xref: /openbmc/qemu/hw/net/virtio-net.c (revision 5242ef88)
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/main-loop.h"
18 #include "qemu/module.h"
19 #include "hw/virtio/virtio.h"
20 #include "net/net.h"
21 #include "net/checksum.h"
22 #include "net/tap.h"
23 #include "qemu/error-report.h"
24 #include "qemu/timer.h"
25 #include "qemu/option.h"
26 #include "qemu/option_int.h"
27 #include "qemu/config-file.h"
28 #include "qapi/qmp/qdict.h"
29 #include "hw/virtio/virtio-net.h"
30 #include "net/vhost_net.h"
31 #include "net/announce.h"
32 #include "hw/virtio/virtio-bus.h"
33 #include "qapi/error.h"
34 #include "qapi/qapi-events-net.h"
35 #include "hw/qdev-properties.h"
36 #include "qapi/qapi-types-migration.h"
37 #include "qapi/qapi-events-migration.h"
38 #include "hw/virtio/virtio-access.h"
39 #include "migration/misc.h"
40 #include "standard-headers/linux/ethtool.h"
41 #include "sysemu/sysemu.h"
42 #include "trace.h"
43 #include "monitor/qdev.h"
44 #include "hw/pci/pci.h"
45 #include "net_rx_pkt.h"
46 #include "hw/virtio/vhost.h"
47 #include "sysemu/qtest.h"
48 
49 #define VIRTIO_NET_VM_VERSION    11
50 
51 #define MAC_TABLE_ENTRIES    64
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 VirtIONetQueue *virtio_net_get_subqueue(NetClientState *nc)
110 {
111     VirtIONet *n = qemu_get_nic_opaque(nc);
112 
113     return &n->vqs[nc->queue_index];
114 }
115 
116 static int vq2q(int queue_index)
117 {
118     return queue_index / 2;
119 }
120 
121 /* TODO
122  * - we could suppress RX interrupt if we were so inclined.
123  */
124 
125 static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
126 {
127     VirtIONet *n = VIRTIO_NET(vdev);
128     struct virtio_net_config netcfg;
129     NetClientState *nc = qemu_get_queue(n->nic);
130     static const MACAddr zero = { .a = { 0, 0, 0, 0, 0, 0 } };
131 
132     int ret = 0;
133     memset(&netcfg, 0 , sizeof(struct virtio_net_config));
134     virtio_stw_p(vdev, &netcfg.status, n->status);
135     virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queue_pairs);
136     virtio_stw_p(vdev, &netcfg.mtu, n->net_conf.mtu);
137     memcpy(netcfg.mac, n->mac, ETH_ALEN);
138     virtio_stl_p(vdev, &netcfg.speed, n->net_conf.speed);
139     netcfg.duplex = n->net_conf.duplex;
140     netcfg.rss_max_key_size = VIRTIO_NET_RSS_MAX_KEY_SIZE;
141     virtio_stw_p(vdev, &netcfg.rss_max_indirection_table_length,
142                  virtio_host_has_feature(vdev, VIRTIO_NET_F_RSS) ?
143                  VIRTIO_NET_RSS_MAX_TABLE_LEN : 1);
144     virtio_stl_p(vdev, &netcfg.supported_hash_types,
145                  VIRTIO_NET_RSS_SUPPORTED_HASHES);
146     memcpy(config, &netcfg, n->config_size);
147 
148     /*
149      * Is this VDPA? No peer means not VDPA: there's no way to
150      * disconnect/reconnect a VDPA peer.
151      */
152     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
153         ret = vhost_net_get_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
154                                    n->config_size);
155         if (ret != -1) {
156             /*
157              * Some NIC/kernel combinations present 0 as the mac address.  As
158              * that is not a legal address, try to proceed with the
159              * address from the QEMU command line in the hope that the
160              * address has been configured correctly elsewhere - just not
161              * reported by the device.
162              */
163             if (memcmp(&netcfg.mac, &zero, sizeof(zero)) == 0) {
164                 info_report("Zero hardware mac address detected. Ignoring.");
165                 memcpy(netcfg.mac, n->mac, ETH_ALEN);
166             }
167             memcpy(config, &netcfg, n->config_size);
168         }
169     }
170 }
171 
172 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
173 {
174     VirtIONet *n = VIRTIO_NET(vdev);
175     struct virtio_net_config netcfg = {};
176     NetClientState *nc = qemu_get_queue(n->nic);
177 
178     memcpy(&netcfg, config, n->config_size);
179 
180     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR) &&
181         !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1) &&
182         memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
183         memcpy(n->mac, netcfg.mac, ETH_ALEN);
184         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
185     }
186 
187     /*
188      * Is this VDPA? No peer means not VDPA: there's no way to
189      * disconnect/reconnect a VDPA peer.
190      */
191     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
192         vhost_net_set_config(get_vhost_net(nc->peer),
193                              (uint8_t *)&netcfg, 0, n->config_size,
194                              VHOST_SET_CONFIG_TYPE_MASTER);
195       }
196 }
197 
198 static bool virtio_net_started(VirtIONet *n, uint8_t status)
199 {
200     VirtIODevice *vdev = VIRTIO_DEVICE(n);
201     return (status & VIRTIO_CONFIG_S_DRIVER_OK) &&
202         (n->status & VIRTIO_NET_S_LINK_UP) && vdev->vm_running;
203 }
204 
205 static void virtio_net_announce_notify(VirtIONet *net)
206 {
207     VirtIODevice *vdev = VIRTIO_DEVICE(net);
208     trace_virtio_net_announce_notify();
209 
210     net->status |= VIRTIO_NET_S_ANNOUNCE;
211     virtio_notify_config(vdev);
212 }
213 
214 static void virtio_net_announce_timer(void *opaque)
215 {
216     VirtIONet *n = opaque;
217     trace_virtio_net_announce_timer(n->announce_timer.round);
218 
219     n->announce_timer.round--;
220     virtio_net_announce_notify(n);
221 }
222 
223 static void virtio_net_announce(NetClientState *nc)
224 {
225     VirtIONet *n = qemu_get_nic_opaque(nc);
226     VirtIODevice *vdev = VIRTIO_DEVICE(n);
227 
228     /*
229      * Make sure the virtio migration announcement timer isn't running
230      * If it is, let it trigger announcement so that we do not cause
231      * confusion.
232      */
233     if (n->announce_timer.round) {
234         return;
235     }
236 
237     if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) &&
238         virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
239             virtio_net_announce_notify(n);
240     }
241 }
242 
243 static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
244 {
245     VirtIODevice *vdev = VIRTIO_DEVICE(n);
246     NetClientState *nc = qemu_get_queue(n->nic);
247     int queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
248     int cvq = n->max_ncs - n->max_queue_pairs;
249 
250     if (!get_vhost_net(nc->peer)) {
251         return;
252     }
253 
254     if ((virtio_net_started(n, status) && !nc->peer->link_down) ==
255         !!n->vhost_started) {
256         return;
257     }
258     if (!n->vhost_started) {
259         int r, i;
260 
261         if (n->needs_vnet_hdr_swap) {
262             error_report("backend does not support %s vnet headers; "
263                          "falling back on userspace virtio",
264                          virtio_is_big_endian(vdev) ? "BE" : "LE");
265             return;
266         }
267 
268         /* Any packets outstanding? Purge them to avoid touching rings
269          * when vhost is running.
270          */
271         for (i = 0;  i < queue_pairs; i++) {
272             NetClientState *qnc = qemu_get_subqueue(n->nic, i);
273 
274             /* Purge both directions: TX and RX. */
275             qemu_net_queue_purge(qnc->peer->incoming_queue, qnc);
276             qemu_net_queue_purge(qnc->incoming_queue, qnc->peer);
277         }
278 
279         if (virtio_has_feature(vdev->guest_features, VIRTIO_NET_F_MTU)) {
280             r = vhost_net_set_mtu(get_vhost_net(nc->peer), n->net_conf.mtu);
281             if (r < 0) {
282                 error_report("%uBytes MTU not supported by the backend",
283                              n->net_conf.mtu);
284 
285                 return;
286             }
287         }
288 
289         n->vhost_started = 1;
290         r = vhost_net_start(vdev, n->nic->ncs, queue_pairs, cvq);
291         if (r < 0) {
292             error_report("unable to start vhost net: %d: "
293                          "falling back on userspace virtio", -r);
294             n->vhost_started = 0;
295         }
296     } else {
297         vhost_net_stop(vdev, n->nic->ncs, queue_pairs, cvq);
298         n->vhost_started = 0;
299     }
300 }
301 
302 static int virtio_net_set_vnet_endian_one(VirtIODevice *vdev,
303                                           NetClientState *peer,
304                                           bool enable)
305 {
306     if (virtio_is_big_endian(vdev)) {
307         return qemu_set_vnet_be(peer, enable);
308     } else {
309         return qemu_set_vnet_le(peer, enable);
310     }
311 }
312 
313 static bool virtio_net_set_vnet_endian(VirtIODevice *vdev, NetClientState *ncs,
314                                        int queue_pairs, bool enable)
315 {
316     int i;
317 
318     for (i = 0; i < queue_pairs; i++) {
319         if (virtio_net_set_vnet_endian_one(vdev, ncs[i].peer, enable) < 0 &&
320             enable) {
321             while (--i >= 0) {
322                 virtio_net_set_vnet_endian_one(vdev, ncs[i].peer, false);
323             }
324 
325             return true;
326         }
327     }
328 
329     return false;
330 }
331 
332 static void virtio_net_vnet_endian_status(VirtIONet *n, uint8_t status)
333 {
334     VirtIODevice *vdev = VIRTIO_DEVICE(n);
335     int queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
336 
337     if (virtio_net_started(n, status)) {
338         /* Before using the device, we tell the network backend about the
339          * endianness to use when parsing vnet headers. If the backend
340          * can't do it, we fallback onto fixing the headers in the core
341          * virtio-net code.
342          */
343         n->needs_vnet_hdr_swap = virtio_net_set_vnet_endian(vdev, n->nic->ncs,
344                                                             queue_pairs, true);
345     } else if (virtio_net_started(n, vdev->status)) {
346         /* After using the device, we need to reset the network backend to
347          * the default (guest native endianness), otherwise the guest may
348          * lose network connectivity if it is rebooted into a different
349          * endianness.
350          */
351         virtio_net_set_vnet_endian(vdev, n->nic->ncs, queue_pairs, false);
352     }
353 }
354 
355 static void virtio_net_drop_tx_queue_data(VirtIODevice *vdev, VirtQueue *vq)
356 {
357     unsigned int dropped = virtqueue_drop_all(vq);
358     if (dropped) {
359         virtio_notify(vdev, vq);
360     }
361 }
362 
363 static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
364 {
365     VirtIONet *n = VIRTIO_NET(vdev);
366     VirtIONetQueue *q;
367     int i;
368     uint8_t queue_status;
369 
370     virtio_net_vnet_endian_status(n, status);
371     virtio_net_vhost_status(n, status);
372 
373     for (i = 0; i < n->max_queue_pairs; i++) {
374         NetClientState *ncs = qemu_get_subqueue(n->nic, i);
375         bool queue_started;
376         q = &n->vqs[i];
377 
378         if ((!n->multiqueue && i != 0) || i >= n->curr_queue_pairs) {
379             queue_status = 0;
380         } else {
381             queue_status = status;
382         }
383         queue_started =
384             virtio_net_started(n, queue_status) && !n->vhost_started;
385 
386         if (queue_started) {
387             qemu_flush_queued_packets(ncs);
388         }
389 
390         if (!q->tx_waiting) {
391             continue;
392         }
393 
394         if (queue_started) {
395             if (q->tx_timer) {
396                 timer_mod(q->tx_timer,
397                                qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
398             } else {
399                 qemu_bh_schedule(q->tx_bh);
400             }
401         } else {
402             if (q->tx_timer) {
403                 timer_del(q->tx_timer);
404             } else {
405                 qemu_bh_cancel(q->tx_bh);
406             }
407             if ((n->status & VIRTIO_NET_S_LINK_UP) == 0 &&
408                 (queue_status & VIRTIO_CONFIG_S_DRIVER_OK) &&
409                 vdev->vm_running) {
410                 /* if tx is waiting we are likely have some packets in tx queue
411                  * and disabled notification */
412                 q->tx_waiting = 0;
413                 virtio_queue_set_notification(q->tx_vq, 1);
414                 virtio_net_drop_tx_queue_data(vdev, q->tx_vq);
415             }
416         }
417     }
418 }
419 
420 static void virtio_net_set_link_status(NetClientState *nc)
421 {
422     VirtIONet *n = qemu_get_nic_opaque(nc);
423     VirtIODevice *vdev = VIRTIO_DEVICE(n);
424     uint16_t old_status = n->status;
425 
426     if (nc->link_down)
427         n->status &= ~VIRTIO_NET_S_LINK_UP;
428     else
429         n->status |= VIRTIO_NET_S_LINK_UP;
430 
431     if (n->status != old_status)
432         virtio_notify_config(vdev);
433 
434     virtio_net_set_status(vdev, vdev->status);
435 }
436 
437 static void rxfilter_notify(NetClientState *nc)
438 {
439     VirtIONet *n = qemu_get_nic_opaque(nc);
440 
441     if (nc->rxfilter_notify_enabled) {
442         char *path = object_get_canonical_path(OBJECT(n->qdev));
443         qapi_event_send_nic_rx_filter_changed(!!n->netclient_name,
444                                               n->netclient_name, path);
445         g_free(path);
446 
447         /* disable event notification to avoid events flooding */
448         nc->rxfilter_notify_enabled = 0;
449     }
450 }
451 
452 static intList *get_vlan_table(VirtIONet *n)
453 {
454     intList *list;
455     int i, j;
456 
457     list = NULL;
458     for (i = 0; i < MAX_VLAN >> 5; i++) {
459         for (j = 0; n->vlans[i] && j <= 0x1f; j++) {
460             if (n->vlans[i] & (1U << j)) {
461                 QAPI_LIST_PREPEND(list, (i << 5) + j);
462             }
463         }
464     }
465 
466     return list;
467 }
468 
469 static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
470 {
471     VirtIONet *n = qemu_get_nic_opaque(nc);
472     VirtIODevice *vdev = VIRTIO_DEVICE(n);
473     RxFilterInfo *info;
474     strList *str_list;
475     int i;
476 
477     info = g_malloc0(sizeof(*info));
478     info->name = g_strdup(nc->name);
479     info->promiscuous = n->promisc;
480 
481     if (n->nouni) {
482         info->unicast = RX_STATE_NONE;
483     } else if (n->alluni) {
484         info->unicast = RX_STATE_ALL;
485     } else {
486         info->unicast = RX_STATE_NORMAL;
487     }
488 
489     if (n->nomulti) {
490         info->multicast = RX_STATE_NONE;
491     } else if (n->allmulti) {
492         info->multicast = RX_STATE_ALL;
493     } else {
494         info->multicast = RX_STATE_NORMAL;
495     }
496 
497     info->broadcast_allowed = n->nobcast;
498     info->multicast_overflow = n->mac_table.multi_overflow;
499     info->unicast_overflow = n->mac_table.uni_overflow;
500 
501     info->main_mac = qemu_mac_strdup_printf(n->mac);
502 
503     str_list = NULL;
504     for (i = 0; i < n->mac_table.first_multi; i++) {
505         QAPI_LIST_PREPEND(str_list,
506                       qemu_mac_strdup_printf(n->mac_table.macs + i * ETH_ALEN));
507     }
508     info->unicast_table = str_list;
509 
510     str_list = NULL;
511     for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
512         QAPI_LIST_PREPEND(str_list,
513                       qemu_mac_strdup_printf(n->mac_table.macs + i * ETH_ALEN));
514     }
515     info->multicast_table = str_list;
516     info->vlan_table = get_vlan_table(n);
517 
518     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VLAN)) {
519         info->vlan = RX_STATE_ALL;
520     } else if (!info->vlan_table) {
521         info->vlan = RX_STATE_NONE;
522     } else {
523         info->vlan = RX_STATE_NORMAL;
524     }
525 
526     /* enable event notification after query */
527     nc->rxfilter_notify_enabled = 1;
528 
529     return info;
530 }
531 
532 static void virtio_net_reset(VirtIODevice *vdev)
533 {
534     VirtIONet *n = VIRTIO_NET(vdev);
535     int i;
536 
537     /* Reset back to compatibility mode */
538     n->promisc = 1;
539     n->allmulti = 0;
540     n->alluni = 0;
541     n->nomulti = 0;
542     n->nouni = 0;
543     n->nobcast = 0;
544     /* multiqueue is disabled by default */
545     n->curr_queue_pairs = 1;
546     timer_del(n->announce_timer.tm);
547     n->announce_timer.round = 0;
548     n->status &= ~VIRTIO_NET_S_ANNOUNCE;
549 
550     /* Flush any MAC and VLAN filter table state */
551     n->mac_table.in_use = 0;
552     n->mac_table.first_multi = 0;
553     n->mac_table.multi_overflow = 0;
554     n->mac_table.uni_overflow = 0;
555     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
556     memcpy(&n->mac[0], &n->nic->conf->macaddr, sizeof(n->mac));
557     qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
558     memset(n->vlans, 0, MAX_VLAN >> 3);
559 
560     /* Flush any async TX */
561     for (i = 0;  i < n->max_queue_pairs; i++) {
562         NetClientState *nc = qemu_get_subqueue(n->nic, i);
563 
564         if (nc->peer) {
565             qemu_flush_or_purge_queued_packets(nc->peer, true);
566             assert(!virtio_net_get_subqueue(nc)->async_tx.elem);
567         }
568     }
569 }
570 
571 static void peer_test_vnet_hdr(VirtIONet *n)
572 {
573     NetClientState *nc = qemu_get_queue(n->nic);
574     if (!nc->peer) {
575         return;
576     }
577 
578     n->has_vnet_hdr = qemu_has_vnet_hdr(nc->peer);
579 }
580 
581 static int peer_has_vnet_hdr(VirtIONet *n)
582 {
583     return n->has_vnet_hdr;
584 }
585 
586 static int peer_has_ufo(VirtIONet *n)
587 {
588     if (!peer_has_vnet_hdr(n))
589         return 0;
590 
591     n->has_ufo = qemu_has_ufo(qemu_get_queue(n->nic)->peer);
592 
593     return n->has_ufo;
594 }
595 
596 static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs,
597                                        int version_1, int hash_report)
598 {
599     int i;
600     NetClientState *nc;
601 
602     n->mergeable_rx_bufs = mergeable_rx_bufs;
603 
604     if (version_1) {
605         n->guest_hdr_len = hash_report ?
606             sizeof(struct virtio_net_hdr_v1_hash) :
607             sizeof(struct virtio_net_hdr_mrg_rxbuf);
608         n->rss_data.populate_hash = !!hash_report;
609     } else {
610         n->guest_hdr_len = n->mergeable_rx_bufs ?
611             sizeof(struct virtio_net_hdr_mrg_rxbuf) :
612             sizeof(struct virtio_net_hdr);
613     }
614 
615     for (i = 0; i < n->max_queue_pairs; i++) {
616         nc = qemu_get_subqueue(n->nic, i);
617 
618         if (peer_has_vnet_hdr(n) &&
619             qemu_has_vnet_hdr_len(nc->peer, n->guest_hdr_len)) {
620             qemu_set_vnet_hdr_len(nc->peer, n->guest_hdr_len);
621             n->host_hdr_len = n->guest_hdr_len;
622         }
623     }
624 }
625 
626 static int virtio_net_max_tx_queue_size(VirtIONet *n)
627 {
628     NetClientState *peer = n->nic_conf.peers.ncs[0];
629 
630     /*
631      * Backends other than vhost-user or vhost-vdpa don't support max queue
632      * size.
633      */
634     if (!peer) {
635         return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE;
636     }
637 
638     switch(peer->info->type) {
639     case NET_CLIENT_DRIVER_VHOST_USER:
640     case NET_CLIENT_DRIVER_VHOST_VDPA:
641         return VIRTQUEUE_MAX_SIZE;
642     default:
643         return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE;
644     };
645 }
646 
647 static int peer_attach(VirtIONet *n, int index)
648 {
649     NetClientState *nc = qemu_get_subqueue(n->nic, index);
650 
651     if (!nc->peer) {
652         return 0;
653     }
654 
655     if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
656         vhost_set_vring_enable(nc->peer, 1);
657     }
658 
659     if (nc->peer->info->type != NET_CLIENT_DRIVER_TAP) {
660         return 0;
661     }
662 
663     if (n->max_queue_pairs == 1) {
664         return 0;
665     }
666 
667     return tap_enable(nc->peer);
668 }
669 
670 static int peer_detach(VirtIONet *n, int index)
671 {
672     NetClientState *nc = qemu_get_subqueue(n->nic, index);
673 
674     if (!nc->peer) {
675         return 0;
676     }
677 
678     if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
679         vhost_set_vring_enable(nc->peer, 0);
680     }
681 
682     if (nc->peer->info->type !=  NET_CLIENT_DRIVER_TAP) {
683         return 0;
684     }
685 
686     return tap_disable(nc->peer);
687 }
688 
689 static void virtio_net_set_queue_pairs(VirtIONet *n)
690 {
691     int i;
692     int r;
693 
694     if (n->nic->peer_deleted) {
695         return;
696     }
697 
698     for (i = 0; i < n->max_queue_pairs; i++) {
699         if (i < n->curr_queue_pairs) {
700             r = peer_attach(n, i);
701             assert(!r);
702         } else {
703             r = peer_detach(n, i);
704             assert(!r);
705         }
706     }
707 }
708 
709 static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue);
710 
711 static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
712                                         Error **errp)
713 {
714     VirtIONet *n = VIRTIO_NET(vdev);
715     NetClientState *nc = qemu_get_queue(n->nic);
716 
717     /* Firstly sync all virtio-net possible supported features */
718     features |= n->host_features;
719 
720     virtio_add_feature(&features, VIRTIO_NET_F_MAC);
721 
722     if (!peer_has_vnet_hdr(n)) {
723         virtio_clear_feature(&features, VIRTIO_NET_F_CSUM);
724         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_TSO4);
725         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_TSO6);
726         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_ECN);
727 
728         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_CSUM);
729         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO4);
730         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO6);
731         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ECN);
732 
733         virtio_clear_feature(&features, VIRTIO_NET_F_HASH_REPORT);
734     }
735 
736     if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
737         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_UFO);
738         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO);
739     }
740 
741     if (!get_vhost_net(nc->peer)) {
742         return features;
743     }
744 
745     if (!ebpf_rss_is_loaded(&n->ebpf_rss)) {
746         virtio_clear_feature(&features, VIRTIO_NET_F_RSS);
747     }
748     features = vhost_net_get_features(get_vhost_net(nc->peer), features);
749     vdev->backend_features = features;
750 
751     if (n->mtu_bypass_backend &&
752             (n->host_features & 1ULL << VIRTIO_NET_F_MTU)) {
753         features |= (1ULL << VIRTIO_NET_F_MTU);
754     }
755 
756     return features;
757 }
758 
759 static uint64_t virtio_net_bad_features(VirtIODevice *vdev)
760 {
761     uint64_t features = 0;
762 
763     /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
764      * but also these: */
765     virtio_add_feature(&features, VIRTIO_NET_F_MAC);
766     virtio_add_feature(&features, VIRTIO_NET_F_CSUM);
767     virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO4);
768     virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO6);
769     virtio_add_feature(&features, VIRTIO_NET_F_HOST_ECN);
770 
771     return features;
772 }
773 
774 static void virtio_net_apply_guest_offloads(VirtIONet *n)
775 {
776     qemu_set_offload(qemu_get_queue(n->nic)->peer,
777             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_CSUM)),
778             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO4)),
779             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO6)),
780             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_ECN)),
781             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_UFO)));
782 }
783 
784 static uint64_t virtio_net_guest_offloads_by_features(uint32_t features)
785 {
786     static const uint64_t guest_offloads_mask =
787         (1ULL << VIRTIO_NET_F_GUEST_CSUM) |
788         (1ULL << VIRTIO_NET_F_GUEST_TSO4) |
789         (1ULL << VIRTIO_NET_F_GUEST_TSO6) |
790         (1ULL << VIRTIO_NET_F_GUEST_ECN)  |
791         (1ULL << VIRTIO_NET_F_GUEST_UFO);
792 
793     return guest_offloads_mask & features;
794 }
795 
796 static inline uint64_t virtio_net_supported_guest_offloads(VirtIONet *n)
797 {
798     VirtIODevice *vdev = VIRTIO_DEVICE(n);
799     return virtio_net_guest_offloads_by_features(vdev->guest_features);
800 }
801 
802 typedef struct {
803     VirtIONet *n;
804     DeviceState *dev;
805 } FailoverDevice;
806 
807 /**
808  * Set the failover primary device
809  *
810  * @opaque: FailoverId to setup
811  * @opts: opts for device we are handling
812  * @errp: returns an error if this function fails
813  */
814 static int failover_set_primary(DeviceState *dev, void *opaque)
815 {
816     FailoverDevice *fdev = opaque;
817     PCIDevice *pci_dev = (PCIDevice *)
818         object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE);
819 
820     if (!pci_dev) {
821         return 0;
822     }
823 
824     if (!g_strcmp0(pci_dev->failover_pair_id, fdev->n->netclient_name)) {
825         fdev->dev = dev;
826         return 1;
827     }
828 
829     return 0;
830 }
831 
832 /**
833  * Find the primary device for this failover virtio-net
834  *
835  * @n: VirtIONet device
836  * @errp: returns an error if this function fails
837  */
838 static DeviceState *failover_find_primary_device(VirtIONet *n)
839 {
840     FailoverDevice fdev = {
841         .n = n,
842     };
843 
844     qbus_walk_children(sysbus_get_default(), failover_set_primary, NULL,
845                        NULL, NULL, &fdev);
846     return fdev.dev;
847 }
848 
849 static void failover_add_primary(VirtIONet *n, Error **errp)
850 {
851     Error *err = NULL;
852     DeviceState *dev = failover_find_primary_device(n);
853 
854     if (dev) {
855         return;
856     }
857 
858     if (!n->primary_opts) {
859         error_setg(errp, "Primary device not found");
860         error_append_hint(errp, "Virtio-net failover will not work. Make "
861                           "sure primary device has parameter"
862                           " failover_pair_id=%s\n", n->netclient_name);
863         return;
864     }
865 
866     dev = qdev_device_add_from_qdict(n->primary_opts,
867                                      n->primary_opts_from_json,
868                                      &err);
869     if (err) {
870         qobject_unref(n->primary_opts);
871         n->primary_opts = NULL;
872     } else {
873         object_unref(OBJECT(dev));
874     }
875     error_propagate(errp, err);
876 }
877 
878 static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features)
879 {
880     VirtIONet *n = VIRTIO_NET(vdev);
881     Error *err = NULL;
882     int i;
883 
884     if (n->mtu_bypass_backend &&
885             !virtio_has_feature(vdev->backend_features, VIRTIO_NET_F_MTU)) {
886         features &= ~(1ULL << VIRTIO_NET_F_MTU);
887     }
888 
889     virtio_net_set_multiqueue(n,
890                               virtio_has_feature(features, VIRTIO_NET_F_RSS) ||
891                               virtio_has_feature(features, VIRTIO_NET_F_MQ));
892 
893     virtio_net_set_mrg_rx_bufs(n,
894                                virtio_has_feature(features,
895                                                   VIRTIO_NET_F_MRG_RXBUF),
896                                virtio_has_feature(features,
897                                                   VIRTIO_F_VERSION_1),
898                                virtio_has_feature(features,
899                                                   VIRTIO_NET_F_HASH_REPORT));
900 
901     n->rsc4_enabled = virtio_has_feature(features, VIRTIO_NET_F_RSC_EXT) &&
902         virtio_has_feature(features, VIRTIO_NET_F_GUEST_TSO4);
903     n->rsc6_enabled = virtio_has_feature(features, VIRTIO_NET_F_RSC_EXT) &&
904         virtio_has_feature(features, VIRTIO_NET_F_GUEST_TSO6);
905     n->rss_data.redirect = virtio_has_feature(features, VIRTIO_NET_F_RSS);
906 
907     if (n->has_vnet_hdr) {
908         n->curr_guest_offloads =
909             virtio_net_guest_offloads_by_features(features);
910         virtio_net_apply_guest_offloads(n);
911     }
912 
913     for (i = 0;  i < n->max_queue_pairs; i++) {
914         NetClientState *nc = qemu_get_subqueue(n->nic, i);
915 
916         if (!get_vhost_net(nc->peer)) {
917             continue;
918         }
919         vhost_net_ack_features(get_vhost_net(nc->peer), features);
920     }
921 
922     if (virtio_has_feature(features, VIRTIO_NET_F_CTRL_VLAN)) {
923         memset(n->vlans, 0, MAX_VLAN >> 3);
924     } else {
925         memset(n->vlans, 0xff, MAX_VLAN >> 3);
926     }
927 
928     if (virtio_has_feature(features, VIRTIO_NET_F_STANDBY)) {
929         qapi_event_send_failover_negotiated(n->netclient_name);
930         qatomic_set(&n->failover_primary_hidden, false);
931         failover_add_primary(n, &err);
932         if (err) {
933             if (!qtest_enabled()) {
934                 warn_report_err(err);
935             } else {
936                 error_free(err);
937             }
938         }
939     }
940 }
941 
942 static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
943                                      struct iovec *iov, unsigned int iov_cnt)
944 {
945     uint8_t on;
946     size_t s;
947     NetClientState *nc = qemu_get_queue(n->nic);
948 
949     s = iov_to_buf(iov, iov_cnt, 0, &on, sizeof(on));
950     if (s != sizeof(on)) {
951         return VIRTIO_NET_ERR;
952     }
953 
954     if (cmd == VIRTIO_NET_CTRL_RX_PROMISC) {
955         n->promisc = on;
956     } else if (cmd == VIRTIO_NET_CTRL_RX_ALLMULTI) {
957         n->allmulti = on;
958     } else if (cmd == VIRTIO_NET_CTRL_RX_ALLUNI) {
959         n->alluni = on;
960     } else if (cmd == VIRTIO_NET_CTRL_RX_NOMULTI) {
961         n->nomulti = on;
962     } else if (cmd == VIRTIO_NET_CTRL_RX_NOUNI) {
963         n->nouni = on;
964     } else if (cmd == VIRTIO_NET_CTRL_RX_NOBCAST) {
965         n->nobcast = on;
966     } else {
967         return VIRTIO_NET_ERR;
968     }
969 
970     rxfilter_notify(nc);
971 
972     return VIRTIO_NET_OK;
973 }
974 
975 static int virtio_net_handle_offloads(VirtIONet *n, uint8_t cmd,
976                                      struct iovec *iov, unsigned int iov_cnt)
977 {
978     VirtIODevice *vdev = VIRTIO_DEVICE(n);
979     uint64_t offloads;
980     size_t s;
981 
982     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
983         return VIRTIO_NET_ERR;
984     }
985 
986     s = iov_to_buf(iov, iov_cnt, 0, &offloads, sizeof(offloads));
987     if (s != sizeof(offloads)) {
988         return VIRTIO_NET_ERR;
989     }
990 
991     if (cmd == VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET) {
992         uint64_t supported_offloads;
993 
994         offloads = virtio_ldq_p(vdev, &offloads);
995 
996         if (!n->has_vnet_hdr) {
997             return VIRTIO_NET_ERR;
998         }
999 
1000         n->rsc4_enabled = virtio_has_feature(offloads, VIRTIO_NET_F_RSC_EXT) &&
1001             virtio_has_feature(offloads, VIRTIO_NET_F_GUEST_TSO4);
1002         n->rsc6_enabled = virtio_has_feature(offloads, VIRTIO_NET_F_RSC_EXT) &&
1003             virtio_has_feature(offloads, VIRTIO_NET_F_GUEST_TSO6);
1004         virtio_clear_feature(&offloads, VIRTIO_NET_F_RSC_EXT);
1005 
1006         supported_offloads = virtio_net_supported_guest_offloads(n);
1007         if (offloads & ~supported_offloads) {
1008             return VIRTIO_NET_ERR;
1009         }
1010 
1011         n->curr_guest_offloads = offloads;
1012         virtio_net_apply_guest_offloads(n);
1013 
1014         return VIRTIO_NET_OK;
1015     } else {
1016         return VIRTIO_NET_ERR;
1017     }
1018 }
1019 
1020 static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
1021                                  struct iovec *iov, unsigned int iov_cnt)
1022 {
1023     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1024     struct virtio_net_ctrl_mac mac_data;
1025     size_t s;
1026     NetClientState *nc = qemu_get_queue(n->nic);
1027 
1028     if (cmd == VIRTIO_NET_CTRL_MAC_ADDR_SET) {
1029         if (iov_size(iov, iov_cnt) != sizeof(n->mac)) {
1030             return VIRTIO_NET_ERR;
1031         }
1032         s = iov_to_buf(iov, iov_cnt, 0, &n->mac, sizeof(n->mac));
1033         assert(s == sizeof(n->mac));
1034         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
1035         rxfilter_notify(nc);
1036 
1037         return VIRTIO_NET_OK;
1038     }
1039 
1040     if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET) {
1041         return VIRTIO_NET_ERR;
1042     }
1043 
1044     int in_use = 0;
1045     int first_multi = 0;
1046     uint8_t uni_overflow = 0;
1047     uint8_t multi_overflow = 0;
1048     uint8_t *macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
1049 
1050     s = iov_to_buf(iov, iov_cnt, 0, &mac_data.entries,
1051                    sizeof(mac_data.entries));
1052     mac_data.entries = virtio_ldl_p(vdev, &mac_data.entries);
1053     if (s != sizeof(mac_data.entries)) {
1054         goto error;
1055     }
1056     iov_discard_front(&iov, &iov_cnt, s);
1057 
1058     if (mac_data.entries * ETH_ALEN > iov_size(iov, iov_cnt)) {
1059         goto error;
1060     }
1061 
1062     if (mac_data.entries <= MAC_TABLE_ENTRIES) {
1063         s = iov_to_buf(iov, iov_cnt, 0, macs,
1064                        mac_data.entries * ETH_ALEN);
1065         if (s != mac_data.entries * ETH_ALEN) {
1066             goto error;
1067         }
1068         in_use += mac_data.entries;
1069     } else {
1070         uni_overflow = 1;
1071     }
1072 
1073     iov_discard_front(&iov, &iov_cnt, mac_data.entries * ETH_ALEN);
1074 
1075     first_multi = in_use;
1076 
1077     s = iov_to_buf(iov, iov_cnt, 0, &mac_data.entries,
1078                    sizeof(mac_data.entries));
1079     mac_data.entries = virtio_ldl_p(vdev, &mac_data.entries);
1080     if (s != sizeof(mac_data.entries)) {
1081         goto error;
1082     }
1083 
1084     iov_discard_front(&iov, &iov_cnt, s);
1085 
1086     if (mac_data.entries * ETH_ALEN != iov_size(iov, iov_cnt)) {
1087         goto error;
1088     }
1089 
1090     if (mac_data.entries <= MAC_TABLE_ENTRIES - in_use) {
1091         s = iov_to_buf(iov, iov_cnt, 0, &macs[in_use * ETH_ALEN],
1092                        mac_data.entries * ETH_ALEN);
1093         if (s != mac_data.entries * ETH_ALEN) {
1094             goto error;
1095         }
1096         in_use += mac_data.entries;
1097     } else {
1098         multi_overflow = 1;
1099     }
1100 
1101     n->mac_table.in_use = in_use;
1102     n->mac_table.first_multi = first_multi;
1103     n->mac_table.uni_overflow = uni_overflow;
1104     n->mac_table.multi_overflow = multi_overflow;
1105     memcpy(n->mac_table.macs, macs, MAC_TABLE_ENTRIES * ETH_ALEN);
1106     g_free(macs);
1107     rxfilter_notify(nc);
1108 
1109     return VIRTIO_NET_OK;
1110 
1111 error:
1112     g_free(macs);
1113     return VIRTIO_NET_ERR;
1114 }
1115 
1116 static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
1117                                         struct iovec *iov, unsigned int iov_cnt)
1118 {
1119     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1120     uint16_t vid;
1121     size_t s;
1122     NetClientState *nc = qemu_get_queue(n->nic);
1123 
1124     s = iov_to_buf(iov, iov_cnt, 0, &vid, sizeof(vid));
1125     vid = virtio_lduw_p(vdev, &vid);
1126     if (s != sizeof(vid)) {
1127         return VIRTIO_NET_ERR;
1128     }
1129 
1130     if (vid >= MAX_VLAN)
1131         return VIRTIO_NET_ERR;
1132 
1133     if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
1134         n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
1135     else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
1136         n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
1137     else
1138         return VIRTIO_NET_ERR;
1139 
1140     rxfilter_notify(nc);
1141 
1142     return VIRTIO_NET_OK;
1143 }
1144 
1145 static int virtio_net_handle_announce(VirtIONet *n, uint8_t cmd,
1146                                       struct iovec *iov, unsigned int iov_cnt)
1147 {
1148     trace_virtio_net_handle_announce(n->announce_timer.round);
1149     if (cmd == VIRTIO_NET_CTRL_ANNOUNCE_ACK &&
1150         n->status & VIRTIO_NET_S_ANNOUNCE) {
1151         n->status &= ~VIRTIO_NET_S_ANNOUNCE;
1152         if (n->announce_timer.round) {
1153             qemu_announce_timer_step(&n->announce_timer);
1154         }
1155         return VIRTIO_NET_OK;
1156     } else {
1157         return VIRTIO_NET_ERR;
1158     }
1159 }
1160 
1161 static void virtio_net_detach_epbf_rss(VirtIONet *n);
1162 
1163 static void virtio_net_disable_rss(VirtIONet *n)
1164 {
1165     if (n->rss_data.enabled) {
1166         trace_virtio_net_rss_disable();
1167     }
1168     n->rss_data.enabled = false;
1169 
1170     virtio_net_detach_epbf_rss(n);
1171 }
1172 
1173 static bool virtio_net_attach_ebpf_to_backend(NICState *nic, int prog_fd)
1174 {
1175     NetClientState *nc = qemu_get_peer(qemu_get_queue(nic), 0);
1176     if (nc == NULL || nc->info->set_steering_ebpf == NULL) {
1177         return false;
1178     }
1179 
1180     return nc->info->set_steering_ebpf(nc, prog_fd);
1181 }
1182 
1183 static void rss_data_to_rss_config(struct VirtioNetRssData *data,
1184                                    struct EBPFRSSConfig *config)
1185 {
1186     config->redirect = data->redirect;
1187     config->populate_hash = data->populate_hash;
1188     config->hash_types = data->hash_types;
1189     config->indirections_len = data->indirections_len;
1190     config->default_queue = data->default_queue;
1191 }
1192 
1193 static bool virtio_net_attach_epbf_rss(VirtIONet *n)
1194 {
1195     struct EBPFRSSConfig config = {};
1196 
1197     if (!ebpf_rss_is_loaded(&n->ebpf_rss)) {
1198         return false;
1199     }
1200 
1201     rss_data_to_rss_config(&n->rss_data, &config);
1202 
1203     if (!ebpf_rss_set_all(&n->ebpf_rss, &config,
1204                           n->rss_data.indirections_table, n->rss_data.key)) {
1205         return false;
1206     }
1207 
1208     if (!virtio_net_attach_ebpf_to_backend(n->nic, n->ebpf_rss.program_fd)) {
1209         return false;
1210     }
1211 
1212     return true;
1213 }
1214 
1215 static void virtio_net_detach_epbf_rss(VirtIONet *n)
1216 {
1217     virtio_net_attach_ebpf_to_backend(n->nic, -1);
1218 }
1219 
1220 static bool virtio_net_load_ebpf(VirtIONet *n)
1221 {
1222     if (!virtio_net_attach_ebpf_to_backend(n->nic, -1)) {
1223         /* backend does't support steering ebpf */
1224         return false;
1225     }
1226 
1227     return ebpf_rss_load(&n->ebpf_rss);
1228 }
1229 
1230 static void virtio_net_unload_ebpf(VirtIONet *n)
1231 {
1232     virtio_net_attach_ebpf_to_backend(n->nic, -1);
1233     ebpf_rss_unload(&n->ebpf_rss);
1234 }
1235 
1236 static uint16_t virtio_net_handle_rss(VirtIONet *n,
1237                                       struct iovec *iov,
1238                                       unsigned int iov_cnt,
1239                                       bool do_rss)
1240 {
1241     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1242     struct virtio_net_rss_config cfg;
1243     size_t s, offset = 0, size_get;
1244     uint16_t queue_pairs, i;
1245     struct {
1246         uint16_t us;
1247         uint8_t b;
1248     } QEMU_PACKED temp;
1249     const char *err_msg = "";
1250     uint32_t err_value = 0;
1251 
1252     if (do_rss && !virtio_vdev_has_feature(vdev, VIRTIO_NET_F_RSS)) {
1253         err_msg = "RSS is not negotiated";
1254         goto error;
1255     }
1256     if (!do_rss && !virtio_vdev_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT)) {
1257         err_msg = "Hash report is not negotiated";
1258         goto error;
1259     }
1260     size_get = offsetof(struct virtio_net_rss_config, indirection_table);
1261     s = iov_to_buf(iov, iov_cnt, offset, &cfg, size_get);
1262     if (s != size_get) {
1263         err_msg = "Short command buffer";
1264         err_value = (uint32_t)s;
1265         goto error;
1266     }
1267     n->rss_data.hash_types = virtio_ldl_p(vdev, &cfg.hash_types);
1268     n->rss_data.indirections_len =
1269         virtio_lduw_p(vdev, &cfg.indirection_table_mask);
1270     n->rss_data.indirections_len++;
1271     if (!do_rss) {
1272         n->rss_data.indirections_len = 1;
1273     }
1274     if (!is_power_of_2(n->rss_data.indirections_len)) {
1275         err_msg = "Invalid size of indirection table";
1276         err_value = n->rss_data.indirections_len;
1277         goto error;
1278     }
1279     if (n->rss_data.indirections_len > VIRTIO_NET_RSS_MAX_TABLE_LEN) {
1280         err_msg = "Too large indirection table";
1281         err_value = n->rss_data.indirections_len;
1282         goto error;
1283     }
1284     n->rss_data.default_queue = do_rss ?
1285         virtio_lduw_p(vdev, &cfg.unclassified_queue) : 0;
1286     if (n->rss_data.default_queue >= n->max_queue_pairs) {
1287         err_msg = "Invalid default queue";
1288         err_value = n->rss_data.default_queue;
1289         goto error;
1290     }
1291     offset += size_get;
1292     size_get = sizeof(uint16_t) * n->rss_data.indirections_len;
1293     g_free(n->rss_data.indirections_table);
1294     n->rss_data.indirections_table = g_malloc(size_get);
1295     if (!n->rss_data.indirections_table) {
1296         err_msg = "Can't allocate indirections table";
1297         err_value = n->rss_data.indirections_len;
1298         goto error;
1299     }
1300     s = iov_to_buf(iov, iov_cnt, offset,
1301                    n->rss_data.indirections_table, size_get);
1302     if (s != size_get) {
1303         err_msg = "Short indirection table buffer";
1304         err_value = (uint32_t)s;
1305         goto error;
1306     }
1307     for (i = 0; i < n->rss_data.indirections_len; ++i) {
1308         uint16_t val = n->rss_data.indirections_table[i];
1309         n->rss_data.indirections_table[i] = virtio_lduw_p(vdev, &val);
1310     }
1311     offset += size_get;
1312     size_get = sizeof(temp);
1313     s = iov_to_buf(iov, iov_cnt, offset, &temp, size_get);
1314     if (s != size_get) {
1315         err_msg = "Can't get queue_pairs";
1316         err_value = (uint32_t)s;
1317         goto error;
1318     }
1319     queue_pairs = do_rss ? virtio_lduw_p(vdev, &temp.us) : n->curr_queue_pairs;
1320     if (queue_pairs == 0 || queue_pairs > n->max_queue_pairs) {
1321         err_msg = "Invalid number of queue_pairs";
1322         err_value = queue_pairs;
1323         goto error;
1324     }
1325     if (temp.b > VIRTIO_NET_RSS_MAX_KEY_SIZE) {
1326         err_msg = "Invalid key size";
1327         err_value = temp.b;
1328         goto error;
1329     }
1330     if (!temp.b && n->rss_data.hash_types) {
1331         err_msg = "No key provided";
1332         err_value = 0;
1333         goto error;
1334     }
1335     if (!temp.b && !n->rss_data.hash_types) {
1336         virtio_net_disable_rss(n);
1337         return queue_pairs;
1338     }
1339     offset += size_get;
1340     size_get = temp.b;
1341     s = iov_to_buf(iov, iov_cnt, offset, n->rss_data.key, size_get);
1342     if (s != size_get) {
1343         err_msg = "Can get key buffer";
1344         err_value = (uint32_t)s;
1345         goto error;
1346     }
1347     n->rss_data.enabled = true;
1348 
1349     if (!n->rss_data.populate_hash) {
1350         if (!virtio_net_attach_epbf_rss(n)) {
1351             /* EBPF must be loaded for vhost */
1352             if (get_vhost_net(qemu_get_queue(n->nic)->peer)) {
1353                 warn_report("Can't load eBPF RSS for vhost");
1354                 goto error;
1355             }
1356             /* fallback to software RSS */
1357             warn_report("Can't load eBPF RSS - fallback to software RSS");
1358             n->rss_data.enabled_software_rss = true;
1359         }
1360     } else {
1361         /* use software RSS for hash populating */
1362         /* and detach eBPF if was loaded before */
1363         virtio_net_detach_epbf_rss(n);
1364         n->rss_data.enabled_software_rss = true;
1365     }
1366 
1367     trace_virtio_net_rss_enable(n->rss_data.hash_types,
1368                                 n->rss_data.indirections_len,
1369                                 temp.b);
1370     return queue_pairs;
1371 error:
1372     trace_virtio_net_rss_error(err_msg, err_value);
1373     virtio_net_disable_rss(n);
1374     return 0;
1375 }
1376 
1377 static int virtio_net_handle_mq(VirtIONet *n, uint8_t cmd,
1378                                 struct iovec *iov, unsigned int iov_cnt)
1379 {
1380     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1381     uint16_t queue_pairs;
1382 
1383     virtio_net_disable_rss(n);
1384     if (cmd == VIRTIO_NET_CTRL_MQ_HASH_CONFIG) {
1385         queue_pairs = virtio_net_handle_rss(n, iov, iov_cnt, false);
1386         return queue_pairs ? VIRTIO_NET_OK : VIRTIO_NET_ERR;
1387     }
1388     if (cmd == VIRTIO_NET_CTRL_MQ_RSS_CONFIG) {
1389         queue_pairs = virtio_net_handle_rss(n, iov, iov_cnt, true);
1390     } else if (cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
1391         struct virtio_net_ctrl_mq mq;
1392         size_t s;
1393         if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ)) {
1394             return VIRTIO_NET_ERR;
1395         }
1396         s = iov_to_buf(iov, iov_cnt, 0, &mq, sizeof(mq));
1397         if (s != sizeof(mq)) {
1398             return VIRTIO_NET_ERR;
1399         }
1400         queue_pairs = virtio_lduw_p(vdev, &mq.virtqueue_pairs);
1401 
1402     } else {
1403         return VIRTIO_NET_ERR;
1404     }
1405 
1406     if (queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1407         queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1408         queue_pairs > n->max_queue_pairs ||
1409         !n->multiqueue) {
1410         return VIRTIO_NET_ERR;
1411     }
1412 
1413     n->curr_queue_pairs = queue_pairs;
1414     /* stop the backend before changing the number of queue_pairs to avoid handling a
1415      * disabled queue */
1416     virtio_net_set_status(vdev, vdev->status);
1417     virtio_net_set_queue_pairs(n);
1418 
1419     return VIRTIO_NET_OK;
1420 }
1421 
1422 static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
1423 {
1424     VirtIONet *n = VIRTIO_NET(vdev);
1425     struct virtio_net_ctrl_hdr ctrl;
1426     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
1427     VirtQueueElement *elem;
1428     size_t s;
1429     struct iovec *iov, *iov2;
1430     unsigned int iov_cnt;
1431 
1432     for (;;) {
1433         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
1434         if (!elem) {
1435             break;
1436         }
1437         if (iov_size(elem->in_sg, elem->in_num) < sizeof(status) ||
1438             iov_size(elem->out_sg, elem->out_num) < sizeof(ctrl)) {
1439             virtio_error(vdev, "virtio-net ctrl missing headers");
1440             virtqueue_detach_element(vq, elem, 0);
1441             g_free(elem);
1442             break;
1443         }
1444 
1445         iov_cnt = elem->out_num;
1446         iov2 = iov = g_memdup(elem->out_sg, sizeof(struct iovec) * elem->out_num);
1447         s = iov_to_buf(iov, iov_cnt, 0, &ctrl, sizeof(ctrl));
1448         iov_discard_front(&iov, &iov_cnt, sizeof(ctrl));
1449         if (s != sizeof(ctrl)) {
1450             status = VIRTIO_NET_ERR;
1451         } else if (ctrl.class == VIRTIO_NET_CTRL_RX) {
1452             status = virtio_net_handle_rx_mode(n, ctrl.cmd, iov, iov_cnt);
1453         } else if (ctrl.class == VIRTIO_NET_CTRL_MAC) {
1454             status = virtio_net_handle_mac(n, ctrl.cmd, iov, iov_cnt);
1455         } else if (ctrl.class == VIRTIO_NET_CTRL_VLAN) {
1456             status = virtio_net_handle_vlan_table(n, ctrl.cmd, iov, iov_cnt);
1457         } else if (ctrl.class == VIRTIO_NET_CTRL_ANNOUNCE) {
1458             status = virtio_net_handle_announce(n, ctrl.cmd, iov, iov_cnt);
1459         } else if (ctrl.class == VIRTIO_NET_CTRL_MQ) {
1460             status = virtio_net_handle_mq(n, ctrl.cmd, iov, iov_cnt);
1461         } else if (ctrl.class == VIRTIO_NET_CTRL_GUEST_OFFLOADS) {
1462             status = virtio_net_handle_offloads(n, ctrl.cmd, iov, iov_cnt);
1463         }
1464 
1465         s = iov_from_buf(elem->in_sg, elem->in_num, 0, &status, sizeof(status));
1466         assert(s == sizeof(status));
1467 
1468         virtqueue_push(vq, elem, sizeof(status));
1469         virtio_notify(vdev, vq);
1470         g_free(iov2);
1471         g_free(elem);
1472     }
1473 }
1474 
1475 /* RX */
1476 
1477 static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
1478 {
1479     VirtIONet *n = VIRTIO_NET(vdev);
1480     int queue_index = vq2q(virtio_get_queue_index(vq));
1481 
1482     qemu_flush_queued_packets(qemu_get_subqueue(n->nic, queue_index));
1483 }
1484 
1485 static bool virtio_net_can_receive(NetClientState *nc)
1486 {
1487     VirtIONet *n = qemu_get_nic_opaque(nc);
1488     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1489     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
1490 
1491     if (!vdev->vm_running) {
1492         return false;
1493     }
1494 
1495     if (nc->queue_index >= n->curr_queue_pairs) {
1496         return false;
1497     }
1498 
1499     if (!virtio_queue_ready(q->rx_vq) ||
1500         !(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
1501         return false;
1502     }
1503 
1504     return true;
1505 }
1506 
1507 static int virtio_net_has_buffers(VirtIONetQueue *q, int bufsize)
1508 {
1509     VirtIONet *n = q->n;
1510     if (virtio_queue_empty(q->rx_vq) ||
1511         (n->mergeable_rx_bufs &&
1512          !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
1513         virtio_queue_set_notification(q->rx_vq, 1);
1514 
1515         /* To avoid a race condition where the guest has made some buffers
1516          * available after the above check but before notification was
1517          * enabled, check for available buffers again.
1518          */
1519         if (virtio_queue_empty(q->rx_vq) ||
1520             (n->mergeable_rx_bufs &&
1521              !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
1522             return 0;
1523         }
1524     }
1525 
1526     virtio_queue_set_notification(q->rx_vq, 0);
1527     return 1;
1528 }
1529 
1530 static void virtio_net_hdr_swap(VirtIODevice *vdev, struct virtio_net_hdr *hdr)
1531 {
1532     virtio_tswap16s(vdev, &hdr->hdr_len);
1533     virtio_tswap16s(vdev, &hdr->gso_size);
1534     virtio_tswap16s(vdev, &hdr->csum_start);
1535     virtio_tswap16s(vdev, &hdr->csum_offset);
1536 }
1537 
1538 /* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
1539  * it never finds out that the packets don't have valid checksums.  This
1540  * causes dhclient to get upset.  Fedora's carried a patch for ages to
1541  * fix this with Xen but it hasn't appeared in an upstream release of
1542  * dhclient yet.
1543  *
1544  * To avoid breaking existing guests, we catch udp packets and add
1545  * checksums.  This is terrible but it's better than hacking the guest
1546  * kernels.
1547  *
1548  * N.B. if we introduce a zero-copy API, this operation is no longer free so
1549  * we should provide a mechanism to disable it to avoid polluting the host
1550  * cache.
1551  */
1552 static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
1553                                         uint8_t *buf, size_t size)
1554 {
1555     if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
1556         (size > 27 && size < 1500) && /* normal sized MTU */
1557         (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
1558         (buf[23] == 17) && /* ip.protocol == UDP */
1559         (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
1560         net_checksum_calculate(buf, size, CSUM_UDP);
1561         hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
1562     }
1563 }
1564 
1565 static void receive_header(VirtIONet *n, const struct iovec *iov, int iov_cnt,
1566                            const void *buf, size_t size)
1567 {
1568     if (n->has_vnet_hdr) {
1569         /* FIXME this cast is evil */
1570         void *wbuf = (void *)buf;
1571         work_around_broken_dhclient(wbuf, wbuf + n->host_hdr_len,
1572                                     size - n->host_hdr_len);
1573 
1574         if (n->needs_vnet_hdr_swap) {
1575             virtio_net_hdr_swap(VIRTIO_DEVICE(n), wbuf);
1576         }
1577         iov_from_buf(iov, iov_cnt, 0, buf, sizeof(struct virtio_net_hdr));
1578     } else {
1579         struct virtio_net_hdr hdr = {
1580             .flags = 0,
1581             .gso_type = VIRTIO_NET_HDR_GSO_NONE
1582         };
1583         iov_from_buf(iov, iov_cnt, 0, &hdr, sizeof hdr);
1584     }
1585 }
1586 
1587 static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
1588 {
1589     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1590     static const uint8_t vlan[] = {0x81, 0x00};
1591     uint8_t *ptr = (uint8_t *)buf;
1592     int i;
1593 
1594     if (n->promisc)
1595         return 1;
1596 
1597     ptr += n->host_hdr_len;
1598 
1599     if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
1600         int vid = lduw_be_p(ptr + 14) & 0xfff;
1601         if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
1602             return 0;
1603     }
1604 
1605     if (ptr[0] & 1) { // multicast
1606         if (!memcmp(ptr, bcast, sizeof(bcast))) {
1607             return !n->nobcast;
1608         } else if (n->nomulti) {
1609             return 0;
1610         } else if (n->allmulti || n->mac_table.multi_overflow) {
1611             return 1;
1612         }
1613 
1614         for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
1615             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
1616                 return 1;
1617             }
1618         }
1619     } else { // unicast
1620         if (n->nouni) {
1621             return 0;
1622         } else if (n->alluni || n->mac_table.uni_overflow) {
1623             return 1;
1624         } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
1625             return 1;
1626         }
1627 
1628         for (i = 0; i < n->mac_table.first_multi; i++) {
1629             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
1630                 return 1;
1631             }
1632         }
1633     }
1634 
1635     return 0;
1636 }
1637 
1638 static uint8_t virtio_net_get_hash_type(bool isip4,
1639                                         bool isip6,
1640                                         bool isudp,
1641                                         bool istcp,
1642                                         uint32_t types)
1643 {
1644     if (isip4) {
1645         if (istcp && (types & VIRTIO_NET_RSS_HASH_TYPE_TCPv4)) {
1646             return NetPktRssIpV4Tcp;
1647         }
1648         if (isudp && (types & VIRTIO_NET_RSS_HASH_TYPE_UDPv4)) {
1649             return NetPktRssIpV4Udp;
1650         }
1651         if (types & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
1652             return NetPktRssIpV4;
1653         }
1654     } else if (isip6) {
1655         uint32_t mask = VIRTIO_NET_RSS_HASH_TYPE_TCP_EX |
1656                         VIRTIO_NET_RSS_HASH_TYPE_TCPv6;
1657 
1658         if (istcp && (types & mask)) {
1659             return (types & VIRTIO_NET_RSS_HASH_TYPE_TCP_EX) ?
1660                 NetPktRssIpV6TcpEx : NetPktRssIpV6Tcp;
1661         }
1662         mask = VIRTIO_NET_RSS_HASH_TYPE_UDP_EX | VIRTIO_NET_RSS_HASH_TYPE_UDPv6;
1663         if (isudp && (types & mask)) {
1664             return (types & VIRTIO_NET_RSS_HASH_TYPE_UDP_EX) ?
1665                 NetPktRssIpV6UdpEx : NetPktRssIpV6Udp;
1666         }
1667         mask = VIRTIO_NET_RSS_HASH_TYPE_IP_EX | VIRTIO_NET_RSS_HASH_TYPE_IPv6;
1668         if (types & mask) {
1669             return (types & VIRTIO_NET_RSS_HASH_TYPE_IP_EX) ?
1670                 NetPktRssIpV6Ex : NetPktRssIpV6;
1671         }
1672     }
1673     return 0xff;
1674 }
1675 
1676 static void virtio_set_packet_hash(const uint8_t *buf, uint8_t report,
1677                                    uint32_t hash)
1678 {
1679     struct virtio_net_hdr_v1_hash *hdr = (void *)buf;
1680     hdr->hash_value = hash;
1681     hdr->hash_report = report;
1682 }
1683 
1684 static int virtio_net_process_rss(NetClientState *nc, const uint8_t *buf,
1685                                   size_t size)
1686 {
1687     VirtIONet *n = qemu_get_nic_opaque(nc);
1688     unsigned int index = nc->queue_index, new_index = index;
1689     struct NetRxPkt *pkt = n->rx_pkt;
1690     uint8_t net_hash_type;
1691     uint32_t hash;
1692     bool isip4, isip6, isudp, istcp;
1693     static const uint8_t reports[NetPktRssIpV6UdpEx + 1] = {
1694         VIRTIO_NET_HASH_REPORT_IPv4,
1695         VIRTIO_NET_HASH_REPORT_TCPv4,
1696         VIRTIO_NET_HASH_REPORT_TCPv6,
1697         VIRTIO_NET_HASH_REPORT_IPv6,
1698         VIRTIO_NET_HASH_REPORT_IPv6_EX,
1699         VIRTIO_NET_HASH_REPORT_TCPv6_EX,
1700         VIRTIO_NET_HASH_REPORT_UDPv4,
1701         VIRTIO_NET_HASH_REPORT_UDPv6,
1702         VIRTIO_NET_HASH_REPORT_UDPv6_EX
1703     };
1704 
1705     net_rx_pkt_set_protocols(pkt, buf + n->host_hdr_len,
1706                              size - n->host_hdr_len);
1707     net_rx_pkt_get_protocols(pkt, &isip4, &isip6, &isudp, &istcp);
1708     if (isip4 && (net_rx_pkt_get_ip4_info(pkt)->fragment)) {
1709         istcp = isudp = false;
1710     }
1711     if (isip6 && (net_rx_pkt_get_ip6_info(pkt)->fragment)) {
1712         istcp = isudp = false;
1713     }
1714     net_hash_type = virtio_net_get_hash_type(isip4, isip6, isudp, istcp,
1715                                              n->rss_data.hash_types);
1716     if (net_hash_type > NetPktRssIpV6UdpEx) {
1717         if (n->rss_data.populate_hash) {
1718             virtio_set_packet_hash(buf, VIRTIO_NET_HASH_REPORT_NONE, 0);
1719         }
1720         return n->rss_data.redirect ? n->rss_data.default_queue : -1;
1721     }
1722 
1723     hash = net_rx_pkt_calc_rss_hash(pkt, net_hash_type, n->rss_data.key);
1724 
1725     if (n->rss_data.populate_hash) {
1726         virtio_set_packet_hash(buf, reports[net_hash_type], hash);
1727     }
1728 
1729     if (n->rss_data.redirect) {
1730         new_index = hash & (n->rss_data.indirections_len - 1);
1731         new_index = n->rss_data.indirections_table[new_index];
1732     }
1733 
1734     return (index == new_index) ? -1 : new_index;
1735 }
1736 
1737 static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
1738                                       size_t size, bool no_rss)
1739 {
1740     VirtIONet *n = qemu_get_nic_opaque(nc);
1741     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
1742     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1743     VirtQueueElement *elems[VIRTQUEUE_MAX_SIZE];
1744     size_t lens[VIRTQUEUE_MAX_SIZE];
1745     struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE];
1746     struct virtio_net_hdr_mrg_rxbuf mhdr;
1747     unsigned mhdr_cnt = 0;
1748     size_t offset, i, guest_offset, j;
1749     ssize_t err;
1750 
1751     if (!virtio_net_can_receive(nc)) {
1752         return -1;
1753     }
1754 
1755     if (!no_rss && n->rss_data.enabled && n->rss_data.enabled_software_rss) {
1756         int index = virtio_net_process_rss(nc, buf, size);
1757         if (index >= 0) {
1758             NetClientState *nc2 = qemu_get_subqueue(n->nic, index);
1759             return virtio_net_receive_rcu(nc2, buf, size, true);
1760         }
1761     }
1762 
1763     /* hdr_len refers to the header we supply to the guest */
1764     if (!virtio_net_has_buffers(q, size + n->guest_hdr_len - n->host_hdr_len)) {
1765         return 0;
1766     }
1767 
1768     if (!receive_filter(n, buf, size))
1769         return size;
1770 
1771     offset = i = 0;
1772 
1773     while (offset < size) {
1774         VirtQueueElement *elem;
1775         int len, total;
1776         const struct iovec *sg;
1777 
1778         total = 0;
1779 
1780         if (i == VIRTQUEUE_MAX_SIZE) {
1781             virtio_error(vdev, "virtio-net unexpected long buffer chain");
1782             err = size;
1783             goto err;
1784         }
1785 
1786         elem = virtqueue_pop(q->rx_vq, sizeof(VirtQueueElement));
1787         if (!elem) {
1788             if (i) {
1789                 virtio_error(vdev, "virtio-net unexpected empty queue: "
1790                              "i %zd mergeable %d offset %zd, size %zd, "
1791                              "guest hdr len %zd, host hdr len %zd "
1792                              "guest features 0x%" PRIx64,
1793                              i, n->mergeable_rx_bufs, offset, size,
1794                              n->guest_hdr_len, n->host_hdr_len,
1795                              vdev->guest_features);
1796             }
1797             err = -1;
1798             goto err;
1799         }
1800 
1801         if (elem->in_num < 1) {
1802             virtio_error(vdev,
1803                          "virtio-net receive queue contains no in buffers");
1804             virtqueue_detach_element(q->rx_vq, elem, 0);
1805             g_free(elem);
1806             err = -1;
1807             goto err;
1808         }
1809 
1810         sg = elem->in_sg;
1811         if (i == 0) {
1812             assert(offset == 0);
1813             if (n->mergeable_rx_bufs) {
1814                 mhdr_cnt = iov_copy(mhdr_sg, ARRAY_SIZE(mhdr_sg),
1815                                     sg, elem->in_num,
1816                                     offsetof(typeof(mhdr), num_buffers),
1817                                     sizeof(mhdr.num_buffers));
1818             }
1819 
1820             receive_header(n, sg, elem->in_num, buf, size);
1821             if (n->rss_data.populate_hash) {
1822                 offset = sizeof(mhdr);
1823                 iov_from_buf(sg, elem->in_num, offset,
1824                              buf + offset, n->host_hdr_len - sizeof(mhdr));
1825             }
1826             offset = n->host_hdr_len;
1827             total += n->guest_hdr_len;
1828             guest_offset = n->guest_hdr_len;
1829         } else {
1830             guest_offset = 0;
1831         }
1832 
1833         /* copy in packet.  ugh */
1834         len = iov_from_buf(sg, elem->in_num, guest_offset,
1835                            buf + offset, size - offset);
1836         total += len;
1837         offset += len;
1838         /* If buffers can't be merged, at this point we
1839          * must have consumed the complete packet.
1840          * Otherwise, drop it. */
1841         if (!n->mergeable_rx_bufs && offset < size) {
1842             virtqueue_unpop(q->rx_vq, elem, total);
1843             g_free(elem);
1844             err = size;
1845             goto err;
1846         }
1847 
1848         elems[i] = elem;
1849         lens[i] = total;
1850         i++;
1851     }
1852 
1853     if (mhdr_cnt) {
1854         virtio_stw_p(vdev, &mhdr.num_buffers, i);
1855         iov_from_buf(mhdr_sg, mhdr_cnt,
1856                      0,
1857                      &mhdr.num_buffers, sizeof mhdr.num_buffers);
1858     }
1859 
1860     for (j = 0; j < i; j++) {
1861         /* signal other side */
1862         virtqueue_fill(q->rx_vq, elems[j], lens[j], j);
1863         g_free(elems[j]);
1864     }
1865 
1866     virtqueue_flush(q->rx_vq, i);
1867     virtio_notify(vdev, q->rx_vq);
1868 
1869     return size;
1870 
1871 err:
1872     for (j = 0; j < i; j++) {
1873         virtqueue_detach_element(q->rx_vq, elems[j], lens[j]);
1874         g_free(elems[j]);
1875     }
1876 
1877     return err;
1878 }
1879 
1880 static ssize_t virtio_net_do_receive(NetClientState *nc, const uint8_t *buf,
1881                                   size_t size)
1882 {
1883     RCU_READ_LOCK_GUARD();
1884 
1885     return virtio_net_receive_rcu(nc, buf, size, false);
1886 }
1887 
1888 static void virtio_net_rsc_extract_unit4(VirtioNetRscChain *chain,
1889                                          const uint8_t *buf,
1890                                          VirtioNetRscUnit *unit)
1891 {
1892     uint16_t ip_hdrlen;
1893     struct ip_header *ip;
1894 
1895     ip = (struct ip_header *)(buf + chain->n->guest_hdr_len
1896                               + sizeof(struct eth_header));
1897     unit->ip = (void *)ip;
1898     ip_hdrlen = (ip->ip_ver_len & 0xF) << 2;
1899     unit->ip_plen = &ip->ip_len;
1900     unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip) + ip_hdrlen);
1901     unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000) >> 10;
1902     unit->payload = htons(*unit->ip_plen) - ip_hdrlen - unit->tcp_hdrlen;
1903 }
1904 
1905 static void virtio_net_rsc_extract_unit6(VirtioNetRscChain *chain,
1906                                          const uint8_t *buf,
1907                                          VirtioNetRscUnit *unit)
1908 {
1909     struct ip6_header *ip6;
1910 
1911     ip6 = (struct ip6_header *)(buf + chain->n->guest_hdr_len
1912                                  + sizeof(struct eth_header));
1913     unit->ip = ip6;
1914     unit->ip_plen = &(ip6->ip6_ctlun.ip6_un1.ip6_un1_plen);
1915     unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip)
1916                                         + sizeof(struct ip6_header));
1917     unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000) >> 10;
1918 
1919     /* There is a difference between payload lenght in ipv4 and v6,
1920        ip header is excluded in ipv6 */
1921     unit->payload = htons(*unit->ip_plen) - unit->tcp_hdrlen;
1922 }
1923 
1924 static size_t virtio_net_rsc_drain_seg(VirtioNetRscChain *chain,
1925                                        VirtioNetRscSeg *seg)
1926 {
1927     int ret;
1928     struct virtio_net_hdr_v1 *h;
1929 
1930     h = (struct virtio_net_hdr_v1 *)seg->buf;
1931     h->flags = 0;
1932     h->gso_type = VIRTIO_NET_HDR_GSO_NONE;
1933 
1934     if (seg->is_coalesced) {
1935         h->rsc.segments = seg->packets;
1936         h->rsc.dup_acks = seg->dup_ack;
1937         h->flags = VIRTIO_NET_HDR_F_RSC_INFO;
1938         if (chain->proto == ETH_P_IP) {
1939             h->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1940         } else {
1941             h->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1942         }
1943     }
1944 
1945     ret = virtio_net_do_receive(seg->nc, seg->buf, seg->size);
1946     QTAILQ_REMOVE(&chain->buffers, seg, next);
1947     g_free(seg->buf);
1948     g_free(seg);
1949 
1950     return ret;
1951 }
1952 
1953 static void virtio_net_rsc_purge(void *opq)
1954 {
1955     VirtioNetRscSeg *seg, *rn;
1956     VirtioNetRscChain *chain = (VirtioNetRscChain *)opq;
1957 
1958     QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn) {
1959         if (virtio_net_rsc_drain_seg(chain, seg) == 0) {
1960             chain->stat.purge_failed++;
1961             continue;
1962         }
1963     }
1964 
1965     chain->stat.timer++;
1966     if (!QTAILQ_EMPTY(&chain->buffers)) {
1967         timer_mod(chain->drain_timer,
1968               qemu_clock_get_ns(QEMU_CLOCK_HOST) + chain->n->rsc_timeout);
1969     }
1970 }
1971 
1972 static void virtio_net_rsc_cleanup(VirtIONet *n)
1973 {
1974     VirtioNetRscChain *chain, *rn_chain;
1975     VirtioNetRscSeg *seg, *rn_seg;
1976 
1977     QTAILQ_FOREACH_SAFE(chain, &n->rsc_chains, next, rn_chain) {
1978         QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn_seg) {
1979             QTAILQ_REMOVE(&chain->buffers, seg, next);
1980             g_free(seg->buf);
1981             g_free(seg);
1982         }
1983 
1984         timer_free(chain->drain_timer);
1985         QTAILQ_REMOVE(&n->rsc_chains, chain, next);
1986         g_free(chain);
1987     }
1988 }
1989 
1990 static void virtio_net_rsc_cache_buf(VirtioNetRscChain *chain,
1991                                      NetClientState *nc,
1992                                      const uint8_t *buf, size_t size)
1993 {
1994     uint16_t hdr_len;
1995     VirtioNetRscSeg *seg;
1996 
1997     hdr_len = chain->n->guest_hdr_len;
1998     seg = g_new(VirtioNetRscSeg, 1);
1999     seg->buf = g_malloc(hdr_len + sizeof(struct eth_header)
2000         + sizeof(struct ip6_header) + VIRTIO_NET_MAX_TCP_PAYLOAD);
2001     memcpy(seg->buf, buf, size);
2002     seg->size = size;
2003     seg->packets = 1;
2004     seg->dup_ack = 0;
2005     seg->is_coalesced = 0;
2006     seg->nc = nc;
2007 
2008     QTAILQ_INSERT_TAIL(&chain->buffers, seg, next);
2009     chain->stat.cache++;
2010 
2011     switch (chain->proto) {
2012     case ETH_P_IP:
2013         virtio_net_rsc_extract_unit4(chain, seg->buf, &seg->unit);
2014         break;
2015     case ETH_P_IPV6:
2016         virtio_net_rsc_extract_unit6(chain, seg->buf, &seg->unit);
2017         break;
2018     default:
2019         g_assert_not_reached();
2020     }
2021 }
2022 
2023 static int32_t virtio_net_rsc_handle_ack(VirtioNetRscChain *chain,
2024                                          VirtioNetRscSeg *seg,
2025                                          const uint8_t *buf,
2026                                          struct tcp_header *n_tcp,
2027                                          struct tcp_header *o_tcp)
2028 {
2029     uint32_t nack, oack;
2030     uint16_t nwin, owin;
2031 
2032     nack = htonl(n_tcp->th_ack);
2033     nwin = htons(n_tcp->th_win);
2034     oack = htonl(o_tcp->th_ack);
2035     owin = htons(o_tcp->th_win);
2036 
2037     if ((nack - oack) >= VIRTIO_NET_MAX_TCP_PAYLOAD) {
2038         chain->stat.ack_out_of_win++;
2039         return RSC_FINAL;
2040     } else if (nack == oack) {
2041         /* duplicated ack or window probe */
2042         if (nwin == owin) {
2043             /* duplicated ack, add dup ack count due to whql test up to 1 */
2044             chain->stat.dup_ack++;
2045             return RSC_FINAL;
2046         } else {
2047             /* Coalesce window update */
2048             o_tcp->th_win = n_tcp->th_win;
2049             chain->stat.win_update++;
2050             return RSC_COALESCE;
2051         }
2052     } else {
2053         /* pure ack, go to 'C', finalize*/
2054         chain->stat.pure_ack++;
2055         return RSC_FINAL;
2056     }
2057 }
2058 
2059 static int32_t virtio_net_rsc_coalesce_data(VirtioNetRscChain *chain,
2060                                             VirtioNetRscSeg *seg,
2061                                             const uint8_t *buf,
2062                                             VirtioNetRscUnit *n_unit)
2063 {
2064     void *data;
2065     uint16_t o_ip_len;
2066     uint32_t nseq, oseq;
2067     VirtioNetRscUnit *o_unit;
2068 
2069     o_unit = &seg->unit;
2070     o_ip_len = htons(*o_unit->ip_plen);
2071     nseq = htonl(n_unit->tcp->th_seq);
2072     oseq = htonl(o_unit->tcp->th_seq);
2073 
2074     /* out of order or retransmitted. */
2075     if ((nseq - oseq) > VIRTIO_NET_MAX_TCP_PAYLOAD) {
2076         chain->stat.data_out_of_win++;
2077         return RSC_FINAL;
2078     }
2079 
2080     data = ((uint8_t *)n_unit->tcp) + n_unit->tcp_hdrlen;
2081     if (nseq == oseq) {
2082         if ((o_unit->payload == 0) && n_unit->payload) {
2083             /* From no payload to payload, normal case, not a dup ack or etc */
2084             chain->stat.data_after_pure_ack++;
2085             goto coalesce;
2086         } else {
2087             return virtio_net_rsc_handle_ack(chain, seg, buf,
2088                                              n_unit->tcp, o_unit->tcp);
2089         }
2090     } else if ((nseq - oseq) != o_unit->payload) {
2091         /* Not a consistent packet, out of order */
2092         chain->stat.data_out_of_order++;
2093         return RSC_FINAL;
2094     } else {
2095 coalesce:
2096         if ((o_ip_len + n_unit->payload) > chain->max_payload) {
2097             chain->stat.over_size++;
2098             return RSC_FINAL;
2099         }
2100 
2101         /* Here comes the right data, the payload length in v4/v6 is different,
2102            so use the field value to update and record the new data len */
2103         o_unit->payload += n_unit->payload; /* update new data len */
2104 
2105         /* update field in ip header */
2106         *o_unit->ip_plen = htons(o_ip_len + n_unit->payload);
2107 
2108         /* Bring 'PUSH' big, the whql test guide says 'PUSH' can be coalesced
2109            for windows guest, while this may change the behavior for linux
2110            guest (only if it uses RSC feature). */
2111         o_unit->tcp->th_offset_flags = n_unit->tcp->th_offset_flags;
2112 
2113         o_unit->tcp->th_ack = n_unit->tcp->th_ack;
2114         o_unit->tcp->th_win = n_unit->tcp->th_win;
2115 
2116         memmove(seg->buf + seg->size, data, n_unit->payload);
2117         seg->size += n_unit->payload;
2118         seg->packets++;
2119         chain->stat.coalesced++;
2120         return RSC_COALESCE;
2121     }
2122 }
2123 
2124 static int32_t virtio_net_rsc_coalesce4(VirtioNetRscChain *chain,
2125                                         VirtioNetRscSeg *seg,
2126                                         const uint8_t *buf, size_t size,
2127                                         VirtioNetRscUnit *unit)
2128 {
2129     struct ip_header *ip1, *ip2;
2130 
2131     ip1 = (struct ip_header *)(unit->ip);
2132     ip2 = (struct ip_header *)(seg->unit.ip);
2133     if ((ip1->ip_src ^ ip2->ip_src) || (ip1->ip_dst ^ ip2->ip_dst)
2134         || (unit->tcp->th_sport ^ seg->unit.tcp->th_sport)
2135         || (unit->tcp->th_dport ^ seg->unit.tcp->th_dport)) {
2136         chain->stat.no_match++;
2137         return RSC_NO_MATCH;
2138     }
2139 
2140     return virtio_net_rsc_coalesce_data(chain, seg, buf, unit);
2141 }
2142 
2143 static int32_t virtio_net_rsc_coalesce6(VirtioNetRscChain *chain,
2144                                         VirtioNetRscSeg *seg,
2145                                         const uint8_t *buf, size_t size,
2146                                         VirtioNetRscUnit *unit)
2147 {
2148     struct ip6_header *ip1, *ip2;
2149 
2150     ip1 = (struct ip6_header *)(unit->ip);
2151     ip2 = (struct ip6_header *)(seg->unit.ip);
2152     if (memcmp(&ip1->ip6_src, &ip2->ip6_src, sizeof(struct in6_address))
2153         || memcmp(&ip1->ip6_dst, &ip2->ip6_dst, sizeof(struct in6_address))
2154         || (unit->tcp->th_sport ^ seg->unit.tcp->th_sport)
2155         || (unit->tcp->th_dport ^ seg->unit.tcp->th_dport)) {
2156             chain->stat.no_match++;
2157             return RSC_NO_MATCH;
2158     }
2159 
2160     return virtio_net_rsc_coalesce_data(chain, seg, buf, unit);
2161 }
2162 
2163 /* Packets with 'SYN' should bypass, other flag should be sent after drain
2164  * to prevent out of order */
2165 static int virtio_net_rsc_tcp_ctrl_check(VirtioNetRscChain *chain,
2166                                          struct tcp_header *tcp)
2167 {
2168     uint16_t tcp_hdr;
2169     uint16_t tcp_flag;
2170 
2171     tcp_flag = htons(tcp->th_offset_flags);
2172     tcp_hdr = (tcp_flag & VIRTIO_NET_TCP_HDR_LENGTH) >> 10;
2173     tcp_flag &= VIRTIO_NET_TCP_FLAG;
2174     if (tcp_flag & TH_SYN) {
2175         chain->stat.tcp_syn++;
2176         return RSC_BYPASS;
2177     }
2178 
2179     if (tcp_flag & (TH_FIN | TH_URG | TH_RST | TH_ECE | TH_CWR)) {
2180         chain->stat.tcp_ctrl_drain++;
2181         return RSC_FINAL;
2182     }
2183 
2184     if (tcp_hdr > sizeof(struct tcp_header)) {
2185         chain->stat.tcp_all_opt++;
2186         return RSC_FINAL;
2187     }
2188 
2189     return RSC_CANDIDATE;
2190 }
2191 
2192 static size_t virtio_net_rsc_do_coalesce(VirtioNetRscChain *chain,
2193                                          NetClientState *nc,
2194                                          const uint8_t *buf, size_t size,
2195                                          VirtioNetRscUnit *unit)
2196 {
2197     int ret;
2198     VirtioNetRscSeg *seg, *nseg;
2199 
2200     if (QTAILQ_EMPTY(&chain->buffers)) {
2201         chain->stat.empty_cache++;
2202         virtio_net_rsc_cache_buf(chain, nc, buf, size);
2203         timer_mod(chain->drain_timer,
2204               qemu_clock_get_ns(QEMU_CLOCK_HOST) + chain->n->rsc_timeout);
2205         return size;
2206     }
2207 
2208     QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) {
2209         if (chain->proto == ETH_P_IP) {
2210             ret = virtio_net_rsc_coalesce4(chain, seg, buf, size, unit);
2211         } else {
2212             ret = virtio_net_rsc_coalesce6(chain, seg, buf, size, unit);
2213         }
2214 
2215         if (ret == RSC_FINAL) {
2216             if (virtio_net_rsc_drain_seg(chain, seg) == 0) {
2217                 /* Send failed */
2218                 chain->stat.final_failed++;
2219                 return 0;
2220             }
2221 
2222             /* Send current packet */
2223             return virtio_net_do_receive(nc, buf, size);
2224         } else if (ret == RSC_NO_MATCH) {
2225             continue;
2226         } else {
2227             /* Coalesced, mark coalesced flag to tell calc cksum for ipv4 */
2228             seg->is_coalesced = 1;
2229             return size;
2230         }
2231     }
2232 
2233     chain->stat.no_match_cache++;
2234     virtio_net_rsc_cache_buf(chain, nc, buf, size);
2235     return size;
2236 }
2237 
2238 /* Drain a connection data, this is to avoid out of order segments */
2239 static size_t virtio_net_rsc_drain_flow(VirtioNetRscChain *chain,
2240                                         NetClientState *nc,
2241                                         const uint8_t *buf, size_t size,
2242                                         uint16_t ip_start, uint16_t ip_size,
2243                                         uint16_t tcp_port)
2244 {
2245     VirtioNetRscSeg *seg, *nseg;
2246     uint32_t ppair1, ppair2;
2247 
2248     ppair1 = *(uint32_t *)(buf + tcp_port);
2249     QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) {
2250         ppair2 = *(uint32_t *)(seg->buf + tcp_port);
2251         if (memcmp(buf + ip_start, seg->buf + ip_start, ip_size)
2252             || (ppair1 != ppair2)) {
2253             continue;
2254         }
2255         if (virtio_net_rsc_drain_seg(chain, seg) == 0) {
2256             chain->stat.drain_failed++;
2257         }
2258 
2259         break;
2260     }
2261 
2262     return virtio_net_do_receive(nc, buf, size);
2263 }
2264 
2265 static int32_t virtio_net_rsc_sanity_check4(VirtioNetRscChain *chain,
2266                                             struct ip_header *ip,
2267                                             const uint8_t *buf, size_t size)
2268 {
2269     uint16_t ip_len;
2270 
2271     /* Not an ipv4 packet */
2272     if (((ip->ip_ver_len & 0xF0) >> 4) != IP_HEADER_VERSION_4) {
2273         chain->stat.ip_option++;
2274         return RSC_BYPASS;
2275     }
2276 
2277     /* Don't handle packets with ip option */
2278     if ((ip->ip_ver_len & 0xF) != VIRTIO_NET_IP4_HEADER_LENGTH) {
2279         chain->stat.ip_option++;
2280         return RSC_BYPASS;
2281     }
2282 
2283     if (ip->ip_p != IPPROTO_TCP) {
2284         chain->stat.bypass_not_tcp++;
2285         return RSC_BYPASS;
2286     }
2287 
2288     /* Don't handle packets with ip fragment */
2289     if (!(htons(ip->ip_off) & IP_DF)) {
2290         chain->stat.ip_frag++;
2291         return RSC_BYPASS;
2292     }
2293 
2294     /* Don't handle packets with ecn flag */
2295     if (IPTOS_ECN(ip->ip_tos)) {
2296         chain->stat.ip_ecn++;
2297         return RSC_BYPASS;
2298     }
2299 
2300     ip_len = htons(ip->ip_len);
2301     if (ip_len < (sizeof(struct ip_header) + sizeof(struct tcp_header))
2302         || ip_len > (size - chain->n->guest_hdr_len -
2303                      sizeof(struct eth_header))) {
2304         chain->stat.ip_hacked++;
2305         return RSC_BYPASS;
2306     }
2307 
2308     return RSC_CANDIDATE;
2309 }
2310 
2311 static size_t virtio_net_rsc_receive4(VirtioNetRscChain *chain,
2312                                       NetClientState *nc,
2313                                       const uint8_t *buf, size_t size)
2314 {
2315     int32_t ret;
2316     uint16_t hdr_len;
2317     VirtioNetRscUnit unit;
2318 
2319     hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len;
2320 
2321     if (size < (hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header)
2322         + sizeof(struct tcp_header))) {
2323         chain->stat.bypass_not_tcp++;
2324         return virtio_net_do_receive(nc, buf, size);
2325     }
2326 
2327     virtio_net_rsc_extract_unit4(chain, buf, &unit);
2328     if (virtio_net_rsc_sanity_check4(chain, unit.ip, buf, size)
2329         != RSC_CANDIDATE) {
2330         return virtio_net_do_receive(nc, buf, size);
2331     }
2332 
2333     ret = virtio_net_rsc_tcp_ctrl_check(chain, unit.tcp);
2334     if (ret == RSC_BYPASS) {
2335         return virtio_net_do_receive(nc, buf, size);
2336     } else if (ret == RSC_FINAL) {
2337         return virtio_net_rsc_drain_flow(chain, nc, buf, size,
2338                 ((hdr_len + sizeof(struct eth_header)) + 12),
2339                 VIRTIO_NET_IP4_ADDR_SIZE,
2340                 hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header));
2341     }
2342 
2343     return virtio_net_rsc_do_coalesce(chain, nc, buf, size, &unit);
2344 }
2345 
2346 static int32_t virtio_net_rsc_sanity_check6(VirtioNetRscChain *chain,
2347                                             struct ip6_header *ip6,
2348                                             const uint8_t *buf, size_t size)
2349 {
2350     uint16_t ip_len;
2351 
2352     if (((ip6->ip6_ctlun.ip6_un1.ip6_un1_flow & 0xF0) >> 4)
2353         != IP_HEADER_VERSION_6) {
2354         return RSC_BYPASS;
2355     }
2356 
2357     /* Both option and protocol is checked in this */
2358     if (ip6->ip6_ctlun.ip6_un1.ip6_un1_nxt != IPPROTO_TCP) {
2359         chain->stat.bypass_not_tcp++;
2360         return RSC_BYPASS;
2361     }
2362 
2363     ip_len = htons(ip6->ip6_ctlun.ip6_un1.ip6_un1_plen);
2364     if (ip_len < sizeof(struct tcp_header) ||
2365         ip_len > (size - chain->n->guest_hdr_len - sizeof(struct eth_header)
2366                   - sizeof(struct ip6_header))) {
2367         chain->stat.ip_hacked++;
2368         return RSC_BYPASS;
2369     }
2370 
2371     /* Don't handle packets with ecn flag */
2372     if (IP6_ECN(ip6->ip6_ctlun.ip6_un3.ip6_un3_ecn)) {
2373         chain->stat.ip_ecn++;
2374         return RSC_BYPASS;
2375     }
2376 
2377     return RSC_CANDIDATE;
2378 }
2379 
2380 static size_t virtio_net_rsc_receive6(void *opq, NetClientState *nc,
2381                                       const uint8_t *buf, size_t size)
2382 {
2383     int32_t ret;
2384     uint16_t hdr_len;
2385     VirtioNetRscChain *chain;
2386     VirtioNetRscUnit unit;
2387 
2388     chain = (VirtioNetRscChain *)opq;
2389     hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len;
2390 
2391     if (size < (hdr_len + sizeof(struct eth_header) + sizeof(struct ip6_header)
2392         + sizeof(tcp_header))) {
2393         return virtio_net_do_receive(nc, buf, size);
2394     }
2395 
2396     virtio_net_rsc_extract_unit6(chain, buf, &unit);
2397     if (RSC_CANDIDATE != virtio_net_rsc_sanity_check6(chain,
2398                                                  unit.ip, buf, size)) {
2399         return virtio_net_do_receive(nc, buf, size);
2400     }
2401 
2402     ret = virtio_net_rsc_tcp_ctrl_check(chain, unit.tcp);
2403     if (ret == RSC_BYPASS) {
2404         return virtio_net_do_receive(nc, buf, size);
2405     } else if (ret == RSC_FINAL) {
2406         return virtio_net_rsc_drain_flow(chain, nc, buf, size,
2407                 ((hdr_len + sizeof(struct eth_header)) + 8),
2408                 VIRTIO_NET_IP6_ADDR_SIZE,
2409                 hdr_len + sizeof(struct eth_header)
2410                 + sizeof(struct ip6_header));
2411     }
2412 
2413     return virtio_net_rsc_do_coalesce(chain, nc, buf, size, &unit);
2414 }
2415 
2416 static VirtioNetRscChain *virtio_net_rsc_lookup_chain(VirtIONet *n,
2417                                                       NetClientState *nc,
2418                                                       uint16_t proto)
2419 {
2420     VirtioNetRscChain *chain;
2421 
2422     if ((proto != (uint16_t)ETH_P_IP) && (proto != (uint16_t)ETH_P_IPV6)) {
2423         return NULL;
2424     }
2425 
2426     QTAILQ_FOREACH(chain, &n->rsc_chains, next) {
2427         if (chain->proto == proto) {
2428             return chain;
2429         }
2430     }
2431 
2432     chain = g_malloc(sizeof(*chain));
2433     chain->n = n;
2434     chain->proto = proto;
2435     if (proto == (uint16_t)ETH_P_IP) {
2436         chain->max_payload = VIRTIO_NET_MAX_IP4_PAYLOAD;
2437         chain->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2438     } else {
2439         chain->max_payload = VIRTIO_NET_MAX_IP6_PAYLOAD;
2440         chain->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2441     }
2442     chain->drain_timer = timer_new_ns(QEMU_CLOCK_HOST,
2443                                       virtio_net_rsc_purge, chain);
2444     memset(&chain->stat, 0, sizeof(chain->stat));
2445 
2446     QTAILQ_INIT(&chain->buffers);
2447     QTAILQ_INSERT_TAIL(&n->rsc_chains, chain, next);
2448 
2449     return chain;
2450 }
2451 
2452 static ssize_t virtio_net_rsc_receive(NetClientState *nc,
2453                                       const uint8_t *buf,
2454                                       size_t size)
2455 {
2456     uint16_t proto;
2457     VirtioNetRscChain *chain;
2458     struct eth_header *eth;
2459     VirtIONet *n;
2460 
2461     n = qemu_get_nic_opaque(nc);
2462     if (size < (n->host_hdr_len + sizeof(struct eth_header))) {
2463         return virtio_net_do_receive(nc, buf, size);
2464     }
2465 
2466     eth = (struct eth_header *)(buf + n->guest_hdr_len);
2467     proto = htons(eth->h_proto);
2468 
2469     chain = virtio_net_rsc_lookup_chain(n, nc, proto);
2470     if (chain) {
2471         chain->stat.received++;
2472         if (proto == (uint16_t)ETH_P_IP && n->rsc4_enabled) {
2473             return virtio_net_rsc_receive4(chain, nc, buf, size);
2474         } else if (proto == (uint16_t)ETH_P_IPV6 && n->rsc6_enabled) {
2475             return virtio_net_rsc_receive6(chain, nc, buf, size);
2476         }
2477     }
2478     return virtio_net_do_receive(nc, buf, size);
2479 }
2480 
2481 static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf,
2482                                   size_t size)
2483 {
2484     VirtIONet *n = qemu_get_nic_opaque(nc);
2485     if ((n->rsc4_enabled || n->rsc6_enabled)) {
2486         return virtio_net_rsc_receive(nc, buf, size);
2487     } else {
2488         return virtio_net_do_receive(nc, buf, size);
2489     }
2490 }
2491 
2492 static int32_t virtio_net_flush_tx(VirtIONetQueue *q);
2493 
2494 static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
2495 {
2496     VirtIONet *n = qemu_get_nic_opaque(nc);
2497     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
2498     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2499 
2500     virtqueue_push(q->tx_vq, q->async_tx.elem, 0);
2501     virtio_notify(vdev, q->tx_vq);
2502 
2503     g_free(q->async_tx.elem);
2504     q->async_tx.elem = NULL;
2505 
2506     virtio_queue_set_notification(q->tx_vq, 1);
2507     virtio_net_flush_tx(q);
2508 }
2509 
2510 /* TX */
2511 static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
2512 {
2513     VirtIONet *n = q->n;
2514     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2515     VirtQueueElement *elem;
2516     int32_t num_packets = 0;
2517     int queue_index = vq2q(virtio_get_queue_index(q->tx_vq));
2518     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
2519         return num_packets;
2520     }
2521 
2522     if (q->async_tx.elem) {
2523         virtio_queue_set_notification(q->tx_vq, 0);
2524         return num_packets;
2525     }
2526 
2527     for (;;) {
2528         ssize_t ret;
2529         unsigned int out_num;
2530         struct iovec sg[VIRTQUEUE_MAX_SIZE], sg2[VIRTQUEUE_MAX_SIZE + 1], *out_sg;
2531         struct virtio_net_hdr_mrg_rxbuf mhdr;
2532 
2533         elem = virtqueue_pop(q->tx_vq, sizeof(VirtQueueElement));
2534         if (!elem) {
2535             break;
2536         }
2537 
2538         out_num = elem->out_num;
2539         out_sg = elem->out_sg;
2540         if (out_num < 1) {
2541             virtio_error(vdev, "virtio-net header not in first element");
2542             virtqueue_detach_element(q->tx_vq, elem, 0);
2543             g_free(elem);
2544             return -EINVAL;
2545         }
2546 
2547         if (n->has_vnet_hdr) {
2548             if (iov_to_buf(out_sg, out_num, 0, &mhdr, n->guest_hdr_len) <
2549                 n->guest_hdr_len) {
2550                 virtio_error(vdev, "virtio-net header incorrect");
2551                 virtqueue_detach_element(q->tx_vq, elem, 0);
2552                 g_free(elem);
2553                 return -EINVAL;
2554             }
2555             if (n->needs_vnet_hdr_swap) {
2556                 virtio_net_hdr_swap(vdev, (void *) &mhdr);
2557                 sg2[0].iov_base = &mhdr;
2558                 sg2[0].iov_len = n->guest_hdr_len;
2559                 out_num = iov_copy(&sg2[1], ARRAY_SIZE(sg2) - 1,
2560                                    out_sg, out_num,
2561                                    n->guest_hdr_len, -1);
2562                 if (out_num == VIRTQUEUE_MAX_SIZE) {
2563                     goto drop;
2564                 }
2565                 out_num += 1;
2566                 out_sg = sg2;
2567             }
2568         }
2569         /*
2570          * If host wants to see the guest header as is, we can
2571          * pass it on unchanged. Otherwise, copy just the parts
2572          * that host is interested in.
2573          */
2574         assert(n->host_hdr_len <= n->guest_hdr_len);
2575         if (n->host_hdr_len != n->guest_hdr_len) {
2576             unsigned sg_num = iov_copy(sg, ARRAY_SIZE(sg),
2577                                        out_sg, out_num,
2578                                        0, n->host_hdr_len);
2579             sg_num += iov_copy(sg + sg_num, ARRAY_SIZE(sg) - sg_num,
2580                              out_sg, out_num,
2581                              n->guest_hdr_len, -1);
2582             out_num = sg_num;
2583             out_sg = sg;
2584         }
2585 
2586         ret = qemu_sendv_packet_async(qemu_get_subqueue(n->nic, queue_index),
2587                                       out_sg, out_num, virtio_net_tx_complete);
2588         if (ret == 0) {
2589             virtio_queue_set_notification(q->tx_vq, 0);
2590             q->async_tx.elem = elem;
2591             return -EBUSY;
2592         }
2593 
2594 drop:
2595         virtqueue_push(q->tx_vq, elem, 0);
2596         virtio_notify(vdev, q->tx_vq);
2597         g_free(elem);
2598 
2599         if (++num_packets >= n->tx_burst) {
2600             break;
2601         }
2602     }
2603     return num_packets;
2604 }
2605 
2606 static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
2607 {
2608     VirtIONet *n = VIRTIO_NET(vdev);
2609     VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
2610 
2611     if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) {
2612         virtio_net_drop_tx_queue_data(vdev, vq);
2613         return;
2614     }
2615 
2616     /* This happens when device was stopped but VCPU wasn't. */
2617     if (!vdev->vm_running) {
2618         q->tx_waiting = 1;
2619         return;
2620     }
2621 
2622     if (q->tx_waiting) {
2623         virtio_queue_set_notification(vq, 1);
2624         timer_del(q->tx_timer);
2625         q->tx_waiting = 0;
2626         if (virtio_net_flush_tx(q) == -EINVAL) {
2627             return;
2628         }
2629     } else {
2630         timer_mod(q->tx_timer,
2631                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
2632         q->tx_waiting = 1;
2633         virtio_queue_set_notification(vq, 0);
2634     }
2635 }
2636 
2637 static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
2638 {
2639     VirtIONet *n = VIRTIO_NET(vdev);
2640     VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
2641 
2642     if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) {
2643         virtio_net_drop_tx_queue_data(vdev, vq);
2644         return;
2645     }
2646 
2647     if (unlikely(q->tx_waiting)) {
2648         return;
2649     }
2650     q->tx_waiting = 1;
2651     /* This happens when device was stopped but VCPU wasn't. */
2652     if (!vdev->vm_running) {
2653         return;
2654     }
2655     virtio_queue_set_notification(vq, 0);
2656     qemu_bh_schedule(q->tx_bh);
2657 }
2658 
2659 static void virtio_net_tx_timer(void *opaque)
2660 {
2661     VirtIONetQueue *q = opaque;
2662     VirtIONet *n = q->n;
2663     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2664     /* This happens when device was stopped but BH wasn't. */
2665     if (!vdev->vm_running) {
2666         /* Make sure tx waiting is set, so we'll run when restarted. */
2667         assert(q->tx_waiting);
2668         return;
2669     }
2670 
2671     q->tx_waiting = 0;
2672 
2673     /* Just in case the driver is not ready on more */
2674     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
2675         return;
2676     }
2677 
2678     virtio_queue_set_notification(q->tx_vq, 1);
2679     virtio_net_flush_tx(q);
2680 }
2681 
2682 static void virtio_net_tx_bh(void *opaque)
2683 {
2684     VirtIONetQueue *q = opaque;
2685     VirtIONet *n = q->n;
2686     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2687     int32_t ret;
2688 
2689     /* This happens when device was stopped but BH wasn't. */
2690     if (!vdev->vm_running) {
2691         /* Make sure tx waiting is set, so we'll run when restarted. */
2692         assert(q->tx_waiting);
2693         return;
2694     }
2695 
2696     q->tx_waiting = 0;
2697 
2698     /* Just in case the driver is not ready on more */
2699     if (unlikely(!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK))) {
2700         return;
2701     }
2702 
2703     ret = virtio_net_flush_tx(q);
2704     if (ret == -EBUSY || ret == -EINVAL) {
2705         return; /* Notification re-enable handled by tx_complete or device
2706                  * broken */
2707     }
2708 
2709     /* If we flush a full burst of packets, assume there are
2710      * more coming and immediately reschedule */
2711     if (ret >= n->tx_burst) {
2712         qemu_bh_schedule(q->tx_bh);
2713         q->tx_waiting = 1;
2714         return;
2715     }
2716 
2717     /* If less than a full burst, re-enable notification and flush
2718      * anything that may have come in while we weren't looking.  If
2719      * we find something, assume the guest is still active and reschedule */
2720     virtio_queue_set_notification(q->tx_vq, 1);
2721     ret = virtio_net_flush_tx(q);
2722     if (ret == -EINVAL) {
2723         return;
2724     } else if (ret > 0) {
2725         virtio_queue_set_notification(q->tx_vq, 0);
2726         qemu_bh_schedule(q->tx_bh);
2727         q->tx_waiting = 1;
2728     }
2729 }
2730 
2731 static void virtio_net_add_queue(VirtIONet *n, int index)
2732 {
2733     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2734 
2735     n->vqs[index].rx_vq = virtio_add_queue(vdev, n->net_conf.rx_queue_size,
2736                                            virtio_net_handle_rx);
2737 
2738     if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
2739         n->vqs[index].tx_vq =
2740             virtio_add_queue(vdev, n->net_conf.tx_queue_size,
2741                              virtio_net_handle_tx_timer);
2742         n->vqs[index].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
2743                                               virtio_net_tx_timer,
2744                                               &n->vqs[index]);
2745     } else {
2746         n->vqs[index].tx_vq =
2747             virtio_add_queue(vdev, n->net_conf.tx_queue_size,
2748                              virtio_net_handle_tx_bh);
2749         n->vqs[index].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[index]);
2750     }
2751 
2752     n->vqs[index].tx_waiting = 0;
2753     n->vqs[index].n = n;
2754 }
2755 
2756 static void virtio_net_del_queue(VirtIONet *n, int index)
2757 {
2758     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2759     VirtIONetQueue *q = &n->vqs[index];
2760     NetClientState *nc = qemu_get_subqueue(n->nic, index);
2761 
2762     qemu_purge_queued_packets(nc);
2763 
2764     virtio_del_queue(vdev, index * 2);
2765     if (q->tx_timer) {
2766         timer_free(q->tx_timer);
2767         q->tx_timer = NULL;
2768     } else {
2769         qemu_bh_delete(q->tx_bh);
2770         q->tx_bh = NULL;
2771     }
2772     q->tx_waiting = 0;
2773     virtio_del_queue(vdev, index * 2 + 1);
2774 }
2775 
2776 static void virtio_net_change_num_queue_pairs(VirtIONet *n, int new_max_queue_pairs)
2777 {
2778     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2779     int old_num_queues = virtio_get_num_queues(vdev);
2780     int new_num_queues = new_max_queue_pairs * 2 + 1;
2781     int i;
2782 
2783     assert(old_num_queues >= 3);
2784     assert(old_num_queues % 2 == 1);
2785 
2786     if (old_num_queues == new_num_queues) {
2787         return;
2788     }
2789 
2790     /*
2791      * We always need to remove and add ctrl vq if
2792      * old_num_queues != new_num_queues. Remove ctrl_vq first,
2793      * and then we only enter one of the following two loops.
2794      */
2795     virtio_del_queue(vdev, old_num_queues - 1);
2796 
2797     for (i = new_num_queues - 1; i < old_num_queues - 1; i += 2) {
2798         /* new_num_queues < old_num_queues */
2799         virtio_net_del_queue(n, i / 2);
2800     }
2801 
2802     for (i = old_num_queues - 1; i < new_num_queues - 1; i += 2) {
2803         /* new_num_queues > old_num_queues */
2804         virtio_net_add_queue(n, i / 2);
2805     }
2806 
2807     /* add ctrl_vq last */
2808     n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
2809 }
2810 
2811 static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue)
2812 {
2813     int max = multiqueue ? n->max_queue_pairs : 1;
2814 
2815     n->multiqueue = multiqueue;
2816     virtio_net_change_num_queue_pairs(n, max);
2817 
2818     virtio_net_set_queue_pairs(n);
2819 }
2820 
2821 static int virtio_net_post_load_device(void *opaque, int version_id)
2822 {
2823     VirtIONet *n = opaque;
2824     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2825     int i, link_down;
2826 
2827     trace_virtio_net_post_load_device();
2828     virtio_net_set_mrg_rx_bufs(n, n->mergeable_rx_bufs,
2829                                virtio_vdev_has_feature(vdev,
2830                                                        VIRTIO_F_VERSION_1),
2831                                virtio_vdev_has_feature(vdev,
2832                                                        VIRTIO_NET_F_HASH_REPORT));
2833 
2834     /* MAC_TABLE_ENTRIES may be different from the saved image */
2835     if (n->mac_table.in_use > MAC_TABLE_ENTRIES) {
2836         n->mac_table.in_use = 0;
2837     }
2838 
2839     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
2840         n->curr_guest_offloads = virtio_net_supported_guest_offloads(n);
2841     }
2842 
2843     /*
2844      * curr_guest_offloads will be later overwritten by the
2845      * virtio_set_features_nocheck call done from the virtio_load.
2846      * Here we make sure it is preserved and restored accordingly
2847      * in the virtio_net_post_load_virtio callback.
2848      */
2849     n->saved_guest_offloads = n->curr_guest_offloads;
2850 
2851     virtio_net_set_queue_pairs(n);
2852 
2853     /* Find the first multicast entry in the saved MAC filter */
2854     for (i = 0; i < n->mac_table.in_use; i++) {
2855         if (n->mac_table.macs[i * ETH_ALEN] & 1) {
2856             break;
2857         }
2858     }
2859     n->mac_table.first_multi = i;
2860 
2861     /* nc.link_down can't be migrated, so infer link_down according
2862      * to link status bit in n->status */
2863     link_down = (n->status & VIRTIO_NET_S_LINK_UP) == 0;
2864     for (i = 0; i < n->max_queue_pairs; i++) {
2865         qemu_get_subqueue(n->nic, i)->link_down = link_down;
2866     }
2867 
2868     if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) &&
2869         virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
2870         qemu_announce_timer_reset(&n->announce_timer, migrate_announce_params(),
2871                                   QEMU_CLOCK_VIRTUAL,
2872                                   virtio_net_announce_timer, n);
2873         if (n->announce_timer.round) {
2874             timer_mod(n->announce_timer.tm,
2875                       qemu_clock_get_ms(n->announce_timer.type));
2876         } else {
2877             qemu_announce_timer_del(&n->announce_timer, false);
2878         }
2879     }
2880 
2881     if (n->rss_data.enabled) {
2882         n->rss_data.enabled_software_rss = n->rss_data.populate_hash;
2883         if (!n->rss_data.populate_hash) {
2884             if (!virtio_net_attach_epbf_rss(n)) {
2885                 if (get_vhost_net(qemu_get_queue(n->nic)->peer)) {
2886                     warn_report("Can't post-load eBPF RSS for vhost");
2887                 } else {
2888                     warn_report("Can't post-load eBPF RSS - "
2889                                 "fallback to software RSS");
2890                     n->rss_data.enabled_software_rss = true;
2891                 }
2892             }
2893         }
2894 
2895         trace_virtio_net_rss_enable(n->rss_data.hash_types,
2896                                     n->rss_data.indirections_len,
2897                                     sizeof(n->rss_data.key));
2898     } else {
2899         trace_virtio_net_rss_disable();
2900     }
2901     return 0;
2902 }
2903 
2904 static int virtio_net_post_load_virtio(VirtIODevice *vdev)
2905 {
2906     VirtIONet *n = VIRTIO_NET(vdev);
2907     /*
2908      * The actual needed state is now in saved_guest_offloads,
2909      * see virtio_net_post_load_device for detail.
2910      * Restore it back and apply the desired offloads.
2911      */
2912     n->curr_guest_offloads = n->saved_guest_offloads;
2913     if (peer_has_vnet_hdr(n)) {
2914         virtio_net_apply_guest_offloads(n);
2915     }
2916 
2917     return 0;
2918 }
2919 
2920 /* tx_waiting field of a VirtIONetQueue */
2921 static const VMStateDescription vmstate_virtio_net_queue_tx_waiting = {
2922     .name = "virtio-net-queue-tx_waiting",
2923     .fields = (VMStateField[]) {
2924         VMSTATE_UINT32(tx_waiting, VirtIONetQueue),
2925         VMSTATE_END_OF_LIST()
2926    },
2927 };
2928 
2929 static bool max_queue_pairs_gt_1(void *opaque, int version_id)
2930 {
2931     return VIRTIO_NET(opaque)->max_queue_pairs > 1;
2932 }
2933 
2934 static bool has_ctrl_guest_offloads(void *opaque, int version_id)
2935 {
2936     return virtio_vdev_has_feature(VIRTIO_DEVICE(opaque),
2937                                    VIRTIO_NET_F_CTRL_GUEST_OFFLOADS);
2938 }
2939 
2940 static bool mac_table_fits(void *opaque, int version_id)
2941 {
2942     return VIRTIO_NET(opaque)->mac_table.in_use <= MAC_TABLE_ENTRIES;
2943 }
2944 
2945 static bool mac_table_doesnt_fit(void *opaque, int version_id)
2946 {
2947     return !mac_table_fits(opaque, version_id);
2948 }
2949 
2950 /* This temporary type is shared by all the WITH_TMP methods
2951  * although only some fields are used by each.
2952  */
2953 struct VirtIONetMigTmp {
2954     VirtIONet      *parent;
2955     VirtIONetQueue *vqs_1;
2956     uint16_t        curr_queue_pairs_1;
2957     uint8_t         has_ufo;
2958     uint32_t        has_vnet_hdr;
2959 };
2960 
2961 /* The 2nd and subsequent tx_waiting flags are loaded later than
2962  * the 1st entry in the queue_pairs and only if there's more than one
2963  * entry.  We use the tmp mechanism to calculate a temporary
2964  * pointer and count and also validate the count.
2965  */
2966 
2967 static int virtio_net_tx_waiting_pre_save(void *opaque)
2968 {
2969     struct VirtIONetMigTmp *tmp = opaque;
2970 
2971     tmp->vqs_1 = tmp->parent->vqs + 1;
2972     tmp->curr_queue_pairs_1 = tmp->parent->curr_queue_pairs - 1;
2973     if (tmp->parent->curr_queue_pairs == 0) {
2974         tmp->curr_queue_pairs_1 = 0;
2975     }
2976 
2977     return 0;
2978 }
2979 
2980 static int virtio_net_tx_waiting_pre_load(void *opaque)
2981 {
2982     struct VirtIONetMigTmp *tmp = opaque;
2983 
2984     /* Reuse the pointer setup from save */
2985     virtio_net_tx_waiting_pre_save(opaque);
2986 
2987     if (tmp->parent->curr_queue_pairs > tmp->parent->max_queue_pairs) {
2988         error_report("virtio-net: curr_queue_pairs %x > max_queue_pairs %x",
2989             tmp->parent->curr_queue_pairs, tmp->parent->max_queue_pairs);
2990 
2991         return -EINVAL;
2992     }
2993 
2994     return 0; /* all good */
2995 }
2996 
2997 static const VMStateDescription vmstate_virtio_net_tx_waiting = {
2998     .name      = "virtio-net-tx_waiting",
2999     .pre_load  = virtio_net_tx_waiting_pre_load,
3000     .pre_save  = virtio_net_tx_waiting_pre_save,
3001     .fields    = (VMStateField[]) {
3002         VMSTATE_STRUCT_VARRAY_POINTER_UINT16(vqs_1, struct VirtIONetMigTmp,
3003                                      curr_queue_pairs_1,
3004                                      vmstate_virtio_net_queue_tx_waiting,
3005                                      struct VirtIONetQueue),
3006         VMSTATE_END_OF_LIST()
3007     },
3008 };
3009 
3010 /* the 'has_ufo' flag is just tested; if the incoming stream has the
3011  * flag set we need to check that we have it
3012  */
3013 static int virtio_net_ufo_post_load(void *opaque, int version_id)
3014 {
3015     struct VirtIONetMigTmp *tmp = opaque;
3016 
3017     if (tmp->has_ufo && !peer_has_ufo(tmp->parent)) {
3018         error_report("virtio-net: saved image requires TUN_F_UFO support");
3019         return -EINVAL;
3020     }
3021 
3022     return 0;
3023 }
3024 
3025 static int virtio_net_ufo_pre_save(void *opaque)
3026 {
3027     struct VirtIONetMigTmp *tmp = opaque;
3028 
3029     tmp->has_ufo = tmp->parent->has_ufo;
3030 
3031     return 0;
3032 }
3033 
3034 static const VMStateDescription vmstate_virtio_net_has_ufo = {
3035     .name      = "virtio-net-ufo",
3036     .post_load = virtio_net_ufo_post_load,
3037     .pre_save  = virtio_net_ufo_pre_save,
3038     .fields    = (VMStateField[]) {
3039         VMSTATE_UINT8(has_ufo, struct VirtIONetMigTmp),
3040         VMSTATE_END_OF_LIST()
3041     },
3042 };
3043 
3044 /* the 'has_vnet_hdr' flag is just tested; if the incoming stream has the
3045  * flag set we need to check that we have it
3046  */
3047 static int virtio_net_vnet_post_load(void *opaque, int version_id)
3048 {
3049     struct VirtIONetMigTmp *tmp = opaque;
3050 
3051     if (tmp->has_vnet_hdr && !peer_has_vnet_hdr(tmp->parent)) {
3052         error_report("virtio-net: saved image requires vnet_hdr=on");
3053         return -EINVAL;
3054     }
3055 
3056     return 0;
3057 }
3058 
3059 static int virtio_net_vnet_pre_save(void *opaque)
3060 {
3061     struct VirtIONetMigTmp *tmp = opaque;
3062 
3063     tmp->has_vnet_hdr = tmp->parent->has_vnet_hdr;
3064 
3065     return 0;
3066 }
3067 
3068 static const VMStateDescription vmstate_virtio_net_has_vnet = {
3069     .name      = "virtio-net-vnet",
3070     .post_load = virtio_net_vnet_post_load,
3071     .pre_save  = virtio_net_vnet_pre_save,
3072     .fields    = (VMStateField[]) {
3073         VMSTATE_UINT32(has_vnet_hdr, struct VirtIONetMigTmp),
3074         VMSTATE_END_OF_LIST()
3075     },
3076 };
3077 
3078 static bool virtio_net_rss_needed(void *opaque)
3079 {
3080     return VIRTIO_NET(opaque)->rss_data.enabled;
3081 }
3082 
3083 static const VMStateDescription vmstate_virtio_net_rss = {
3084     .name      = "virtio-net-device/rss",
3085     .version_id = 1,
3086     .minimum_version_id = 1,
3087     .needed = virtio_net_rss_needed,
3088     .fields = (VMStateField[]) {
3089         VMSTATE_BOOL(rss_data.enabled, VirtIONet),
3090         VMSTATE_BOOL(rss_data.redirect, VirtIONet),
3091         VMSTATE_BOOL(rss_data.populate_hash, VirtIONet),
3092         VMSTATE_UINT32(rss_data.hash_types, VirtIONet),
3093         VMSTATE_UINT16(rss_data.indirections_len, VirtIONet),
3094         VMSTATE_UINT16(rss_data.default_queue, VirtIONet),
3095         VMSTATE_UINT8_ARRAY(rss_data.key, VirtIONet,
3096                             VIRTIO_NET_RSS_MAX_KEY_SIZE),
3097         VMSTATE_VARRAY_UINT16_ALLOC(rss_data.indirections_table, VirtIONet,
3098                                     rss_data.indirections_len, 0,
3099                                     vmstate_info_uint16, uint16_t),
3100         VMSTATE_END_OF_LIST()
3101     },
3102 };
3103 
3104 static const VMStateDescription vmstate_virtio_net_device = {
3105     .name = "virtio-net-device",
3106     .version_id = VIRTIO_NET_VM_VERSION,
3107     .minimum_version_id = VIRTIO_NET_VM_VERSION,
3108     .post_load = virtio_net_post_load_device,
3109     .fields = (VMStateField[]) {
3110         VMSTATE_UINT8_ARRAY(mac, VirtIONet, ETH_ALEN),
3111         VMSTATE_STRUCT_POINTER(vqs, VirtIONet,
3112                                vmstate_virtio_net_queue_tx_waiting,
3113                                VirtIONetQueue),
3114         VMSTATE_UINT32(mergeable_rx_bufs, VirtIONet),
3115         VMSTATE_UINT16(status, VirtIONet),
3116         VMSTATE_UINT8(promisc, VirtIONet),
3117         VMSTATE_UINT8(allmulti, VirtIONet),
3118         VMSTATE_UINT32(mac_table.in_use, VirtIONet),
3119 
3120         /* Guarded pair: If it fits we load it, else we throw it away
3121          * - can happen if source has a larger MAC table.; post-load
3122          *  sets flags in this case.
3123          */
3124         VMSTATE_VBUFFER_MULTIPLY(mac_table.macs, VirtIONet,
3125                                 0, mac_table_fits, mac_table.in_use,
3126                                  ETH_ALEN),
3127         VMSTATE_UNUSED_VARRAY_UINT32(VirtIONet, mac_table_doesnt_fit, 0,
3128                                      mac_table.in_use, ETH_ALEN),
3129 
3130         /* Note: This is an array of uint32's that's always been saved as a
3131          * buffer; hold onto your endiannesses; it's actually used as a bitmap
3132          * but based on the uint.
3133          */
3134         VMSTATE_BUFFER_POINTER_UNSAFE(vlans, VirtIONet, 0, MAX_VLAN >> 3),
3135         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
3136                          vmstate_virtio_net_has_vnet),
3137         VMSTATE_UINT8(mac_table.multi_overflow, VirtIONet),
3138         VMSTATE_UINT8(mac_table.uni_overflow, VirtIONet),
3139         VMSTATE_UINT8(alluni, VirtIONet),
3140         VMSTATE_UINT8(nomulti, VirtIONet),
3141         VMSTATE_UINT8(nouni, VirtIONet),
3142         VMSTATE_UINT8(nobcast, VirtIONet),
3143         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
3144                          vmstate_virtio_net_has_ufo),
3145         VMSTATE_SINGLE_TEST(max_queue_pairs, VirtIONet, max_queue_pairs_gt_1, 0,
3146                             vmstate_info_uint16_equal, uint16_t),
3147         VMSTATE_UINT16_TEST(curr_queue_pairs, VirtIONet, max_queue_pairs_gt_1),
3148         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
3149                          vmstate_virtio_net_tx_waiting),
3150         VMSTATE_UINT64_TEST(curr_guest_offloads, VirtIONet,
3151                             has_ctrl_guest_offloads),
3152         VMSTATE_END_OF_LIST()
3153    },
3154     .subsections = (const VMStateDescription * []) {
3155         &vmstate_virtio_net_rss,
3156         NULL
3157     }
3158 };
3159 
3160 static NetClientInfo net_virtio_info = {
3161     .type = NET_CLIENT_DRIVER_NIC,
3162     .size = sizeof(NICState),
3163     .can_receive = virtio_net_can_receive,
3164     .receive = virtio_net_receive,
3165     .link_status_changed = virtio_net_set_link_status,
3166     .query_rx_filter = virtio_net_query_rxfilter,
3167     .announce = virtio_net_announce,
3168 };
3169 
3170 static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
3171 {
3172     VirtIONet *n = VIRTIO_NET(vdev);
3173     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
3174     assert(n->vhost_started);
3175     return vhost_net_virtqueue_pending(get_vhost_net(nc->peer), idx);
3176 }
3177 
3178 static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
3179                                            bool mask)
3180 {
3181     VirtIONet *n = VIRTIO_NET(vdev);
3182     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
3183     assert(n->vhost_started);
3184     vhost_net_virtqueue_mask(get_vhost_net(nc->peer),
3185                              vdev, idx, mask);
3186 }
3187 
3188 static void virtio_net_set_config_size(VirtIONet *n, uint64_t host_features)
3189 {
3190     virtio_add_feature(&host_features, VIRTIO_NET_F_MAC);
3191 
3192     n->config_size = virtio_feature_get_config_size(feature_sizes,
3193                                                     host_features);
3194 }
3195 
3196 void virtio_net_set_netclient_name(VirtIONet *n, const char *name,
3197                                    const char *type)
3198 {
3199     /*
3200      * The name can be NULL, the netclient name will be type.x.
3201      */
3202     assert(type != NULL);
3203 
3204     g_free(n->netclient_name);
3205     g_free(n->netclient_type);
3206     n->netclient_name = g_strdup(name);
3207     n->netclient_type = g_strdup(type);
3208 }
3209 
3210 static bool failover_unplug_primary(VirtIONet *n, DeviceState *dev)
3211 {
3212     HotplugHandler *hotplug_ctrl;
3213     PCIDevice *pci_dev;
3214     Error *err = NULL;
3215 
3216     hotplug_ctrl = qdev_get_hotplug_handler(dev);
3217     if (hotplug_ctrl) {
3218         pci_dev = PCI_DEVICE(dev);
3219         pci_dev->partially_hotplugged = true;
3220         hotplug_handler_unplug_request(hotplug_ctrl, dev, &err);
3221         if (err) {
3222             error_report_err(err);
3223             return false;
3224         }
3225     } else {
3226         return false;
3227     }
3228     return true;
3229 }
3230 
3231 static bool failover_replug_primary(VirtIONet *n, DeviceState *dev,
3232                                     Error **errp)
3233 {
3234     Error *err = NULL;
3235     HotplugHandler *hotplug_ctrl;
3236     PCIDevice *pdev = PCI_DEVICE(dev);
3237     BusState *primary_bus;
3238 
3239     if (!pdev->partially_hotplugged) {
3240         return true;
3241     }
3242     primary_bus = dev->parent_bus;
3243     if (!primary_bus) {
3244         error_setg(errp, "virtio_net: couldn't find primary bus");
3245         return false;
3246     }
3247     qdev_set_parent_bus(dev, primary_bus, &error_abort);
3248     qatomic_set(&n->failover_primary_hidden, false);
3249     hotplug_ctrl = qdev_get_hotplug_handler(dev);
3250     if (hotplug_ctrl) {
3251         hotplug_handler_pre_plug(hotplug_ctrl, dev, &err);
3252         if (err) {
3253             goto out;
3254         }
3255         hotplug_handler_plug(hotplug_ctrl, dev, &err);
3256     }
3257     pdev->partially_hotplugged = false;
3258 
3259 out:
3260     error_propagate(errp, err);
3261     return !err;
3262 }
3263 
3264 static void virtio_net_handle_migration_primary(VirtIONet *n, MigrationState *s)
3265 {
3266     bool should_be_hidden;
3267     Error *err = NULL;
3268     DeviceState *dev = failover_find_primary_device(n);
3269 
3270     if (!dev) {
3271         return;
3272     }
3273 
3274     should_be_hidden = qatomic_read(&n->failover_primary_hidden);
3275 
3276     if (migration_in_setup(s) && !should_be_hidden) {
3277         if (failover_unplug_primary(n, dev)) {
3278             vmstate_unregister(VMSTATE_IF(dev), qdev_get_vmsd(dev), dev);
3279             qapi_event_send_unplug_primary(dev->id);
3280             qatomic_set(&n->failover_primary_hidden, true);
3281         } else {
3282             warn_report("couldn't unplug primary device");
3283         }
3284     } else if (migration_has_failed(s)) {
3285         /* We already unplugged the device let's plug it back */
3286         if (!failover_replug_primary(n, dev, &err)) {
3287             if (err) {
3288                 error_report_err(err);
3289             }
3290         }
3291     }
3292 }
3293 
3294 static void virtio_net_migration_state_notifier(Notifier *notifier, void *data)
3295 {
3296     MigrationState *s = data;
3297     VirtIONet *n = container_of(notifier, VirtIONet, migration_state);
3298     virtio_net_handle_migration_primary(n, s);
3299 }
3300 
3301 static bool failover_hide_primary_device(DeviceListener *listener,
3302                                          const QDict *device_opts,
3303                                          bool from_json,
3304                                          Error **errp)
3305 {
3306     VirtIONet *n = container_of(listener, VirtIONet, primary_listener);
3307     const char *standby_id;
3308 
3309     if (!device_opts) {
3310         return false;
3311     }
3312 
3313     if (!qdict_haskey(device_opts, "failover_pair_id")) {
3314         return false;
3315     }
3316 
3317     if (!qdict_haskey(device_opts, "id")) {
3318         error_setg(errp, "Device with failover_pair_id needs to have id");
3319         return false;
3320     }
3321 
3322     standby_id = qdict_get_str(device_opts, "failover_pair_id");
3323     if (g_strcmp0(standby_id, n->netclient_name) != 0) {
3324         return false;
3325     }
3326 
3327     /*
3328      * The hide helper can be called several times for a given device.
3329      * Check there is only one primary for a virtio-net device but
3330      * don't duplicate the qdict several times if it's called for the same
3331      * device.
3332      */
3333     if (n->primary_opts) {
3334         const char *old, *new;
3335         /* devices with failover_pair_id always have an id */
3336         old = qdict_get_str(n->primary_opts, "id");
3337         new = qdict_get_str(device_opts, "id");
3338         if (strcmp(old, new) != 0) {
3339             error_setg(errp, "Cannot attach more than one primary device to "
3340                        "'%s': '%s' and '%s'", n->netclient_name, old, new);
3341             return false;
3342         }
3343     } else {
3344         n->primary_opts = qdict_clone_shallow(device_opts);
3345         n->primary_opts_from_json = from_json;
3346     }
3347 
3348     /* failover_primary_hidden is set during feature negotiation */
3349     return qatomic_read(&n->failover_primary_hidden);
3350 }
3351 
3352 static void virtio_net_device_realize(DeviceState *dev, Error **errp)
3353 {
3354     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
3355     VirtIONet *n = VIRTIO_NET(dev);
3356     NetClientState *nc;
3357     int i;
3358 
3359     if (n->net_conf.mtu) {
3360         n->host_features |= (1ULL << VIRTIO_NET_F_MTU);
3361     }
3362 
3363     if (n->net_conf.duplex_str) {
3364         if (strncmp(n->net_conf.duplex_str, "half", 5) == 0) {
3365             n->net_conf.duplex = DUPLEX_HALF;
3366         } else if (strncmp(n->net_conf.duplex_str, "full", 5) == 0) {
3367             n->net_conf.duplex = DUPLEX_FULL;
3368         } else {
3369             error_setg(errp, "'duplex' must be 'half' or 'full'");
3370             return;
3371         }
3372         n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
3373     } else {
3374         n->net_conf.duplex = DUPLEX_UNKNOWN;
3375     }
3376 
3377     if (n->net_conf.speed < SPEED_UNKNOWN) {
3378         error_setg(errp, "'speed' must be between 0 and INT_MAX");
3379         return;
3380     }
3381     if (n->net_conf.speed >= 0) {
3382         n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
3383     }
3384 
3385     if (n->failover) {
3386         n->primary_listener.hide_device = failover_hide_primary_device;
3387         qatomic_set(&n->failover_primary_hidden, true);
3388         device_listener_register(&n->primary_listener);
3389         n->migration_state.notify = virtio_net_migration_state_notifier;
3390         add_migration_state_change_notifier(&n->migration_state);
3391         n->host_features |= (1ULL << VIRTIO_NET_F_STANDBY);
3392     }
3393 
3394     virtio_net_set_config_size(n, n->host_features);
3395     virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, n->config_size);
3396 
3397     /*
3398      * We set a lower limit on RX queue size to what it always was.
3399      * Guests that want a smaller ring can always resize it without
3400      * help from us (using virtio 1 and up).
3401      */
3402     if (n->net_conf.rx_queue_size < VIRTIO_NET_RX_QUEUE_MIN_SIZE ||
3403         n->net_conf.rx_queue_size > VIRTQUEUE_MAX_SIZE ||
3404         !is_power_of_2(n->net_conf.rx_queue_size)) {
3405         error_setg(errp, "Invalid rx_queue_size (= %" PRIu16 "), "
3406                    "must be a power of 2 between %d and %d.",
3407                    n->net_conf.rx_queue_size, VIRTIO_NET_RX_QUEUE_MIN_SIZE,
3408                    VIRTQUEUE_MAX_SIZE);
3409         virtio_cleanup(vdev);
3410         return;
3411     }
3412 
3413     if (n->net_conf.tx_queue_size < VIRTIO_NET_TX_QUEUE_MIN_SIZE ||
3414         n->net_conf.tx_queue_size > VIRTQUEUE_MAX_SIZE ||
3415         !is_power_of_2(n->net_conf.tx_queue_size)) {
3416         error_setg(errp, "Invalid tx_queue_size (= %" PRIu16 "), "
3417                    "must be a power of 2 between %d and %d",
3418                    n->net_conf.tx_queue_size, VIRTIO_NET_TX_QUEUE_MIN_SIZE,
3419                    VIRTQUEUE_MAX_SIZE);
3420         virtio_cleanup(vdev);
3421         return;
3422     }
3423 
3424     n->max_ncs = MAX(n->nic_conf.peers.queues, 1);
3425 
3426     /*
3427      * Figure out the datapath queue pairs since the backend could
3428      * provide control queue via peers as well.
3429      */
3430     if (n->nic_conf.peers.queues) {
3431         for (i = 0; i < n->max_ncs; i++) {
3432             if (n->nic_conf.peers.ncs[i]->is_datapath) {
3433                 ++n->max_queue_pairs;
3434             }
3435         }
3436     }
3437     n->max_queue_pairs = MAX(n->max_queue_pairs, 1);
3438 
3439     if (n->max_queue_pairs * 2 + 1 > VIRTIO_QUEUE_MAX) {
3440         error_setg(errp, "Invalid number of queue pairs (= %" PRIu32 "), "
3441                    "must be a positive integer less than %d.",
3442                    n->max_queue_pairs, (VIRTIO_QUEUE_MAX - 1) / 2);
3443         virtio_cleanup(vdev);
3444         return;
3445     }
3446     n->vqs = g_new0(VirtIONetQueue, n->max_queue_pairs);
3447     n->curr_queue_pairs = 1;
3448     n->tx_timeout = n->net_conf.txtimer;
3449 
3450     if (n->net_conf.tx && strcmp(n->net_conf.tx, "timer")
3451                        && strcmp(n->net_conf.tx, "bh")) {
3452         warn_report("virtio-net: "
3453                     "Unknown option tx=%s, valid options: \"timer\" \"bh\"",
3454                     n->net_conf.tx);
3455         error_printf("Defaulting to \"bh\"");
3456     }
3457 
3458     n->net_conf.tx_queue_size = MIN(virtio_net_max_tx_queue_size(n),
3459                                     n->net_conf.tx_queue_size);
3460 
3461     for (i = 0; i < n->max_queue_pairs; i++) {
3462         virtio_net_add_queue(n, i);
3463     }
3464 
3465     n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
3466     qemu_macaddr_default_if_unset(&n->nic_conf.macaddr);
3467     memcpy(&n->mac[0], &n->nic_conf.macaddr, sizeof(n->mac));
3468     n->status = VIRTIO_NET_S_LINK_UP;
3469     qemu_announce_timer_reset(&n->announce_timer, migrate_announce_params(),
3470                               QEMU_CLOCK_VIRTUAL,
3471                               virtio_net_announce_timer, n);
3472     n->announce_timer.round = 0;
3473 
3474     if (n->netclient_type) {
3475         /*
3476          * Happen when virtio_net_set_netclient_name has been called.
3477          */
3478         n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
3479                               n->netclient_type, n->netclient_name, n);
3480     } else {
3481         n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
3482                               object_get_typename(OBJECT(dev)), dev->id, n);
3483     }
3484 
3485     for (i = 0; i < n->max_queue_pairs; i++) {
3486         n->nic->ncs[i].do_not_pad = true;
3487     }
3488 
3489     peer_test_vnet_hdr(n);
3490     if (peer_has_vnet_hdr(n)) {
3491         for (i = 0; i < n->max_queue_pairs; i++) {
3492             qemu_using_vnet_hdr(qemu_get_subqueue(n->nic, i)->peer, true);
3493         }
3494         n->host_hdr_len = sizeof(struct virtio_net_hdr);
3495     } else {
3496         n->host_hdr_len = 0;
3497     }
3498 
3499     qemu_format_nic_info_str(qemu_get_queue(n->nic), n->nic_conf.macaddr.a);
3500 
3501     n->vqs[0].tx_waiting = 0;
3502     n->tx_burst = n->net_conf.txburst;
3503     virtio_net_set_mrg_rx_bufs(n, 0, 0, 0);
3504     n->promisc = 1; /* for compatibility */
3505 
3506     n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
3507 
3508     n->vlans = g_malloc0(MAX_VLAN >> 3);
3509 
3510     nc = qemu_get_queue(n->nic);
3511     nc->rxfilter_notify_enabled = 1;
3512 
3513    if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
3514         struct virtio_net_config netcfg = {};
3515         memcpy(&netcfg.mac, &n->nic_conf.macaddr, ETH_ALEN);
3516         vhost_net_set_config(get_vhost_net(nc->peer),
3517             (uint8_t *)&netcfg, 0, ETH_ALEN, VHOST_SET_CONFIG_TYPE_MASTER);
3518     }
3519     QTAILQ_INIT(&n->rsc_chains);
3520     n->qdev = dev;
3521 
3522     net_rx_pkt_init(&n->rx_pkt, false);
3523 
3524     if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS)) {
3525         virtio_net_load_ebpf(n);
3526     }
3527 }
3528 
3529 static void virtio_net_device_unrealize(DeviceState *dev)
3530 {
3531     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
3532     VirtIONet *n = VIRTIO_NET(dev);
3533     int i, max_queue_pairs;
3534 
3535     if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS)) {
3536         virtio_net_unload_ebpf(n);
3537     }
3538 
3539     /* This will stop vhost backend if appropriate. */
3540     virtio_net_set_status(vdev, 0);
3541 
3542     g_free(n->netclient_name);
3543     n->netclient_name = NULL;
3544     g_free(n->netclient_type);
3545     n->netclient_type = NULL;
3546 
3547     g_free(n->mac_table.macs);
3548     g_free(n->vlans);
3549 
3550     if (n->failover) {
3551         qobject_unref(n->primary_opts);
3552         device_listener_unregister(&n->primary_listener);
3553         remove_migration_state_change_notifier(&n->migration_state);
3554     } else {
3555         assert(n->primary_opts == NULL);
3556     }
3557 
3558     max_queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
3559     for (i = 0; i < max_queue_pairs; i++) {
3560         virtio_net_del_queue(n, i);
3561     }
3562     /* delete also control vq */
3563     virtio_del_queue(vdev, max_queue_pairs * 2);
3564     qemu_announce_timer_del(&n->announce_timer, false);
3565     g_free(n->vqs);
3566     qemu_del_nic(n->nic);
3567     virtio_net_rsc_cleanup(n);
3568     g_free(n->rss_data.indirections_table);
3569     net_rx_pkt_uninit(n->rx_pkt);
3570     virtio_cleanup(vdev);
3571 }
3572 
3573 static void virtio_net_instance_init(Object *obj)
3574 {
3575     VirtIONet *n = VIRTIO_NET(obj);
3576 
3577     /*
3578      * The default config_size is sizeof(struct virtio_net_config).
3579      * Can be overriden with virtio_net_set_config_size.
3580      */
3581     n->config_size = sizeof(struct virtio_net_config);
3582     device_add_bootindex_property(obj, &n->nic_conf.bootindex,
3583                                   "bootindex", "/ethernet-phy@0",
3584                                   DEVICE(n));
3585 
3586     ebpf_rss_init(&n->ebpf_rss);
3587 }
3588 
3589 static int virtio_net_pre_save(void *opaque)
3590 {
3591     VirtIONet *n = opaque;
3592 
3593     /* At this point, backend must be stopped, otherwise
3594      * it might keep writing to memory. */
3595     assert(!n->vhost_started);
3596 
3597     return 0;
3598 }
3599 
3600 static bool primary_unplug_pending(void *opaque)
3601 {
3602     DeviceState *dev = opaque;
3603     DeviceState *primary;
3604     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
3605     VirtIONet *n = VIRTIO_NET(vdev);
3606 
3607     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
3608         return false;
3609     }
3610     primary = failover_find_primary_device(n);
3611     return primary ? primary->pending_deleted_event : false;
3612 }
3613 
3614 static bool dev_unplug_pending(void *opaque)
3615 {
3616     DeviceState *dev = opaque;
3617     VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev);
3618 
3619     return vdc->primary_unplug_pending(dev);
3620 }
3621 
3622 static const VMStateDescription vmstate_virtio_net = {
3623     .name = "virtio-net",
3624     .minimum_version_id = VIRTIO_NET_VM_VERSION,
3625     .version_id = VIRTIO_NET_VM_VERSION,
3626     .fields = (VMStateField[]) {
3627         VMSTATE_VIRTIO_DEVICE,
3628         VMSTATE_END_OF_LIST()
3629     },
3630     .pre_save = virtio_net_pre_save,
3631     .dev_unplug_pending = dev_unplug_pending,
3632 };
3633 
3634 static Property virtio_net_properties[] = {
3635     DEFINE_PROP_BIT64("csum", VirtIONet, host_features,
3636                     VIRTIO_NET_F_CSUM, true),
3637     DEFINE_PROP_BIT64("guest_csum", VirtIONet, host_features,
3638                     VIRTIO_NET_F_GUEST_CSUM, true),
3639     DEFINE_PROP_BIT64("gso", VirtIONet, host_features, VIRTIO_NET_F_GSO, true),
3640     DEFINE_PROP_BIT64("guest_tso4", VirtIONet, host_features,
3641                     VIRTIO_NET_F_GUEST_TSO4, true),
3642     DEFINE_PROP_BIT64("guest_tso6", VirtIONet, host_features,
3643                     VIRTIO_NET_F_GUEST_TSO6, true),
3644     DEFINE_PROP_BIT64("guest_ecn", VirtIONet, host_features,
3645                     VIRTIO_NET_F_GUEST_ECN, true),
3646     DEFINE_PROP_BIT64("guest_ufo", VirtIONet, host_features,
3647                     VIRTIO_NET_F_GUEST_UFO, true),
3648     DEFINE_PROP_BIT64("guest_announce", VirtIONet, host_features,
3649                     VIRTIO_NET_F_GUEST_ANNOUNCE, true),
3650     DEFINE_PROP_BIT64("host_tso4", VirtIONet, host_features,
3651                     VIRTIO_NET_F_HOST_TSO4, true),
3652     DEFINE_PROP_BIT64("host_tso6", VirtIONet, host_features,
3653                     VIRTIO_NET_F_HOST_TSO6, true),
3654     DEFINE_PROP_BIT64("host_ecn", VirtIONet, host_features,
3655                     VIRTIO_NET_F_HOST_ECN, true),
3656     DEFINE_PROP_BIT64("host_ufo", VirtIONet, host_features,
3657                     VIRTIO_NET_F_HOST_UFO, true),
3658     DEFINE_PROP_BIT64("mrg_rxbuf", VirtIONet, host_features,
3659                     VIRTIO_NET_F_MRG_RXBUF, true),
3660     DEFINE_PROP_BIT64("status", VirtIONet, host_features,
3661                     VIRTIO_NET_F_STATUS, true),
3662     DEFINE_PROP_BIT64("ctrl_vq", VirtIONet, host_features,
3663                     VIRTIO_NET_F_CTRL_VQ, true),
3664     DEFINE_PROP_BIT64("ctrl_rx", VirtIONet, host_features,
3665                     VIRTIO_NET_F_CTRL_RX, true),
3666     DEFINE_PROP_BIT64("ctrl_vlan", VirtIONet, host_features,
3667                     VIRTIO_NET_F_CTRL_VLAN, true),
3668     DEFINE_PROP_BIT64("ctrl_rx_extra", VirtIONet, host_features,
3669                     VIRTIO_NET_F_CTRL_RX_EXTRA, true),
3670     DEFINE_PROP_BIT64("ctrl_mac_addr", VirtIONet, host_features,
3671                     VIRTIO_NET_F_CTRL_MAC_ADDR, true),
3672     DEFINE_PROP_BIT64("ctrl_guest_offloads", VirtIONet, host_features,
3673                     VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, true),
3674     DEFINE_PROP_BIT64("mq", VirtIONet, host_features, VIRTIO_NET_F_MQ, false),
3675     DEFINE_PROP_BIT64("rss", VirtIONet, host_features,
3676                     VIRTIO_NET_F_RSS, false),
3677     DEFINE_PROP_BIT64("hash", VirtIONet, host_features,
3678                     VIRTIO_NET_F_HASH_REPORT, false),
3679     DEFINE_PROP_BIT64("guest_rsc_ext", VirtIONet, host_features,
3680                     VIRTIO_NET_F_RSC_EXT, false),
3681     DEFINE_PROP_UINT32("rsc_interval", VirtIONet, rsc_timeout,
3682                        VIRTIO_NET_RSC_DEFAULT_INTERVAL),
3683     DEFINE_NIC_PROPERTIES(VirtIONet, nic_conf),
3684     DEFINE_PROP_UINT32("x-txtimer", VirtIONet, net_conf.txtimer,
3685                        TX_TIMER_INTERVAL),
3686     DEFINE_PROP_INT32("x-txburst", VirtIONet, net_conf.txburst, TX_BURST),
3687     DEFINE_PROP_STRING("tx", VirtIONet, net_conf.tx),
3688     DEFINE_PROP_UINT16("rx_queue_size", VirtIONet, net_conf.rx_queue_size,
3689                        VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE),
3690     DEFINE_PROP_UINT16("tx_queue_size", VirtIONet, net_conf.tx_queue_size,
3691                        VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE),
3692     DEFINE_PROP_UINT16("host_mtu", VirtIONet, net_conf.mtu, 0),
3693     DEFINE_PROP_BOOL("x-mtu-bypass-backend", VirtIONet, mtu_bypass_backend,
3694                      true),
3695     DEFINE_PROP_INT32("speed", VirtIONet, net_conf.speed, SPEED_UNKNOWN),
3696     DEFINE_PROP_STRING("duplex", VirtIONet, net_conf.duplex_str),
3697     DEFINE_PROP_BOOL("failover", VirtIONet, failover, false),
3698     DEFINE_PROP_END_OF_LIST(),
3699 };
3700 
3701 static void virtio_net_class_init(ObjectClass *klass, void *data)
3702 {
3703     DeviceClass *dc = DEVICE_CLASS(klass);
3704     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
3705 
3706     device_class_set_props(dc, virtio_net_properties);
3707     dc->vmsd = &vmstate_virtio_net;
3708     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
3709     vdc->realize = virtio_net_device_realize;
3710     vdc->unrealize = virtio_net_device_unrealize;
3711     vdc->get_config = virtio_net_get_config;
3712     vdc->set_config = virtio_net_set_config;
3713     vdc->get_features = virtio_net_get_features;
3714     vdc->set_features = virtio_net_set_features;
3715     vdc->bad_features = virtio_net_bad_features;
3716     vdc->reset = virtio_net_reset;
3717     vdc->set_status = virtio_net_set_status;
3718     vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
3719     vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;
3720     vdc->legacy_features |= (0x1 << VIRTIO_NET_F_GSO);
3721     vdc->post_load = virtio_net_post_load_virtio;
3722     vdc->vmsd = &vmstate_virtio_net_device;
3723     vdc->primary_unplug_pending = primary_unplug_pending;
3724 }
3725 
3726 static const TypeInfo virtio_net_info = {
3727     .name = TYPE_VIRTIO_NET,
3728     .parent = TYPE_VIRTIO_DEVICE,
3729     .instance_size = sizeof(VirtIONet),
3730     .instance_init = virtio_net_instance_init,
3731     .class_init = virtio_net_class_init,
3732 };
3733 
3734 static void virtio_register_types(void)
3735 {
3736     type_register_static(&virtio_net_info);
3737 }
3738 
3739 type_init(virtio_register_types)
3740