xref: /openbmc/qemu/hw/net/virtio-net.c (revision c0ce7b4a)
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/atomic.h"
16 #include "qemu/iov.h"
17 #include "qemu/log.h"
18 #include "qemu/main-loop.h"
19 #include "qemu/module.h"
20 #include "hw/virtio/virtio.h"
21 #include "net/net.h"
22 #include "net/checksum.h"
23 #include "net/tap.h"
24 #include "qemu/error-report.h"
25 #include "qemu/timer.h"
26 #include "qemu/option.h"
27 #include "qemu/option_int.h"
28 #include "qemu/config-file.h"
29 #include "qapi/qmp/qdict.h"
30 #include "hw/virtio/virtio-net.h"
31 #include "net/vhost_net.h"
32 #include "net/announce.h"
33 #include "hw/virtio/virtio-bus.h"
34 #include "qapi/error.h"
35 #include "qapi/qapi-events-net.h"
36 #include "hw/qdev-properties.h"
37 #include "qapi/qapi-types-migration.h"
38 #include "qapi/qapi-events-migration.h"
39 #include "hw/virtio/virtio-access.h"
40 #include "migration/misc.h"
41 #include "standard-headers/linux/ethtool.h"
42 #include "sysemu/sysemu.h"
43 #include "trace.h"
44 #include "monitor/qdev.h"
45 #include "hw/pci/pci_device.h"
46 #include "net_rx_pkt.h"
47 #include "hw/virtio/vhost.h"
48 #include "sysemu/qtest.h"
49 
50 #define VIRTIO_NET_VM_VERSION    11
51 
52 #define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
53 
54 /* previously fixed value */
55 #define VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE 256
56 #define VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE 256
57 
58 /* for now, only allow larger queue_pairs; with virtio-1, guest can downsize */
59 #define VIRTIO_NET_RX_QUEUE_MIN_SIZE VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE
60 #define VIRTIO_NET_TX_QUEUE_MIN_SIZE VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE
61 
62 #define VIRTIO_NET_IP4_ADDR_SIZE   8        /* ipv4 saddr + daddr */
63 
64 #define VIRTIO_NET_TCP_FLAG         0x3F
65 #define VIRTIO_NET_TCP_HDR_LENGTH   0xF000
66 
67 /* IPv4 max payload, 16 bits in the header */
68 #define VIRTIO_NET_MAX_IP4_PAYLOAD (65535 - sizeof(struct ip_header))
69 #define VIRTIO_NET_MAX_TCP_PAYLOAD 65535
70 
71 /* header length value in ip header without option */
72 #define VIRTIO_NET_IP4_HEADER_LENGTH 5
73 
74 #define VIRTIO_NET_IP6_ADDR_SIZE   32      /* ipv6 saddr + daddr */
75 #define VIRTIO_NET_MAX_IP6_PAYLOAD VIRTIO_NET_MAX_TCP_PAYLOAD
76 
77 /* Purge coalesced packets timer interval, This value affects the performance
78    a lot, and should be tuned carefully, '300000'(300us) is the recommended
79    value to pass the WHQL test, '50000' can gain 2x netperf throughput with
80    tso/gso/gro 'off'. */
81 #define VIRTIO_NET_RSC_DEFAULT_INTERVAL 300000
82 
83 #define VIRTIO_NET_RSS_SUPPORTED_HASHES (VIRTIO_NET_RSS_HASH_TYPE_IPv4 | \
84                                          VIRTIO_NET_RSS_HASH_TYPE_TCPv4 | \
85                                          VIRTIO_NET_RSS_HASH_TYPE_UDPv4 | \
86                                          VIRTIO_NET_RSS_HASH_TYPE_IPv6 | \
87                                          VIRTIO_NET_RSS_HASH_TYPE_TCPv6 | \
88                                          VIRTIO_NET_RSS_HASH_TYPE_UDPv6 | \
89                                          VIRTIO_NET_RSS_HASH_TYPE_IP_EX | \
90                                          VIRTIO_NET_RSS_HASH_TYPE_TCP_EX | \
91                                          VIRTIO_NET_RSS_HASH_TYPE_UDP_EX)
92 
93 static const VirtIOFeature feature_sizes[] = {
94     {.flags = 1ULL << VIRTIO_NET_F_MAC,
95      .end = endof(struct virtio_net_config, mac)},
96     {.flags = 1ULL << VIRTIO_NET_F_STATUS,
97      .end = endof(struct virtio_net_config, status)},
98     {.flags = 1ULL << VIRTIO_NET_F_MQ,
99      .end = endof(struct virtio_net_config, max_virtqueue_pairs)},
100     {.flags = 1ULL << VIRTIO_NET_F_MTU,
101      .end = endof(struct virtio_net_config, mtu)},
102     {.flags = 1ULL << VIRTIO_NET_F_SPEED_DUPLEX,
103      .end = endof(struct virtio_net_config, duplex)},
104     {.flags = (1ULL << VIRTIO_NET_F_RSS) | (1ULL << VIRTIO_NET_F_HASH_REPORT),
105      .end = endof(struct virtio_net_config, supported_hash_types)},
106     {}
107 };
108 
109 static const VirtIOConfigSizeParams cfg_size_params = {
110     .min_size = endof(struct virtio_net_config, mac),
111     .max_size = sizeof(struct virtio_net_config),
112     .feature_sizes = feature_sizes
113 };
114 
115 static VirtIONetQueue *virtio_net_get_subqueue(NetClientState *nc)
116 {
117     VirtIONet *n = qemu_get_nic_opaque(nc);
118 
119     return &n->vqs[nc->queue_index];
120 }
121 
122 static int vq2q(int queue_index)
123 {
124     return queue_index / 2;
125 }
126 
127 static void flush_or_purge_queued_packets(NetClientState *nc)
128 {
129     if (!nc->peer) {
130         return;
131     }
132 
133     qemu_flush_or_purge_queued_packets(nc->peer, true);
134     assert(!virtio_net_get_subqueue(nc)->async_tx.elem);
135 }
136 
137 /* TODO
138  * - we could suppress RX interrupt if we were so inclined.
139  */
140 
141 static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
142 {
143     VirtIONet *n = VIRTIO_NET(vdev);
144     struct virtio_net_config netcfg;
145     NetClientState *nc = qemu_get_queue(n->nic);
146     static const MACAddr zero = { .a = { 0, 0, 0, 0, 0, 0 } };
147 
148     int ret = 0;
149     memset(&netcfg, 0 , sizeof(struct virtio_net_config));
150     virtio_stw_p(vdev, &netcfg.status, n->status);
151     virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queue_pairs);
152     virtio_stw_p(vdev, &netcfg.mtu, n->net_conf.mtu);
153     memcpy(netcfg.mac, n->mac, ETH_ALEN);
154     virtio_stl_p(vdev, &netcfg.speed, n->net_conf.speed);
155     netcfg.duplex = n->net_conf.duplex;
156     netcfg.rss_max_key_size = VIRTIO_NET_RSS_MAX_KEY_SIZE;
157     virtio_stw_p(vdev, &netcfg.rss_max_indirection_table_length,
158                  virtio_host_has_feature(vdev, VIRTIO_NET_F_RSS) ?
159                  VIRTIO_NET_RSS_MAX_TABLE_LEN : 1);
160     virtio_stl_p(vdev, &netcfg.supported_hash_types,
161                  VIRTIO_NET_RSS_SUPPORTED_HASHES);
162     memcpy(config, &netcfg, n->config_size);
163 
164     /*
165      * Is this VDPA? No peer means not VDPA: there's no way to
166      * disconnect/reconnect a VDPA peer.
167      */
168     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
169         ret = vhost_net_get_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
170                                    n->config_size);
171         if (ret == -1) {
172             return;
173         }
174 
175         /*
176          * Some NIC/kernel combinations present 0 as the mac address.  As that
177          * is not a legal address, try to proceed with the address from the
178          * QEMU command line in the hope that the address has been configured
179          * correctly elsewhere - just not reported by the device.
180          */
181         if (memcmp(&netcfg.mac, &zero, sizeof(zero)) == 0) {
182             info_report("Zero hardware mac address detected. Ignoring.");
183             memcpy(netcfg.mac, n->mac, ETH_ALEN);
184         }
185 
186         netcfg.status |= virtio_tswap16(vdev,
187                                         n->status & VIRTIO_NET_S_ANNOUNCE);
188         memcpy(config, &netcfg, n->config_size);
189     }
190 }
191 
192 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
193 {
194     VirtIONet *n = VIRTIO_NET(vdev);
195     struct virtio_net_config netcfg = {};
196     NetClientState *nc = qemu_get_queue(n->nic);
197 
198     memcpy(&netcfg, config, n->config_size);
199 
200     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR) &&
201         !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1) &&
202         memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
203         memcpy(n->mac, netcfg.mac, ETH_ALEN);
204         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
205     }
206 
207     /*
208      * Is this VDPA? No peer means not VDPA: there's no way to
209      * disconnect/reconnect a VDPA peer.
210      */
211     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
212         vhost_net_set_config(get_vhost_net(nc->peer),
213                              (uint8_t *)&netcfg, 0, n->config_size,
214                              VHOST_SET_CONFIG_TYPE_FRONTEND);
215       }
216 }
217 
218 static bool virtio_net_started(VirtIONet *n, uint8_t status)
219 {
220     VirtIODevice *vdev = VIRTIO_DEVICE(n);
221     return (status & VIRTIO_CONFIG_S_DRIVER_OK) &&
222         (n->status & VIRTIO_NET_S_LINK_UP) && vdev->vm_running;
223 }
224 
225 static void virtio_net_announce_notify(VirtIONet *net)
226 {
227     VirtIODevice *vdev = VIRTIO_DEVICE(net);
228     trace_virtio_net_announce_notify();
229 
230     net->status |= VIRTIO_NET_S_ANNOUNCE;
231     virtio_notify_config(vdev);
232 }
233 
234 static void virtio_net_announce_timer(void *opaque)
235 {
236     VirtIONet *n = opaque;
237     trace_virtio_net_announce_timer(n->announce_timer.round);
238 
239     n->announce_timer.round--;
240     virtio_net_announce_notify(n);
241 }
242 
243 static void virtio_net_announce(NetClientState *nc)
244 {
245     VirtIONet *n = qemu_get_nic_opaque(nc);
246     VirtIODevice *vdev = VIRTIO_DEVICE(n);
247 
248     /*
249      * Make sure the virtio migration announcement timer isn't running
250      * If it is, let it trigger announcement so that we do not cause
251      * confusion.
252      */
253     if (n->announce_timer.round) {
254         return;
255     }
256 
257     if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) &&
258         virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
259             virtio_net_announce_notify(n);
260     }
261 }
262 
263 static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
264 {
265     VirtIODevice *vdev = VIRTIO_DEVICE(n);
266     NetClientState *nc = qemu_get_queue(n->nic);
267     int queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
268     int cvq = virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) ?
269               n->max_ncs - n->max_queue_pairs : 0;
270 
271     if (!get_vhost_net(nc->peer)) {
272         return;
273     }
274 
275     if ((virtio_net_started(n, status) && !nc->peer->link_down) ==
276         !!n->vhost_started) {
277         return;
278     }
279     if (!n->vhost_started) {
280         int r, i;
281 
282         if (n->needs_vnet_hdr_swap) {
283             error_report("backend does not support %s vnet headers; "
284                          "falling back on userspace virtio",
285                          virtio_is_big_endian(vdev) ? "BE" : "LE");
286             return;
287         }
288 
289         /* Any packets outstanding? Purge them to avoid touching rings
290          * when vhost is running.
291          */
292         for (i = 0;  i < queue_pairs; i++) {
293             NetClientState *qnc = qemu_get_subqueue(n->nic, i);
294 
295             /* Purge both directions: TX and RX. */
296             qemu_net_queue_purge(qnc->peer->incoming_queue, qnc);
297             qemu_net_queue_purge(qnc->incoming_queue, qnc->peer);
298         }
299 
300         if (virtio_has_feature(vdev->guest_features, VIRTIO_NET_F_MTU)) {
301             r = vhost_net_set_mtu(get_vhost_net(nc->peer), n->net_conf.mtu);
302             if (r < 0) {
303                 error_report("%uBytes MTU not supported by the backend",
304                              n->net_conf.mtu);
305 
306                 return;
307             }
308         }
309 
310         n->vhost_started = 1;
311         r = vhost_net_start(vdev, n->nic->ncs, queue_pairs, cvq);
312         if (r < 0) {
313             error_report("unable to start vhost net: %d: "
314                          "falling back on userspace virtio", -r);
315             n->vhost_started = 0;
316         }
317     } else {
318         vhost_net_stop(vdev, n->nic->ncs, queue_pairs, cvq);
319         n->vhost_started = 0;
320     }
321 }
322 
323 static int virtio_net_set_vnet_endian_one(VirtIODevice *vdev,
324                                           NetClientState *peer,
325                                           bool enable)
326 {
327     if (virtio_is_big_endian(vdev)) {
328         return qemu_set_vnet_be(peer, enable);
329     } else {
330         return qemu_set_vnet_le(peer, enable);
331     }
332 }
333 
334 static bool virtio_net_set_vnet_endian(VirtIODevice *vdev, NetClientState *ncs,
335                                        int queue_pairs, bool enable)
336 {
337     int i;
338 
339     for (i = 0; i < queue_pairs; i++) {
340         if (virtio_net_set_vnet_endian_one(vdev, ncs[i].peer, enable) < 0 &&
341             enable) {
342             while (--i >= 0) {
343                 virtio_net_set_vnet_endian_one(vdev, ncs[i].peer, false);
344             }
345 
346             return true;
347         }
348     }
349 
350     return false;
351 }
352 
353 static void virtio_net_vnet_endian_status(VirtIONet *n, uint8_t status)
354 {
355     VirtIODevice *vdev = VIRTIO_DEVICE(n);
356     int queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
357 
358     if (virtio_net_started(n, status)) {
359         /* Before using the device, we tell the network backend about the
360          * endianness to use when parsing vnet headers. If the backend
361          * can't do it, we fallback onto fixing the headers in the core
362          * virtio-net code.
363          */
364         n->needs_vnet_hdr_swap = virtio_net_set_vnet_endian(vdev, n->nic->ncs,
365                                                             queue_pairs, true);
366     } else if (virtio_net_started(n, vdev->status)) {
367         /* After using the device, we need to reset the network backend to
368          * the default (guest native endianness), otherwise the guest may
369          * lose network connectivity if it is rebooted into a different
370          * endianness.
371          */
372         virtio_net_set_vnet_endian(vdev, n->nic->ncs, queue_pairs, false);
373     }
374 }
375 
376 static void virtio_net_drop_tx_queue_data(VirtIODevice *vdev, VirtQueue *vq)
377 {
378     unsigned int dropped = virtqueue_drop_all(vq);
379     if (dropped) {
380         virtio_notify(vdev, vq);
381     }
382 }
383 
384 static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
385 {
386     VirtIONet *n = VIRTIO_NET(vdev);
387     VirtIONetQueue *q;
388     int i;
389     uint8_t queue_status;
390 
391     virtio_net_vnet_endian_status(n, status);
392     virtio_net_vhost_status(n, status);
393 
394     for (i = 0; i < n->max_queue_pairs; i++) {
395         NetClientState *ncs = qemu_get_subqueue(n->nic, i);
396         bool queue_started;
397         q = &n->vqs[i];
398 
399         if ((!n->multiqueue && i != 0) || i >= n->curr_queue_pairs) {
400             queue_status = 0;
401         } else {
402             queue_status = status;
403         }
404         queue_started =
405             virtio_net_started(n, queue_status) && !n->vhost_started;
406 
407         if (queue_started) {
408             qemu_flush_queued_packets(ncs);
409         }
410 
411         if (!q->tx_waiting) {
412             continue;
413         }
414 
415         if (queue_started) {
416             if (q->tx_timer) {
417                 timer_mod(q->tx_timer,
418                                qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
419             } else {
420                 qemu_bh_schedule(q->tx_bh);
421             }
422         } else {
423             if (q->tx_timer) {
424                 timer_del(q->tx_timer);
425             } else {
426                 qemu_bh_cancel(q->tx_bh);
427             }
428             if ((n->status & VIRTIO_NET_S_LINK_UP) == 0 &&
429                 (queue_status & VIRTIO_CONFIG_S_DRIVER_OK) &&
430                 vdev->vm_running) {
431                 /* if tx is waiting we are likely have some packets in tx queue
432                  * and disabled notification */
433                 q->tx_waiting = 0;
434                 virtio_queue_set_notification(q->tx_vq, 1);
435                 virtio_net_drop_tx_queue_data(vdev, q->tx_vq);
436             }
437         }
438     }
439 }
440 
441 static void virtio_net_set_link_status(NetClientState *nc)
442 {
443     VirtIONet *n = qemu_get_nic_opaque(nc);
444     VirtIODevice *vdev = VIRTIO_DEVICE(n);
445     uint16_t old_status = n->status;
446 
447     if (nc->link_down)
448         n->status &= ~VIRTIO_NET_S_LINK_UP;
449     else
450         n->status |= VIRTIO_NET_S_LINK_UP;
451 
452     if (n->status != old_status)
453         virtio_notify_config(vdev);
454 
455     virtio_net_set_status(vdev, vdev->status);
456 }
457 
458 static void rxfilter_notify(NetClientState *nc)
459 {
460     VirtIONet *n = qemu_get_nic_opaque(nc);
461 
462     if (nc->rxfilter_notify_enabled) {
463         char *path = object_get_canonical_path(OBJECT(n->qdev));
464         qapi_event_send_nic_rx_filter_changed(n->netclient_name, path);
465         g_free(path);
466 
467         /* disable event notification to avoid events flooding */
468         nc->rxfilter_notify_enabled = 0;
469     }
470 }
471 
472 static intList *get_vlan_table(VirtIONet *n)
473 {
474     intList *list;
475     int i, j;
476 
477     list = NULL;
478     for (i = 0; i < MAX_VLAN >> 5; i++) {
479         for (j = 0; n->vlans[i] && j <= 0x1f; j++) {
480             if (n->vlans[i] & (1U << j)) {
481                 QAPI_LIST_PREPEND(list, (i << 5) + j);
482             }
483         }
484     }
485 
486     return list;
487 }
488 
489 static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
490 {
491     VirtIONet *n = qemu_get_nic_opaque(nc);
492     VirtIODevice *vdev = VIRTIO_DEVICE(n);
493     RxFilterInfo *info;
494     strList *str_list;
495     int i;
496 
497     info = g_malloc0(sizeof(*info));
498     info->name = g_strdup(nc->name);
499     info->promiscuous = n->promisc;
500 
501     if (n->nouni) {
502         info->unicast = RX_STATE_NONE;
503     } else if (n->alluni) {
504         info->unicast = RX_STATE_ALL;
505     } else {
506         info->unicast = RX_STATE_NORMAL;
507     }
508 
509     if (n->nomulti) {
510         info->multicast = RX_STATE_NONE;
511     } else if (n->allmulti) {
512         info->multicast = RX_STATE_ALL;
513     } else {
514         info->multicast = RX_STATE_NORMAL;
515     }
516 
517     info->broadcast_allowed = n->nobcast;
518     info->multicast_overflow = n->mac_table.multi_overflow;
519     info->unicast_overflow = n->mac_table.uni_overflow;
520 
521     info->main_mac = qemu_mac_strdup_printf(n->mac);
522 
523     str_list = NULL;
524     for (i = 0; i < n->mac_table.first_multi; i++) {
525         QAPI_LIST_PREPEND(str_list,
526                       qemu_mac_strdup_printf(n->mac_table.macs + i * ETH_ALEN));
527     }
528     info->unicast_table = str_list;
529 
530     str_list = NULL;
531     for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
532         QAPI_LIST_PREPEND(str_list,
533                       qemu_mac_strdup_printf(n->mac_table.macs + i * ETH_ALEN));
534     }
535     info->multicast_table = str_list;
536     info->vlan_table = get_vlan_table(n);
537 
538     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VLAN)) {
539         info->vlan = RX_STATE_ALL;
540     } else if (!info->vlan_table) {
541         info->vlan = RX_STATE_NONE;
542     } else {
543         info->vlan = RX_STATE_NORMAL;
544     }
545 
546     /* enable event notification after query */
547     nc->rxfilter_notify_enabled = 1;
548 
549     return info;
550 }
551 
552 static void virtio_net_queue_reset(VirtIODevice *vdev, uint32_t queue_index)
553 {
554     VirtIONet *n = VIRTIO_NET(vdev);
555     NetClientState *nc;
556 
557     /* validate queue_index and skip for cvq */
558     if (queue_index >= n->max_queue_pairs * 2) {
559         return;
560     }
561 
562     nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
563 
564     if (!nc->peer) {
565         return;
566     }
567 
568     if (get_vhost_net(nc->peer) &&
569         nc->peer->info->type == NET_CLIENT_DRIVER_TAP) {
570         vhost_net_virtqueue_reset(vdev, nc, queue_index);
571     }
572 
573     flush_or_purge_queued_packets(nc);
574 }
575 
576 static void virtio_net_queue_enable(VirtIODevice *vdev, uint32_t queue_index)
577 {
578     VirtIONet *n = VIRTIO_NET(vdev);
579     NetClientState *nc;
580     int r;
581 
582     /* validate queue_index and skip for cvq */
583     if (queue_index >= n->max_queue_pairs * 2) {
584         return;
585     }
586 
587     nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
588 
589     if (!nc->peer || !vdev->vhost_started) {
590         return;
591     }
592 
593     if (get_vhost_net(nc->peer) &&
594         nc->peer->info->type == NET_CLIENT_DRIVER_TAP) {
595         r = vhost_net_virtqueue_restart(vdev, nc, queue_index);
596         if (r < 0) {
597             error_report("unable to restart vhost net virtqueue: %d, "
598                             "when resetting the queue", queue_index);
599         }
600     }
601 }
602 
603 static void virtio_net_reset(VirtIODevice *vdev)
604 {
605     VirtIONet *n = VIRTIO_NET(vdev);
606     int i;
607 
608     /* Reset back to compatibility mode */
609     n->promisc = 1;
610     n->allmulti = 0;
611     n->alluni = 0;
612     n->nomulti = 0;
613     n->nouni = 0;
614     n->nobcast = 0;
615     /* multiqueue is disabled by default */
616     n->curr_queue_pairs = 1;
617     timer_del(n->announce_timer.tm);
618     n->announce_timer.round = 0;
619     n->status &= ~VIRTIO_NET_S_ANNOUNCE;
620 
621     /* Flush any MAC and VLAN filter table state */
622     n->mac_table.in_use = 0;
623     n->mac_table.first_multi = 0;
624     n->mac_table.multi_overflow = 0;
625     n->mac_table.uni_overflow = 0;
626     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
627     memcpy(&n->mac[0], &n->nic->conf->macaddr, sizeof(n->mac));
628     qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
629     memset(n->vlans, 0, MAX_VLAN >> 3);
630 
631     /* Flush any async TX */
632     for (i = 0;  i < n->max_queue_pairs; i++) {
633         flush_or_purge_queued_packets(qemu_get_subqueue(n->nic, i));
634     }
635 }
636 
637 static void peer_test_vnet_hdr(VirtIONet *n)
638 {
639     NetClientState *nc = qemu_get_queue(n->nic);
640     if (!nc->peer) {
641         return;
642     }
643 
644     n->has_vnet_hdr = qemu_has_vnet_hdr(nc->peer);
645 }
646 
647 static int peer_has_vnet_hdr(VirtIONet *n)
648 {
649     return n->has_vnet_hdr;
650 }
651 
652 static int peer_has_ufo(VirtIONet *n)
653 {
654     if (!peer_has_vnet_hdr(n))
655         return 0;
656 
657     n->has_ufo = qemu_has_ufo(qemu_get_queue(n->nic)->peer);
658 
659     return n->has_ufo;
660 }
661 
662 static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs,
663                                        int version_1, int hash_report)
664 {
665     int i;
666     NetClientState *nc;
667 
668     n->mergeable_rx_bufs = mergeable_rx_bufs;
669 
670     if (version_1) {
671         n->guest_hdr_len = hash_report ?
672             sizeof(struct virtio_net_hdr_v1_hash) :
673             sizeof(struct virtio_net_hdr_mrg_rxbuf);
674         n->rss_data.populate_hash = !!hash_report;
675     } else {
676         n->guest_hdr_len = n->mergeable_rx_bufs ?
677             sizeof(struct virtio_net_hdr_mrg_rxbuf) :
678             sizeof(struct virtio_net_hdr);
679     }
680 
681     for (i = 0; i < n->max_queue_pairs; i++) {
682         nc = qemu_get_subqueue(n->nic, i);
683 
684         if (peer_has_vnet_hdr(n) &&
685             qemu_has_vnet_hdr_len(nc->peer, n->guest_hdr_len)) {
686             qemu_set_vnet_hdr_len(nc->peer, n->guest_hdr_len);
687             n->host_hdr_len = n->guest_hdr_len;
688         }
689     }
690 }
691 
692 static int virtio_net_max_tx_queue_size(VirtIONet *n)
693 {
694     NetClientState *peer = n->nic_conf.peers.ncs[0];
695 
696     /*
697      * Backends other than vhost-user or vhost-vdpa don't support max queue
698      * size.
699      */
700     if (!peer) {
701         return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE;
702     }
703 
704     switch(peer->info->type) {
705     case NET_CLIENT_DRIVER_VHOST_USER:
706     case NET_CLIENT_DRIVER_VHOST_VDPA:
707         return VIRTQUEUE_MAX_SIZE;
708     default:
709         return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE;
710     };
711 }
712 
713 static int peer_attach(VirtIONet *n, int index)
714 {
715     NetClientState *nc = qemu_get_subqueue(n->nic, index);
716 
717     if (!nc->peer) {
718         return 0;
719     }
720 
721     if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
722         vhost_set_vring_enable(nc->peer, 1);
723     }
724 
725     if (nc->peer->info->type != NET_CLIENT_DRIVER_TAP) {
726         return 0;
727     }
728 
729     if (n->max_queue_pairs == 1) {
730         return 0;
731     }
732 
733     return tap_enable(nc->peer);
734 }
735 
736 static int peer_detach(VirtIONet *n, int index)
737 {
738     NetClientState *nc = qemu_get_subqueue(n->nic, index);
739 
740     if (!nc->peer) {
741         return 0;
742     }
743 
744     if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
745         vhost_set_vring_enable(nc->peer, 0);
746     }
747 
748     if (nc->peer->info->type !=  NET_CLIENT_DRIVER_TAP) {
749         return 0;
750     }
751 
752     return tap_disable(nc->peer);
753 }
754 
755 static void virtio_net_set_queue_pairs(VirtIONet *n)
756 {
757     int i;
758     int r;
759 
760     if (n->nic->peer_deleted) {
761         return;
762     }
763 
764     for (i = 0; i < n->max_queue_pairs; i++) {
765         if (i < n->curr_queue_pairs) {
766             r = peer_attach(n, i);
767             assert(!r);
768         } else {
769             r = peer_detach(n, i);
770             assert(!r);
771         }
772     }
773 }
774 
775 static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue);
776 
777 static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
778                                         Error **errp)
779 {
780     VirtIONet *n = VIRTIO_NET(vdev);
781     NetClientState *nc = qemu_get_queue(n->nic);
782 
783     /* Firstly sync all virtio-net possible supported features */
784     features |= n->host_features;
785 
786     virtio_add_feature(&features, VIRTIO_NET_F_MAC);
787 
788     if (!peer_has_vnet_hdr(n)) {
789         virtio_clear_feature(&features, VIRTIO_NET_F_CSUM);
790         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_TSO4);
791         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_TSO6);
792         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_ECN);
793 
794         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_CSUM);
795         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO4);
796         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO6);
797         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ECN);
798 
799         virtio_clear_feature(&features, VIRTIO_NET_F_HASH_REPORT);
800     }
801 
802     if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
803         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_UFO);
804         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO);
805     }
806 
807     if (!get_vhost_net(nc->peer)) {
808         return features;
809     }
810 
811     if (!ebpf_rss_is_loaded(&n->ebpf_rss)) {
812         virtio_clear_feature(&features, VIRTIO_NET_F_RSS);
813     }
814     features = vhost_net_get_features(get_vhost_net(nc->peer), features);
815     vdev->backend_features = features;
816 
817     if (n->mtu_bypass_backend &&
818             (n->host_features & 1ULL << VIRTIO_NET_F_MTU)) {
819         features |= (1ULL << VIRTIO_NET_F_MTU);
820     }
821 
822     /*
823      * Since GUEST_ANNOUNCE is emulated the feature bit could be set without
824      * enabled. This happens in the vDPA case.
825      *
826      * Make sure the feature set is not incoherent, as the driver could refuse
827      * to start.
828      *
829      * TODO: QEMU is able to emulate a CVQ just for guest_announce purposes,
830      * helping guest to notify the new location with vDPA devices that does not
831      * support it.
832      */
833     if (!virtio_has_feature(vdev->backend_features, VIRTIO_NET_F_CTRL_VQ)) {
834         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE);
835     }
836 
837     return features;
838 }
839 
840 static uint64_t virtio_net_bad_features(VirtIODevice *vdev)
841 {
842     uint64_t features = 0;
843 
844     /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
845      * but also these: */
846     virtio_add_feature(&features, VIRTIO_NET_F_MAC);
847     virtio_add_feature(&features, VIRTIO_NET_F_CSUM);
848     virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO4);
849     virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO6);
850     virtio_add_feature(&features, VIRTIO_NET_F_HOST_ECN);
851 
852     return features;
853 }
854 
855 static void virtio_net_apply_guest_offloads(VirtIONet *n)
856 {
857     qemu_set_offload(qemu_get_queue(n->nic)->peer,
858             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_CSUM)),
859             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO4)),
860             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO6)),
861             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_ECN)),
862             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_UFO)));
863 }
864 
865 static uint64_t virtio_net_guest_offloads_by_features(uint32_t features)
866 {
867     static const uint64_t guest_offloads_mask =
868         (1ULL << VIRTIO_NET_F_GUEST_CSUM) |
869         (1ULL << VIRTIO_NET_F_GUEST_TSO4) |
870         (1ULL << VIRTIO_NET_F_GUEST_TSO6) |
871         (1ULL << VIRTIO_NET_F_GUEST_ECN)  |
872         (1ULL << VIRTIO_NET_F_GUEST_UFO);
873 
874     return guest_offloads_mask & features;
875 }
876 
877 uint64_t virtio_net_supported_guest_offloads(const VirtIONet *n)
878 {
879     VirtIODevice *vdev = VIRTIO_DEVICE(n);
880     return virtio_net_guest_offloads_by_features(vdev->guest_features);
881 }
882 
883 typedef struct {
884     VirtIONet *n;
885     DeviceState *dev;
886 } FailoverDevice;
887 
888 /**
889  * Set the failover primary device
890  *
891  * @opaque: FailoverId to setup
892  * @opts: opts for device we are handling
893  * @errp: returns an error if this function fails
894  */
895 static int failover_set_primary(DeviceState *dev, void *opaque)
896 {
897     FailoverDevice *fdev = opaque;
898     PCIDevice *pci_dev = (PCIDevice *)
899         object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE);
900 
901     if (!pci_dev) {
902         return 0;
903     }
904 
905     if (!g_strcmp0(pci_dev->failover_pair_id, fdev->n->netclient_name)) {
906         fdev->dev = dev;
907         return 1;
908     }
909 
910     return 0;
911 }
912 
913 /**
914  * Find the primary device for this failover virtio-net
915  *
916  * @n: VirtIONet device
917  * @errp: returns an error if this function fails
918  */
919 static DeviceState *failover_find_primary_device(VirtIONet *n)
920 {
921     FailoverDevice fdev = {
922         .n = n,
923     };
924 
925     qbus_walk_children(sysbus_get_default(), failover_set_primary, NULL,
926                        NULL, NULL, &fdev);
927     return fdev.dev;
928 }
929 
930 static void failover_add_primary(VirtIONet *n, Error **errp)
931 {
932     Error *err = NULL;
933     DeviceState *dev = failover_find_primary_device(n);
934 
935     if (dev) {
936         return;
937     }
938 
939     if (!n->primary_opts) {
940         error_setg(errp, "Primary device not found");
941         error_append_hint(errp, "Virtio-net failover will not work. Make "
942                           "sure primary device has parameter"
943                           " failover_pair_id=%s\n", n->netclient_name);
944         return;
945     }
946 
947     dev = qdev_device_add_from_qdict(n->primary_opts,
948                                      n->primary_opts_from_json,
949                                      &err);
950     if (err) {
951         qobject_unref(n->primary_opts);
952         n->primary_opts = NULL;
953     } else {
954         object_unref(OBJECT(dev));
955     }
956     error_propagate(errp, err);
957 }
958 
959 static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features)
960 {
961     VirtIONet *n = VIRTIO_NET(vdev);
962     Error *err = NULL;
963     int i;
964 
965     if (n->mtu_bypass_backend &&
966             !virtio_has_feature(vdev->backend_features, VIRTIO_NET_F_MTU)) {
967         features &= ~(1ULL << VIRTIO_NET_F_MTU);
968     }
969 
970     virtio_net_set_multiqueue(n,
971                               virtio_has_feature(features, VIRTIO_NET_F_RSS) ||
972                               virtio_has_feature(features, VIRTIO_NET_F_MQ));
973 
974     virtio_net_set_mrg_rx_bufs(n,
975                                virtio_has_feature(features,
976                                                   VIRTIO_NET_F_MRG_RXBUF),
977                                virtio_has_feature(features,
978                                                   VIRTIO_F_VERSION_1),
979                                virtio_has_feature(features,
980                                                   VIRTIO_NET_F_HASH_REPORT));
981 
982     n->rsc4_enabled = virtio_has_feature(features, VIRTIO_NET_F_RSC_EXT) &&
983         virtio_has_feature(features, VIRTIO_NET_F_GUEST_TSO4);
984     n->rsc6_enabled = virtio_has_feature(features, VIRTIO_NET_F_RSC_EXT) &&
985         virtio_has_feature(features, VIRTIO_NET_F_GUEST_TSO6);
986     n->rss_data.redirect = virtio_has_feature(features, VIRTIO_NET_F_RSS);
987 
988     if (n->has_vnet_hdr) {
989         n->curr_guest_offloads =
990             virtio_net_guest_offloads_by_features(features);
991         virtio_net_apply_guest_offloads(n);
992     }
993 
994     for (i = 0;  i < n->max_queue_pairs; i++) {
995         NetClientState *nc = qemu_get_subqueue(n->nic, i);
996 
997         if (!get_vhost_net(nc->peer)) {
998             continue;
999         }
1000         vhost_net_ack_features(get_vhost_net(nc->peer), features);
1001 
1002         /*
1003          * keep acked_features in NetVhostUserState up-to-date so it
1004          * can't miss any features configured by guest virtio driver.
1005          */
1006         vhost_net_save_acked_features(nc->peer);
1007     }
1008 
1009     if (virtio_has_feature(features, VIRTIO_NET_F_CTRL_VLAN)) {
1010         memset(n->vlans, 0, MAX_VLAN >> 3);
1011     } else {
1012         memset(n->vlans, 0xff, MAX_VLAN >> 3);
1013     }
1014 
1015     if (virtio_has_feature(features, VIRTIO_NET_F_STANDBY)) {
1016         qapi_event_send_failover_negotiated(n->netclient_name);
1017         qatomic_set(&n->failover_primary_hidden, false);
1018         failover_add_primary(n, &err);
1019         if (err) {
1020             if (!qtest_enabled()) {
1021                 warn_report_err(err);
1022             } else {
1023                 error_free(err);
1024             }
1025         }
1026     }
1027 }
1028 
1029 static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
1030                                      struct iovec *iov, unsigned int iov_cnt)
1031 {
1032     uint8_t on;
1033     size_t s;
1034     NetClientState *nc = qemu_get_queue(n->nic);
1035 
1036     s = iov_to_buf(iov, iov_cnt, 0, &on, sizeof(on));
1037     if (s != sizeof(on)) {
1038         return VIRTIO_NET_ERR;
1039     }
1040 
1041     if (cmd == VIRTIO_NET_CTRL_RX_PROMISC) {
1042         n->promisc = on;
1043     } else if (cmd == VIRTIO_NET_CTRL_RX_ALLMULTI) {
1044         n->allmulti = on;
1045     } else if (cmd == VIRTIO_NET_CTRL_RX_ALLUNI) {
1046         n->alluni = on;
1047     } else if (cmd == VIRTIO_NET_CTRL_RX_NOMULTI) {
1048         n->nomulti = on;
1049     } else if (cmd == VIRTIO_NET_CTRL_RX_NOUNI) {
1050         n->nouni = on;
1051     } else if (cmd == VIRTIO_NET_CTRL_RX_NOBCAST) {
1052         n->nobcast = on;
1053     } else {
1054         return VIRTIO_NET_ERR;
1055     }
1056 
1057     rxfilter_notify(nc);
1058 
1059     return VIRTIO_NET_OK;
1060 }
1061 
1062 static int virtio_net_handle_offloads(VirtIONet *n, uint8_t cmd,
1063                                      struct iovec *iov, unsigned int iov_cnt)
1064 {
1065     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1066     uint64_t offloads;
1067     size_t s;
1068 
1069     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
1070         return VIRTIO_NET_ERR;
1071     }
1072 
1073     s = iov_to_buf(iov, iov_cnt, 0, &offloads, sizeof(offloads));
1074     if (s != sizeof(offloads)) {
1075         return VIRTIO_NET_ERR;
1076     }
1077 
1078     if (cmd == VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET) {
1079         uint64_t supported_offloads;
1080 
1081         offloads = virtio_ldq_p(vdev, &offloads);
1082 
1083         if (!n->has_vnet_hdr) {
1084             return VIRTIO_NET_ERR;
1085         }
1086 
1087         n->rsc4_enabled = virtio_has_feature(offloads, VIRTIO_NET_F_RSC_EXT) &&
1088             virtio_has_feature(offloads, VIRTIO_NET_F_GUEST_TSO4);
1089         n->rsc6_enabled = virtio_has_feature(offloads, VIRTIO_NET_F_RSC_EXT) &&
1090             virtio_has_feature(offloads, VIRTIO_NET_F_GUEST_TSO6);
1091         virtio_clear_feature(&offloads, VIRTIO_NET_F_RSC_EXT);
1092 
1093         supported_offloads = virtio_net_supported_guest_offloads(n);
1094         if (offloads & ~supported_offloads) {
1095             return VIRTIO_NET_ERR;
1096         }
1097 
1098         n->curr_guest_offloads = offloads;
1099         virtio_net_apply_guest_offloads(n);
1100 
1101         return VIRTIO_NET_OK;
1102     } else {
1103         return VIRTIO_NET_ERR;
1104     }
1105 }
1106 
1107 static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
1108                                  struct iovec *iov, unsigned int iov_cnt)
1109 {
1110     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1111     struct virtio_net_ctrl_mac mac_data;
1112     size_t s;
1113     NetClientState *nc = qemu_get_queue(n->nic);
1114 
1115     if (cmd == VIRTIO_NET_CTRL_MAC_ADDR_SET) {
1116         if (iov_size(iov, iov_cnt) != sizeof(n->mac)) {
1117             return VIRTIO_NET_ERR;
1118         }
1119         s = iov_to_buf(iov, iov_cnt, 0, &n->mac, sizeof(n->mac));
1120         assert(s == sizeof(n->mac));
1121         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
1122         rxfilter_notify(nc);
1123 
1124         return VIRTIO_NET_OK;
1125     }
1126 
1127     if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET) {
1128         return VIRTIO_NET_ERR;
1129     }
1130 
1131     int in_use = 0;
1132     int first_multi = 0;
1133     uint8_t uni_overflow = 0;
1134     uint8_t multi_overflow = 0;
1135     uint8_t *macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
1136 
1137     s = iov_to_buf(iov, iov_cnt, 0, &mac_data.entries,
1138                    sizeof(mac_data.entries));
1139     mac_data.entries = virtio_ldl_p(vdev, &mac_data.entries);
1140     if (s != sizeof(mac_data.entries)) {
1141         goto error;
1142     }
1143     iov_discard_front(&iov, &iov_cnt, s);
1144 
1145     if (mac_data.entries * ETH_ALEN > iov_size(iov, iov_cnt)) {
1146         goto error;
1147     }
1148 
1149     if (mac_data.entries <= MAC_TABLE_ENTRIES) {
1150         s = iov_to_buf(iov, iov_cnt, 0, macs,
1151                        mac_data.entries * ETH_ALEN);
1152         if (s != mac_data.entries * ETH_ALEN) {
1153             goto error;
1154         }
1155         in_use += mac_data.entries;
1156     } else {
1157         uni_overflow = 1;
1158     }
1159 
1160     iov_discard_front(&iov, &iov_cnt, mac_data.entries * ETH_ALEN);
1161 
1162     first_multi = in_use;
1163 
1164     s = iov_to_buf(iov, iov_cnt, 0, &mac_data.entries,
1165                    sizeof(mac_data.entries));
1166     mac_data.entries = virtio_ldl_p(vdev, &mac_data.entries);
1167     if (s != sizeof(mac_data.entries)) {
1168         goto error;
1169     }
1170 
1171     iov_discard_front(&iov, &iov_cnt, s);
1172 
1173     if (mac_data.entries * ETH_ALEN != iov_size(iov, iov_cnt)) {
1174         goto error;
1175     }
1176 
1177     if (mac_data.entries <= MAC_TABLE_ENTRIES - in_use) {
1178         s = iov_to_buf(iov, iov_cnt, 0, &macs[in_use * ETH_ALEN],
1179                        mac_data.entries * ETH_ALEN);
1180         if (s != mac_data.entries * ETH_ALEN) {
1181             goto error;
1182         }
1183         in_use += mac_data.entries;
1184     } else {
1185         multi_overflow = 1;
1186     }
1187 
1188     n->mac_table.in_use = in_use;
1189     n->mac_table.first_multi = first_multi;
1190     n->mac_table.uni_overflow = uni_overflow;
1191     n->mac_table.multi_overflow = multi_overflow;
1192     memcpy(n->mac_table.macs, macs, MAC_TABLE_ENTRIES * ETH_ALEN);
1193     g_free(macs);
1194     rxfilter_notify(nc);
1195 
1196     return VIRTIO_NET_OK;
1197 
1198 error:
1199     g_free(macs);
1200     return VIRTIO_NET_ERR;
1201 }
1202 
1203 static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
1204                                         struct iovec *iov, unsigned int iov_cnt)
1205 {
1206     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1207     uint16_t vid;
1208     size_t s;
1209     NetClientState *nc = qemu_get_queue(n->nic);
1210 
1211     s = iov_to_buf(iov, iov_cnt, 0, &vid, sizeof(vid));
1212     vid = virtio_lduw_p(vdev, &vid);
1213     if (s != sizeof(vid)) {
1214         return VIRTIO_NET_ERR;
1215     }
1216 
1217     if (vid >= MAX_VLAN)
1218         return VIRTIO_NET_ERR;
1219 
1220     if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
1221         n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
1222     else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
1223         n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
1224     else
1225         return VIRTIO_NET_ERR;
1226 
1227     rxfilter_notify(nc);
1228 
1229     return VIRTIO_NET_OK;
1230 }
1231 
1232 static int virtio_net_handle_announce(VirtIONet *n, uint8_t cmd,
1233                                       struct iovec *iov, unsigned int iov_cnt)
1234 {
1235     trace_virtio_net_handle_announce(n->announce_timer.round);
1236     if (cmd == VIRTIO_NET_CTRL_ANNOUNCE_ACK &&
1237         n->status & VIRTIO_NET_S_ANNOUNCE) {
1238         n->status &= ~VIRTIO_NET_S_ANNOUNCE;
1239         if (n->announce_timer.round) {
1240             qemu_announce_timer_step(&n->announce_timer);
1241         }
1242         return VIRTIO_NET_OK;
1243     } else {
1244         return VIRTIO_NET_ERR;
1245     }
1246 }
1247 
1248 static void virtio_net_detach_epbf_rss(VirtIONet *n);
1249 
1250 static void virtio_net_disable_rss(VirtIONet *n)
1251 {
1252     if (n->rss_data.enabled) {
1253         trace_virtio_net_rss_disable();
1254     }
1255     n->rss_data.enabled = false;
1256 
1257     virtio_net_detach_epbf_rss(n);
1258 }
1259 
1260 static bool virtio_net_attach_ebpf_to_backend(NICState *nic, int prog_fd)
1261 {
1262     NetClientState *nc = qemu_get_peer(qemu_get_queue(nic), 0);
1263     if (nc == NULL || nc->info->set_steering_ebpf == NULL) {
1264         return false;
1265     }
1266 
1267     return nc->info->set_steering_ebpf(nc, prog_fd);
1268 }
1269 
1270 static void rss_data_to_rss_config(struct VirtioNetRssData *data,
1271                                    struct EBPFRSSConfig *config)
1272 {
1273     config->redirect = data->redirect;
1274     config->populate_hash = data->populate_hash;
1275     config->hash_types = data->hash_types;
1276     config->indirections_len = data->indirections_len;
1277     config->default_queue = data->default_queue;
1278 }
1279 
1280 static bool virtio_net_attach_epbf_rss(VirtIONet *n)
1281 {
1282     struct EBPFRSSConfig config = {};
1283 
1284     if (!ebpf_rss_is_loaded(&n->ebpf_rss)) {
1285         return false;
1286     }
1287 
1288     rss_data_to_rss_config(&n->rss_data, &config);
1289 
1290     if (!ebpf_rss_set_all(&n->ebpf_rss, &config,
1291                           n->rss_data.indirections_table, n->rss_data.key)) {
1292         return false;
1293     }
1294 
1295     if (!virtio_net_attach_ebpf_to_backend(n->nic, n->ebpf_rss.program_fd)) {
1296         return false;
1297     }
1298 
1299     return true;
1300 }
1301 
1302 static void virtio_net_detach_epbf_rss(VirtIONet *n)
1303 {
1304     virtio_net_attach_ebpf_to_backend(n->nic, -1);
1305 }
1306 
1307 static bool virtio_net_load_ebpf(VirtIONet *n)
1308 {
1309     if (!virtio_net_attach_ebpf_to_backend(n->nic, -1)) {
1310         /* backend does't support steering ebpf */
1311         return false;
1312     }
1313 
1314     return ebpf_rss_load(&n->ebpf_rss);
1315 }
1316 
1317 static void virtio_net_unload_ebpf(VirtIONet *n)
1318 {
1319     virtio_net_attach_ebpf_to_backend(n->nic, -1);
1320     ebpf_rss_unload(&n->ebpf_rss);
1321 }
1322 
1323 static uint16_t virtio_net_handle_rss(VirtIONet *n,
1324                                       struct iovec *iov,
1325                                       unsigned int iov_cnt,
1326                                       bool do_rss)
1327 {
1328     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1329     struct virtio_net_rss_config cfg;
1330     size_t s, offset = 0, size_get;
1331     uint16_t queue_pairs, i;
1332     struct {
1333         uint16_t us;
1334         uint8_t b;
1335     } QEMU_PACKED temp;
1336     const char *err_msg = "";
1337     uint32_t err_value = 0;
1338 
1339     if (do_rss && !virtio_vdev_has_feature(vdev, VIRTIO_NET_F_RSS)) {
1340         err_msg = "RSS is not negotiated";
1341         goto error;
1342     }
1343     if (!do_rss && !virtio_vdev_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT)) {
1344         err_msg = "Hash report is not negotiated";
1345         goto error;
1346     }
1347     size_get = offsetof(struct virtio_net_rss_config, indirection_table);
1348     s = iov_to_buf(iov, iov_cnt, offset, &cfg, size_get);
1349     if (s != size_get) {
1350         err_msg = "Short command buffer";
1351         err_value = (uint32_t)s;
1352         goto error;
1353     }
1354     n->rss_data.hash_types = virtio_ldl_p(vdev, &cfg.hash_types);
1355     n->rss_data.indirections_len =
1356         virtio_lduw_p(vdev, &cfg.indirection_table_mask);
1357     n->rss_data.indirections_len++;
1358     if (!do_rss) {
1359         n->rss_data.indirections_len = 1;
1360     }
1361     if (!is_power_of_2(n->rss_data.indirections_len)) {
1362         err_msg = "Invalid size of indirection table";
1363         err_value = n->rss_data.indirections_len;
1364         goto error;
1365     }
1366     if (n->rss_data.indirections_len > VIRTIO_NET_RSS_MAX_TABLE_LEN) {
1367         err_msg = "Too large indirection table";
1368         err_value = n->rss_data.indirections_len;
1369         goto error;
1370     }
1371     n->rss_data.default_queue = do_rss ?
1372         virtio_lduw_p(vdev, &cfg.unclassified_queue) : 0;
1373     if (n->rss_data.default_queue >= n->max_queue_pairs) {
1374         err_msg = "Invalid default queue";
1375         err_value = n->rss_data.default_queue;
1376         goto error;
1377     }
1378     offset += size_get;
1379     size_get = sizeof(uint16_t) * n->rss_data.indirections_len;
1380     g_free(n->rss_data.indirections_table);
1381     n->rss_data.indirections_table = g_malloc(size_get);
1382     if (!n->rss_data.indirections_table) {
1383         err_msg = "Can't allocate indirections table";
1384         err_value = n->rss_data.indirections_len;
1385         goto error;
1386     }
1387     s = iov_to_buf(iov, iov_cnt, offset,
1388                    n->rss_data.indirections_table, size_get);
1389     if (s != size_get) {
1390         err_msg = "Short indirection table buffer";
1391         err_value = (uint32_t)s;
1392         goto error;
1393     }
1394     for (i = 0; i < n->rss_data.indirections_len; ++i) {
1395         uint16_t val = n->rss_data.indirections_table[i];
1396         n->rss_data.indirections_table[i] = virtio_lduw_p(vdev, &val);
1397     }
1398     offset += size_get;
1399     size_get = sizeof(temp);
1400     s = iov_to_buf(iov, iov_cnt, offset, &temp, size_get);
1401     if (s != size_get) {
1402         err_msg = "Can't get queue_pairs";
1403         err_value = (uint32_t)s;
1404         goto error;
1405     }
1406     queue_pairs = do_rss ? virtio_lduw_p(vdev, &temp.us) : n->curr_queue_pairs;
1407     if (queue_pairs == 0 || queue_pairs > n->max_queue_pairs) {
1408         err_msg = "Invalid number of queue_pairs";
1409         err_value = queue_pairs;
1410         goto error;
1411     }
1412     if (temp.b > VIRTIO_NET_RSS_MAX_KEY_SIZE) {
1413         err_msg = "Invalid key size";
1414         err_value = temp.b;
1415         goto error;
1416     }
1417     if (!temp.b && n->rss_data.hash_types) {
1418         err_msg = "No key provided";
1419         err_value = 0;
1420         goto error;
1421     }
1422     if (!temp.b && !n->rss_data.hash_types) {
1423         virtio_net_disable_rss(n);
1424         return queue_pairs;
1425     }
1426     offset += size_get;
1427     size_get = temp.b;
1428     s = iov_to_buf(iov, iov_cnt, offset, n->rss_data.key, size_get);
1429     if (s != size_get) {
1430         err_msg = "Can get key buffer";
1431         err_value = (uint32_t)s;
1432         goto error;
1433     }
1434     n->rss_data.enabled = true;
1435 
1436     if (!n->rss_data.populate_hash) {
1437         if (!virtio_net_attach_epbf_rss(n)) {
1438             /* EBPF must be loaded for vhost */
1439             if (get_vhost_net(qemu_get_queue(n->nic)->peer)) {
1440                 warn_report("Can't load eBPF RSS for vhost");
1441                 goto error;
1442             }
1443             /* fallback to software RSS */
1444             warn_report("Can't load eBPF RSS - fallback to software RSS");
1445             n->rss_data.enabled_software_rss = true;
1446         }
1447     } else {
1448         /* use software RSS for hash populating */
1449         /* and detach eBPF if was loaded before */
1450         virtio_net_detach_epbf_rss(n);
1451         n->rss_data.enabled_software_rss = true;
1452     }
1453 
1454     trace_virtio_net_rss_enable(n->rss_data.hash_types,
1455                                 n->rss_data.indirections_len,
1456                                 temp.b);
1457     return queue_pairs;
1458 error:
1459     trace_virtio_net_rss_error(err_msg, err_value);
1460     virtio_net_disable_rss(n);
1461     return 0;
1462 }
1463 
1464 static int virtio_net_handle_mq(VirtIONet *n, uint8_t cmd,
1465                                 struct iovec *iov, unsigned int iov_cnt)
1466 {
1467     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1468     uint16_t queue_pairs;
1469     NetClientState *nc = qemu_get_queue(n->nic);
1470 
1471     virtio_net_disable_rss(n);
1472     if (cmd == VIRTIO_NET_CTRL_MQ_HASH_CONFIG) {
1473         queue_pairs = virtio_net_handle_rss(n, iov, iov_cnt, false);
1474         return queue_pairs ? VIRTIO_NET_OK : VIRTIO_NET_ERR;
1475     }
1476     if (cmd == VIRTIO_NET_CTRL_MQ_RSS_CONFIG) {
1477         queue_pairs = virtio_net_handle_rss(n, iov, iov_cnt, true);
1478     } else if (cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
1479         struct virtio_net_ctrl_mq mq;
1480         size_t s;
1481         if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ)) {
1482             return VIRTIO_NET_ERR;
1483         }
1484         s = iov_to_buf(iov, iov_cnt, 0, &mq, sizeof(mq));
1485         if (s != sizeof(mq)) {
1486             return VIRTIO_NET_ERR;
1487         }
1488         queue_pairs = virtio_lduw_p(vdev, &mq.virtqueue_pairs);
1489 
1490     } else {
1491         return VIRTIO_NET_ERR;
1492     }
1493 
1494     if (queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1495         queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1496         queue_pairs > n->max_queue_pairs ||
1497         !n->multiqueue) {
1498         return VIRTIO_NET_ERR;
1499     }
1500 
1501     n->curr_queue_pairs = queue_pairs;
1502     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
1503         /*
1504          * Avoid updating the backend for a vdpa device: We're only interested
1505          * in updating the device model queues.
1506          */
1507         return VIRTIO_NET_OK;
1508     }
1509     /* stop the backend before changing the number of queue_pairs to avoid handling a
1510      * disabled queue */
1511     virtio_net_set_status(vdev, vdev->status);
1512     virtio_net_set_queue_pairs(n);
1513 
1514     return VIRTIO_NET_OK;
1515 }
1516 
1517 size_t virtio_net_handle_ctrl_iov(VirtIODevice *vdev,
1518                                   const struct iovec *in_sg, unsigned in_num,
1519                                   const struct iovec *out_sg,
1520                                   unsigned out_num)
1521 {
1522     VirtIONet *n = VIRTIO_NET(vdev);
1523     struct virtio_net_ctrl_hdr ctrl;
1524     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
1525     size_t s;
1526     struct iovec *iov, *iov2;
1527 
1528     if (iov_size(in_sg, in_num) < sizeof(status) ||
1529         iov_size(out_sg, out_num) < sizeof(ctrl)) {
1530         virtio_error(vdev, "virtio-net ctrl missing headers");
1531         return 0;
1532     }
1533 
1534     iov2 = iov = g_memdup2(out_sg, sizeof(struct iovec) * out_num);
1535     s = iov_to_buf(iov, out_num, 0, &ctrl, sizeof(ctrl));
1536     iov_discard_front(&iov, &out_num, sizeof(ctrl));
1537     if (s != sizeof(ctrl)) {
1538         status = VIRTIO_NET_ERR;
1539     } else if (ctrl.class == VIRTIO_NET_CTRL_RX) {
1540         status = virtio_net_handle_rx_mode(n, ctrl.cmd, iov, out_num);
1541     } else if (ctrl.class == VIRTIO_NET_CTRL_MAC) {
1542         status = virtio_net_handle_mac(n, ctrl.cmd, iov, out_num);
1543     } else if (ctrl.class == VIRTIO_NET_CTRL_VLAN) {
1544         status = virtio_net_handle_vlan_table(n, ctrl.cmd, iov, out_num);
1545     } else if (ctrl.class == VIRTIO_NET_CTRL_ANNOUNCE) {
1546         status = virtio_net_handle_announce(n, ctrl.cmd, iov, out_num);
1547     } else if (ctrl.class == VIRTIO_NET_CTRL_MQ) {
1548         status = virtio_net_handle_mq(n, ctrl.cmd, iov, out_num);
1549     } else if (ctrl.class == VIRTIO_NET_CTRL_GUEST_OFFLOADS) {
1550         status = virtio_net_handle_offloads(n, ctrl.cmd, iov, out_num);
1551     }
1552 
1553     s = iov_from_buf(in_sg, in_num, 0, &status, sizeof(status));
1554     assert(s == sizeof(status));
1555 
1556     g_free(iov2);
1557     return sizeof(status);
1558 }
1559 
1560 static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
1561 {
1562     VirtQueueElement *elem;
1563 
1564     for (;;) {
1565         size_t written;
1566         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
1567         if (!elem) {
1568             break;
1569         }
1570 
1571         written = virtio_net_handle_ctrl_iov(vdev, elem->in_sg, elem->in_num,
1572                                              elem->out_sg, elem->out_num);
1573         if (written > 0) {
1574             virtqueue_push(vq, elem, written);
1575             virtio_notify(vdev, vq);
1576             g_free(elem);
1577         } else {
1578             virtqueue_detach_element(vq, elem, 0);
1579             g_free(elem);
1580             break;
1581         }
1582     }
1583 }
1584 
1585 /* RX */
1586 
1587 static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
1588 {
1589     VirtIONet *n = VIRTIO_NET(vdev);
1590     int queue_index = vq2q(virtio_get_queue_index(vq));
1591 
1592     qemu_flush_queued_packets(qemu_get_subqueue(n->nic, queue_index));
1593 }
1594 
1595 static bool virtio_net_can_receive(NetClientState *nc)
1596 {
1597     VirtIONet *n = qemu_get_nic_opaque(nc);
1598     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1599     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
1600 
1601     if (!vdev->vm_running) {
1602         return false;
1603     }
1604 
1605     if (nc->queue_index >= n->curr_queue_pairs) {
1606         return false;
1607     }
1608 
1609     if (!virtio_queue_ready(q->rx_vq) ||
1610         !(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
1611         return false;
1612     }
1613 
1614     return true;
1615 }
1616 
1617 static int virtio_net_has_buffers(VirtIONetQueue *q, int bufsize)
1618 {
1619     VirtIONet *n = q->n;
1620     if (virtio_queue_empty(q->rx_vq) ||
1621         (n->mergeable_rx_bufs &&
1622          !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
1623         virtio_queue_set_notification(q->rx_vq, 1);
1624 
1625         /* To avoid a race condition where the guest has made some buffers
1626          * available after the above check but before notification was
1627          * enabled, check for available buffers again.
1628          */
1629         if (virtio_queue_empty(q->rx_vq) ||
1630             (n->mergeable_rx_bufs &&
1631              !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
1632             return 0;
1633         }
1634     }
1635 
1636     virtio_queue_set_notification(q->rx_vq, 0);
1637     return 1;
1638 }
1639 
1640 static void virtio_net_hdr_swap(VirtIODevice *vdev, struct virtio_net_hdr *hdr)
1641 {
1642     virtio_tswap16s(vdev, &hdr->hdr_len);
1643     virtio_tswap16s(vdev, &hdr->gso_size);
1644     virtio_tswap16s(vdev, &hdr->csum_start);
1645     virtio_tswap16s(vdev, &hdr->csum_offset);
1646 }
1647 
1648 /* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
1649  * it never finds out that the packets don't have valid checksums.  This
1650  * causes dhclient to get upset.  Fedora's carried a patch for ages to
1651  * fix this with Xen but it hasn't appeared in an upstream release of
1652  * dhclient yet.
1653  *
1654  * To avoid breaking existing guests, we catch udp packets and add
1655  * checksums.  This is terrible but it's better than hacking the guest
1656  * kernels.
1657  *
1658  * N.B. if we introduce a zero-copy API, this operation is no longer free so
1659  * we should provide a mechanism to disable it to avoid polluting the host
1660  * cache.
1661  */
1662 static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
1663                                         uint8_t *buf, size_t size)
1664 {
1665     if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
1666         (size > 27 && size < 1500) && /* normal sized MTU */
1667         (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
1668         (buf[23] == 17) && /* ip.protocol == UDP */
1669         (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
1670         net_checksum_calculate(buf, size, CSUM_UDP);
1671         hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
1672     }
1673 }
1674 
1675 static void receive_header(VirtIONet *n, const struct iovec *iov, int iov_cnt,
1676                            const void *buf, size_t size)
1677 {
1678     if (n->has_vnet_hdr) {
1679         /* FIXME this cast is evil */
1680         void *wbuf = (void *)buf;
1681         work_around_broken_dhclient(wbuf, wbuf + n->host_hdr_len,
1682                                     size - n->host_hdr_len);
1683 
1684         if (n->needs_vnet_hdr_swap) {
1685             virtio_net_hdr_swap(VIRTIO_DEVICE(n), wbuf);
1686         }
1687         iov_from_buf(iov, iov_cnt, 0, buf, sizeof(struct virtio_net_hdr));
1688     } else {
1689         struct virtio_net_hdr hdr = {
1690             .flags = 0,
1691             .gso_type = VIRTIO_NET_HDR_GSO_NONE
1692         };
1693         iov_from_buf(iov, iov_cnt, 0, &hdr, sizeof hdr);
1694     }
1695 }
1696 
1697 static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
1698 {
1699     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1700     static const uint8_t vlan[] = {0x81, 0x00};
1701     uint8_t *ptr = (uint8_t *)buf;
1702     int i;
1703 
1704     if (n->promisc)
1705         return 1;
1706 
1707     ptr += n->host_hdr_len;
1708 
1709     if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
1710         int vid = lduw_be_p(ptr + 14) & 0xfff;
1711         if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
1712             return 0;
1713     }
1714 
1715     if (ptr[0] & 1) { // multicast
1716         if (!memcmp(ptr, bcast, sizeof(bcast))) {
1717             return !n->nobcast;
1718         } else if (n->nomulti) {
1719             return 0;
1720         } else if (n->allmulti || n->mac_table.multi_overflow) {
1721             return 1;
1722         }
1723 
1724         for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
1725             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
1726                 return 1;
1727             }
1728         }
1729     } else { // unicast
1730         if (n->nouni) {
1731             return 0;
1732         } else if (n->alluni || n->mac_table.uni_overflow) {
1733             return 1;
1734         } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
1735             return 1;
1736         }
1737 
1738         for (i = 0; i < n->mac_table.first_multi; i++) {
1739             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
1740                 return 1;
1741             }
1742         }
1743     }
1744 
1745     return 0;
1746 }
1747 
1748 static uint8_t virtio_net_get_hash_type(bool hasip4,
1749                                         bool hasip6,
1750                                         EthL4HdrProto l4hdr_proto,
1751                                         uint32_t types)
1752 {
1753     if (hasip4) {
1754         switch (l4hdr_proto) {
1755         case ETH_L4_HDR_PROTO_TCP:
1756             if (types & VIRTIO_NET_RSS_HASH_TYPE_TCPv4) {
1757                 return NetPktRssIpV4Tcp;
1758             }
1759             break;
1760 
1761         case ETH_L4_HDR_PROTO_UDP:
1762             if (types & VIRTIO_NET_RSS_HASH_TYPE_UDPv4) {
1763                 return NetPktRssIpV4Udp;
1764             }
1765             break;
1766 
1767         default:
1768             break;
1769         }
1770 
1771         if (types & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
1772             return NetPktRssIpV4;
1773         }
1774     } else if (hasip6) {
1775         switch (l4hdr_proto) {
1776         case ETH_L4_HDR_PROTO_TCP:
1777             if (types & VIRTIO_NET_RSS_HASH_TYPE_TCP_EX) {
1778                 return NetPktRssIpV6TcpEx;
1779             }
1780             if (types & VIRTIO_NET_RSS_HASH_TYPE_TCPv6) {
1781                 return NetPktRssIpV6Tcp;
1782             }
1783             break;
1784 
1785         case ETH_L4_HDR_PROTO_UDP:
1786             if (types & VIRTIO_NET_RSS_HASH_TYPE_UDP_EX) {
1787                 return NetPktRssIpV6UdpEx;
1788             }
1789             if (types & VIRTIO_NET_RSS_HASH_TYPE_UDPv6) {
1790                 return NetPktRssIpV6Udp;
1791             }
1792             break;
1793 
1794         default:
1795             break;
1796         }
1797 
1798         if (types & VIRTIO_NET_RSS_HASH_TYPE_IP_EX) {
1799             return NetPktRssIpV6Ex;
1800         }
1801         if (types & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
1802             return NetPktRssIpV6;
1803         }
1804     }
1805     return 0xff;
1806 }
1807 
1808 static void virtio_set_packet_hash(const uint8_t *buf, uint8_t report,
1809                                    uint32_t hash)
1810 {
1811     struct virtio_net_hdr_v1_hash *hdr = (void *)buf;
1812     hdr->hash_value = hash;
1813     hdr->hash_report = report;
1814 }
1815 
1816 static int virtio_net_process_rss(NetClientState *nc, const uint8_t *buf,
1817                                   size_t size)
1818 {
1819     VirtIONet *n = qemu_get_nic_opaque(nc);
1820     unsigned int index = nc->queue_index, new_index = index;
1821     struct NetRxPkt *pkt = n->rx_pkt;
1822     uint8_t net_hash_type;
1823     uint32_t hash;
1824     bool hasip4, hasip6;
1825     EthL4HdrProto l4hdr_proto;
1826     static const uint8_t reports[NetPktRssIpV6UdpEx + 1] = {
1827         VIRTIO_NET_HASH_REPORT_IPv4,
1828         VIRTIO_NET_HASH_REPORT_TCPv4,
1829         VIRTIO_NET_HASH_REPORT_TCPv6,
1830         VIRTIO_NET_HASH_REPORT_IPv6,
1831         VIRTIO_NET_HASH_REPORT_IPv6_EX,
1832         VIRTIO_NET_HASH_REPORT_TCPv6_EX,
1833         VIRTIO_NET_HASH_REPORT_UDPv4,
1834         VIRTIO_NET_HASH_REPORT_UDPv6,
1835         VIRTIO_NET_HASH_REPORT_UDPv6_EX
1836     };
1837     struct iovec iov = {
1838         .iov_base = (void *)buf,
1839         .iov_len = size
1840     };
1841 
1842     net_rx_pkt_set_protocols(pkt, &iov, 1, n->host_hdr_len);
1843     net_rx_pkt_get_protocols(pkt, &hasip4, &hasip6, &l4hdr_proto);
1844     net_hash_type = virtio_net_get_hash_type(hasip4, hasip6, l4hdr_proto,
1845                                              n->rss_data.hash_types);
1846     if (net_hash_type > NetPktRssIpV6UdpEx) {
1847         if (n->rss_data.populate_hash) {
1848             virtio_set_packet_hash(buf, VIRTIO_NET_HASH_REPORT_NONE, 0);
1849         }
1850         return n->rss_data.redirect ? n->rss_data.default_queue : -1;
1851     }
1852 
1853     hash = net_rx_pkt_calc_rss_hash(pkt, net_hash_type, n->rss_data.key);
1854 
1855     if (n->rss_data.populate_hash) {
1856         virtio_set_packet_hash(buf, reports[net_hash_type], hash);
1857     }
1858 
1859     if (n->rss_data.redirect) {
1860         new_index = hash & (n->rss_data.indirections_len - 1);
1861         new_index = n->rss_data.indirections_table[new_index];
1862     }
1863 
1864     return (index == new_index) ? -1 : new_index;
1865 }
1866 
1867 static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
1868                                       size_t size, bool no_rss)
1869 {
1870     VirtIONet *n = qemu_get_nic_opaque(nc);
1871     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
1872     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1873     VirtQueueElement *elems[VIRTQUEUE_MAX_SIZE];
1874     size_t lens[VIRTQUEUE_MAX_SIZE];
1875     struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE];
1876     struct virtio_net_hdr_mrg_rxbuf mhdr;
1877     unsigned mhdr_cnt = 0;
1878     size_t offset, i, guest_offset, j;
1879     ssize_t err;
1880 
1881     if (!virtio_net_can_receive(nc)) {
1882         return -1;
1883     }
1884 
1885     if (!no_rss && n->rss_data.enabled && n->rss_data.enabled_software_rss) {
1886         int index = virtio_net_process_rss(nc, buf, size);
1887         if (index >= 0) {
1888             NetClientState *nc2 = qemu_get_subqueue(n->nic, index);
1889             return virtio_net_receive_rcu(nc2, buf, size, true);
1890         }
1891     }
1892 
1893     /* hdr_len refers to the header we supply to the guest */
1894     if (!virtio_net_has_buffers(q, size + n->guest_hdr_len - n->host_hdr_len)) {
1895         return 0;
1896     }
1897 
1898     if (!receive_filter(n, buf, size))
1899         return size;
1900 
1901     offset = i = 0;
1902 
1903     while (offset < size) {
1904         VirtQueueElement *elem;
1905         int len, total;
1906         const struct iovec *sg;
1907 
1908         total = 0;
1909 
1910         if (i == VIRTQUEUE_MAX_SIZE) {
1911             virtio_error(vdev, "virtio-net unexpected long buffer chain");
1912             err = size;
1913             goto err;
1914         }
1915 
1916         elem = virtqueue_pop(q->rx_vq, sizeof(VirtQueueElement));
1917         if (!elem) {
1918             if (i) {
1919                 virtio_error(vdev, "virtio-net unexpected empty queue: "
1920                              "i %zd mergeable %d offset %zd, size %zd, "
1921                              "guest hdr len %zd, host hdr len %zd "
1922                              "guest features 0x%" PRIx64,
1923                              i, n->mergeable_rx_bufs, offset, size,
1924                              n->guest_hdr_len, n->host_hdr_len,
1925                              vdev->guest_features);
1926             }
1927             err = -1;
1928             goto err;
1929         }
1930 
1931         if (elem->in_num < 1) {
1932             virtio_error(vdev,
1933                          "virtio-net receive queue contains no in buffers");
1934             virtqueue_detach_element(q->rx_vq, elem, 0);
1935             g_free(elem);
1936             err = -1;
1937             goto err;
1938         }
1939 
1940         sg = elem->in_sg;
1941         if (i == 0) {
1942             assert(offset == 0);
1943             if (n->mergeable_rx_bufs) {
1944                 mhdr_cnt = iov_copy(mhdr_sg, ARRAY_SIZE(mhdr_sg),
1945                                     sg, elem->in_num,
1946                                     offsetof(typeof(mhdr), num_buffers),
1947                                     sizeof(mhdr.num_buffers));
1948             }
1949 
1950             receive_header(n, sg, elem->in_num, buf, size);
1951             if (n->rss_data.populate_hash) {
1952                 offset = sizeof(mhdr);
1953                 iov_from_buf(sg, elem->in_num, offset,
1954                              buf + offset, n->host_hdr_len - sizeof(mhdr));
1955             }
1956             offset = n->host_hdr_len;
1957             total += n->guest_hdr_len;
1958             guest_offset = n->guest_hdr_len;
1959         } else {
1960             guest_offset = 0;
1961         }
1962 
1963         /* copy in packet.  ugh */
1964         len = iov_from_buf(sg, elem->in_num, guest_offset,
1965                            buf + offset, size - offset);
1966         total += len;
1967         offset += len;
1968         /* If buffers can't be merged, at this point we
1969          * must have consumed the complete packet.
1970          * Otherwise, drop it. */
1971         if (!n->mergeable_rx_bufs && offset < size) {
1972             virtqueue_unpop(q->rx_vq, elem, total);
1973             g_free(elem);
1974             err = size;
1975             goto err;
1976         }
1977 
1978         elems[i] = elem;
1979         lens[i] = total;
1980         i++;
1981     }
1982 
1983     if (mhdr_cnt) {
1984         virtio_stw_p(vdev, &mhdr.num_buffers, i);
1985         iov_from_buf(mhdr_sg, mhdr_cnt,
1986                      0,
1987                      &mhdr.num_buffers, sizeof mhdr.num_buffers);
1988     }
1989 
1990     for (j = 0; j < i; j++) {
1991         /* signal other side */
1992         virtqueue_fill(q->rx_vq, elems[j], lens[j], j);
1993         g_free(elems[j]);
1994     }
1995 
1996     virtqueue_flush(q->rx_vq, i);
1997     virtio_notify(vdev, q->rx_vq);
1998 
1999     return size;
2000 
2001 err:
2002     for (j = 0; j < i; j++) {
2003         virtqueue_detach_element(q->rx_vq, elems[j], lens[j]);
2004         g_free(elems[j]);
2005     }
2006 
2007     return err;
2008 }
2009 
2010 static ssize_t virtio_net_do_receive(NetClientState *nc, const uint8_t *buf,
2011                                   size_t size)
2012 {
2013     RCU_READ_LOCK_GUARD();
2014 
2015     return virtio_net_receive_rcu(nc, buf, size, false);
2016 }
2017 
2018 static void virtio_net_rsc_extract_unit4(VirtioNetRscChain *chain,
2019                                          const uint8_t *buf,
2020                                          VirtioNetRscUnit *unit)
2021 {
2022     uint16_t ip_hdrlen;
2023     struct ip_header *ip;
2024 
2025     ip = (struct ip_header *)(buf + chain->n->guest_hdr_len
2026                               + sizeof(struct eth_header));
2027     unit->ip = (void *)ip;
2028     ip_hdrlen = (ip->ip_ver_len & 0xF) << 2;
2029     unit->ip_plen = &ip->ip_len;
2030     unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip) + ip_hdrlen);
2031     unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000) >> 10;
2032     unit->payload = htons(*unit->ip_plen) - ip_hdrlen - unit->tcp_hdrlen;
2033 }
2034 
2035 static void virtio_net_rsc_extract_unit6(VirtioNetRscChain *chain,
2036                                          const uint8_t *buf,
2037                                          VirtioNetRscUnit *unit)
2038 {
2039     struct ip6_header *ip6;
2040 
2041     ip6 = (struct ip6_header *)(buf + chain->n->guest_hdr_len
2042                                  + sizeof(struct eth_header));
2043     unit->ip = ip6;
2044     unit->ip_plen = &(ip6->ip6_ctlun.ip6_un1.ip6_un1_plen);
2045     unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip)
2046                                         + sizeof(struct ip6_header));
2047     unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000) >> 10;
2048 
2049     /* There is a difference between payload lenght in ipv4 and v6,
2050        ip header is excluded in ipv6 */
2051     unit->payload = htons(*unit->ip_plen) - unit->tcp_hdrlen;
2052 }
2053 
2054 static size_t virtio_net_rsc_drain_seg(VirtioNetRscChain *chain,
2055                                        VirtioNetRscSeg *seg)
2056 {
2057     int ret;
2058     struct virtio_net_hdr_v1 *h;
2059 
2060     h = (struct virtio_net_hdr_v1 *)seg->buf;
2061     h->flags = 0;
2062     h->gso_type = VIRTIO_NET_HDR_GSO_NONE;
2063 
2064     if (seg->is_coalesced) {
2065         h->rsc.segments = seg->packets;
2066         h->rsc.dup_acks = seg->dup_ack;
2067         h->flags = VIRTIO_NET_HDR_F_RSC_INFO;
2068         if (chain->proto == ETH_P_IP) {
2069             h->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2070         } else {
2071             h->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2072         }
2073     }
2074 
2075     ret = virtio_net_do_receive(seg->nc, seg->buf, seg->size);
2076     QTAILQ_REMOVE(&chain->buffers, seg, next);
2077     g_free(seg->buf);
2078     g_free(seg);
2079 
2080     return ret;
2081 }
2082 
2083 static void virtio_net_rsc_purge(void *opq)
2084 {
2085     VirtioNetRscSeg *seg, *rn;
2086     VirtioNetRscChain *chain = (VirtioNetRscChain *)opq;
2087 
2088     QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn) {
2089         if (virtio_net_rsc_drain_seg(chain, seg) == 0) {
2090             chain->stat.purge_failed++;
2091             continue;
2092         }
2093     }
2094 
2095     chain->stat.timer++;
2096     if (!QTAILQ_EMPTY(&chain->buffers)) {
2097         timer_mod(chain->drain_timer,
2098               qemu_clock_get_ns(QEMU_CLOCK_HOST) + chain->n->rsc_timeout);
2099     }
2100 }
2101 
2102 static void virtio_net_rsc_cleanup(VirtIONet *n)
2103 {
2104     VirtioNetRscChain *chain, *rn_chain;
2105     VirtioNetRscSeg *seg, *rn_seg;
2106 
2107     QTAILQ_FOREACH_SAFE(chain, &n->rsc_chains, next, rn_chain) {
2108         QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn_seg) {
2109             QTAILQ_REMOVE(&chain->buffers, seg, next);
2110             g_free(seg->buf);
2111             g_free(seg);
2112         }
2113 
2114         timer_free(chain->drain_timer);
2115         QTAILQ_REMOVE(&n->rsc_chains, chain, next);
2116         g_free(chain);
2117     }
2118 }
2119 
2120 static void virtio_net_rsc_cache_buf(VirtioNetRscChain *chain,
2121                                      NetClientState *nc,
2122                                      const uint8_t *buf, size_t size)
2123 {
2124     uint16_t hdr_len;
2125     VirtioNetRscSeg *seg;
2126 
2127     hdr_len = chain->n->guest_hdr_len;
2128     seg = g_new(VirtioNetRscSeg, 1);
2129     seg->buf = g_malloc(hdr_len + sizeof(struct eth_header)
2130         + sizeof(struct ip6_header) + VIRTIO_NET_MAX_TCP_PAYLOAD);
2131     memcpy(seg->buf, buf, size);
2132     seg->size = size;
2133     seg->packets = 1;
2134     seg->dup_ack = 0;
2135     seg->is_coalesced = 0;
2136     seg->nc = nc;
2137 
2138     QTAILQ_INSERT_TAIL(&chain->buffers, seg, next);
2139     chain->stat.cache++;
2140 
2141     switch (chain->proto) {
2142     case ETH_P_IP:
2143         virtio_net_rsc_extract_unit4(chain, seg->buf, &seg->unit);
2144         break;
2145     case ETH_P_IPV6:
2146         virtio_net_rsc_extract_unit6(chain, seg->buf, &seg->unit);
2147         break;
2148     default:
2149         g_assert_not_reached();
2150     }
2151 }
2152 
2153 static int32_t virtio_net_rsc_handle_ack(VirtioNetRscChain *chain,
2154                                          VirtioNetRscSeg *seg,
2155                                          const uint8_t *buf,
2156                                          struct tcp_header *n_tcp,
2157                                          struct tcp_header *o_tcp)
2158 {
2159     uint32_t nack, oack;
2160     uint16_t nwin, owin;
2161 
2162     nack = htonl(n_tcp->th_ack);
2163     nwin = htons(n_tcp->th_win);
2164     oack = htonl(o_tcp->th_ack);
2165     owin = htons(o_tcp->th_win);
2166 
2167     if ((nack - oack) >= VIRTIO_NET_MAX_TCP_PAYLOAD) {
2168         chain->stat.ack_out_of_win++;
2169         return RSC_FINAL;
2170     } else if (nack == oack) {
2171         /* duplicated ack or window probe */
2172         if (nwin == owin) {
2173             /* duplicated ack, add dup ack count due to whql test up to 1 */
2174             chain->stat.dup_ack++;
2175             return RSC_FINAL;
2176         } else {
2177             /* Coalesce window update */
2178             o_tcp->th_win = n_tcp->th_win;
2179             chain->stat.win_update++;
2180             return RSC_COALESCE;
2181         }
2182     } else {
2183         /* pure ack, go to 'C', finalize*/
2184         chain->stat.pure_ack++;
2185         return RSC_FINAL;
2186     }
2187 }
2188 
2189 static int32_t virtio_net_rsc_coalesce_data(VirtioNetRscChain *chain,
2190                                             VirtioNetRscSeg *seg,
2191                                             const uint8_t *buf,
2192                                             VirtioNetRscUnit *n_unit)
2193 {
2194     void *data;
2195     uint16_t o_ip_len;
2196     uint32_t nseq, oseq;
2197     VirtioNetRscUnit *o_unit;
2198 
2199     o_unit = &seg->unit;
2200     o_ip_len = htons(*o_unit->ip_plen);
2201     nseq = htonl(n_unit->tcp->th_seq);
2202     oseq = htonl(o_unit->tcp->th_seq);
2203 
2204     /* out of order or retransmitted. */
2205     if ((nseq - oseq) > VIRTIO_NET_MAX_TCP_PAYLOAD) {
2206         chain->stat.data_out_of_win++;
2207         return RSC_FINAL;
2208     }
2209 
2210     data = ((uint8_t *)n_unit->tcp) + n_unit->tcp_hdrlen;
2211     if (nseq == oseq) {
2212         if ((o_unit->payload == 0) && n_unit->payload) {
2213             /* From no payload to payload, normal case, not a dup ack or etc */
2214             chain->stat.data_after_pure_ack++;
2215             goto coalesce;
2216         } else {
2217             return virtio_net_rsc_handle_ack(chain, seg, buf,
2218                                              n_unit->tcp, o_unit->tcp);
2219         }
2220     } else if ((nseq - oseq) != o_unit->payload) {
2221         /* Not a consistent packet, out of order */
2222         chain->stat.data_out_of_order++;
2223         return RSC_FINAL;
2224     } else {
2225 coalesce:
2226         if ((o_ip_len + n_unit->payload) > chain->max_payload) {
2227             chain->stat.over_size++;
2228             return RSC_FINAL;
2229         }
2230 
2231         /* Here comes the right data, the payload length in v4/v6 is different,
2232            so use the field value to update and record the new data len */
2233         o_unit->payload += n_unit->payload; /* update new data len */
2234 
2235         /* update field in ip header */
2236         *o_unit->ip_plen = htons(o_ip_len + n_unit->payload);
2237 
2238         /* Bring 'PUSH' big, the whql test guide says 'PUSH' can be coalesced
2239            for windows guest, while this may change the behavior for linux
2240            guest (only if it uses RSC feature). */
2241         o_unit->tcp->th_offset_flags = n_unit->tcp->th_offset_flags;
2242 
2243         o_unit->tcp->th_ack = n_unit->tcp->th_ack;
2244         o_unit->tcp->th_win = n_unit->tcp->th_win;
2245 
2246         memmove(seg->buf + seg->size, data, n_unit->payload);
2247         seg->size += n_unit->payload;
2248         seg->packets++;
2249         chain->stat.coalesced++;
2250         return RSC_COALESCE;
2251     }
2252 }
2253 
2254 static int32_t virtio_net_rsc_coalesce4(VirtioNetRscChain *chain,
2255                                         VirtioNetRscSeg *seg,
2256                                         const uint8_t *buf, size_t size,
2257                                         VirtioNetRscUnit *unit)
2258 {
2259     struct ip_header *ip1, *ip2;
2260 
2261     ip1 = (struct ip_header *)(unit->ip);
2262     ip2 = (struct ip_header *)(seg->unit.ip);
2263     if ((ip1->ip_src ^ ip2->ip_src) || (ip1->ip_dst ^ ip2->ip_dst)
2264         || (unit->tcp->th_sport ^ seg->unit.tcp->th_sport)
2265         || (unit->tcp->th_dport ^ seg->unit.tcp->th_dport)) {
2266         chain->stat.no_match++;
2267         return RSC_NO_MATCH;
2268     }
2269 
2270     return virtio_net_rsc_coalesce_data(chain, seg, buf, unit);
2271 }
2272 
2273 static int32_t virtio_net_rsc_coalesce6(VirtioNetRscChain *chain,
2274                                         VirtioNetRscSeg *seg,
2275                                         const uint8_t *buf, size_t size,
2276                                         VirtioNetRscUnit *unit)
2277 {
2278     struct ip6_header *ip1, *ip2;
2279 
2280     ip1 = (struct ip6_header *)(unit->ip);
2281     ip2 = (struct ip6_header *)(seg->unit.ip);
2282     if (memcmp(&ip1->ip6_src, &ip2->ip6_src, sizeof(struct in6_address))
2283         || memcmp(&ip1->ip6_dst, &ip2->ip6_dst, sizeof(struct in6_address))
2284         || (unit->tcp->th_sport ^ seg->unit.tcp->th_sport)
2285         || (unit->tcp->th_dport ^ seg->unit.tcp->th_dport)) {
2286             chain->stat.no_match++;
2287             return RSC_NO_MATCH;
2288     }
2289 
2290     return virtio_net_rsc_coalesce_data(chain, seg, buf, unit);
2291 }
2292 
2293 /* Packets with 'SYN' should bypass, other flag should be sent after drain
2294  * to prevent out of order */
2295 static int virtio_net_rsc_tcp_ctrl_check(VirtioNetRscChain *chain,
2296                                          struct tcp_header *tcp)
2297 {
2298     uint16_t tcp_hdr;
2299     uint16_t tcp_flag;
2300 
2301     tcp_flag = htons(tcp->th_offset_flags);
2302     tcp_hdr = (tcp_flag & VIRTIO_NET_TCP_HDR_LENGTH) >> 10;
2303     tcp_flag &= VIRTIO_NET_TCP_FLAG;
2304     if (tcp_flag & TH_SYN) {
2305         chain->stat.tcp_syn++;
2306         return RSC_BYPASS;
2307     }
2308 
2309     if (tcp_flag & (TH_FIN | TH_URG | TH_RST | TH_ECE | TH_CWR)) {
2310         chain->stat.tcp_ctrl_drain++;
2311         return RSC_FINAL;
2312     }
2313 
2314     if (tcp_hdr > sizeof(struct tcp_header)) {
2315         chain->stat.tcp_all_opt++;
2316         return RSC_FINAL;
2317     }
2318 
2319     return RSC_CANDIDATE;
2320 }
2321 
2322 static size_t virtio_net_rsc_do_coalesce(VirtioNetRscChain *chain,
2323                                          NetClientState *nc,
2324                                          const uint8_t *buf, size_t size,
2325                                          VirtioNetRscUnit *unit)
2326 {
2327     int ret;
2328     VirtioNetRscSeg *seg, *nseg;
2329 
2330     if (QTAILQ_EMPTY(&chain->buffers)) {
2331         chain->stat.empty_cache++;
2332         virtio_net_rsc_cache_buf(chain, nc, buf, size);
2333         timer_mod(chain->drain_timer,
2334               qemu_clock_get_ns(QEMU_CLOCK_HOST) + chain->n->rsc_timeout);
2335         return size;
2336     }
2337 
2338     QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) {
2339         if (chain->proto == ETH_P_IP) {
2340             ret = virtio_net_rsc_coalesce4(chain, seg, buf, size, unit);
2341         } else {
2342             ret = virtio_net_rsc_coalesce6(chain, seg, buf, size, unit);
2343         }
2344 
2345         if (ret == RSC_FINAL) {
2346             if (virtio_net_rsc_drain_seg(chain, seg) == 0) {
2347                 /* Send failed */
2348                 chain->stat.final_failed++;
2349                 return 0;
2350             }
2351 
2352             /* Send current packet */
2353             return virtio_net_do_receive(nc, buf, size);
2354         } else if (ret == RSC_NO_MATCH) {
2355             continue;
2356         } else {
2357             /* Coalesced, mark coalesced flag to tell calc cksum for ipv4 */
2358             seg->is_coalesced = 1;
2359             return size;
2360         }
2361     }
2362 
2363     chain->stat.no_match_cache++;
2364     virtio_net_rsc_cache_buf(chain, nc, buf, size);
2365     return size;
2366 }
2367 
2368 /* Drain a connection data, this is to avoid out of order segments */
2369 static size_t virtio_net_rsc_drain_flow(VirtioNetRscChain *chain,
2370                                         NetClientState *nc,
2371                                         const uint8_t *buf, size_t size,
2372                                         uint16_t ip_start, uint16_t ip_size,
2373                                         uint16_t tcp_port)
2374 {
2375     VirtioNetRscSeg *seg, *nseg;
2376     uint32_t ppair1, ppair2;
2377 
2378     ppair1 = *(uint32_t *)(buf + tcp_port);
2379     QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) {
2380         ppair2 = *(uint32_t *)(seg->buf + tcp_port);
2381         if (memcmp(buf + ip_start, seg->buf + ip_start, ip_size)
2382             || (ppair1 != ppair2)) {
2383             continue;
2384         }
2385         if (virtio_net_rsc_drain_seg(chain, seg) == 0) {
2386             chain->stat.drain_failed++;
2387         }
2388 
2389         break;
2390     }
2391 
2392     return virtio_net_do_receive(nc, buf, size);
2393 }
2394 
2395 static int32_t virtio_net_rsc_sanity_check4(VirtioNetRscChain *chain,
2396                                             struct ip_header *ip,
2397                                             const uint8_t *buf, size_t size)
2398 {
2399     uint16_t ip_len;
2400 
2401     /* Not an ipv4 packet */
2402     if (((ip->ip_ver_len & 0xF0) >> 4) != IP_HEADER_VERSION_4) {
2403         chain->stat.ip_option++;
2404         return RSC_BYPASS;
2405     }
2406 
2407     /* Don't handle packets with ip option */
2408     if ((ip->ip_ver_len & 0xF) != VIRTIO_NET_IP4_HEADER_LENGTH) {
2409         chain->stat.ip_option++;
2410         return RSC_BYPASS;
2411     }
2412 
2413     if (ip->ip_p != IPPROTO_TCP) {
2414         chain->stat.bypass_not_tcp++;
2415         return RSC_BYPASS;
2416     }
2417 
2418     /* Don't handle packets with ip fragment */
2419     if (!(htons(ip->ip_off) & IP_DF)) {
2420         chain->stat.ip_frag++;
2421         return RSC_BYPASS;
2422     }
2423 
2424     /* Don't handle packets with ecn flag */
2425     if (IPTOS_ECN(ip->ip_tos)) {
2426         chain->stat.ip_ecn++;
2427         return RSC_BYPASS;
2428     }
2429 
2430     ip_len = htons(ip->ip_len);
2431     if (ip_len < (sizeof(struct ip_header) + sizeof(struct tcp_header))
2432         || ip_len > (size - chain->n->guest_hdr_len -
2433                      sizeof(struct eth_header))) {
2434         chain->stat.ip_hacked++;
2435         return RSC_BYPASS;
2436     }
2437 
2438     return RSC_CANDIDATE;
2439 }
2440 
2441 static size_t virtio_net_rsc_receive4(VirtioNetRscChain *chain,
2442                                       NetClientState *nc,
2443                                       const uint8_t *buf, size_t size)
2444 {
2445     int32_t ret;
2446     uint16_t hdr_len;
2447     VirtioNetRscUnit unit;
2448 
2449     hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len;
2450 
2451     if (size < (hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header)
2452         + sizeof(struct tcp_header))) {
2453         chain->stat.bypass_not_tcp++;
2454         return virtio_net_do_receive(nc, buf, size);
2455     }
2456 
2457     virtio_net_rsc_extract_unit4(chain, buf, &unit);
2458     if (virtio_net_rsc_sanity_check4(chain, unit.ip, buf, size)
2459         != RSC_CANDIDATE) {
2460         return virtio_net_do_receive(nc, buf, size);
2461     }
2462 
2463     ret = virtio_net_rsc_tcp_ctrl_check(chain, unit.tcp);
2464     if (ret == RSC_BYPASS) {
2465         return virtio_net_do_receive(nc, buf, size);
2466     } else if (ret == RSC_FINAL) {
2467         return virtio_net_rsc_drain_flow(chain, nc, buf, size,
2468                 ((hdr_len + sizeof(struct eth_header)) + 12),
2469                 VIRTIO_NET_IP4_ADDR_SIZE,
2470                 hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header));
2471     }
2472 
2473     return virtio_net_rsc_do_coalesce(chain, nc, buf, size, &unit);
2474 }
2475 
2476 static int32_t virtio_net_rsc_sanity_check6(VirtioNetRscChain *chain,
2477                                             struct ip6_header *ip6,
2478                                             const uint8_t *buf, size_t size)
2479 {
2480     uint16_t ip_len;
2481 
2482     if (((ip6->ip6_ctlun.ip6_un1.ip6_un1_flow & 0xF0) >> 4)
2483         != IP_HEADER_VERSION_6) {
2484         return RSC_BYPASS;
2485     }
2486 
2487     /* Both option and protocol is checked in this */
2488     if (ip6->ip6_ctlun.ip6_un1.ip6_un1_nxt != IPPROTO_TCP) {
2489         chain->stat.bypass_not_tcp++;
2490         return RSC_BYPASS;
2491     }
2492 
2493     ip_len = htons(ip6->ip6_ctlun.ip6_un1.ip6_un1_plen);
2494     if (ip_len < sizeof(struct tcp_header) ||
2495         ip_len > (size - chain->n->guest_hdr_len - sizeof(struct eth_header)
2496                   - sizeof(struct ip6_header))) {
2497         chain->stat.ip_hacked++;
2498         return RSC_BYPASS;
2499     }
2500 
2501     /* Don't handle packets with ecn flag */
2502     if (IP6_ECN(ip6->ip6_ctlun.ip6_un3.ip6_un3_ecn)) {
2503         chain->stat.ip_ecn++;
2504         return RSC_BYPASS;
2505     }
2506 
2507     return RSC_CANDIDATE;
2508 }
2509 
2510 static size_t virtio_net_rsc_receive6(void *opq, NetClientState *nc,
2511                                       const uint8_t *buf, size_t size)
2512 {
2513     int32_t ret;
2514     uint16_t hdr_len;
2515     VirtioNetRscChain *chain;
2516     VirtioNetRscUnit unit;
2517 
2518     chain = opq;
2519     hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len;
2520 
2521     if (size < (hdr_len + sizeof(struct eth_header) + sizeof(struct ip6_header)
2522         + sizeof(tcp_header))) {
2523         return virtio_net_do_receive(nc, buf, size);
2524     }
2525 
2526     virtio_net_rsc_extract_unit6(chain, buf, &unit);
2527     if (RSC_CANDIDATE != virtio_net_rsc_sanity_check6(chain,
2528                                                  unit.ip, buf, size)) {
2529         return virtio_net_do_receive(nc, buf, size);
2530     }
2531 
2532     ret = virtio_net_rsc_tcp_ctrl_check(chain, unit.tcp);
2533     if (ret == RSC_BYPASS) {
2534         return virtio_net_do_receive(nc, buf, size);
2535     } else if (ret == RSC_FINAL) {
2536         return virtio_net_rsc_drain_flow(chain, nc, buf, size,
2537                 ((hdr_len + sizeof(struct eth_header)) + 8),
2538                 VIRTIO_NET_IP6_ADDR_SIZE,
2539                 hdr_len + sizeof(struct eth_header)
2540                 + sizeof(struct ip6_header));
2541     }
2542 
2543     return virtio_net_rsc_do_coalesce(chain, nc, buf, size, &unit);
2544 }
2545 
2546 static VirtioNetRscChain *virtio_net_rsc_lookup_chain(VirtIONet *n,
2547                                                       NetClientState *nc,
2548                                                       uint16_t proto)
2549 {
2550     VirtioNetRscChain *chain;
2551 
2552     if ((proto != (uint16_t)ETH_P_IP) && (proto != (uint16_t)ETH_P_IPV6)) {
2553         return NULL;
2554     }
2555 
2556     QTAILQ_FOREACH(chain, &n->rsc_chains, next) {
2557         if (chain->proto == proto) {
2558             return chain;
2559         }
2560     }
2561 
2562     chain = g_malloc(sizeof(*chain));
2563     chain->n = n;
2564     chain->proto = proto;
2565     if (proto == (uint16_t)ETH_P_IP) {
2566         chain->max_payload = VIRTIO_NET_MAX_IP4_PAYLOAD;
2567         chain->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2568     } else {
2569         chain->max_payload = VIRTIO_NET_MAX_IP6_PAYLOAD;
2570         chain->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2571     }
2572     chain->drain_timer = timer_new_ns(QEMU_CLOCK_HOST,
2573                                       virtio_net_rsc_purge, chain);
2574     memset(&chain->stat, 0, sizeof(chain->stat));
2575 
2576     QTAILQ_INIT(&chain->buffers);
2577     QTAILQ_INSERT_TAIL(&n->rsc_chains, chain, next);
2578 
2579     return chain;
2580 }
2581 
2582 static ssize_t virtio_net_rsc_receive(NetClientState *nc,
2583                                       const uint8_t *buf,
2584                                       size_t size)
2585 {
2586     uint16_t proto;
2587     VirtioNetRscChain *chain;
2588     struct eth_header *eth;
2589     VirtIONet *n;
2590 
2591     n = qemu_get_nic_opaque(nc);
2592     if (size < (n->host_hdr_len + sizeof(struct eth_header))) {
2593         return virtio_net_do_receive(nc, buf, size);
2594     }
2595 
2596     eth = (struct eth_header *)(buf + n->guest_hdr_len);
2597     proto = htons(eth->h_proto);
2598 
2599     chain = virtio_net_rsc_lookup_chain(n, nc, proto);
2600     if (chain) {
2601         chain->stat.received++;
2602         if (proto == (uint16_t)ETH_P_IP && n->rsc4_enabled) {
2603             return virtio_net_rsc_receive4(chain, nc, buf, size);
2604         } else if (proto == (uint16_t)ETH_P_IPV6 && n->rsc6_enabled) {
2605             return virtio_net_rsc_receive6(chain, nc, buf, size);
2606         }
2607     }
2608     return virtio_net_do_receive(nc, buf, size);
2609 }
2610 
2611 static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf,
2612                                   size_t size)
2613 {
2614     VirtIONet *n = qemu_get_nic_opaque(nc);
2615     if ((n->rsc4_enabled || n->rsc6_enabled)) {
2616         return virtio_net_rsc_receive(nc, buf, size);
2617     } else {
2618         return virtio_net_do_receive(nc, buf, size);
2619     }
2620 }
2621 
2622 static int32_t virtio_net_flush_tx(VirtIONetQueue *q);
2623 
2624 static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
2625 {
2626     VirtIONet *n = qemu_get_nic_opaque(nc);
2627     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
2628     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2629     int ret;
2630 
2631     virtqueue_push(q->tx_vq, q->async_tx.elem, 0);
2632     virtio_notify(vdev, q->tx_vq);
2633 
2634     g_free(q->async_tx.elem);
2635     q->async_tx.elem = NULL;
2636 
2637     virtio_queue_set_notification(q->tx_vq, 1);
2638     ret = virtio_net_flush_tx(q);
2639     if (ret >= n->tx_burst) {
2640         /*
2641          * the flush has been stopped by tx_burst
2642          * we will not receive notification for the
2643          * remainining part, so re-schedule
2644          */
2645         virtio_queue_set_notification(q->tx_vq, 0);
2646         if (q->tx_bh) {
2647             qemu_bh_schedule(q->tx_bh);
2648         } else {
2649             timer_mod(q->tx_timer,
2650                       qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
2651         }
2652         q->tx_waiting = 1;
2653     }
2654 }
2655 
2656 /* TX */
2657 static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
2658 {
2659     VirtIONet *n = q->n;
2660     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2661     VirtQueueElement *elem;
2662     int32_t num_packets = 0;
2663     int queue_index = vq2q(virtio_get_queue_index(q->tx_vq));
2664     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
2665         return num_packets;
2666     }
2667 
2668     if (q->async_tx.elem) {
2669         virtio_queue_set_notification(q->tx_vq, 0);
2670         return num_packets;
2671     }
2672 
2673     for (;;) {
2674         ssize_t ret;
2675         unsigned int out_num;
2676         struct iovec sg[VIRTQUEUE_MAX_SIZE], sg2[VIRTQUEUE_MAX_SIZE + 1], *out_sg;
2677         struct virtio_net_hdr_mrg_rxbuf mhdr;
2678 
2679         elem = virtqueue_pop(q->tx_vq, sizeof(VirtQueueElement));
2680         if (!elem) {
2681             break;
2682         }
2683 
2684         out_num = elem->out_num;
2685         out_sg = elem->out_sg;
2686         if (out_num < 1) {
2687             virtio_error(vdev, "virtio-net header not in first element");
2688             virtqueue_detach_element(q->tx_vq, elem, 0);
2689             g_free(elem);
2690             return -EINVAL;
2691         }
2692 
2693         if (n->has_vnet_hdr) {
2694             if (iov_to_buf(out_sg, out_num, 0, &mhdr, n->guest_hdr_len) <
2695                 n->guest_hdr_len) {
2696                 virtio_error(vdev, "virtio-net header incorrect");
2697                 virtqueue_detach_element(q->tx_vq, elem, 0);
2698                 g_free(elem);
2699                 return -EINVAL;
2700             }
2701             if (n->needs_vnet_hdr_swap) {
2702                 virtio_net_hdr_swap(vdev, (void *) &mhdr);
2703                 sg2[0].iov_base = &mhdr;
2704                 sg2[0].iov_len = n->guest_hdr_len;
2705                 out_num = iov_copy(&sg2[1], ARRAY_SIZE(sg2) - 1,
2706                                    out_sg, out_num,
2707                                    n->guest_hdr_len, -1);
2708                 if (out_num == VIRTQUEUE_MAX_SIZE) {
2709                     goto drop;
2710                 }
2711                 out_num += 1;
2712                 out_sg = sg2;
2713             }
2714         }
2715         /*
2716          * If host wants to see the guest header as is, we can
2717          * pass it on unchanged. Otherwise, copy just the parts
2718          * that host is interested in.
2719          */
2720         assert(n->host_hdr_len <= n->guest_hdr_len);
2721         if (n->host_hdr_len != n->guest_hdr_len) {
2722             unsigned sg_num = iov_copy(sg, ARRAY_SIZE(sg),
2723                                        out_sg, out_num,
2724                                        0, n->host_hdr_len);
2725             sg_num += iov_copy(sg + sg_num, ARRAY_SIZE(sg) - sg_num,
2726                              out_sg, out_num,
2727                              n->guest_hdr_len, -1);
2728             out_num = sg_num;
2729             out_sg = sg;
2730         }
2731 
2732         ret = qemu_sendv_packet_async(qemu_get_subqueue(n->nic, queue_index),
2733                                       out_sg, out_num, virtio_net_tx_complete);
2734         if (ret == 0) {
2735             virtio_queue_set_notification(q->tx_vq, 0);
2736             q->async_tx.elem = elem;
2737             return -EBUSY;
2738         }
2739 
2740 drop:
2741         virtqueue_push(q->tx_vq, elem, 0);
2742         virtio_notify(vdev, q->tx_vq);
2743         g_free(elem);
2744 
2745         if (++num_packets >= n->tx_burst) {
2746             break;
2747         }
2748     }
2749     return num_packets;
2750 }
2751 
2752 static void virtio_net_tx_timer(void *opaque);
2753 
2754 static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
2755 {
2756     VirtIONet *n = VIRTIO_NET(vdev);
2757     VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
2758 
2759     if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) {
2760         virtio_net_drop_tx_queue_data(vdev, vq);
2761         return;
2762     }
2763 
2764     /* This happens when device was stopped but VCPU wasn't. */
2765     if (!vdev->vm_running) {
2766         q->tx_waiting = 1;
2767         return;
2768     }
2769 
2770     if (q->tx_waiting) {
2771         /* We already have queued packets, immediately flush */
2772         timer_del(q->tx_timer);
2773         virtio_net_tx_timer(q);
2774     } else {
2775         /* re-arm timer to flush it (and more) on next tick */
2776         timer_mod(q->tx_timer,
2777                   qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
2778         q->tx_waiting = 1;
2779         virtio_queue_set_notification(vq, 0);
2780     }
2781 }
2782 
2783 static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
2784 {
2785     VirtIONet *n = VIRTIO_NET(vdev);
2786     VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
2787 
2788     if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) {
2789         virtio_net_drop_tx_queue_data(vdev, vq);
2790         return;
2791     }
2792 
2793     if (unlikely(q->tx_waiting)) {
2794         return;
2795     }
2796     q->tx_waiting = 1;
2797     /* This happens when device was stopped but VCPU wasn't. */
2798     if (!vdev->vm_running) {
2799         return;
2800     }
2801     virtio_queue_set_notification(vq, 0);
2802     qemu_bh_schedule(q->tx_bh);
2803 }
2804 
2805 static void virtio_net_tx_timer(void *opaque)
2806 {
2807     VirtIONetQueue *q = opaque;
2808     VirtIONet *n = q->n;
2809     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2810     int ret;
2811 
2812     /* This happens when device was stopped but BH wasn't. */
2813     if (!vdev->vm_running) {
2814         /* Make sure tx waiting is set, so we'll run when restarted. */
2815         assert(q->tx_waiting);
2816         return;
2817     }
2818 
2819     q->tx_waiting = 0;
2820 
2821     /* Just in case the driver is not ready on more */
2822     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
2823         return;
2824     }
2825 
2826     ret = virtio_net_flush_tx(q);
2827     if (ret == -EBUSY || ret == -EINVAL) {
2828         return;
2829     }
2830     /*
2831      * If we flush a full burst of packets, assume there are
2832      * more coming and immediately rearm
2833      */
2834     if (ret >= n->tx_burst) {
2835         q->tx_waiting = 1;
2836         timer_mod(q->tx_timer,
2837                   qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
2838         return;
2839     }
2840     /*
2841      * If less than a full burst, re-enable notification and flush
2842      * anything that may have come in while we weren't looking.  If
2843      * we find something, assume the guest is still active and rearm
2844      */
2845     virtio_queue_set_notification(q->tx_vq, 1);
2846     ret = virtio_net_flush_tx(q);
2847     if (ret > 0) {
2848         virtio_queue_set_notification(q->tx_vq, 0);
2849         q->tx_waiting = 1;
2850         timer_mod(q->tx_timer,
2851                   qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
2852     }
2853 }
2854 
2855 static void virtio_net_tx_bh(void *opaque)
2856 {
2857     VirtIONetQueue *q = opaque;
2858     VirtIONet *n = q->n;
2859     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2860     int32_t ret;
2861 
2862     /* This happens when device was stopped but BH wasn't. */
2863     if (!vdev->vm_running) {
2864         /* Make sure tx waiting is set, so we'll run when restarted. */
2865         assert(q->tx_waiting);
2866         return;
2867     }
2868 
2869     q->tx_waiting = 0;
2870 
2871     /* Just in case the driver is not ready on more */
2872     if (unlikely(!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK))) {
2873         return;
2874     }
2875 
2876     ret = virtio_net_flush_tx(q);
2877     if (ret == -EBUSY || ret == -EINVAL) {
2878         return; /* Notification re-enable handled by tx_complete or device
2879                  * broken */
2880     }
2881 
2882     /* If we flush a full burst of packets, assume there are
2883      * more coming and immediately reschedule */
2884     if (ret >= n->tx_burst) {
2885         qemu_bh_schedule(q->tx_bh);
2886         q->tx_waiting = 1;
2887         return;
2888     }
2889 
2890     /* If less than a full burst, re-enable notification and flush
2891      * anything that may have come in while we weren't looking.  If
2892      * we find something, assume the guest is still active and reschedule */
2893     virtio_queue_set_notification(q->tx_vq, 1);
2894     ret = virtio_net_flush_tx(q);
2895     if (ret == -EINVAL) {
2896         return;
2897     } else if (ret > 0) {
2898         virtio_queue_set_notification(q->tx_vq, 0);
2899         qemu_bh_schedule(q->tx_bh);
2900         q->tx_waiting = 1;
2901     }
2902 }
2903 
2904 static void virtio_net_add_queue(VirtIONet *n, int index)
2905 {
2906     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2907 
2908     n->vqs[index].rx_vq = virtio_add_queue(vdev, n->net_conf.rx_queue_size,
2909                                            virtio_net_handle_rx);
2910 
2911     if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
2912         n->vqs[index].tx_vq =
2913             virtio_add_queue(vdev, n->net_conf.tx_queue_size,
2914                              virtio_net_handle_tx_timer);
2915         n->vqs[index].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
2916                                               virtio_net_tx_timer,
2917                                               &n->vqs[index]);
2918     } else {
2919         n->vqs[index].tx_vq =
2920             virtio_add_queue(vdev, n->net_conf.tx_queue_size,
2921                              virtio_net_handle_tx_bh);
2922         n->vqs[index].tx_bh = qemu_bh_new_guarded(virtio_net_tx_bh, &n->vqs[index],
2923                                                   &DEVICE(vdev)->mem_reentrancy_guard);
2924     }
2925 
2926     n->vqs[index].tx_waiting = 0;
2927     n->vqs[index].n = n;
2928 }
2929 
2930 static void virtio_net_del_queue(VirtIONet *n, int index)
2931 {
2932     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2933     VirtIONetQueue *q = &n->vqs[index];
2934     NetClientState *nc = qemu_get_subqueue(n->nic, index);
2935 
2936     qemu_purge_queued_packets(nc);
2937 
2938     virtio_del_queue(vdev, index * 2);
2939     if (q->tx_timer) {
2940         timer_free(q->tx_timer);
2941         q->tx_timer = NULL;
2942     } else {
2943         qemu_bh_delete(q->tx_bh);
2944         q->tx_bh = NULL;
2945     }
2946     q->tx_waiting = 0;
2947     virtio_del_queue(vdev, index * 2 + 1);
2948 }
2949 
2950 static void virtio_net_change_num_queue_pairs(VirtIONet *n, int new_max_queue_pairs)
2951 {
2952     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2953     int old_num_queues = virtio_get_num_queues(vdev);
2954     int new_num_queues = new_max_queue_pairs * 2 + 1;
2955     int i;
2956 
2957     assert(old_num_queues >= 3);
2958     assert(old_num_queues % 2 == 1);
2959 
2960     if (old_num_queues == new_num_queues) {
2961         return;
2962     }
2963 
2964     /*
2965      * We always need to remove and add ctrl vq if
2966      * old_num_queues != new_num_queues. Remove ctrl_vq first,
2967      * and then we only enter one of the following two loops.
2968      */
2969     virtio_del_queue(vdev, old_num_queues - 1);
2970 
2971     for (i = new_num_queues - 1; i < old_num_queues - 1; i += 2) {
2972         /* new_num_queues < old_num_queues */
2973         virtio_net_del_queue(n, i / 2);
2974     }
2975 
2976     for (i = old_num_queues - 1; i < new_num_queues - 1; i += 2) {
2977         /* new_num_queues > old_num_queues */
2978         virtio_net_add_queue(n, i / 2);
2979     }
2980 
2981     /* add ctrl_vq last */
2982     n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
2983 }
2984 
2985 static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue)
2986 {
2987     int max = multiqueue ? n->max_queue_pairs : 1;
2988 
2989     n->multiqueue = multiqueue;
2990     virtio_net_change_num_queue_pairs(n, max);
2991 
2992     virtio_net_set_queue_pairs(n);
2993 }
2994 
2995 static int virtio_net_post_load_device(void *opaque, int version_id)
2996 {
2997     VirtIONet *n = opaque;
2998     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2999     int i, link_down;
3000 
3001     trace_virtio_net_post_load_device();
3002     virtio_net_set_mrg_rx_bufs(n, n->mergeable_rx_bufs,
3003                                virtio_vdev_has_feature(vdev,
3004                                                        VIRTIO_F_VERSION_1),
3005                                virtio_vdev_has_feature(vdev,
3006                                                        VIRTIO_NET_F_HASH_REPORT));
3007 
3008     /* MAC_TABLE_ENTRIES may be different from the saved image */
3009     if (n->mac_table.in_use > MAC_TABLE_ENTRIES) {
3010         n->mac_table.in_use = 0;
3011     }
3012 
3013     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
3014         n->curr_guest_offloads = virtio_net_supported_guest_offloads(n);
3015     }
3016 
3017     /*
3018      * curr_guest_offloads will be later overwritten by the
3019      * virtio_set_features_nocheck call done from the virtio_load.
3020      * Here we make sure it is preserved and restored accordingly
3021      * in the virtio_net_post_load_virtio callback.
3022      */
3023     n->saved_guest_offloads = n->curr_guest_offloads;
3024 
3025     virtio_net_set_queue_pairs(n);
3026 
3027     /* Find the first multicast entry in the saved MAC filter */
3028     for (i = 0; i < n->mac_table.in_use; i++) {
3029         if (n->mac_table.macs[i * ETH_ALEN] & 1) {
3030             break;
3031         }
3032     }
3033     n->mac_table.first_multi = i;
3034 
3035     /* nc.link_down can't be migrated, so infer link_down according
3036      * to link status bit in n->status */
3037     link_down = (n->status & VIRTIO_NET_S_LINK_UP) == 0;
3038     for (i = 0; i < n->max_queue_pairs; i++) {
3039         qemu_get_subqueue(n->nic, i)->link_down = link_down;
3040     }
3041 
3042     if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) &&
3043         virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
3044         qemu_announce_timer_reset(&n->announce_timer, migrate_announce_params(),
3045                                   QEMU_CLOCK_VIRTUAL,
3046                                   virtio_net_announce_timer, n);
3047         if (n->announce_timer.round) {
3048             timer_mod(n->announce_timer.tm,
3049                       qemu_clock_get_ms(n->announce_timer.type));
3050         } else {
3051             qemu_announce_timer_del(&n->announce_timer, false);
3052         }
3053     }
3054 
3055     if (n->rss_data.enabled) {
3056         n->rss_data.enabled_software_rss = n->rss_data.populate_hash;
3057         if (!n->rss_data.populate_hash) {
3058             if (!virtio_net_attach_epbf_rss(n)) {
3059                 if (get_vhost_net(qemu_get_queue(n->nic)->peer)) {
3060                     warn_report("Can't post-load eBPF RSS for vhost");
3061                 } else {
3062                     warn_report("Can't post-load eBPF RSS - "
3063                                 "fallback to software RSS");
3064                     n->rss_data.enabled_software_rss = true;
3065                 }
3066             }
3067         }
3068 
3069         trace_virtio_net_rss_enable(n->rss_data.hash_types,
3070                                     n->rss_data.indirections_len,
3071                                     sizeof(n->rss_data.key));
3072     } else {
3073         trace_virtio_net_rss_disable();
3074     }
3075     return 0;
3076 }
3077 
3078 static int virtio_net_post_load_virtio(VirtIODevice *vdev)
3079 {
3080     VirtIONet *n = VIRTIO_NET(vdev);
3081     /*
3082      * The actual needed state is now in saved_guest_offloads,
3083      * see virtio_net_post_load_device for detail.
3084      * Restore it back and apply the desired offloads.
3085      */
3086     n->curr_guest_offloads = n->saved_guest_offloads;
3087     if (peer_has_vnet_hdr(n)) {
3088         virtio_net_apply_guest_offloads(n);
3089     }
3090 
3091     return 0;
3092 }
3093 
3094 /* tx_waiting field of a VirtIONetQueue */
3095 static const VMStateDescription vmstate_virtio_net_queue_tx_waiting = {
3096     .name = "virtio-net-queue-tx_waiting",
3097     .fields = (VMStateField[]) {
3098         VMSTATE_UINT32(tx_waiting, VirtIONetQueue),
3099         VMSTATE_END_OF_LIST()
3100    },
3101 };
3102 
3103 static bool max_queue_pairs_gt_1(void *opaque, int version_id)
3104 {
3105     return VIRTIO_NET(opaque)->max_queue_pairs > 1;
3106 }
3107 
3108 static bool has_ctrl_guest_offloads(void *opaque, int version_id)
3109 {
3110     return virtio_vdev_has_feature(VIRTIO_DEVICE(opaque),
3111                                    VIRTIO_NET_F_CTRL_GUEST_OFFLOADS);
3112 }
3113 
3114 static bool mac_table_fits(void *opaque, int version_id)
3115 {
3116     return VIRTIO_NET(opaque)->mac_table.in_use <= MAC_TABLE_ENTRIES;
3117 }
3118 
3119 static bool mac_table_doesnt_fit(void *opaque, int version_id)
3120 {
3121     return !mac_table_fits(opaque, version_id);
3122 }
3123 
3124 /* This temporary type is shared by all the WITH_TMP methods
3125  * although only some fields are used by each.
3126  */
3127 struct VirtIONetMigTmp {
3128     VirtIONet      *parent;
3129     VirtIONetQueue *vqs_1;
3130     uint16_t        curr_queue_pairs_1;
3131     uint8_t         has_ufo;
3132     uint32_t        has_vnet_hdr;
3133 };
3134 
3135 /* The 2nd and subsequent tx_waiting flags are loaded later than
3136  * the 1st entry in the queue_pairs and only if there's more than one
3137  * entry.  We use the tmp mechanism to calculate a temporary
3138  * pointer and count and also validate the count.
3139  */
3140 
3141 static int virtio_net_tx_waiting_pre_save(void *opaque)
3142 {
3143     struct VirtIONetMigTmp *tmp = opaque;
3144 
3145     tmp->vqs_1 = tmp->parent->vqs + 1;
3146     tmp->curr_queue_pairs_1 = tmp->parent->curr_queue_pairs - 1;
3147     if (tmp->parent->curr_queue_pairs == 0) {
3148         tmp->curr_queue_pairs_1 = 0;
3149     }
3150 
3151     return 0;
3152 }
3153 
3154 static int virtio_net_tx_waiting_pre_load(void *opaque)
3155 {
3156     struct VirtIONetMigTmp *tmp = opaque;
3157 
3158     /* Reuse the pointer setup from save */
3159     virtio_net_tx_waiting_pre_save(opaque);
3160 
3161     if (tmp->parent->curr_queue_pairs > tmp->parent->max_queue_pairs) {
3162         error_report("virtio-net: curr_queue_pairs %x > max_queue_pairs %x",
3163             tmp->parent->curr_queue_pairs, tmp->parent->max_queue_pairs);
3164 
3165         return -EINVAL;
3166     }
3167 
3168     return 0; /* all good */
3169 }
3170 
3171 static const VMStateDescription vmstate_virtio_net_tx_waiting = {
3172     .name      = "virtio-net-tx_waiting",
3173     .pre_load  = virtio_net_tx_waiting_pre_load,
3174     .pre_save  = virtio_net_tx_waiting_pre_save,
3175     .fields    = (VMStateField[]) {
3176         VMSTATE_STRUCT_VARRAY_POINTER_UINT16(vqs_1, struct VirtIONetMigTmp,
3177                                      curr_queue_pairs_1,
3178                                      vmstate_virtio_net_queue_tx_waiting,
3179                                      struct VirtIONetQueue),
3180         VMSTATE_END_OF_LIST()
3181     },
3182 };
3183 
3184 /* the 'has_ufo' flag is just tested; if the incoming stream has the
3185  * flag set we need to check that we have it
3186  */
3187 static int virtio_net_ufo_post_load(void *opaque, int version_id)
3188 {
3189     struct VirtIONetMigTmp *tmp = opaque;
3190 
3191     if (tmp->has_ufo && !peer_has_ufo(tmp->parent)) {
3192         error_report("virtio-net: saved image requires TUN_F_UFO support");
3193         return -EINVAL;
3194     }
3195 
3196     return 0;
3197 }
3198 
3199 static int virtio_net_ufo_pre_save(void *opaque)
3200 {
3201     struct VirtIONetMigTmp *tmp = opaque;
3202 
3203     tmp->has_ufo = tmp->parent->has_ufo;
3204 
3205     return 0;
3206 }
3207 
3208 static const VMStateDescription vmstate_virtio_net_has_ufo = {
3209     .name      = "virtio-net-ufo",
3210     .post_load = virtio_net_ufo_post_load,
3211     .pre_save  = virtio_net_ufo_pre_save,
3212     .fields    = (VMStateField[]) {
3213         VMSTATE_UINT8(has_ufo, struct VirtIONetMigTmp),
3214         VMSTATE_END_OF_LIST()
3215     },
3216 };
3217 
3218 /* the 'has_vnet_hdr' flag is just tested; if the incoming stream has the
3219  * flag set we need to check that we have it
3220  */
3221 static int virtio_net_vnet_post_load(void *opaque, int version_id)
3222 {
3223     struct VirtIONetMigTmp *tmp = opaque;
3224 
3225     if (tmp->has_vnet_hdr && !peer_has_vnet_hdr(tmp->parent)) {
3226         error_report("virtio-net: saved image requires vnet_hdr=on");
3227         return -EINVAL;
3228     }
3229 
3230     return 0;
3231 }
3232 
3233 static int virtio_net_vnet_pre_save(void *opaque)
3234 {
3235     struct VirtIONetMigTmp *tmp = opaque;
3236 
3237     tmp->has_vnet_hdr = tmp->parent->has_vnet_hdr;
3238 
3239     return 0;
3240 }
3241 
3242 static const VMStateDescription vmstate_virtio_net_has_vnet = {
3243     .name      = "virtio-net-vnet",
3244     .post_load = virtio_net_vnet_post_load,
3245     .pre_save  = virtio_net_vnet_pre_save,
3246     .fields    = (VMStateField[]) {
3247         VMSTATE_UINT32(has_vnet_hdr, struct VirtIONetMigTmp),
3248         VMSTATE_END_OF_LIST()
3249     },
3250 };
3251 
3252 static bool virtio_net_rss_needed(void *opaque)
3253 {
3254     return VIRTIO_NET(opaque)->rss_data.enabled;
3255 }
3256 
3257 static const VMStateDescription vmstate_virtio_net_rss = {
3258     .name      = "virtio-net-device/rss",
3259     .version_id = 1,
3260     .minimum_version_id = 1,
3261     .needed = virtio_net_rss_needed,
3262     .fields = (VMStateField[]) {
3263         VMSTATE_BOOL(rss_data.enabled, VirtIONet),
3264         VMSTATE_BOOL(rss_data.redirect, VirtIONet),
3265         VMSTATE_BOOL(rss_data.populate_hash, VirtIONet),
3266         VMSTATE_UINT32(rss_data.hash_types, VirtIONet),
3267         VMSTATE_UINT16(rss_data.indirections_len, VirtIONet),
3268         VMSTATE_UINT16(rss_data.default_queue, VirtIONet),
3269         VMSTATE_UINT8_ARRAY(rss_data.key, VirtIONet,
3270                             VIRTIO_NET_RSS_MAX_KEY_SIZE),
3271         VMSTATE_VARRAY_UINT16_ALLOC(rss_data.indirections_table, VirtIONet,
3272                                     rss_data.indirections_len, 0,
3273                                     vmstate_info_uint16, uint16_t),
3274         VMSTATE_END_OF_LIST()
3275     },
3276 };
3277 
3278 static const VMStateDescription vmstate_virtio_net_device = {
3279     .name = "virtio-net-device",
3280     .version_id = VIRTIO_NET_VM_VERSION,
3281     .minimum_version_id = VIRTIO_NET_VM_VERSION,
3282     .post_load = virtio_net_post_load_device,
3283     .fields = (VMStateField[]) {
3284         VMSTATE_UINT8_ARRAY(mac, VirtIONet, ETH_ALEN),
3285         VMSTATE_STRUCT_POINTER(vqs, VirtIONet,
3286                                vmstate_virtio_net_queue_tx_waiting,
3287                                VirtIONetQueue),
3288         VMSTATE_UINT32(mergeable_rx_bufs, VirtIONet),
3289         VMSTATE_UINT16(status, VirtIONet),
3290         VMSTATE_UINT8(promisc, VirtIONet),
3291         VMSTATE_UINT8(allmulti, VirtIONet),
3292         VMSTATE_UINT32(mac_table.in_use, VirtIONet),
3293 
3294         /* Guarded pair: If it fits we load it, else we throw it away
3295          * - can happen if source has a larger MAC table.; post-load
3296          *  sets flags in this case.
3297          */
3298         VMSTATE_VBUFFER_MULTIPLY(mac_table.macs, VirtIONet,
3299                                 0, mac_table_fits, mac_table.in_use,
3300                                  ETH_ALEN),
3301         VMSTATE_UNUSED_VARRAY_UINT32(VirtIONet, mac_table_doesnt_fit, 0,
3302                                      mac_table.in_use, ETH_ALEN),
3303 
3304         /* Note: This is an array of uint32's that's always been saved as a
3305          * buffer; hold onto your endiannesses; it's actually used as a bitmap
3306          * but based on the uint.
3307          */
3308         VMSTATE_BUFFER_POINTER_UNSAFE(vlans, VirtIONet, 0, MAX_VLAN >> 3),
3309         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
3310                          vmstate_virtio_net_has_vnet),
3311         VMSTATE_UINT8(mac_table.multi_overflow, VirtIONet),
3312         VMSTATE_UINT8(mac_table.uni_overflow, VirtIONet),
3313         VMSTATE_UINT8(alluni, VirtIONet),
3314         VMSTATE_UINT8(nomulti, VirtIONet),
3315         VMSTATE_UINT8(nouni, VirtIONet),
3316         VMSTATE_UINT8(nobcast, VirtIONet),
3317         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
3318                          vmstate_virtio_net_has_ufo),
3319         VMSTATE_SINGLE_TEST(max_queue_pairs, VirtIONet, max_queue_pairs_gt_1, 0,
3320                             vmstate_info_uint16_equal, uint16_t),
3321         VMSTATE_UINT16_TEST(curr_queue_pairs, VirtIONet, max_queue_pairs_gt_1),
3322         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
3323                          vmstate_virtio_net_tx_waiting),
3324         VMSTATE_UINT64_TEST(curr_guest_offloads, VirtIONet,
3325                             has_ctrl_guest_offloads),
3326         VMSTATE_END_OF_LIST()
3327    },
3328     .subsections = (const VMStateDescription * []) {
3329         &vmstate_virtio_net_rss,
3330         NULL
3331     }
3332 };
3333 
3334 static NetClientInfo net_virtio_info = {
3335     .type = NET_CLIENT_DRIVER_NIC,
3336     .size = sizeof(NICState),
3337     .can_receive = virtio_net_can_receive,
3338     .receive = virtio_net_receive,
3339     .link_status_changed = virtio_net_set_link_status,
3340     .query_rx_filter = virtio_net_query_rxfilter,
3341     .announce = virtio_net_announce,
3342 };
3343 
3344 static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
3345 {
3346     VirtIONet *n = VIRTIO_NET(vdev);
3347     NetClientState *nc;
3348     assert(n->vhost_started);
3349     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ) && idx == 2) {
3350         /* Must guard against invalid features and bogus queue index
3351          * from being set by malicious guest, or penetrated through
3352          * buggy migration stream.
3353          */
3354         if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
3355             qemu_log_mask(LOG_GUEST_ERROR,
3356                           "%s: bogus vq index ignored\n", __func__);
3357             return false;
3358         }
3359         nc = qemu_get_subqueue(n->nic, n->max_queue_pairs);
3360     } else {
3361         nc = qemu_get_subqueue(n->nic, vq2q(idx));
3362     }
3363     /*
3364      * Add the check for configure interrupt, Use VIRTIO_CONFIG_IRQ_IDX -1
3365      * as the macro of configure interrupt's IDX, If this driver does not
3366      * support, the function will return false
3367      */
3368 
3369     if (idx == VIRTIO_CONFIG_IRQ_IDX) {
3370         return vhost_net_config_pending(get_vhost_net(nc->peer));
3371     }
3372     return vhost_net_virtqueue_pending(get_vhost_net(nc->peer), idx);
3373 }
3374 
3375 static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
3376                                            bool mask)
3377 {
3378     VirtIONet *n = VIRTIO_NET(vdev);
3379     NetClientState *nc;
3380     assert(n->vhost_started);
3381     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ) && idx == 2) {
3382         /* Must guard against invalid features and bogus queue index
3383          * from being set by malicious guest, or penetrated through
3384          * buggy migration stream.
3385          */
3386         if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
3387             qemu_log_mask(LOG_GUEST_ERROR,
3388                           "%s: bogus vq index ignored\n", __func__);
3389             return;
3390         }
3391         nc = qemu_get_subqueue(n->nic, n->max_queue_pairs);
3392     } else {
3393         nc = qemu_get_subqueue(n->nic, vq2q(idx));
3394     }
3395     /*
3396      *Add the check for configure interrupt, Use VIRTIO_CONFIG_IRQ_IDX -1
3397      * as the macro of configure interrupt's IDX, If this driver does not
3398      * support, the function will return
3399      */
3400 
3401     if (idx == VIRTIO_CONFIG_IRQ_IDX) {
3402         vhost_net_config_mask(get_vhost_net(nc->peer), vdev, mask);
3403         return;
3404     }
3405     vhost_net_virtqueue_mask(get_vhost_net(nc->peer), vdev, idx, mask);
3406 }
3407 
3408 static void virtio_net_set_config_size(VirtIONet *n, uint64_t host_features)
3409 {
3410     virtio_add_feature(&host_features, VIRTIO_NET_F_MAC);
3411 
3412     n->config_size = virtio_get_config_size(&cfg_size_params, host_features);
3413 }
3414 
3415 void virtio_net_set_netclient_name(VirtIONet *n, const char *name,
3416                                    const char *type)
3417 {
3418     /*
3419      * The name can be NULL, the netclient name will be type.x.
3420      */
3421     assert(type != NULL);
3422 
3423     g_free(n->netclient_name);
3424     g_free(n->netclient_type);
3425     n->netclient_name = g_strdup(name);
3426     n->netclient_type = g_strdup(type);
3427 }
3428 
3429 static bool failover_unplug_primary(VirtIONet *n, DeviceState *dev)
3430 {
3431     HotplugHandler *hotplug_ctrl;
3432     PCIDevice *pci_dev;
3433     Error *err = NULL;
3434 
3435     hotplug_ctrl = qdev_get_hotplug_handler(dev);
3436     if (hotplug_ctrl) {
3437         pci_dev = PCI_DEVICE(dev);
3438         pci_dev->partially_hotplugged = true;
3439         hotplug_handler_unplug_request(hotplug_ctrl, dev, &err);
3440         if (err) {
3441             error_report_err(err);
3442             return false;
3443         }
3444     } else {
3445         return false;
3446     }
3447     return true;
3448 }
3449 
3450 static bool failover_replug_primary(VirtIONet *n, DeviceState *dev,
3451                                     Error **errp)
3452 {
3453     Error *err = NULL;
3454     HotplugHandler *hotplug_ctrl;
3455     PCIDevice *pdev = PCI_DEVICE(dev);
3456     BusState *primary_bus;
3457 
3458     if (!pdev->partially_hotplugged) {
3459         return true;
3460     }
3461     primary_bus = dev->parent_bus;
3462     if (!primary_bus) {
3463         error_setg(errp, "virtio_net: couldn't find primary bus");
3464         return false;
3465     }
3466     qdev_set_parent_bus(dev, primary_bus, &error_abort);
3467     qatomic_set(&n->failover_primary_hidden, false);
3468     hotplug_ctrl = qdev_get_hotplug_handler(dev);
3469     if (hotplug_ctrl) {
3470         hotplug_handler_pre_plug(hotplug_ctrl, dev, &err);
3471         if (err) {
3472             goto out;
3473         }
3474         hotplug_handler_plug(hotplug_ctrl, dev, &err);
3475     }
3476     pdev->partially_hotplugged = false;
3477 
3478 out:
3479     error_propagate(errp, err);
3480     return !err;
3481 }
3482 
3483 static void virtio_net_handle_migration_primary(VirtIONet *n, MigrationState *s)
3484 {
3485     bool should_be_hidden;
3486     Error *err = NULL;
3487     DeviceState *dev = failover_find_primary_device(n);
3488 
3489     if (!dev) {
3490         return;
3491     }
3492 
3493     should_be_hidden = qatomic_read(&n->failover_primary_hidden);
3494 
3495     if (migration_in_setup(s) && !should_be_hidden) {
3496         if (failover_unplug_primary(n, dev)) {
3497             vmstate_unregister(VMSTATE_IF(dev), qdev_get_vmsd(dev), dev);
3498             qapi_event_send_unplug_primary(dev->id);
3499             qatomic_set(&n->failover_primary_hidden, true);
3500         } else {
3501             warn_report("couldn't unplug primary device");
3502         }
3503     } else if (migration_has_failed(s)) {
3504         /* We already unplugged the device let's plug it back */
3505         if (!failover_replug_primary(n, dev, &err)) {
3506             if (err) {
3507                 error_report_err(err);
3508             }
3509         }
3510     }
3511 }
3512 
3513 static void virtio_net_migration_state_notifier(Notifier *notifier, void *data)
3514 {
3515     MigrationState *s = data;
3516     VirtIONet *n = container_of(notifier, VirtIONet, migration_state);
3517     virtio_net_handle_migration_primary(n, s);
3518 }
3519 
3520 static bool failover_hide_primary_device(DeviceListener *listener,
3521                                          const QDict *device_opts,
3522                                          bool from_json,
3523                                          Error **errp)
3524 {
3525     VirtIONet *n = container_of(listener, VirtIONet, primary_listener);
3526     const char *standby_id;
3527 
3528     if (!device_opts) {
3529         return false;
3530     }
3531 
3532     if (!qdict_haskey(device_opts, "failover_pair_id")) {
3533         return false;
3534     }
3535 
3536     if (!qdict_haskey(device_opts, "id")) {
3537         error_setg(errp, "Device with failover_pair_id needs to have id");
3538         return false;
3539     }
3540 
3541     standby_id = qdict_get_str(device_opts, "failover_pair_id");
3542     if (g_strcmp0(standby_id, n->netclient_name) != 0) {
3543         return false;
3544     }
3545 
3546     /*
3547      * The hide helper can be called several times for a given device.
3548      * Check there is only one primary for a virtio-net device but
3549      * don't duplicate the qdict several times if it's called for the same
3550      * device.
3551      */
3552     if (n->primary_opts) {
3553         const char *old, *new;
3554         /* devices with failover_pair_id always have an id */
3555         old = qdict_get_str(n->primary_opts, "id");
3556         new = qdict_get_str(device_opts, "id");
3557         if (strcmp(old, new) != 0) {
3558             error_setg(errp, "Cannot attach more than one primary device to "
3559                        "'%s': '%s' and '%s'", n->netclient_name, old, new);
3560             return false;
3561         }
3562     } else {
3563         n->primary_opts = qdict_clone_shallow(device_opts);
3564         n->primary_opts_from_json = from_json;
3565     }
3566 
3567     /* failover_primary_hidden is set during feature negotiation */
3568     return qatomic_read(&n->failover_primary_hidden);
3569 }
3570 
3571 static void virtio_net_device_realize(DeviceState *dev, Error **errp)
3572 {
3573     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
3574     VirtIONet *n = VIRTIO_NET(dev);
3575     NetClientState *nc;
3576     int i;
3577 
3578     if (n->net_conf.mtu) {
3579         n->host_features |= (1ULL << VIRTIO_NET_F_MTU);
3580     }
3581 
3582     if (n->net_conf.duplex_str) {
3583         if (strncmp(n->net_conf.duplex_str, "half", 5) == 0) {
3584             n->net_conf.duplex = DUPLEX_HALF;
3585         } else if (strncmp(n->net_conf.duplex_str, "full", 5) == 0) {
3586             n->net_conf.duplex = DUPLEX_FULL;
3587         } else {
3588             error_setg(errp, "'duplex' must be 'half' or 'full'");
3589             return;
3590         }
3591         n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
3592     } else {
3593         n->net_conf.duplex = DUPLEX_UNKNOWN;
3594     }
3595 
3596     if (n->net_conf.speed < SPEED_UNKNOWN) {
3597         error_setg(errp, "'speed' must be between 0 and INT_MAX");
3598         return;
3599     }
3600     if (n->net_conf.speed >= 0) {
3601         n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
3602     }
3603 
3604     if (n->failover) {
3605         n->primary_listener.hide_device = failover_hide_primary_device;
3606         qatomic_set(&n->failover_primary_hidden, true);
3607         device_listener_register(&n->primary_listener);
3608         n->migration_state.notify = virtio_net_migration_state_notifier;
3609         add_migration_state_change_notifier(&n->migration_state);
3610         n->host_features |= (1ULL << VIRTIO_NET_F_STANDBY);
3611     }
3612 
3613     virtio_net_set_config_size(n, n->host_features);
3614     virtio_init(vdev, VIRTIO_ID_NET, n->config_size);
3615 
3616     /*
3617      * We set a lower limit on RX queue size to what it always was.
3618      * Guests that want a smaller ring can always resize it without
3619      * help from us (using virtio 1 and up).
3620      */
3621     if (n->net_conf.rx_queue_size < VIRTIO_NET_RX_QUEUE_MIN_SIZE ||
3622         n->net_conf.rx_queue_size > VIRTQUEUE_MAX_SIZE ||
3623         !is_power_of_2(n->net_conf.rx_queue_size)) {
3624         error_setg(errp, "Invalid rx_queue_size (= %" PRIu16 "), "
3625                    "must be a power of 2 between %d and %d.",
3626                    n->net_conf.rx_queue_size, VIRTIO_NET_RX_QUEUE_MIN_SIZE,
3627                    VIRTQUEUE_MAX_SIZE);
3628         virtio_cleanup(vdev);
3629         return;
3630     }
3631 
3632     if (n->net_conf.tx_queue_size < VIRTIO_NET_TX_QUEUE_MIN_SIZE ||
3633         n->net_conf.tx_queue_size > virtio_net_max_tx_queue_size(n) ||
3634         !is_power_of_2(n->net_conf.tx_queue_size)) {
3635         error_setg(errp, "Invalid tx_queue_size (= %" PRIu16 "), "
3636                    "must be a power of 2 between %d and %d",
3637                    n->net_conf.tx_queue_size, VIRTIO_NET_TX_QUEUE_MIN_SIZE,
3638                    virtio_net_max_tx_queue_size(n));
3639         virtio_cleanup(vdev);
3640         return;
3641     }
3642 
3643     n->max_ncs = MAX(n->nic_conf.peers.queues, 1);
3644 
3645     /*
3646      * Figure out the datapath queue pairs since the backend could
3647      * provide control queue via peers as well.
3648      */
3649     if (n->nic_conf.peers.queues) {
3650         for (i = 0; i < n->max_ncs; i++) {
3651             if (n->nic_conf.peers.ncs[i]->is_datapath) {
3652                 ++n->max_queue_pairs;
3653             }
3654         }
3655     }
3656     n->max_queue_pairs = MAX(n->max_queue_pairs, 1);
3657 
3658     if (n->max_queue_pairs * 2 + 1 > VIRTIO_QUEUE_MAX) {
3659         error_setg(errp, "Invalid number of queue pairs (= %" PRIu32 "), "
3660                    "must be a positive integer less than %d.",
3661                    n->max_queue_pairs, (VIRTIO_QUEUE_MAX - 1) / 2);
3662         virtio_cleanup(vdev);
3663         return;
3664     }
3665     n->vqs = g_new0(VirtIONetQueue, n->max_queue_pairs);
3666     n->curr_queue_pairs = 1;
3667     n->tx_timeout = n->net_conf.txtimer;
3668 
3669     if (n->net_conf.tx && strcmp(n->net_conf.tx, "timer")
3670                        && strcmp(n->net_conf.tx, "bh")) {
3671         warn_report("virtio-net: "
3672                     "Unknown option tx=%s, valid options: \"timer\" \"bh\"",
3673                     n->net_conf.tx);
3674         error_printf("Defaulting to \"bh\"");
3675     }
3676 
3677     n->net_conf.tx_queue_size = MIN(virtio_net_max_tx_queue_size(n),
3678                                     n->net_conf.tx_queue_size);
3679 
3680     for (i = 0; i < n->max_queue_pairs; i++) {
3681         virtio_net_add_queue(n, i);
3682     }
3683 
3684     n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
3685     qemu_macaddr_default_if_unset(&n->nic_conf.macaddr);
3686     memcpy(&n->mac[0], &n->nic_conf.macaddr, sizeof(n->mac));
3687     n->status = VIRTIO_NET_S_LINK_UP;
3688     qemu_announce_timer_reset(&n->announce_timer, migrate_announce_params(),
3689                               QEMU_CLOCK_VIRTUAL,
3690                               virtio_net_announce_timer, n);
3691     n->announce_timer.round = 0;
3692 
3693     if (n->netclient_type) {
3694         /*
3695          * Happen when virtio_net_set_netclient_name has been called.
3696          */
3697         n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
3698                               n->netclient_type, n->netclient_name, n);
3699     } else {
3700         n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
3701                               object_get_typename(OBJECT(dev)), dev->id, n);
3702     }
3703 
3704     for (i = 0; i < n->max_queue_pairs; i++) {
3705         n->nic->ncs[i].do_not_pad = true;
3706     }
3707 
3708     peer_test_vnet_hdr(n);
3709     if (peer_has_vnet_hdr(n)) {
3710         for (i = 0; i < n->max_queue_pairs; i++) {
3711             qemu_using_vnet_hdr(qemu_get_subqueue(n->nic, i)->peer, true);
3712         }
3713         n->host_hdr_len = sizeof(struct virtio_net_hdr);
3714     } else {
3715         n->host_hdr_len = 0;
3716     }
3717 
3718     qemu_format_nic_info_str(qemu_get_queue(n->nic), n->nic_conf.macaddr.a);
3719 
3720     n->vqs[0].tx_waiting = 0;
3721     n->tx_burst = n->net_conf.txburst;
3722     virtio_net_set_mrg_rx_bufs(n, 0, 0, 0);
3723     n->promisc = 1; /* for compatibility */
3724 
3725     n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
3726 
3727     n->vlans = g_malloc0(MAX_VLAN >> 3);
3728 
3729     nc = qemu_get_queue(n->nic);
3730     nc->rxfilter_notify_enabled = 1;
3731 
3732    if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
3733         struct virtio_net_config netcfg = {};
3734         memcpy(&netcfg.mac, &n->nic_conf.macaddr, ETH_ALEN);
3735         vhost_net_set_config(get_vhost_net(nc->peer),
3736             (uint8_t *)&netcfg, 0, ETH_ALEN, VHOST_SET_CONFIG_TYPE_FRONTEND);
3737     }
3738     QTAILQ_INIT(&n->rsc_chains);
3739     n->qdev = dev;
3740 
3741     net_rx_pkt_init(&n->rx_pkt);
3742 
3743     if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS)) {
3744         virtio_net_load_ebpf(n);
3745     }
3746 }
3747 
3748 static void virtio_net_device_unrealize(DeviceState *dev)
3749 {
3750     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
3751     VirtIONet *n = VIRTIO_NET(dev);
3752     int i, max_queue_pairs;
3753 
3754     if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS)) {
3755         virtio_net_unload_ebpf(n);
3756     }
3757 
3758     /* This will stop vhost backend if appropriate. */
3759     virtio_net_set_status(vdev, 0);
3760 
3761     g_free(n->netclient_name);
3762     n->netclient_name = NULL;
3763     g_free(n->netclient_type);
3764     n->netclient_type = NULL;
3765 
3766     g_free(n->mac_table.macs);
3767     g_free(n->vlans);
3768 
3769     if (n->failover) {
3770         qobject_unref(n->primary_opts);
3771         device_listener_unregister(&n->primary_listener);
3772         remove_migration_state_change_notifier(&n->migration_state);
3773     } else {
3774         assert(n->primary_opts == NULL);
3775     }
3776 
3777     max_queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
3778     for (i = 0; i < max_queue_pairs; i++) {
3779         virtio_net_del_queue(n, i);
3780     }
3781     /* delete also control vq */
3782     virtio_del_queue(vdev, max_queue_pairs * 2);
3783     qemu_announce_timer_del(&n->announce_timer, false);
3784     g_free(n->vqs);
3785     qemu_del_nic(n->nic);
3786     virtio_net_rsc_cleanup(n);
3787     g_free(n->rss_data.indirections_table);
3788     net_rx_pkt_uninit(n->rx_pkt);
3789     virtio_cleanup(vdev);
3790 }
3791 
3792 static void virtio_net_instance_init(Object *obj)
3793 {
3794     VirtIONet *n = VIRTIO_NET(obj);
3795 
3796     /*
3797      * The default config_size is sizeof(struct virtio_net_config).
3798      * Can be overriden with virtio_net_set_config_size.
3799      */
3800     n->config_size = sizeof(struct virtio_net_config);
3801     device_add_bootindex_property(obj, &n->nic_conf.bootindex,
3802                                   "bootindex", "/ethernet-phy@0",
3803                                   DEVICE(n));
3804 
3805     ebpf_rss_init(&n->ebpf_rss);
3806 }
3807 
3808 static int virtio_net_pre_save(void *opaque)
3809 {
3810     VirtIONet *n = opaque;
3811 
3812     /* At this point, backend must be stopped, otherwise
3813      * it might keep writing to memory. */
3814     assert(!n->vhost_started);
3815 
3816     return 0;
3817 }
3818 
3819 static bool primary_unplug_pending(void *opaque)
3820 {
3821     DeviceState *dev = opaque;
3822     DeviceState *primary;
3823     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
3824     VirtIONet *n = VIRTIO_NET(vdev);
3825 
3826     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
3827         return false;
3828     }
3829     primary = failover_find_primary_device(n);
3830     return primary ? primary->pending_deleted_event : false;
3831 }
3832 
3833 static bool dev_unplug_pending(void *opaque)
3834 {
3835     DeviceState *dev = opaque;
3836     VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev);
3837 
3838     return vdc->primary_unplug_pending(dev);
3839 }
3840 
3841 static struct vhost_dev *virtio_net_get_vhost(VirtIODevice *vdev)
3842 {
3843     VirtIONet *n = VIRTIO_NET(vdev);
3844     NetClientState *nc = qemu_get_queue(n->nic);
3845     struct vhost_net *net = get_vhost_net(nc->peer);
3846     return &net->dev;
3847 }
3848 
3849 static const VMStateDescription vmstate_virtio_net = {
3850     .name = "virtio-net",
3851     .minimum_version_id = VIRTIO_NET_VM_VERSION,
3852     .version_id = VIRTIO_NET_VM_VERSION,
3853     .fields = (VMStateField[]) {
3854         VMSTATE_VIRTIO_DEVICE,
3855         VMSTATE_END_OF_LIST()
3856     },
3857     .pre_save = virtio_net_pre_save,
3858     .dev_unplug_pending = dev_unplug_pending,
3859 };
3860 
3861 static Property virtio_net_properties[] = {
3862     DEFINE_PROP_BIT64("csum", VirtIONet, host_features,
3863                     VIRTIO_NET_F_CSUM, true),
3864     DEFINE_PROP_BIT64("guest_csum", VirtIONet, host_features,
3865                     VIRTIO_NET_F_GUEST_CSUM, true),
3866     DEFINE_PROP_BIT64("gso", VirtIONet, host_features, VIRTIO_NET_F_GSO, true),
3867     DEFINE_PROP_BIT64("guest_tso4", VirtIONet, host_features,
3868                     VIRTIO_NET_F_GUEST_TSO4, true),
3869     DEFINE_PROP_BIT64("guest_tso6", VirtIONet, host_features,
3870                     VIRTIO_NET_F_GUEST_TSO6, true),
3871     DEFINE_PROP_BIT64("guest_ecn", VirtIONet, host_features,
3872                     VIRTIO_NET_F_GUEST_ECN, true),
3873     DEFINE_PROP_BIT64("guest_ufo", VirtIONet, host_features,
3874                     VIRTIO_NET_F_GUEST_UFO, true),
3875     DEFINE_PROP_BIT64("guest_announce", VirtIONet, host_features,
3876                     VIRTIO_NET_F_GUEST_ANNOUNCE, true),
3877     DEFINE_PROP_BIT64("host_tso4", VirtIONet, host_features,
3878                     VIRTIO_NET_F_HOST_TSO4, true),
3879     DEFINE_PROP_BIT64("host_tso6", VirtIONet, host_features,
3880                     VIRTIO_NET_F_HOST_TSO6, true),
3881     DEFINE_PROP_BIT64("host_ecn", VirtIONet, host_features,
3882                     VIRTIO_NET_F_HOST_ECN, true),
3883     DEFINE_PROP_BIT64("host_ufo", VirtIONet, host_features,
3884                     VIRTIO_NET_F_HOST_UFO, true),
3885     DEFINE_PROP_BIT64("mrg_rxbuf", VirtIONet, host_features,
3886                     VIRTIO_NET_F_MRG_RXBUF, true),
3887     DEFINE_PROP_BIT64("status", VirtIONet, host_features,
3888                     VIRTIO_NET_F_STATUS, true),
3889     DEFINE_PROP_BIT64("ctrl_vq", VirtIONet, host_features,
3890                     VIRTIO_NET_F_CTRL_VQ, true),
3891     DEFINE_PROP_BIT64("ctrl_rx", VirtIONet, host_features,
3892                     VIRTIO_NET_F_CTRL_RX, true),
3893     DEFINE_PROP_BIT64("ctrl_vlan", VirtIONet, host_features,
3894                     VIRTIO_NET_F_CTRL_VLAN, true),
3895     DEFINE_PROP_BIT64("ctrl_rx_extra", VirtIONet, host_features,
3896                     VIRTIO_NET_F_CTRL_RX_EXTRA, true),
3897     DEFINE_PROP_BIT64("ctrl_mac_addr", VirtIONet, host_features,
3898                     VIRTIO_NET_F_CTRL_MAC_ADDR, true),
3899     DEFINE_PROP_BIT64("ctrl_guest_offloads", VirtIONet, host_features,
3900                     VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, true),
3901     DEFINE_PROP_BIT64("mq", VirtIONet, host_features, VIRTIO_NET_F_MQ, false),
3902     DEFINE_PROP_BIT64("rss", VirtIONet, host_features,
3903                     VIRTIO_NET_F_RSS, false),
3904     DEFINE_PROP_BIT64("hash", VirtIONet, host_features,
3905                     VIRTIO_NET_F_HASH_REPORT, false),
3906     DEFINE_PROP_BIT64("guest_rsc_ext", VirtIONet, host_features,
3907                     VIRTIO_NET_F_RSC_EXT, false),
3908     DEFINE_PROP_UINT32("rsc_interval", VirtIONet, rsc_timeout,
3909                        VIRTIO_NET_RSC_DEFAULT_INTERVAL),
3910     DEFINE_NIC_PROPERTIES(VirtIONet, nic_conf),
3911     DEFINE_PROP_UINT32("x-txtimer", VirtIONet, net_conf.txtimer,
3912                        TX_TIMER_INTERVAL),
3913     DEFINE_PROP_INT32("x-txburst", VirtIONet, net_conf.txburst, TX_BURST),
3914     DEFINE_PROP_STRING("tx", VirtIONet, net_conf.tx),
3915     DEFINE_PROP_UINT16("rx_queue_size", VirtIONet, net_conf.rx_queue_size,
3916                        VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE),
3917     DEFINE_PROP_UINT16("tx_queue_size", VirtIONet, net_conf.tx_queue_size,
3918                        VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE),
3919     DEFINE_PROP_UINT16("host_mtu", VirtIONet, net_conf.mtu, 0),
3920     DEFINE_PROP_BOOL("x-mtu-bypass-backend", VirtIONet, mtu_bypass_backend,
3921                      true),
3922     DEFINE_PROP_INT32("speed", VirtIONet, net_conf.speed, SPEED_UNKNOWN),
3923     DEFINE_PROP_STRING("duplex", VirtIONet, net_conf.duplex_str),
3924     DEFINE_PROP_BOOL("failover", VirtIONet, failover, false),
3925     DEFINE_PROP_END_OF_LIST(),
3926 };
3927 
3928 static void virtio_net_class_init(ObjectClass *klass, void *data)
3929 {
3930     DeviceClass *dc = DEVICE_CLASS(klass);
3931     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
3932 
3933     device_class_set_props(dc, virtio_net_properties);
3934     dc->vmsd = &vmstate_virtio_net;
3935     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
3936     vdc->realize = virtio_net_device_realize;
3937     vdc->unrealize = virtio_net_device_unrealize;
3938     vdc->get_config = virtio_net_get_config;
3939     vdc->set_config = virtio_net_set_config;
3940     vdc->get_features = virtio_net_get_features;
3941     vdc->set_features = virtio_net_set_features;
3942     vdc->bad_features = virtio_net_bad_features;
3943     vdc->reset = virtio_net_reset;
3944     vdc->queue_reset = virtio_net_queue_reset;
3945     vdc->queue_enable = virtio_net_queue_enable;
3946     vdc->set_status = virtio_net_set_status;
3947     vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
3948     vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;
3949     vdc->legacy_features |= (0x1 << VIRTIO_NET_F_GSO);
3950     vdc->post_load = virtio_net_post_load_virtio;
3951     vdc->vmsd = &vmstate_virtio_net_device;
3952     vdc->primary_unplug_pending = primary_unplug_pending;
3953     vdc->get_vhost = virtio_net_get_vhost;
3954     vdc->toggle_device_iotlb = vhost_toggle_device_iotlb;
3955 }
3956 
3957 static const TypeInfo virtio_net_info = {
3958     .name = TYPE_VIRTIO_NET,
3959     .parent = TYPE_VIRTIO_DEVICE,
3960     .instance_size = sizeof(VirtIONet),
3961     .instance_init = virtio_net_instance_init,
3962     .class_init = virtio_net_class_init,
3963 };
3964 
3965 static void virtio_register_types(void)
3966 {
3967     type_register_static(&virtio_net_info);
3968 }
3969 
3970 type_init(virtio_register_types)
3971