;
1328         struct iovec sg[VIRTQUEUE_MAX_SIZE], sg2[VIRTQUEUE_MAX_SIZE + 1], *out_sg;
1329         struct virtio_net_hdr_mrg_rxbuf mhdr;
1330 
1331         elem = virtqueue_pop(q->tx_vq, sizeof(VirtQueueElement));
1332         if (!elem) {
1333             break;
1334         }
1335 
1336         out_num = elem->out_num;
1337         out_sg = elem->out_sg;
1338         if (out_num < 1) {
1339             virtio_error(vdev, "virtio-net header not in first element");
1340             virtqueue_detach_element(q->tx_vq, elem, 0);
1341             g_free(elem);
1342             return -EINVAL;
1343         }
1344 
1345         if (n->has_vnet_hdr) {
1346             if (iov_to_buf(out_sg, out_num, 0, &mhdr, n->guest_hdr_len) <
1347                 n->guest_hdr_len) {
1348                 virtio_error(vdev, "virtio-net header incorrect");
1349                 virtqueue_detach_element(q->tx_vq, elem, 0);
1350                 g_free(elem);
1351                 return -EINVAL;
1352             }
1353             if (n->needs_vnet_hdr_swap) {
1354                 virtio_net_hdr_swap(vdev, (void *) &mhdr);
1355                 sg2[0].iov_base = &mhdr;
1356                 sg2[0].iov_len = n->guest_hdr_len;
1357                 out_num = iov_copy(&sg2[1], ARRAY_SIZE(sg2) - 1,
1358                                    out_sg, out_num,
1359                                    n->guest_hdr_len, -1);
1360                 if (out_num == VIRTQUEUE_MAX_SIZE) {
1361                     goto drop;
1362 		}
1363                 out_num += 1;
1364                 out_sg = sg2;
1365 	    }
1366         }
1367         /*
1368          * If host wants to see the guest header as is, we can
1369          * pass it on unchanged. Otherwise, copy just the parts
1370          * that host is interested in.
1371          */
1372         assert(n->host_hdr_len <= n->guest_hdr_len);
1373         if (n->host_hdr_len != n->guest_hdr_len) {
1374             unsigned sg_num = iov_copy(sg, ARRAY_SIZE(sg),
1375                                        out_sg, out_num,
1376                                        0, n->host_hdr_len);
1377             sg_num += iov_copy(sg + sg_num, ARRAY_SIZE(sg) - sg_num,
1378                              out_sg, out_num,
1379                              n->guest_hdr_len, -1);
1380             out_num = sg_num;
1381             out_sg = sg;
1382         }
1383 
1384         ret = qemu_sendv_packet_async(qemu_get_subqueue(n->nic, queue_index),
1385                                       out_sg, out_num, virtio_net_tx_complete);
1386         if (ret == 0) {
1387             virtio_queue_set_notification(q->tx_vq, 0);
1388             q->async_tx.elem = elem;
1389             return -EBUSY;
1390         }
1391 
1392 drop:
1393         virtqueue_push(q->tx_vq, elem, 0);
1394         virtio_notify(vdev, q->tx_vq);
1395         g_free(elem);
1396 
1397         if (++num_packets >= n->tx_burst) {
1398             break;
1399         }
1400     }
1401     return num_packets;
1402 }
1403 
1404 static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
1405 {
1406     VirtIONet *n = VIRTIO_NET(vdev);
1407     VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
1408 
1409     if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) {
1410         virtio_net_drop_tx_queue_data(vdev, vq);
1411         return;
1412     }
1413 
1414     /* This happens when device was stopped but VCPU wasn't. */
1415     if (!vdev->vm_running) {
1416         q->tx_waiting = 1;
1417         return;
1418     }
1419 
1420     if (q->tx_waiting) {
1421         virtio_queue_set_notification(vq, 1);
1422         timer_del(q->tx_timer);
1423         q->tx_waiting = 0;
1424         if (virtio_net_flush_tx(q) == -EINVAL) {
1425             return;
1426         }
1427     } else {
1428         timer_mod(q->tx_timer,
1429                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
1430         q->tx_waiting = 1;
1431         virtio_queue_set_notification(vq, 0);
1432     }
1433 }
1434 
1435 static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
1436 {
1437     VirtIONet *n = VIRTIO_NET(vdev);
1438     VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
1439 
1440     if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) {
1441         virtio_net_drop_tx_queue_data(vdev, vq);
1442         return;
1443     }
1444 
1445     if (unlikely(q->tx_waiting)) {
1446         return;
1447     }
1448     q->tx_waiting = 1;
1449     /* This happens when device was stopped but VCPU wasn't. */
1450     if (!vdev->vm_running) {
1451         return;
1452     }
1453     virtio_queue_set_notification(vq, 0);
1454     qemu_bh_schedule(q->tx_bh);
1455 }
1456 
1457 static void virtio_net_tx_timer(void *opaque)
1458 {
1459     VirtIONetQueue *q = opaque;
1460     VirtIONet *n = q->n;
1461     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1462     /* This happens when device was stopped but BH wasn't. */
1463     if (!vdev->vm_running) {
1464         /* Make sure tx waiting is set, so we'll run when restarted. */
1465         assert(q->tx_waiting);
1466         return;
1467     }
1468 
1469     q->tx_waiting = 0;
1470 
1471     /* Just in case the driver is not ready on more */
1472     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
1473         return;
1474     }
1475 
1476     virtio_queue_set_notification(q->tx_vq, 1);
1477     virtio_net_flush_tx(q);
1478 }
1479 
1480 static void virtio_net_tx_bh(void *opaque)
1481 {
1482     VirtIONetQueue *q = opaque;
1483     VirtIONet *n = q->n;
1484     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1485     int32_t ret;
1486 
1487     /* This happens when device was stopped but BH wasn't. */
1488     if (!vdev->vm_running) {
1489         /* Make sure tx waiting is set, so we'll run when restarted. */
1490         assert(q->tx_waiting);
1491         return;
1492     }
1493 
1494     q->tx_waiting = 0;
1495 
1496     /* Just in case the driver is not ready on more */
1497     if (unlikely(!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK))) {
1498         return;
1499     }
1500 
1501     ret = virtio_net_flush_tx(q);
1502     if (ret == -EBUSY || ret == -EINVAL) {
1503         return; /* Notification re-enable handled by tx_complete or device
1504                  * broken */
1505     }
1506 
1507     /* If we flush a full burst of packets, assume there are
1508      * more coming and immediately reschedule */
1509     if (ret >= n->tx_burst) {
1510         qemu_bh_schedule(q->tx_bh);
1511         q->tx_waiting = 1;
1512         return;
1513     }
1514 
1515     /* If less than a full burst, re-enable notification and flush
1516      * anything that may have come in while we weren't looking.  If
1517      * we find something, assume the guest is still active and reschedule */
1518     virtio_queue_set_notification(q->tx_vq, 1);
1519     ret = virtio_net_flush_tx(q);
1520     if (ret == -EINVAL) {
1521         return;
1522     } else if (ret > 0) {
1523         virtio_queue_set_notification(q->tx_vq, 0);
1524         qemu_bh_schedule(q->tx_bh);
1525         q->tx_waiting = 1;
1526     }
1527 }
1528 
1529 static void virtio_net_add_queue(VirtIONet *n, int index)
1530 {
1531     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1532 
1533     n->vqs[index].rx_vq = virtio_add_queue(vdev, n->net_conf.rx_queue_size,
1534                                            virtio_net_handle_rx);
1535 
1536     if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
1537         n->vqs[index].tx_vq =
1538             virtio_add_queue(vdev, n->net_conf.tx_queue_size,
1539                              virtio_net_handle_tx_timer);
1540         n->vqs[index].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
1541                                               virtio_net_tx_timer,
1542                                               &n->vqs[index]);
1543     } else {
1544         n->vqs[index].tx_vq =
1545             virtio_add_queue(vdev, n->net_conf.tx_queue_size,
1546                              virtio_net_handle_tx_bh);
1547         n->vqs[index].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[index]);
1548     }
1549 
1550     n->vqs[index].tx_waiting = 0;
1551     n->vqs[index].n = n;
1552 }
1553 
1554 static void virtio_net_del_queue(VirtIONet *n, int index)
1555 {
1556     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1557     VirtIONetQueue *q = &n->vqs[index];
1558     NetClientState *nc = qemu_get_subqueue(n->nic, index);
1559 
1560     qemu_purge_queued_packets(nc);
1561 
1562     virtio_del_queue(vdev, index * 2);
1563     if (q->tx_timer) {
1564         timer_del(q->tx_timer);
1565         timer_free(q->tx_timer);
1566         q->tx_timer = NULL;
1567     } else {
1568         qemu_bh_delete(q->tx_bh);
1569         q->tx_bh = NULL;
1570     }
1571     q->tx_waiting = 0;
1572     virtio_del_queue(vdev, index * 2 + 1);
1573 }
1574 
1575 static void virtio_net_change_num_queues(VirtIONet *n, int new_max_queues)
1576 {
1577     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1578     int old_num_queues = virtio_get_num_queues(vdev);
1579     int new_num_queues = new_max_queues * 2 + 1;
1580     int i;
1581 
1582     assert(old_num_queues >= 3);
1583     assert(old_num_queues % 2 == 1);
1584 
1585     if (old_num_queues == new_num_queues) {
1586         return;
1587     }
1588 
1589     /*
1590      * We always need to remove and add ctrl vq if
1591      * old_num_queues != new_num_queues. Remove ctrl_vq first,
1592      * and then we only enter one of the following too loops.
1593      */
1594     virtio_del_queue(vdev, old_num_queues - 1);
1595 
1596     for (i = new_num_queues - 1; i < old_num_queues - 1; i += 2) {
1597         /* new_num_queues < old_num_queues */
1598         virtio_net_del_queue(n, i / 2);
1599     }
1600 
1601     for (i = old_num_queues - 1; i < new_num_queues - 1; i += 2) {
1602         /* new_num_queues > old_num_queues */
1603         virtio_net_add_queue(n, i / 2);
1604     }
1605 
1606     /* add ctrl_vq last */
1607     n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
1608 }
1609 
1610 static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue)
1611 {
1612     int max = multiqueue ? n->max_queues : 1;
1613 
1614     n->multiqueue = multiqueue;
1615     virtio_net_change_num_queues(n, max);
1616 
1617     virtio_net_set_queues(n);
1618 }
1619 
1620 static int virtio_net_post_load_device(void *opaque, int version_id)
1621 {
1622     VirtIONet *n = opaque;
1623     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1624     int i, link_down;
1625 
1626     virtio_net_set_mrg_rx_bufs(n, n->mergeable_rx_bufs,
1627                                virtio_vdev_has_feature(vdev,
1628                                                        VIRTIO_F_VERSION_1));
1629 
1630     /* MAC_TABLE_ENTRIES may be different from the saved image */
1631     if (n->mac_table.in_use > MAC_TABLE_ENTRIES) {
1632         n->mac_table.in_use = 0;
1633     }
1634 
1635     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
1636         n->curr_guest_offloads = virtio_net_supported_guest_offloads(n);
1637     }
1638 
1639     if (peer_has_vnet_hdr(n)) {
1640         virtio_net_apply_guest_offloads(n);
1641     }
1642 
1643     virtio_net_set_queues(n);
1644 
1645     /* Find the first multicast entry in the saved MAC filter */
1646     for (i = 0; i < n->mac_table.in_use; i++) {
1647         if (n->mac_table.macs[i * ETH_ALEN] & 1) {
1648             break;
1649         }
1650     }
1651     n->mac_table.first_multi = i;
1652 
1653     /* nc.link_down can't be migrated, so infer link_down according
1654      * to link status bit in n->status */
1655     link_down = (n->status & VIRTIO_NET_S_LINK_UP) == 0;
1656     for (i = 0; i < n->max_queues; i++) {
1657         qemu_get_subqueue(n->nic, i)->link_down = link_down;
1658     }
1659 
1660     if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) &&
1661         virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
1662         n->announce_counter = SELF_ANNOUNCE_ROUNDS;
1663         timer_mod(n->announce_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL));
1664     }
1665 
1666     return 0;
1667 }
1668 
1669 /* tx_waiting field of a VirtIONetQueue */
1670 static const VMStateDescription vmstate_virtio_net_queue_tx_waiting = {
1671     .name = "virtio-net-queue-tx_waiting",
1672     .fields = (VMStateField[]) {
1673         VMSTATE_UINT32(tx_waiting, VirtIONetQueue),
1674         VMSTATE_END_OF_LIST()
1675    },
1676 };
1677 
1678 static bool max_queues_gt_1(void *opaque, int version_id)
1679 {
1680     return VIRTIO_NET(opaque)->max_queues > 1;
1681 }
1682 
1683 static bool has_ctrl_guest_offloads(void *opaque, int version_id)
1684 {
1685     return virtio_vdev_has_feature(VIRTIO_DEVICE(opaque),
1686                                    VIRTIO_NET_F_CTRL_GUEST_OFFLOADS);
1687 }
1688 
1689 static bool mac_table_fits(void *opaque, int version_id)
1690 {
1691     return VIRTIO_NET(opaque)->mac_table.in_use <= MAC_TABLE_ENTRIES;
1692 }
1693 
1694 static bool mac_table_doesnt_fit(void *opaque, int version_id)
1695 {
1696     return !mac_table_fits(opaque, version_id);
1697 }
1698 
1699 /* This temporary type is shared by all the WITH_TMP methods
1700  * although only some fields are used by each.
1701  */
1702 struct VirtIONetMigTmp {
1703     VirtIONet      *parent;
1704     VirtIONetQueue *vqs_1;
1705     uint16_t        curr_queues_1;
1706     uint8_t         has_ufo;
1707     uint32_t        has_vnet_hdr;
1708 };
1709 
1710 /* The 2nd and subsequent tx_waiting flags are loaded later than
1711  * the 1st entry in the queues and only if there's more than one
1712  * entry.  We use the tmp mechanism to calculate a temporary
1713  * pointer and count and also validate the count.
1714  */
1715 
1716 static int virtio_net_tx_waiting_pre_save(void *opaque)
1717 {
1718     struct VirtIONetMigTmp *tmp = opaque;
1719 
1720     tmp->vqs_1 = tmp->parent->vqs + 1;
1721     tmp->curr_queues_1 = tmp->parent->curr_queues - 1;
1722     if (tmp->parent->curr_queues == 0) {
1723         tmp->curr_queues_1 = 0;
1724     }
1725 
1726     return 0;
1727 }
1728 
1729 static int virtio_net_tx_waiting_pre_load(void *opaque)
1730 {
1731     struct VirtIONetMigTmp *tmp = opaque;
1732 
1733     /* Reuse the pointer setup from save */
1734     virtio_net_tx_waiting_pre_save(opaque);
1735 
1736     if (tmp->parent->curr_queues > tmp->parent->max_queues) {
1737         error_report("virtio-net: curr_queues %x > max_queues %x",
1738             tmp->parent->curr_queues, tmp->parent->max_queues);
1739 
1740         return -EINVAL;
1741     }
1742 
1743     return 0; /* all good */
1744 }
1745 
1746 static const VMStateDescription vmstate_virtio_net_tx_waiting = {
1747     .name      = "virtio-net-tx_waiting",
1748     .pre_load  = virtio_net_tx_waiting_pre_load,
1749     .pre_save  = virtio_net_tx_waiting_pre_save,
1750     .fields    = (VMStateField[]) {
1751         VMSTATE_STRUCT_VARRAY_POINTER_UINT16(vqs_1, struct VirtIONetMigTmp,
1752                                      curr_queues_1,
1753                                      vmstate_virtio_net_queue_tx_waiting,
1754                                      struct VirtIONetQueue),
1755         VMSTATE_END_OF_LIST()
1756     },
1757 };
1758 
1759 /* the 'has_ufo' flag is just tested; if the incoming stream has the
1760  * flag set we need to check that we have it
1761  */
1762 static int virtio_net_ufo_post_load(void *opaque, int version_id)
1763 {
1764     struct VirtIONetMigTmp *tmp = opaque;
1765 
1766     if (tmp->has_ufo && !peer_has_ufo(tmp->parent)) {
1767         error_report("virtio-net: saved image requires TUN_F_UFO support");
1768         return -EINVAL;
1769     }
1770 
1771     return 0;
1772 }
1773 
1774 static int virtio_net_ufo_pre_save(void *opaque)
1775 {
1776     struct VirtIONetMigTmp *tmp = opaque;
1777 
1778     tmp->has_ufo = tmp->parent->has_ufo;
1779 
1780     return 0;
1781 }
1782 
1783 static const VMStateDescription vmstate_virtio_net_has_ufo = {
1784     .name      = "virtio-net-ufo",
1785     .post_load = virtio_net_ufo_post_load,
1786     .pre_save  = virtio_net_ufo_pre_save,
1787     .fields    = (VMStateField[]) {
1788         VMSTATE_UINT8(has_ufo, struct VirtIONetMigTmp),
1789         VMSTATE_END_OF_LIST()
1790     },
1791 };
1792 
1793 /* the 'has_vnet_hdr' flag is just tested; if the incoming stream has the
1794  * flag set we need to check that we have it
1795  */
1796 static int virtio_net_vnet_post_load(void *opaque, int version_id)
1797 {
1798     struct VirtIONetMigTmp *tmp = opaque;
1799 
1800     if (tmp->has_vnet_hdr && !peer_has_vnet_hdr(tmp->parent)) {
1801         error_report("virtio-net: saved image requires vnet_hdr=on");
1802         return -EINVAL;
1803     }
1804 
1805     return 0;
1806 }
1807 
1808 static int virtio_net_vnet_pre_save(void *opaque)
1809 {
1810     struct VirtIONetMigTmp *tmp = opaque;
1811 
1812     tmp->has_vnet_hdr = tmp->parent->has_vnet_hdr;
1813 
1814     return 0;
1815 }
1816 
1817 static const VMStateDescription vmstate_virtio_net_has_vnet = {
1818     .name      = "virtio-net-vnet",
1819     .post_load = virtio_net_vnet_post_load,
1820     .pre_save  = virtio_net_vnet_pre_save,
1821     .fields    = (VMStateField[]) {
1822         VMSTATE_UINT32(has_vnet_hdr, struct VirtIONetMigTmp),
1823         VMSTATE_END_OF_LIST()
1824     },
1825 };
1826 
1827 static const VMStateDescription vmstate_virtio_net_device = {
1828     .name = "virtio-net-device",
1829     .version_id = VIRTIO_NET_VM_VERSION,
1830     .minimum_version_id = VIRTIO_NET_VM_VERSION,
1831     .post_load = virtio_net_post_load_device,
1832     .fields = (VMStateField[]) {
1833         VMSTATE_UINT8_ARRAY(mac, VirtIONet, ETH_ALEN),
1834         VMSTATE_STRUCT_POINTER(vqs, VirtIONet,
1835                                vmstate_virtio_net_queue_tx_waiting,
1836                                VirtIONetQueue),
1837         VMSTATE_UINT32(mergeable_rx_bufs, VirtIONet),
1838         VMSTATE_UINT16(status, VirtIONet),
1839         VMSTATE_UINT8(promisc, VirtIONet),
1840         VMSTATE_UINT8(allmulti, VirtIONet),
1841         VMSTATE_UINT32(mac_table.in_use, VirtIONet),
1842 
1843         /* Guarded pair: If it fits we load it, else we throw it away
1844          * - can happen if source has a larger MAC table.; post-load
1845          *  sets flags in this case.
1846          */
1847         VMSTATE_VBUFFER_MULTIPLY(mac_table.macs, VirtIONet,
1848                                 0, mac_table_fits, mac_table.in_use,
1849                                  ETH_ALEN),
1850         VMSTATE_UNUSED_VARRAY_UINT32(VirtIONet, mac_table_doesnt_fit, 0,
1851                                      mac_table.in_use, ETH_ALEN),
1852 
1853         /* Note: This is an array of uint32's that's always been saved as a
1854          * buffer; hold onto your endiannesses; it's actually used as a bitmap
1855          * but based on the uint.
1856          */
1857         VMSTATE_BUFFER_POINTER_UNSAFE(vlans, VirtIONet, 0, MAX_VLAN >> 3),
1858         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
1859                          vmstate_virtio_net_has_vnet),
1860         VMSTATE_UINT8(mac_table.multi_overflow, VirtIONet),
1861         VMSTATE_UINT8(mac_table.uni_overflow, VirtIONet),
1862         VMSTATE_UINT8(alluni, VirtIONet),
1863         VMSTATE_UINT8(nomulti, VirtIONet),
1864         VMSTATE_UINT8(nouni, VirtIONet),
1865         VMSTATE_UINT8(nobcast, VirtIONet),
1866         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
1867                          vmstate_virtio_net_has_ufo),
1868         VMSTATE_SINGLE_TEST(max_queues, VirtIONet, max_queues_gt_1, 0,
1869                             vmstate_info_uint16_equal, uint16_t),
1870         VMSTATE_UINT16_TEST(curr_queues, VirtIONet, max_queues_gt_1),
1871         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
1872                          vmstate_virtio_net_tx_waiting),
1873         VMSTATE_UINT64_TEST(curr_guest_offloads, VirtIONet,
1874                             has_ctrl_guest_offloads),
1875         VMSTATE_END_OF_LIST()
1876    },
1877 };
1878 
1879 static NetClientInfo net_virtio_info = {
1880     .type = NET_CLIENT_DRIVER_NIC,
1881     .size = sizeof(NICState),
1882     .can_receive = virtio_net_can_receive,
1883     .receive = virtio_net_receive,
1884     .link_status_changed = virtio_net_set_link_status,
1885     .query_rx_filter = virtio_net_query_rxfilter,
1886 };
1887 
1888 static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
1889 {
1890     VirtIONet *n = VIRTIO_NET(vdev);
1891     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
1892     assert(n->vhost_started);
1893     return vhost_net_virtqueue_pending(get_vhost_net(nc->peer), idx);
1894 }
1895 
1896 static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
1897                                            bool mask)
1898 {
1899     VirtIONet *n = VIRTIO_NET(vdev);
1900     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
1901     assert(n->vhost_started);
1902     vhost_net_virtqueue_mask(get_vhost_net(nc->peer),
1903                              vdev, idx, mask);
1904 }
1905 
1906 static void virtio_net_set_config_size(VirtIONet *n, uint64_t host_features)
1907 {
1908     int i, config_size = 0;
1909     virtio_add_feature(&host_features, VIRTIO_NET_F_MAC);
1910 
1911     for (i = 0; feature_sizes[i].flags != 0; i++) {
1912         if (host_features & feature_sizes[i].flags) {
1913             config_size = MAX(feature_sizes[i].end, config_size);
1914         }
1915     }
1916     n->config_size = config_size;
1917 }
1918 
1919 void virtio_net_set_netclient_name(VirtIONet *n, const char *name,
1920                                    const char *type)
1921 {
1922     /*
1923      * The name can be NULL, the netclient name will be type.x.
1924      */
1925     assert(type != NULL);
1926 
1927     g_free(n->netclient_name);
1928     g_free(n->netclient_type);
1929     n->netclient_name = g_strdup(name);
1930     n->netclient_type = g_strdup(type);
1931 }
1932 
1933 static void virtio_net_device_realize(DeviceState *dev, Error **errp)
1934 {
1935     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1936     VirtIONet *n = VIRTIO_NET(dev);
1937     NetClientState *nc;
1938     int i;
1939 
1940     if (n->net_conf.mtu) {
1941         n->host_features |= (0x1 << VIRTIO_NET_F_MTU);
1942     }
1943 
1944     virtio_net_set_config_size(n, n->host_features);
1945     virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, n->config_size);
1946 
1947     /*
1948      * We set a lower limit on RX queue size to what it always was.
1949      * Guests that want a smaller ring can always resize it without
1950      * help from us (using virtio 1 and up).
1951      */
1952     if (n->net_conf.rx_queue_size < VIRTIO_NET_RX_QUEUE_MIN_SIZE ||
1953         n->net_conf.rx_queue_size > VIRTQUEUE_MAX_SIZE ||
1954         !is_power_of_2(n->net_conf.rx_queue_size)) {
1955         error_setg(errp, "Invalid rx_queue_size (= %" PRIu16 "), "
1956                    "must be a power of 2 between %d and %d.",
1957                    n->net_conf.rx_queue_size, VIRTIO_NET_RX_QUEUE_MIN_SIZE,
1958                    VIRTQUEUE_MAX_SIZE);
1959         virtio_cleanup(vdev);
1960         return;
1961     }
1962 
1963     if (n->net_conf.tx_queue_size < VIRTIO_NET_TX_QUEUE_MIN_SIZE ||
1964         n->net_conf.tx_queue_size > VIRTQUEUE_MAX_SIZE ||
1965         !is_power_of_2(n->net_conf.tx_queue_size)) {
1966         error_setg(errp, "Invalid tx_queue_size (= %" PRIu16 "), "
1967                    "must be a power of 2 between %d and %d",
1968                    n->net_conf.tx_queue_size, VIRTIO_NET_TX_QUEUE_MIN_SIZE,
1969                    VIRTQUEUE_MAX_SIZE);
1970         virtio_cleanup(vdev);
1971         return;
1972     }
1973 
1974     n->max_queues = MAX(n->nic_conf.peers.queues, 1);
1975     if (n->max_queues * 2 + 1 > VIRTIO_QUEUE_MAX) {
1976         error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
1977                    "must be a positive integer less than %d.",
1978                    n->max_queues, (VIRTIO_QUEUE_MAX - 1) / 2);
1979         virtio_cleanup(vdev);
1980         return;
1981     }
1982     n->vqs = g_malloc0(sizeof(VirtIONetQueue) * n->max_queues);
1983     n->curr_queues = 1;
1984     n->tx_timeout = n->net_conf.txtimer;
1985 
1986     if (n->net_conf.tx && strcmp(n->net_conf.tx, "timer")
1987                        && strcmp(n->net_conf.tx, "bh")) {
1988         error_report("virtio-net: "
1989                      "Unknown option tx=%s, valid options: \"timer\" \"bh\"",
1990                      n->net_conf.tx);
1991         error_report("Defaulting to \"bh\"");
1992     }
1993 
1994     n->net_conf.tx_queue_size = MIN(virtio_net_max_tx_queue_size(n),
1995                                     n->net_conf.tx_queue_size);
1996 
1997     for (i = 0; i < n->max_queues; i++) {
1998         virtio_net_add_queue(n, i);
1999     }
2000 
2001     n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
2002     qemu_macaddr_default_if_unset(&n->nic_conf.macaddr);
2003     memcpy(&n->mac[0], &n->nic_conf.macaddr, sizeof(n->mac));
2004     n->status = VIRTIO_NET_S_LINK_UP;
2005     n->announce_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
2006                                      virtio_net_announce_timer, n);
2007 
2008     if (n->netclient_type) {
2009         /*
2010          * Happen when virtio_net_set_netclient_name has been called.
2011          */
2012         n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
2013                               n->netclient_type, n->netclient_name, n);
2014     } else {
2015         n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
2016                               object_get_typename(OBJECT(dev)), dev->id, n);
2017     }
2018 
2019     peer_test_vnet_hdr(n);
2020     if (peer_has_vnet_hdr(n)) {
2021         for (i = 0; i < n->max_queues; i++) {
2022             qemu_using_vnet_hdr(qemu_get_subqueue(n->nic, i)->peer, true);
2023         }
2024         n->host_hdr_len = sizeof(struct virtio_net_hdr);
2025     } else {
2026         n->host_hdr_len = 0;
2027     }
2028 
2029     qemu_format_nic_info_str(qemu_get_queue(n->nic), n->nic_conf.macaddr.a);
2030 
2031     n->vqs[0].tx_waiting = 0;
2032     n->tx_burst = n->net_conf.txburst;
2033     virtio_net_set_mrg_rx_bufs(n, 0, 0);
2034     n->promisc = 1; /* for compatibility */
2035 
2036     n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
2037 
2038     n->vlans = g_malloc0(MAX_VLAN >> 3);
2039 
2040     nc = qemu_get_queue(n->nic);
2041     nc->rxfilter_notify_enabled = 1;
2042 
2043     n->qdev = dev;
2044 }
2045 
2046 static void virtio_net_device_unrealize(DeviceState *dev, Error **errp)
2047 {
2048     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
2049     VirtIONet *n = VIRTIO_NET(dev);
2050     int i, max_queues;
2051 
2052     /* This will stop vhost backend if appropriate. */
2053     virtio_net_set_status(vdev, 0);
2054 
2055     g_free(n->netclient_name);
2056     n->netclient_name = NULL;
2057     g_free(n->netclient_type);
2058     n->netclient_type = NULL;
2059 
2060     g_free(n->mac_table.macs);
2061     g_free(n->vlans);
2062 
2063     max_queues = n->multiqueue ? n->max_queues : 1;
2064     for (i = 0; i < max_queues; i++) {
2065         virtio_net_del_queue(n, i);
2066     }
2067 
2068     timer_del(n->announce_timer);
2069     timer_free(n->announce_timer);
2070     g_free(n->vqs);
2071     qemu_del_nic(n->nic);
2072     virtio_cleanup(vdev);
2073 }
2074 
2075 static void virtio_net_instance_init(Object *obj)
2076 {
2077     VirtIONet *n = VIRTIO_NET(obj);
2078 
2079     /*
2080      * The default config_size is sizeof(struct virtio_net_config).
2081      * Can be overriden with virtio_net_set_config_size.
2082      */
2083     n->config_size = sizeof(struct virtio_net_config);
2084     device_add_bootindex_property(obj, &n->nic_conf.bootindex,
2085                                   "bootindex", "/ethernet-phy@0",
2086                                   DEVICE(n), NULL);
2087 }
2088 
2089 static int virtio_net_pre_save(void *opaque)
2090 {
2091     VirtIONet *n = opaque;
2092 
2093     /* At this point, backend must be stopped, otherwise
2094      * it might keep writing to memory. */
2095     assert(!n->vhost_started);
2096 
2097     return 0;
2098 }
2099 
2100 static const VMStateDescription vmstate_virtio_net = {
2101     .name = "virtio-net",
2102     .minimum_version_id = VIRTIO_NET_VM_VERSION,
2103     .version_id = VIRTIO_NET_VM_VERSION,
2104     .fields = (VMStateField[]) {
2105         VMSTATE_VIRTIO_DEVICE,
2106         VMSTATE_END_OF_LIST()
2107     },
2108     .pre_save = virtio_net_pre_save,
2109 };
2110 
2111 static Property virtio_net_properties[] = {
2112     DEFINE_PROP_BIT("csum", VirtIONet, host_features, VIRTIO_NET_F_CSUM, true),
2113     DEFINE_PROP_BIT("guest_csum", VirtIONet, host_features,
2114                     VIRTIO_NET_F_GUEST_CSUM, true),
2115     DEFINE_PROP_BIT("gso", VirtIONet, host_features, VIRTIO_NET_F_GSO, true),
2116     DEFINE_PROP_BIT("guest_tso4", VirtIONet, host_features,
2117                     VIRTIO_NET_F_GUEST_TSO4, true),
2118     DEFINE_PROP_BIT("guest_tso6", VirtIONet, host_features,
2119                     VIRTIO_NET_F_GUEST_TSO6, true),
2120     DEFINE_PROP_BIT("guest_ecn", VirtIONet, host_features,
2121                     VIRTIO_NET_F_GUEST_ECN, true),
2122     DEFINE_PROP_BIT("guest_ufo", VirtIONet, host_features,
2123                     VIRTIO_NET_F_GUEST_UFO, true),
2124     DEFINE_PROP_BIT("guest_announce", VirtIONet, host_features,
2125                     VIRTIO_NET_F_GUEST_ANNOUNCE, true),
2126     DEFINE_PROP_BIT("host_tso4", VirtIONet, host_features,
2127                     VIRTIO_NET_F_HOST_TSO4, true),
2128     DEFINE_PROP_BIT("host_tso6", VirtIONet, host_features,
2129                     VIRTIO_NET_F_HOST_TSO6, true),
2130     DEFINE_PROP_BIT("host_ecn", VirtIONet, host_features,
2131                     VIRTIO_NET_F_HOST_ECN, true),
2132     DEFINE_PROP_BIT("host_ufo", VirtIONet, host_features,
2133                     VIRTIO_NET_F_HOST_UFO, true),
2134     DEFINE_PROP_BIT("mrg_rxbuf", VirtIONet, host_features,
2135                     VIRTIO_NET_F_MRG_RXBUF, true),
2136     DEFINE_PROP_BIT("status", VirtIONet, host_features,
2137                     VIRTIO_NET_F_STATUS, true),
2138     DEFINE_PROP_BIT("ctrl_vq", VirtIONet, host_features,
2139                     VIRTIO_NET_F_CTRL_VQ, true),
2140     DEFINE_PROP_BIT("ctrl_rx", VirtIONet, host_features,
2141                     VIRTIO_NET_F_CTRL_RX, true),
2142     DEFINE_PROP_BIT("ctrl_vlan", VirtIONet, host_features,
2143                     VIRTIO_NET_F_CTRL_VLAN, true),
2144     DEFINE_PROP_BIT("ctrl_rx_extra", VirtIONet, host_features,
2145                     VIRTIO_NET_F_CTRL_RX_EXTRA, true),
2146     DEFINE_PROP_BIT("ctrl_mac_addr", VirtIONet, host_features,
2147                     VIRTIO_NET_F_CTRL_MAC_ADDR, true),
2148     DEFINE_PROP_BIT("ctrl_guest_offloads", VirtIONet, host_features,
2149                     VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, true),
2150     DEFINE_PROP_BIT("mq", VirtIONet, host_features, VIRTIO_NET_F_MQ, false),
2151     DEFINE_NIC_PROPERTIES(VirtIONet, nic_conf),
2152     DEFINE_PROP_UINT32("x-txtimer", VirtIONet, net_conf.txtimer,
2153                        TX_TIMER_INTERVAL),
2154     DEFINE_PROP_INT32("x-txburst", VirtIONet, net_conf.txburst, TX_BURST),
2155     DEFINE_PROP_STRING("tx", VirtIONet, net_conf.tx),
2156     DEFINE_PROP_UINT16("rx_queue_size", VirtIONet, net_conf.rx_queue_size,
2157                        VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE),
2158     DEFINE_PROP_UINT16("tx_queue_size", VirtIONet, net_conf.tx_queue_size,
2159                        VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE),
2160     DEFINE_PROP_UINT16("host_mtu", VirtIONet, net_conf.mtu, 0),
2161     DEFINE_PROP_BOOL("x-mtu-bypass-backend", VirtIONet, mtu_bypass_backend,
2162                      true),
2163     DEFINE_PROP_END_OF_LIST(),
2164 };
2165 
2166 static void virtio_net_class_init(ObjectClass *klass, void *data)
2167 {
2168     DeviceClass *dc = DEVICE_CLASS(klass);
2169     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
2170 
2171     dc->props = virtio_net_properties;
2172     dc->vmsd = &vmstate_virtio_net;
2173     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
2174     vdc->realize = virtio_net_device_realize;
2175     vdc->unrealize = virtio_net_device_unrealize;
2176     vdc->get_config = virtio_net_get_config;
2177     vdc->set_config = virtio_net_set_config;
2178     vdc->get_features = virtio_net_get_features;
2179     vdc->set_features = virtio_net_set_features;
2180     vdc->bad_features = virtio_net_bad_features;
2181     vdc->reset = virtio_net_reset;
2182     vdc->set_status = virtio_net_set_status;
2183     vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
2184     vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;
2185     vdc->legacy_features |= (0x1 << VIRTIO_NET_F_GSO);
2186     vdc->vmsd = &vmstate_virtio_net_device;
2187 }
2188 
2189 static const TypeInfo virtio_net_info = {
2190     .name = TYPE_VIRTIO_NET,
2191     .parent = TYPE_VIRTIO_DEVICE,
2192     .instance_size = sizeof(VirtIONet),
2193     .instance_init = virtio_net_instance_init,
2194     .class_init = virtio_net_class_init,
2195 };
2196 
2197 static void virtio_register_types(void)
2198 {
2199     type_register_static(&virtio_net_info);
2200 }
2201 
2202 type_init(virtio_register_types)
2203