xref: /openbmc/qemu/hw/net/virtio-net.c (revision f6e33708)
1 /*
2  * Virtio Network Device
3  *
4  * Copyright IBM, Corp. 2007
5  *
6  * Authors:
7  *  Anthony Liguori   <aliguori@us.ibm.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2.  See
10  * the COPYING file in the top-level directory.
11  *
12  */
13 
14 #include "qemu/osdep.h"
15 #include "qemu/atomic.h"
16 #include "qemu/iov.h"
17 #include "qemu/log.h"
18 #include "qemu/main-loop.h"
19 #include "qemu/module.h"
20 #include "hw/virtio/virtio.h"
21 #include "net/net.h"
22 #include "net/checksum.h"
23 #include "net/tap.h"
24 #include "qemu/error-report.h"
25 #include "qemu/timer.h"
26 #include "qemu/option.h"
27 #include "qemu/option_int.h"
28 #include "qemu/config-file.h"
29 #include "qapi/qmp/qdict.h"
30 #include "hw/virtio/virtio-net.h"
31 #include "net/vhost_net.h"
32 #include "net/announce.h"
33 #include "hw/virtio/virtio-bus.h"
34 #include "qapi/error.h"
35 #include "qapi/qapi-events-net.h"
36 #include "hw/qdev-properties.h"
37 #include "qapi/qapi-types-migration.h"
38 #include "qapi/qapi-events-migration.h"
39 #include "hw/virtio/virtio-access.h"
40 #include "migration/misc.h"
41 #include "standard-headers/linux/ethtool.h"
42 #include "sysemu/sysemu.h"
43 #include "trace.h"
44 #include "monitor/qdev.h"
45 #include "hw/pci/pci_device.h"
46 #include "net_rx_pkt.h"
47 #include "hw/virtio/vhost.h"
48 #include "sysemu/qtest.h"
49 
50 #define VIRTIO_NET_VM_VERSION    11
51 
52 /* previously fixed value */
53 #define VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE 256
54 #define VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE 256
55 
56 /* for now, only allow larger queue_pairs; with virtio-1, guest can downsize */
57 #define VIRTIO_NET_RX_QUEUE_MIN_SIZE VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE
58 #define VIRTIO_NET_TX_QUEUE_MIN_SIZE VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE
59 
60 #define VIRTIO_NET_IP4_ADDR_SIZE   8        /* ipv4 saddr + daddr */
61 
62 #define VIRTIO_NET_TCP_FLAG         0x3F
63 #define VIRTIO_NET_TCP_HDR_LENGTH   0xF000
64 
65 /* IPv4 max payload, 16 bits in the header */
66 #define VIRTIO_NET_MAX_IP4_PAYLOAD (65535 - sizeof(struct ip_header))
67 #define VIRTIO_NET_MAX_TCP_PAYLOAD 65535
68 
69 /* header length value in ip header without option */
70 #define VIRTIO_NET_IP4_HEADER_LENGTH 5
71 
72 #define VIRTIO_NET_IP6_ADDR_SIZE   32      /* ipv6 saddr + daddr */
73 #define VIRTIO_NET_MAX_IP6_PAYLOAD VIRTIO_NET_MAX_TCP_PAYLOAD
74 
75 /* Purge coalesced packets timer interval, This value affects the performance
76    a lot, and should be tuned carefully, '300000'(300us) is the recommended
77    value to pass the WHQL test, '50000' can gain 2x netperf throughput with
78    tso/gso/gro 'off'. */
79 #define VIRTIO_NET_RSC_DEFAULT_INTERVAL 300000
80 
81 #define VIRTIO_NET_RSS_SUPPORTED_HASHES (VIRTIO_NET_RSS_HASH_TYPE_IPv4 | \
82                                          VIRTIO_NET_RSS_HASH_TYPE_TCPv4 | \
83                                          VIRTIO_NET_RSS_HASH_TYPE_UDPv4 | \
84                                          VIRTIO_NET_RSS_HASH_TYPE_IPv6 | \
85                                          VIRTIO_NET_RSS_HASH_TYPE_TCPv6 | \
86                                          VIRTIO_NET_RSS_HASH_TYPE_UDPv6 | \
87                                          VIRTIO_NET_RSS_HASH_TYPE_IP_EX | \
88                                          VIRTIO_NET_RSS_HASH_TYPE_TCP_EX | \
89                                          VIRTIO_NET_RSS_HASH_TYPE_UDP_EX)
90 
91 static const VirtIOFeature feature_sizes[] = {
92     {.flags = 1ULL << VIRTIO_NET_F_MAC,
93      .end = endof(struct virtio_net_config, mac)},
94     {.flags = 1ULL << VIRTIO_NET_F_STATUS,
95      .end = endof(struct virtio_net_config, status)},
96     {.flags = 1ULL << VIRTIO_NET_F_MQ,
97      .end = endof(struct virtio_net_config, max_virtqueue_pairs)},
98     {.flags = 1ULL << VIRTIO_NET_F_MTU,
99      .end = endof(struct virtio_net_config, mtu)},
100     {.flags = 1ULL << VIRTIO_NET_F_SPEED_DUPLEX,
101      .end = endof(struct virtio_net_config, duplex)},
102     {.flags = (1ULL << VIRTIO_NET_F_RSS) | (1ULL << VIRTIO_NET_F_HASH_REPORT),
103      .end = endof(struct virtio_net_config, supported_hash_types)},
104     {}
105 };
106 
107 static const VirtIOConfigSizeParams cfg_size_params = {
108     .min_size = endof(struct virtio_net_config, mac),
109     .max_size = sizeof(struct virtio_net_config),
110     .feature_sizes = feature_sizes
111 };
112 
113 static VirtIONetQueue *virtio_net_get_subqueue(NetClientState *nc)
114 {
115     VirtIONet *n = qemu_get_nic_opaque(nc);
116 
117     return &n->vqs[nc->queue_index];
118 }
119 
120 static int vq2q(int queue_index)
121 {
122     return queue_index / 2;
123 }
124 
125 static void flush_or_purge_queued_packets(NetClientState *nc)
126 {
127     if (!nc->peer) {
128         return;
129     }
130 
131     qemu_flush_or_purge_queued_packets(nc->peer, true);
132     assert(!virtio_net_get_subqueue(nc)->async_tx.elem);
133 }
134 
135 /* TODO
136  * - we could suppress RX interrupt if we were so inclined.
137  */
138 
139 static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
140 {
141     VirtIONet *n = VIRTIO_NET(vdev);
142     struct virtio_net_config netcfg;
143     NetClientState *nc = qemu_get_queue(n->nic);
144     static const MACAddr zero = { .a = { 0, 0, 0, 0, 0, 0 } };
145 
146     int ret = 0;
147     memset(&netcfg, 0 , sizeof(struct virtio_net_config));
148     virtio_stw_p(vdev, &netcfg.status, n->status);
149     virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queue_pairs);
150     virtio_stw_p(vdev, &netcfg.mtu, n->net_conf.mtu);
151     memcpy(netcfg.mac, n->mac, ETH_ALEN);
152     virtio_stl_p(vdev, &netcfg.speed, n->net_conf.speed);
153     netcfg.duplex = n->net_conf.duplex;
154     netcfg.rss_max_key_size = VIRTIO_NET_RSS_MAX_KEY_SIZE;
155     virtio_stw_p(vdev, &netcfg.rss_max_indirection_table_length,
156                  virtio_host_has_feature(vdev, VIRTIO_NET_F_RSS) ?
157                  VIRTIO_NET_RSS_MAX_TABLE_LEN : 1);
158     virtio_stl_p(vdev, &netcfg.supported_hash_types,
159                  VIRTIO_NET_RSS_SUPPORTED_HASHES);
160     memcpy(config, &netcfg, n->config_size);
161 
162     /*
163      * Is this VDPA? No peer means not VDPA: there's no way to
164      * disconnect/reconnect a VDPA peer.
165      */
166     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
167         ret = vhost_net_get_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
168                                    n->config_size);
169         if (ret == -1) {
170             return;
171         }
172 
173         /*
174          * Some NIC/kernel combinations present 0 as the mac address.  As that
175          * is not a legal address, try to proceed with the address from the
176          * QEMU command line in the hope that the address has been configured
177          * correctly elsewhere - just not reported by the device.
178          */
179         if (memcmp(&netcfg.mac, &zero, sizeof(zero)) == 0) {
180             info_report("Zero hardware mac address detected. Ignoring.");
181             memcpy(netcfg.mac, n->mac, ETH_ALEN);
182         }
183 
184         netcfg.status |= virtio_tswap16(vdev,
185                                         n->status & VIRTIO_NET_S_ANNOUNCE);
186         memcpy(config, &netcfg, n->config_size);
187     }
188 }
189 
190 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
191 {
192     VirtIONet *n = VIRTIO_NET(vdev);
193     struct virtio_net_config netcfg = {};
194     NetClientState *nc = qemu_get_queue(n->nic);
195 
196     memcpy(&netcfg, config, n->config_size);
197 
198     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR) &&
199         !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1) &&
200         memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
201         memcpy(n->mac, netcfg.mac, ETH_ALEN);
202         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
203     }
204 
205     /*
206      * Is this VDPA? No peer means not VDPA: there's no way to
207      * disconnect/reconnect a VDPA peer.
208      */
209     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
210         vhost_net_set_config(get_vhost_net(nc->peer),
211                              (uint8_t *)&netcfg, 0, n->config_size,
212                              VHOST_SET_CONFIG_TYPE_FRONTEND);
213       }
214 }
215 
216 static bool virtio_net_started(VirtIONet *n, uint8_t status)
217 {
218     VirtIODevice *vdev = VIRTIO_DEVICE(n);
219     return (status & VIRTIO_CONFIG_S_DRIVER_OK) &&
220         (n->status & VIRTIO_NET_S_LINK_UP) && vdev->vm_running;
221 }
222 
223 static void virtio_net_announce_notify(VirtIONet *net)
224 {
225     VirtIODevice *vdev = VIRTIO_DEVICE(net);
226     trace_virtio_net_announce_notify();
227 
228     net->status |= VIRTIO_NET_S_ANNOUNCE;
229     virtio_notify_config(vdev);
230 }
231 
232 static void virtio_net_announce_timer(void *opaque)
233 {
234     VirtIONet *n = opaque;
235     trace_virtio_net_announce_timer(n->announce_timer.round);
236 
237     n->announce_timer.round--;
238     virtio_net_announce_notify(n);
239 }
240 
241 static void virtio_net_announce(NetClientState *nc)
242 {
243     VirtIONet *n = qemu_get_nic_opaque(nc);
244     VirtIODevice *vdev = VIRTIO_DEVICE(n);
245 
246     /*
247      * Make sure the virtio migration announcement timer isn't running
248      * If it is, let it trigger announcement so that we do not cause
249      * confusion.
250      */
251     if (n->announce_timer.round) {
252         return;
253     }
254 
255     if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) &&
256         virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
257             virtio_net_announce_notify(n);
258     }
259 }
260 
261 static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
262 {
263     VirtIODevice *vdev = VIRTIO_DEVICE(n);
264     NetClientState *nc = qemu_get_queue(n->nic);
265     int queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
266     int cvq = virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) ?
267               n->max_ncs - n->max_queue_pairs : 0;
268 
269     if (!get_vhost_net(nc->peer)) {
270         return;
271     }
272 
273     if ((virtio_net_started(n, status) && !nc->peer->link_down) ==
274         !!n->vhost_started) {
275         return;
276     }
277     if (!n->vhost_started) {
278         int r, i;
279 
280         if (n->needs_vnet_hdr_swap) {
281             error_report("backend does not support %s vnet headers; "
282                          "falling back on userspace virtio",
283                          virtio_is_big_endian(vdev) ? "BE" : "LE");
284             return;
285         }
286 
287         /* Any packets outstanding? Purge them to avoid touching rings
288          * when vhost is running.
289          */
290         for (i = 0;  i < queue_pairs; i++) {
291             NetClientState *qnc = qemu_get_subqueue(n->nic, i);
292 
293             /* Purge both directions: TX and RX. */
294             qemu_net_queue_purge(qnc->peer->incoming_queue, qnc);
295             qemu_net_queue_purge(qnc->incoming_queue, qnc->peer);
296         }
297 
298         if (virtio_has_feature(vdev->guest_features, VIRTIO_NET_F_MTU)) {
299             r = vhost_net_set_mtu(get_vhost_net(nc->peer), n->net_conf.mtu);
300             if (r < 0) {
301                 error_report("%uBytes MTU not supported by the backend",
302                              n->net_conf.mtu);
303 
304                 return;
305             }
306         }
307 
308         n->vhost_started = 1;
309         r = vhost_net_start(vdev, n->nic->ncs, queue_pairs, cvq);
310         if (r < 0) {
311             error_report("unable to start vhost net: %d: "
312                          "falling back on userspace virtio", -r);
313             n->vhost_started = 0;
314         }
315     } else {
316         vhost_net_stop(vdev, n->nic->ncs, queue_pairs, cvq);
317         n->vhost_started = 0;
318     }
319 }
320 
321 static int virtio_net_set_vnet_endian_one(VirtIODevice *vdev,
322                                           NetClientState *peer,
323                                           bool enable)
324 {
325     if (virtio_is_big_endian(vdev)) {
326         return qemu_set_vnet_be(peer, enable);
327     } else {
328         return qemu_set_vnet_le(peer, enable);
329     }
330 }
331 
332 static bool virtio_net_set_vnet_endian(VirtIODevice *vdev, NetClientState *ncs,
333                                        int queue_pairs, bool enable)
334 {
335     int i;
336 
337     for (i = 0; i < queue_pairs; i++) {
338         if (virtio_net_set_vnet_endian_one(vdev, ncs[i].peer, enable) < 0 &&
339             enable) {
340             while (--i >= 0) {
341                 virtio_net_set_vnet_endian_one(vdev, ncs[i].peer, false);
342             }
343 
344             return true;
345         }
346     }
347 
348     return false;
349 }
350 
351 static void virtio_net_vnet_endian_status(VirtIONet *n, uint8_t status)
352 {
353     VirtIODevice *vdev = VIRTIO_DEVICE(n);
354     int queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
355 
356     if (virtio_net_started(n, status)) {
357         /* Before using the device, we tell the network backend about the
358          * endianness to use when parsing vnet headers. If the backend
359          * can't do it, we fallback onto fixing the headers in the core
360          * virtio-net code.
361          */
362         n->needs_vnet_hdr_swap = virtio_net_set_vnet_endian(vdev, n->nic->ncs,
363                                                             queue_pairs, true);
364     } else if (virtio_net_started(n, vdev->status)) {
365         /* After using the device, we need to reset the network backend to
366          * the default (guest native endianness), otherwise the guest may
367          * lose network connectivity if it is rebooted into a different
368          * endianness.
369          */
370         virtio_net_set_vnet_endian(vdev, n->nic->ncs, queue_pairs, false);
371     }
372 }
373 
374 static void virtio_net_drop_tx_queue_data(VirtIODevice *vdev, VirtQueue *vq)
375 {
376     unsigned int dropped = virtqueue_drop_all(vq);
377     if (dropped) {
378         virtio_notify(vdev, vq);
379     }
380 }
381 
382 static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
383 {
384     VirtIONet *n = VIRTIO_NET(vdev);
385     VirtIONetQueue *q;
386     int i;
387     uint8_t queue_status;
388 
389     virtio_net_vnet_endian_status(n, status);
390     virtio_net_vhost_status(n, status);
391 
392     for (i = 0; i < n->max_queue_pairs; i++) {
393         NetClientState *ncs = qemu_get_subqueue(n->nic, i);
394         bool queue_started;
395         q = &n->vqs[i];
396 
397         if ((!n->multiqueue && i != 0) || i >= n->curr_queue_pairs) {
398             queue_status = 0;
399         } else {
400             queue_status = status;
401         }
402         queue_started =
403             virtio_net_started(n, queue_status) && !n->vhost_started;
404 
405         if (queue_started) {
406             qemu_flush_queued_packets(ncs);
407         }
408 
409         if (!q->tx_waiting) {
410             continue;
411         }
412 
413         if (queue_started) {
414             if (q->tx_timer) {
415                 timer_mod(q->tx_timer,
416                                qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
417             } else {
418                 qemu_bh_schedule(q->tx_bh);
419             }
420         } else {
421             if (q->tx_timer) {
422                 timer_del(q->tx_timer);
423             } else {
424                 qemu_bh_cancel(q->tx_bh);
425             }
426             if ((n->status & VIRTIO_NET_S_LINK_UP) == 0 &&
427                 (queue_status & VIRTIO_CONFIG_S_DRIVER_OK) &&
428                 vdev->vm_running) {
429                 /* if tx is waiting we are likely have some packets in tx queue
430                  * and disabled notification */
431                 q->tx_waiting = 0;
432                 virtio_queue_set_notification(q->tx_vq, 1);
433                 virtio_net_drop_tx_queue_data(vdev, q->tx_vq);
434             }
435         }
436     }
437 }
438 
439 static void virtio_net_set_link_status(NetClientState *nc)
440 {
441     VirtIONet *n = qemu_get_nic_opaque(nc);
442     VirtIODevice *vdev = VIRTIO_DEVICE(n);
443     uint16_t old_status = n->status;
444 
445     if (nc->link_down)
446         n->status &= ~VIRTIO_NET_S_LINK_UP;
447     else
448         n->status |= VIRTIO_NET_S_LINK_UP;
449 
450     if (n->status != old_status)
451         virtio_notify_config(vdev);
452 
453     virtio_net_set_status(vdev, vdev->status);
454 }
455 
456 static void rxfilter_notify(NetClientState *nc)
457 {
458     VirtIONet *n = qemu_get_nic_opaque(nc);
459 
460     if (nc->rxfilter_notify_enabled) {
461         char *path = object_get_canonical_path(OBJECT(n->qdev));
462         qapi_event_send_nic_rx_filter_changed(n->netclient_name, path);
463         g_free(path);
464 
465         /* disable event notification to avoid events flooding */
466         nc->rxfilter_notify_enabled = 0;
467     }
468 }
469 
470 static intList *get_vlan_table(VirtIONet *n)
471 {
472     intList *list;
473     int i, j;
474 
475     list = NULL;
476     for (i = 0; i < MAX_VLAN >> 5; i++) {
477         for (j = 0; n->vlans[i] && j <= 0x1f; j++) {
478             if (n->vlans[i] & (1U << j)) {
479                 QAPI_LIST_PREPEND(list, (i << 5) + j);
480             }
481         }
482     }
483 
484     return list;
485 }
486 
487 static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
488 {
489     VirtIONet *n = qemu_get_nic_opaque(nc);
490     VirtIODevice *vdev = VIRTIO_DEVICE(n);
491     RxFilterInfo *info;
492     strList *str_list;
493     int i;
494 
495     info = g_malloc0(sizeof(*info));
496     info->name = g_strdup(nc->name);
497     info->promiscuous = n->promisc;
498 
499     if (n->nouni) {
500         info->unicast = RX_STATE_NONE;
501     } else if (n->alluni) {
502         info->unicast = RX_STATE_ALL;
503     } else {
504         info->unicast = RX_STATE_NORMAL;
505     }
506 
507     if (n->nomulti) {
508         info->multicast = RX_STATE_NONE;
509     } else if (n->allmulti) {
510         info->multicast = RX_STATE_ALL;
511     } else {
512         info->multicast = RX_STATE_NORMAL;
513     }
514 
515     info->broadcast_allowed = n->nobcast;
516     info->multicast_overflow = n->mac_table.multi_overflow;
517     info->unicast_overflow = n->mac_table.uni_overflow;
518 
519     info->main_mac = qemu_mac_strdup_printf(n->mac);
520 
521     str_list = NULL;
522     for (i = 0; i < n->mac_table.first_multi; i++) {
523         QAPI_LIST_PREPEND(str_list,
524                       qemu_mac_strdup_printf(n->mac_table.macs + i * ETH_ALEN));
525     }
526     info->unicast_table = str_list;
527 
528     str_list = NULL;
529     for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
530         QAPI_LIST_PREPEND(str_list,
531                       qemu_mac_strdup_printf(n->mac_table.macs + i * ETH_ALEN));
532     }
533     info->multicast_table = str_list;
534     info->vlan_table = get_vlan_table(n);
535 
536     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VLAN)) {
537         info->vlan = RX_STATE_ALL;
538     } else if (!info->vlan_table) {
539         info->vlan = RX_STATE_NONE;
540     } else {
541         info->vlan = RX_STATE_NORMAL;
542     }
543 
544     /* enable event notification after query */
545     nc->rxfilter_notify_enabled = 1;
546 
547     return info;
548 }
549 
550 static void virtio_net_queue_reset(VirtIODevice *vdev, uint32_t queue_index)
551 {
552     VirtIONet *n = VIRTIO_NET(vdev);
553     NetClientState *nc;
554 
555     /* validate queue_index and skip for cvq */
556     if (queue_index >= n->max_queue_pairs * 2) {
557         return;
558     }
559 
560     nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
561 
562     if (!nc->peer) {
563         return;
564     }
565 
566     if (get_vhost_net(nc->peer) &&
567         nc->peer->info->type == NET_CLIENT_DRIVER_TAP) {
568         vhost_net_virtqueue_reset(vdev, nc, queue_index);
569     }
570 
571     flush_or_purge_queued_packets(nc);
572 }
573 
574 static void virtio_net_queue_enable(VirtIODevice *vdev, uint32_t queue_index)
575 {
576     VirtIONet *n = VIRTIO_NET(vdev);
577     NetClientState *nc;
578     int r;
579 
580     /* validate queue_index and skip for cvq */
581     if (queue_index >= n->max_queue_pairs * 2) {
582         return;
583     }
584 
585     nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
586 
587     if (!nc->peer || !vdev->vhost_started) {
588         return;
589     }
590 
591     if (get_vhost_net(nc->peer) &&
592         nc->peer->info->type == NET_CLIENT_DRIVER_TAP) {
593         r = vhost_net_virtqueue_restart(vdev, nc, queue_index);
594         if (r < 0) {
595             error_report("unable to restart vhost net virtqueue: %d, "
596                             "when resetting the queue", queue_index);
597         }
598     }
599 }
600 
601 static void virtio_net_reset(VirtIODevice *vdev)
602 {
603     VirtIONet *n = VIRTIO_NET(vdev);
604     int i;
605 
606     /* Reset back to compatibility mode */
607     n->promisc = 1;
608     n->allmulti = 0;
609     n->alluni = 0;
610     n->nomulti = 0;
611     n->nouni = 0;
612     n->nobcast = 0;
613     /* multiqueue is disabled by default */
614     n->curr_queue_pairs = 1;
615     timer_del(n->announce_timer.tm);
616     n->announce_timer.round = 0;
617     n->status &= ~VIRTIO_NET_S_ANNOUNCE;
618 
619     /* Flush any MAC and VLAN filter table state */
620     n->mac_table.in_use = 0;
621     n->mac_table.first_multi = 0;
622     n->mac_table.multi_overflow = 0;
623     n->mac_table.uni_overflow = 0;
624     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
625     memcpy(&n->mac[0], &n->nic->conf->macaddr, sizeof(n->mac));
626     qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
627     memset(n->vlans, 0, MAX_VLAN >> 3);
628 
629     /* Flush any async TX */
630     for (i = 0;  i < n->max_queue_pairs; i++) {
631         flush_or_purge_queued_packets(qemu_get_subqueue(n->nic, i));
632     }
633 }
634 
635 static void peer_test_vnet_hdr(VirtIONet *n)
636 {
637     NetClientState *nc = qemu_get_queue(n->nic);
638     if (!nc->peer) {
639         return;
640     }
641 
642     n->has_vnet_hdr = qemu_has_vnet_hdr(nc->peer);
643 }
644 
645 static int peer_has_vnet_hdr(VirtIONet *n)
646 {
647     return n->has_vnet_hdr;
648 }
649 
650 static int peer_has_ufo(VirtIONet *n)
651 {
652     if (!peer_has_vnet_hdr(n))
653         return 0;
654 
655     n->has_ufo = qemu_has_ufo(qemu_get_queue(n->nic)->peer);
656 
657     return n->has_ufo;
658 }
659 
660 static int peer_has_uso(VirtIONet *n)
661 {
662     if (!peer_has_vnet_hdr(n)) {
663         return 0;
664     }
665 
666     return qemu_has_uso(qemu_get_queue(n->nic)->peer);
667 }
668 
669 static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs,
670                                        int version_1, int hash_report)
671 {
672     int i;
673     NetClientState *nc;
674 
675     n->mergeable_rx_bufs = mergeable_rx_bufs;
676 
677     /*
678      * Note: when extending the vnet header, please make sure to
679      * change the vnet header copying logic in virtio_net_flush_tx()
680      * as well.
681      */
682     if (version_1) {
683         n->guest_hdr_len = hash_report ?
684             sizeof(struct virtio_net_hdr_v1_hash) :
685             sizeof(struct virtio_net_hdr_mrg_rxbuf);
686         n->rss_data.populate_hash = !!hash_report;
687     } else {
688         n->guest_hdr_len = n->mergeable_rx_bufs ?
689             sizeof(struct virtio_net_hdr_mrg_rxbuf) :
690             sizeof(struct virtio_net_hdr);
691     }
692 
693     for (i = 0; i < n->max_queue_pairs; i++) {
694         nc = qemu_get_subqueue(n->nic, i);
695 
696         if (peer_has_vnet_hdr(n) &&
697             qemu_has_vnet_hdr_len(nc->peer, n->guest_hdr_len)) {
698             qemu_set_vnet_hdr_len(nc->peer, n->guest_hdr_len);
699             n->host_hdr_len = n->guest_hdr_len;
700         }
701     }
702 }
703 
704 static int virtio_net_max_tx_queue_size(VirtIONet *n)
705 {
706     NetClientState *peer = n->nic_conf.peers.ncs[0];
707 
708     /*
709      * Backends other than vhost-user or vhost-vdpa don't support max queue
710      * size.
711      */
712     if (!peer) {
713         return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE;
714     }
715 
716     switch(peer->info->type) {
717     case NET_CLIENT_DRIVER_VHOST_USER:
718     case NET_CLIENT_DRIVER_VHOST_VDPA:
719         return VIRTQUEUE_MAX_SIZE;
720     default:
721         return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE;
722     };
723 }
724 
725 static int peer_attach(VirtIONet *n, int index)
726 {
727     NetClientState *nc = qemu_get_subqueue(n->nic, index);
728 
729     if (!nc->peer) {
730         return 0;
731     }
732 
733     if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
734         vhost_set_vring_enable(nc->peer, 1);
735     }
736 
737     if (nc->peer->info->type != NET_CLIENT_DRIVER_TAP) {
738         return 0;
739     }
740 
741     if (n->max_queue_pairs == 1) {
742         return 0;
743     }
744 
745     return tap_enable(nc->peer);
746 }
747 
748 static int peer_detach(VirtIONet *n, int index)
749 {
750     NetClientState *nc = qemu_get_subqueue(n->nic, index);
751 
752     if (!nc->peer) {
753         return 0;
754     }
755 
756     if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
757         vhost_set_vring_enable(nc->peer, 0);
758     }
759 
760     if (nc->peer->info->type !=  NET_CLIENT_DRIVER_TAP) {
761         return 0;
762     }
763 
764     return tap_disable(nc->peer);
765 }
766 
767 static void virtio_net_set_queue_pairs(VirtIONet *n)
768 {
769     int i;
770     int r;
771 
772     if (n->nic->peer_deleted) {
773         return;
774     }
775 
776     for (i = 0; i < n->max_queue_pairs; i++) {
777         if (i < n->curr_queue_pairs) {
778             r = peer_attach(n, i);
779             assert(!r);
780         } else {
781             r = peer_detach(n, i);
782             assert(!r);
783         }
784     }
785 }
786 
787 static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue);
788 
789 static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
790                                         Error **errp)
791 {
792     VirtIONet *n = VIRTIO_NET(vdev);
793     NetClientState *nc = qemu_get_queue(n->nic);
794 
795     /* Firstly sync all virtio-net possible supported features */
796     features |= n->host_features;
797 
798     virtio_add_feature(&features, VIRTIO_NET_F_MAC);
799 
800     if (!peer_has_vnet_hdr(n)) {
801         virtio_clear_feature(&features, VIRTIO_NET_F_CSUM);
802         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_TSO4);
803         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_TSO6);
804         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_ECN);
805 
806         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_CSUM);
807         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO4);
808         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO6);
809         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ECN);
810 
811         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_USO);
812         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_USO4);
813         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_USO6);
814 
815         virtio_clear_feature(&features, VIRTIO_NET_F_HASH_REPORT);
816     }
817 
818     if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
819         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_UFO);
820         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO);
821     }
822 
823     if (!peer_has_uso(n)) {
824         virtio_clear_feature(&features, VIRTIO_NET_F_HOST_USO);
825         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_USO4);
826         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_USO6);
827     }
828 
829     if (!get_vhost_net(nc->peer)) {
830         return features;
831     }
832 
833     if (!ebpf_rss_is_loaded(&n->ebpf_rss)) {
834         virtio_clear_feature(&features, VIRTIO_NET_F_RSS);
835     }
836     features = vhost_net_get_features(get_vhost_net(nc->peer), features);
837     vdev->backend_features = features;
838 
839     if (n->mtu_bypass_backend &&
840             (n->host_features & 1ULL << VIRTIO_NET_F_MTU)) {
841         features |= (1ULL << VIRTIO_NET_F_MTU);
842     }
843 
844     /*
845      * Since GUEST_ANNOUNCE is emulated the feature bit could be set without
846      * enabled. This happens in the vDPA case.
847      *
848      * Make sure the feature set is not incoherent, as the driver could refuse
849      * to start.
850      *
851      * TODO: QEMU is able to emulate a CVQ just for guest_announce purposes,
852      * helping guest to notify the new location with vDPA devices that does not
853      * support it.
854      */
855     if (!virtio_has_feature(vdev->backend_features, VIRTIO_NET_F_CTRL_VQ)) {
856         virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ANNOUNCE);
857     }
858 
859     return features;
860 }
861 
862 static uint64_t virtio_net_bad_features(VirtIODevice *vdev)
863 {
864     uint64_t features = 0;
865 
866     /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
867      * but also these: */
868     virtio_add_feature(&features, VIRTIO_NET_F_MAC);
869     virtio_add_feature(&features, VIRTIO_NET_F_CSUM);
870     virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO4);
871     virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO6);
872     virtio_add_feature(&features, VIRTIO_NET_F_HOST_ECN);
873 
874     return features;
875 }
876 
877 static void virtio_net_apply_guest_offloads(VirtIONet *n)
878 {
879     qemu_set_offload(qemu_get_queue(n->nic)->peer,
880             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_CSUM)),
881             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO4)),
882             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO6)),
883             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_ECN)),
884             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_UFO)),
885             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_USO4)),
886             !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_USO6)));
887 }
888 
889 static uint64_t virtio_net_guest_offloads_by_features(uint64_t features)
890 {
891     static const uint64_t guest_offloads_mask =
892         (1ULL << VIRTIO_NET_F_GUEST_CSUM) |
893         (1ULL << VIRTIO_NET_F_GUEST_TSO4) |
894         (1ULL << VIRTIO_NET_F_GUEST_TSO6) |
895         (1ULL << VIRTIO_NET_F_GUEST_ECN)  |
896         (1ULL << VIRTIO_NET_F_GUEST_UFO)  |
897         (1ULL << VIRTIO_NET_F_GUEST_USO4) |
898         (1ULL << VIRTIO_NET_F_GUEST_USO6);
899 
900     return guest_offloads_mask & features;
901 }
902 
903 uint64_t virtio_net_supported_guest_offloads(const VirtIONet *n)
904 {
905     VirtIODevice *vdev = VIRTIO_DEVICE(n);
906     return virtio_net_guest_offloads_by_features(vdev->guest_features);
907 }
908 
909 typedef struct {
910     VirtIONet *n;
911     DeviceState *dev;
912 } FailoverDevice;
913 
914 /**
915  * Set the failover primary device
916  *
917  * @opaque: FailoverId to setup
918  * @opts: opts for device we are handling
919  * @errp: returns an error if this function fails
920  */
921 static int failover_set_primary(DeviceState *dev, void *opaque)
922 {
923     FailoverDevice *fdev = opaque;
924     PCIDevice *pci_dev = (PCIDevice *)
925         object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE);
926 
927     if (!pci_dev) {
928         return 0;
929     }
930 
931     if (!g_strcmp0(pci_dev->failover_pair_id, fdev->n->netclient_name)) {
932         fdev->dev = dev;
933         return 1;
934     }
935 
936     return 0;
937 }
938 
939 /**
940  * Find the primary device for this failover virtio-net
941  *
942  * @n: VirtIONet device
943  * @errp: returns an error if this function fails
944  */
945 static DeviceState *failover_find_primary_device(VirtIONet *n)
946 {
947     FailoverDevice fdev = {
948         .n = n,
949     };
950 
951     qbus_walk_children(sysbus_get_default(), failover_set_primary, NULL,
952                        NULL, NULL, &fdev);
953     return fdev.dev;
954 }
955 
956 static void failover_add_primary(VirtIONet *n, Error **errp)
957 {
958     Error *err = NULL;
959     DeviceState *dev = failover_find_primary_device(n);
960 
961     if (dev) {
962         return;
963     }
964 
965     if (!n->primary_opts) {
966         error_setg(errp, "Primary device not found");
967         error_append_hint(errp, "Virtio-net failover will not work. Make "
968                           "sure primary device has parameter"
969                           " failover_pair_id=%s\n", n->netclient_name);
970         return;
971     }
972 
973     dev = qdev_device_add_from_qdict(n->primary_opts,
974                                      n->primary_opts_from_json,
975                                      &err);
976     if (err) {
977         qobject_unref(n->primary_opts);
978         n->primary_opts = NULL;
979     } else {
980         object_unref(OBJECT(dev));
981     }
982     error_propagate(errp, err);
983 }
984 
985 static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features)
986 {
987     VirtIONet *n = VIRTIO_NET(vdev);
988     Error *err = NULL;
989     int i;
990 
991     if (n->mtu_bypass_backend &&
992             !virtio_has_feature(vdev->backend_features, VIRTIO_NET_F_MTU)) {
993         features &= ~(1ULL << VIRTIO_NET_F_MTU);
994     }
995 
996     virtio_net_set_multiqueue(n,
997                               virtio_has_feature(features, VIRTIO_NET_F_RSS) ||
998                               virtio_has_feature(features, VIRTIO_NET_F_MQ));
999 
1000     virtio_net_set_mrg_rx_bufs(n,
1001                                virtio_has_feature(features,
1002                                                   VIRTIO_NET_F_MRG_RXBUF),
1003                                virtio_has_feature(features,
1004                                                   VIRTIO_F_VERSION_1),
1005                                virtio_has_feature(features,
1006                                                   VIRTIO_NET_F_HASH_REPORT));
1007 
1008     n->rsc4_enabled = virtio_has_feature(features, VIRTIO_NET_F_RSC_EXT) &&
1009         virtio_has_feature(features, VIRTIO_NET_F_GUEST_TSO4);
1010     n->rsc6_enabled = virtio_has_feature(features, VIRTIO_NET_F_RSC_EXT) &&
1011         virtio_has_feature(features, VIRTIO_NET_F_GUEST_TSO6);
1012     n->rss_data.redirect = virtio_has_feature(features, VIRTIO_NET_F_RSS);
1013 
1014     if (n->has_vnet_hdr) {
1015         n->curr_guest_offloads =
1016             virtio_net_guest_offloads_by_features(features);
1017         virtio_net_apply_guest_offloads(n);
1018     }
1019 
1020     for (i = 0;  i < n->max_queue_pairs; i++) {
1021         NetClientState *nc = qemu_get_subqueue(n->nic, i);
1022 
1023         if (!get_vhost_net(nc->peer)) {
1024             continue;
1025         }
1026         vhost_net_ack_features(get_vhost_net(nc->peer), features);
1027 
1028         /*
1029          * keep acked_features in NetVhostUserState up-to-date so it
1030          * can't miss any features configured by guest virtio driver.
1031          */
1032         vhost_net_save_acked_features(nc->peer);
1033     }
1034 
1035     if (!virtio_has_feature(features, VIRTIO_NET_F_CTRL_VLAN)) {
1036         memset(n->vlans, 0xff, MAX_VLAN >> 3);
1037     }
1038 
1039     if (virtio_has_feature(features, VIRTIO_NET_F_STANDBY)) {
1040         qapi_event_send_failover_negotiated(n->netclient_name);
1041         qatomic_set(&n->failover_primary_hidden, false);
1042         failover_add_primary(n, &err);
1043         if (err) {
1044             if (!qtest_enabled()) {
1045                 warn_report_err(err);
1046             } else {
1047                 error_free(err);
1048             }
1049         }
1050     }
1051 }
1052 
1053 static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
1054                                      struct iovec *iov, unsigned int iov_cnt)
1055 {
1056     uint8_t on;
1057     size_t s;
1058     NetClientState *nc = qemu_get_queue(n->nic);
1059 
1060     s = iov_to_buf(iov, iov_cnt, 0, &on, sizeof(on));
1061     if (s != sizeof(on)) {
1062         return VIRTIO_NET_ERR;
1063     }
1064 
1065     if (cmd == VIRTIO_NET_CTRL_RX_PROMISC) {
1066         n->promisc = on;
1067     } else if (cmd == VIRTIO_NET_CTRL_RX_ALLMULTI) {
1068         n->allmulti = on;
1069     } else if (cmd == VIRTIO_NET_CTRL_RX_ALLUNI) {
1070         n->alluni = on;
1071     } else if (cmd == VIRTIO_NET_CTRL_RX_NOMULTI) {
1072         n->nomulti = on;
1073     } else if (cmd == VIRTIO_NET_CTRL_RX_NOUNI) {
1074         n->nouni = on;
1075     } else if (cmd == VIRTIO_NET_CTRL_RX_NOBCAST) {
1076         n->nobcast = on;
1077     } else {
1078         return VIRTIO_NET_ERR;
1079     }
1080 
1081     rxfilter_notify(nc);
1082 
1083     return VIRTIO_NET_OK;
1084 }
1085 
1086 static int virtio_net_handle_offloads(VirtIONet *n, uint8_t cmd,
1087                                      struct iovec *iov, unsigned int iov_cnt)
1088 {
1089     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1090     uint64_t offloads;
1091     size_t s;
1092 
1093     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
1094         return VIRTIO_NET_ERR;
1095     }
1096 
1097     s = iov_to_buf(iov, iov_cnt, 0, &offloads, sizeof(offloads));
1098     if (s != sizeof(offloads)) {
1099         return VIRTIO_NET_ERR;
1100     }
1101 
1102     if (cmd == VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET) {
1103         uint64_t supported_offloads;
1104 
1105         offloads = virtio_ldq_p(vdev, &offloads);
1106 
1107         if (!n->has_vnet_hdr) {
1108             return VIRTIO_NET_ERR;
1109         }
1110 
1111         n->rsc4_enabled = virtio_has_feature(offloads, VIRTIO_NET_F_RSC_EXT) &&
1112             virtio_has_feature(offloads, VIRTIO_NET_F_GUEST_TSO4);
1113         n->rsc6_enabled = virtio_has_feature(offloads, VIRTIO_NET_F_RSC_EXT) &&
1114             virtio_has_feature(offloads, VIRTIO_NET_F_GUEST_TSO6);
1115         virtio_clear_feature(&offloads, VIRTIO_NET_F_RSC_EXT);
1116 
1117         supported_offloads = virtio_net_supported_guest_offloads(n);
1118         if (offloads & ~supported_offloads) {
1119             return VIRTIO_NET_ERR;
1120         }
1121 
1122         n->curr_guest_offloads = offloads;
1123         virtio_net_apply_guest_offloads(n);
1124 
1125         return VIRTIO_NET_OK;
1126     } else {
1127         return VIRTIO_NET_ERR;
1128     }
1129 }
1130 
1131 static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
1132                                  struct iovec *iov, unsigned int iov_cnt)
1133 {
1134     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1135     struct virtio_net_ctrl_mac mac_data;
1136     size_t s;
1137     NetClientState *nc = qemu_get_queue(n->nic);
1138 
1139     if (cmd == VIRTIO_NET_CTRL_MAC_ADDR_SET) {
1140         if (iov_size(iov, iov_cnt) != sizeof(n->mac)) {
1141             return VIRTIO_NET_ERR;
1142         }
1143         s = iov_to_buf(iov, iov_cnt, 0, &n->mac, sizeof(n->mac));
1144         assert(s == sizeof(n->mac));
1145         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
1146         rxfilter_notify(nc);
1147 
1148         return VIRTIO_NET_OK;
1149     }
1150 
1151     if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET) {
1152         return VIRTIO_NET_ERR;
1153     }
1154 
1155     int in_use = 0;
1156     int first_multi = 0;
1157     uint8_t uni_overflow = 0;
1158     uint8_t multi_overflow = 0;
1159     uint8_t *macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
1160 
1161     s = iov_to_buf(iov, iov_cnt, 0, &mac_data.entries,
1162                    sizeof(mac_data.entries));
1163     mac_data.entries = virtio_ldl_p(vdev, &mac_data.entries);
1164     if (s != sizeof(mac_data.entries)) {
1165         goto error;
1166     }
1167     iov_discard_front(&iov, &iov_cnt, s);
1168 
1169     if (mac_data.entries * ETH_ALEN > iov_size(iov, iov_cnt)) {
1170         goto error;
1171     }
1172 
1173     if (mac_data.entries <= MAC_TABLE_ENTRIES) {
1174         s = iov_to_buf(iov, iov_cnt, 0, macs,
1175                        mac_data.entries * ETH_ALEN);
1176         if (s != mac_data.entries * ETH_ALEN) {
1177             goto error;
1178         }
1179         in_use += mac_data.entries;
1180     } else {
1181         uni_overflow = 1;
1182     }
1183 
1184     iov_discard_front(&iov, &iov_cnt, mac_data.entries * ETH_ALEN);
1185 
1186     first_multi = in_use;
1187 
1188     s = iov_to_buf(iov, iov_cnt, 0, &mac_data.entries,
1189                    sizeof(mac_data.entries));
1190     mac_data.entries = virtio_ldl_p(vdev, &mac_data.entries);
1191     if (s != sizeof(mac_data.entries)) {
1192         goto error;
1193     }
1194 
1195     iov_discard_front(&iov, &iov_cnt, s);
1196 
1197     if (mac_data.entries * ETH_ALEN != iov_size(iov, iov_cnt)) {
1198         goto error;
1199     }
1200 
1201     if (mac_data.entries <= MAC_TABLE_ENTRIES - in_use) {
1202         s = iov_to_buf(iov, iov_cnt, 0, &macs[in_use * ETH_ALEN],
1203                        mac_data.entries * ETH_ALEN);
1204         if (s != mac_data.entries * ETH_ALEN) {
1205             goto error;
1206         }
1207         in_use += mac_data.entries;
1208     } else {
1209         multi_overflow = 1;
1210     }
1211 
1212     n->mac_table.in_use = in_use;
1213     n->mac_table.first_multi = first_multi;
1214     n->mac_table.uni_overflow = uni_overflow;
1215     n->mac_table.multi_overflow = multi_overflow;
1216     memcpy(n->mac_table.macs, macs, MAC_TABLE_ENTRIES * ETH_ALEN);
1217     g_free(macs);
1218     rxfilter_notify(nc);
1219 
1220     return VIRTIO_NET_OK;
1221 
1222 error:
1223     g_free(macs);
1224     return VIRTIO_NET_ERR;
1225 }
1226 
1227 static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
1228                                         struct iovec *iov, unsigned int iov_cnt)
1229 {
1230     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1231     uint16_t vid;
1232     size_t s;
1233     NetClientState *nc = qemu_get_queue(n->nic);
1234 
1235     s = iov_to_buf(iov, iov_cnt, 0, &vid, sizeof(vid));
1236     vid = virtio_lduw_p(vdev, &vid);
1237     if (s != sizeof(vid)) {
1238         return VIRTIO_NET_ERR;
1239     }
1240 
1241     if (vid >= MAX_VLAN)
1242         return VIRTIO_NET_ERR;
1243 
1244     if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
1245         n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
1246     else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
1247         n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
1248     else
1249         return VIRTIO_NET_ERR;
1250 
1251     rxfilter_notify(nc);
1252 
1253     return VIRTIO_NET_OK;
1254 }
1255 
1256 static int virtio_net_handle_announce(VirtIONet *n, uint8_t cmd,
1257                                       struct iovec *iov, unsigned int iov_cnt)
1258 {
1259     trace_virtio_net_handle_announce(n->announce_timer.round);
1260     if (cmd == VIRTIO_NET_CTRL_ANNOUNCE_ACK &&
1261         n->status & VIRTIO_NET_S_ANNOUNCE) {
1262         n->status &= ~VIRTIO_NET_S_ANNOUNCE;
1263         if (n->announce_timer.round) {
1264             qemu_announce_timer_step(&n->announce_timer);
1265         }
1266         return VIRTIO_NET_OK;
1267     } else {
1268         return VIRTIO_NET_ERR;
1269     }
1270 }
1271 
1272 static void virtio_net_detach_epbf_rss(VirtIONet *n);
1273 
1274 static void virtio_net_disable_rss(VirtIONet *n)
1275 {
1276     if (n->rss_data.enabled) {
1277         trace_virtio_net_rss_disable();
1278     }
1279     n->rss_data.enabled = false;
1280 
1281     virtio_net_detach_epbf_rss(n);
1282 }
1283 
1284 static bool virtio_net_attach_ebpf_to_backend(NICState *nic, int prog_fd)
1285 {
1286     NetClientState *nc = qemu_get_peer(qemu_get_queue(nic), 0);
1287     if (nc == NULL || nc->info->set_steering_ebpf == NULL) {
1288         return false;
1289     }
1290 
1291     return nc->info->set_steering_ebpf(nc, prog_fd);
1292 }
1293 
1294 static void rss_data_to_rss_config(struct VirtioNetRssData *data,
1295                                    struct EBPFRSSConfig *config)
1296 {
1297     config->redirect = data->redirect;
1298     config->populate_hash = data->populate_hash;
1299     config->hash_types = data->hash_types;
1300     config->indirections_len = data->indirections_len;
1301     config->default_queue = data->default_queue;
1302 }
1303 
1304 static bool virtio_net_attach_epbf_rss(VirtIONet *n)
1305 {
1306     struct EBPFRSSConfig config = {};
1307 
1308     if (!ebpf_rss_is_loaded(&n->ebpf_rss)) {
1309         return false;
1310     }
1311 
1312     rss_data_to_rss_config(&n->rss_data, &config);
1313 
1314     if (!ebpf_rss_set_all(&n->ebpf_rss, &config,
1315                           n->rss_data.indirections_table, n->rss_data.key)) {
1316         return false;
1317     }
1318 
1319     if (!virtio_net_attach_ebpf_to_backend(n->nic, n->ebpf_rss.program_fd)) {
1320         return false;
1321     }
1322 
1323     return true;
1324 }
1325 
1326 static void virtio_net_detach_epbf_rss(VirtIONet *n)
1327 {
1328     virtio_net_attach_ebpf_to_backend(n->nic, -1);
1329 }
1330 
1331 static bool virtio_net_load_ebpf(VirtIONet *n)
1332 {
1333     if (!virtio_net_attach_ebpf_to_backend(n->nic, -1)) {
1334         /* backend doesn't support steering ebpf */
1335         return false;
1336     }
1337 
1338     return ebpf_rss_load(&n->ebpf_rss);
1339 }
1340 
1341 static void virtio_net_unload_ebpf(VirtIONet *n)
1342 {
1343     virtio_net_attach_ebpf_to_backend(n->nic, -1);
1344     ebpf_rss_unload(&n->ebpf_rss);
1345 }
1346 
1347 static uint16_t virtio_net_handle_rss(VirtIONet *n,
1348                                       struct iovec *iov,
1349                                       unsigned int iov_cnt,
1350                                       bool do_rss)
1351 {
1352     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1353     struct virtio_net_rss_config cfg;
1354     size_t s, offset = 0, size_get;
1355     uint16_t queue_pairs, i;
1356     struct {
1357         uint16_t us;
1358         uint8_t b;
1359     } QEMU_PACKED temp;
1360     const char *err_msg = "";
1361     uint32_t err_value = 0;
1362 
1363     if (do_rss && !virtio_vdev_has_feature(vdev, VIRTIO_NET_F_RSS)) {
1364         err_msg = "RSS is not negotiated";
1365         goto error;
1366     }
1367     if (!do_rss && !virtio_vdev_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT)) {
1368         err_msg = "Hash report is not negotiated";
1369         goto error;
1370     }
1371     size_get = offsetof(struct virtio_net_rss_config, indirection_table);
1372     s = iov_to_buf(iov, iov_cnt, offset, &cfg, size_get);
1373     if (s != size_get) {
1374         err_msg = "Short command buffer";
1375         err_value = (uint32_t)s;
1376         goto error;
1377     }
1378     n->rss_data.hash_types = virtio_ldl_p(vdev, &cfg.hash_types);
1379     n->rss_data.indirections_len =
1380         virtio_lduw_p(vdev, &cfg.indirection_table_mask);
1381     n->rss_data.indirections_len++;
1382     if (!do_rss) {
1383         n->rss_data.indirections_len = 1;
1384     }
1385     if (!is_power_of_2(n->rss_data.indirections_len)) {
1386         err_msg = "Invalid size of indirection table";
1387         err_value = n->rss_data.indirections_len;
1388         goto error;
1389     }
1390     if (n->rss_data.indirections_len > VIRTIO_NET_RSS_MAX_TABLE_LEN) {
1391         err_msg = "Too large indirection table";
1392         err_value = n->rss_data.indirections_len;
1393         goto error;
1394     }
1395     n->rss_data.default_queue = do_rss ?
1396         virtio_lduw_p(vdev, &cfg.unclassified_queue) : 0;
1397     if (n->rss_data.default_queue >= n->max_queue_pairs) {
1398         err_msg = "Invalid default queue";
1399         err_value = n->rss_data.default_queue;
1400         goto error;
1401     }
1402     offset += size_get;
1403     size_get = sizeof(uint16_t) * n->rss_data.indirections_len;
1404     g_free(n->rss_data.indirections_table);
1405     n->rss_data.indirections_table = g_malloc(size_get);
1406     if (!n->rss_data.indirections_table) {
1407         err_msg = "Can't allocate indirections table";
1408         err_value = n->rss_data.indirections_len;
1409         goto error;
1410     }
1411     s = iov_to_buf(iov, iov_cnt, offset,
1412                    n->rss_data.indirections_table, size_get);
1413     if (s != size_get) {
1414         err_msg = "Short indirection table buffer";
1415         err_value = (uint32_t)s;
1416         goto error;
1417     }
1418     for (i = 0; i < n->rss_data.indirections_len; ++i) {
1419         uint16_t val = n->rss_data.indirections_table[i];
1420         n->rss_data.indirections_table[i] = virtio_lduw_p(vdev, &val);
1421     }
1422     offset += size_get;
1423     size_get = sizeof(temp);
1424     s = iov_to_buf(iov, iov_cnt, offset, &temp, size_get);
1425     if (s != size_get) {
1426         err_msg = "Can't get queue_pairs";
1427         err_value = (uint32_t)s;
1428         goto error;
1429     }
1430     queue_pairs = do_rss ? virtio_lduw_p(vdev, &temp.us) : n->curr_queue_pairs;
1431     if (queue_pairs == 0 || queue_pairs > n->max_queue_pairs) {
1432         err_msg = "Invalid number of queue_pairs";
1433         err_value = queue_pairs;
1434         goto error;
1435     }
1436     if (temp.b > VIRTIO_NET_RSS_MAX_KEY_SIZE) {
1437         err_msg = "Invalid key size";
1438         err_value = temp.b;
1439         goto error;
1440     }
1441     if (!temp.b && n->rss_data.hash_types) {
1442         err_msg = "No key provided";
1443         err_value = 0;
1444         goto error;
1445     }
1446     if (!temp.b && !n->rss_data.hash_types) {
1447         virtio_net_disable_rss(n);
1448         return queue_pairs;
1449     }
1450     offset += size_get;
1451     size_get = temp.b;
1452     s = iov_to_buf(iov, iov_cnt, offset, n->rss_data.key, size_get);
1453     if (s != size_get) {
1454         err_msg = "Can get key buffer";
1455         err_value = (uint32_t)s;
1456         goto error;
1457     }
1458     n->rss_data.enabled = true;
1459 
1460     if (!n->rss_data.populate_hash) {
1461         if (!virtio_net_attach_epbf_rss(n)) {
1462             /* EBPF must be loaded for vhost */
1463             if (get_vhost_net(qemu_get_queue(n->nic)->peer)) {
1464                 warn_report("Can't load eBPF RSS for vhost");
1465                 goto error;
1466             }
1467             /* fallback to software RSS */
1468             warn_report("Can't load eBPF RSS - fallback to software RSS");
1469             n->rss_data.enabled_software_rss = true;
1470         }
1471     } else {
1472         /* use software RSS for hash populating */
1473         /* and detach eBPF if was loaded before */
1474         virtio_net_detach_epbf_rss(n);
1475         n->rss_data.enabled_software_rss = true;
1476     }
1477 
1478     trace_virtio_net_rss_enable(n->rss_data.hash_types,
1479                                 n->rss_data.indirections_len,
1480                                 temp.b);
1481     return queue_pairs;
1482 error:
1483     trace_virtio_net_rss_error(err_msg, err_value);
1484     virtio_net_disable_rss(n);
1485     return 0;
1486 }
1487 
1488 static int virtio_net_handle_mq(VirtIONet *n, uint8_t cmd,
1489                                 struct iovec *iov, unsigned int iov_cnt)
1490 {
1491     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1492     uint16_t queue_pairs;
1493     NetClientState *nc = qemu_get_queue(n->nic);
1494 
1495     virtio_net_disable_rss(n);
1496     if (cmd == VIRTIO_NET_CTRL_MQ_HASH_CONFIG) {
1497         queue_pairs = virtio_net_handle_rss(n, iov, iov_cnt, false);
1498         return queue_pairs ? VIRTIO_NET_OK : VIRTIO_NET_ERR;
1499     }
1500     if (cmd == VIRTIO_NET_CTRL_MQ_RSS_CONFIG) {
1501         queue_pairs = virtio_net_handle_rss(n, iov, iov_cnt, true);
1502     } else if (cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
1503         struct virtio_net_ctrl_mq mq;
1504         size_t s;
1505         if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ)) {
1506             return VIRTIO_NET_ERR;
1507         }
1508         s = iov_to_buf(iov, iov_cnt, 0, &mq, sizeof(mq));
1509         if (s != sizeof(mq)) {
1510             return VIRTIO_NET_ERR;
1511         }
1512         queue_pairs = virtio_lduw_p(vdev, &mq.virtqueue_pairs);
1513 
1514     } else {
1515         return VIRTIO_NET_ERR;
1516     }
1517 
1518     if (queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
1519         queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
1520         queue_pairs > n->max_queue_pairs ||
1521         !n->multiqueue) {
1522         return VIRTIO_NET_ERR;
1523     }
1524 
1525     n->curr_queue_pairs = queue_pairs;
1526     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
1527         /*
1528          * Avoid updating the backend for a vdpa device: We're only interested
1529          * in updating the device model queues.
1530          */
1531         return VIRTIO_NET_OK;
1532     }
1533     /* stop the backend before changing the number of queue_pairs to avoid handling a
1534      * disabled queue */
1535     virtio_net_set_status(vdev, vdev->status);
1536     virtio_net_set_queue_pairs(n);
1537 
1538     return VIRTIO_NET_OK;
1539 }
1540 
1541 size_t virtio_net_handle_ctrl_iov(VirtIODevice *vdev,
1542                                   const struct iovec *in_sg, unsigned in_num,
1543                                   const struct iovec *out_sg,
1544                                   unsigned out_num)
1545 {
1546     VirtIONet *n = VIRTIO_NET(vdev);
1547     struct virtio_net_ctrl_hdr ctrl;
1548     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
1549     size_t s;
1550     struct iovec *iov, *iov2;
1551 
1552     if (iov_size(in_sg, in_num) < sizeof(status) ||
1553         iov_size(out_sg, out_num) < sizeof(ctrl)) {
1554         virtio_error(vdev, "virtio-net ctrl missing headers");
1555         return 0;
1556     }
1557 
1558     iov2 = iov = g_memdup2(out_sg, sizeof(struct iovec) * out_num);
1559     s = iov_to_buf(iov, out_num, 0, &ctrl, sizeof(ctrl));
1560     iov_discard_front(&iov, &out_num, sizeof(ctrl));
1561     if (s != sizeof(ctrl)) {
1562         status = VIRTIO_NET_ERR;
1563     } else if (ctrl.class == VIRTIO_NET_CTRL_RX) {
1564         status = virtio_net_handle_rx_mode(n, ctrl.cmd, iov, out_num);
1565     } else if (ctrl.class == VIRTIO_NET_CTRL_MAC) {
1566         status = virtio_net_handle_mac(n, ctrl.cmd, iov, out_num);
1567     } else if (ctrl.class == VIRTIO_NET_CTRL_VLAN) {
1568         status = virtio_net_handle_vlan_table(n, ctrl.cmd, iov, out_num);
1569     } else if (ctrl.class == VIRTIO_NET_CTRL_ANNOUNCE) {
1570         status = virtio_net_handle_announce(n, ctrl.cmd, iov, out_num);
1571     } else if (ctrl.class == VIRTIO_NET_CTRL_MQ) {
1572         status = virtio_net_handle_mq(n, ctrl.cmd, iov, out_num);
1573     } else if (ctrl.class == VIRTIO_NET_CTRL_GUEST_OFFLOADS) {
1574         status = virtio_net_handle_offloads(n, ctrl.cmd, iov, out_num);
1575     }
1576 
1577     s = iov_from_buf(in_sg, in_num, 0, &status, sizeof(status));
1578     assert(s == sizeof(status));
1579 
1580     g_free(iov2);
1581     return sizeof(status);
1582 }
1583 
1584 static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
1585 {
1586     VirtQueueElement *elem;
1587 
1588     for (;;) {
1589         size_t written;
1590         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
1591         if (!elem) {
1592             break;
1593         }
1594 
1595         written = virtio_net_handle_ctrl_iov(vdev, elem->in_sg, elem->in_num,
1596                                              elem->out_sg, elem->out_num);
1597         if (written > 0) {
1598             virtqueue_push(vq, elem, written);
1599             virtio_notify(vdev, vq);
1600             g_free(elem);
1601         } else {
1602             virtqueue_detach_element(vq, elem, 0);
1603             g_free(elem);
1604             break;
1605         }
1606     }
1607 }
1608 
1609 /* RX */
1610 
1611 static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
1612 {
1613     VirtIONet *n = VIRTIO_NET(vdev);
1614     int queue_index = vq2q(virtio_get_queue_index(vq));
1615 
1616     qemu_flush_queued_packets(qemu_get_subqueue(n->nic, queue_index));
1617 }
1618 
1619 static bool virtio_net_can_receive(NetClientState *nc)
1620 {
1621     VirtIONet *n = qemu_get_nic_opaque(nc);
1622     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1623     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
1624 
1625     if (!vdev->vm_running) {
1626         return false;
1627     }
1628 
1629     if (nc->queue_index >= n->curr_queue_pairs) {
1630         return false;
1631     }
1632 
1633     if (!virtio_queue_ready(q->rx_vq) ||
1634         !(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
1635         return false;
1636     }
1637 
1638     return true;
1639 }
1640 
1641 static int virtio_net_has_buffers(VirtIONetQueue *q, int bufsize)
1642 {
1643     VirtIONet *n = q->n;
1644     if (virtio_queue_empty(q->rx_vq) ||
1645         (n->mergeable_rx_bufs &&
1646          !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
1647         virtio_queue_set_notification(q->rx_vq, 1);
1648 
1649         /* To avoid a race condition where the guest has made some buffers
1650          * available after the above check but before notification was
1651          * enabled, check for available buffers again.
1652          */
1653         if (virtio_queue_empty(q->rx_vq) ||
1654             (n->mergeable_rx_bufs &&
1655              !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
1656             return 0;
1657         }
1658     }
1659 
1660     virtio_queue_set_notification(q->rx_vq, 0);
1661     return 1;
1662 }
1663 
1664 static void virtio_net_hdr_swap(VirtIODevice *vdev, struct virtio_net_hdr *hdr)
1665 {
1666     virtio_tswap16s(vdev, &hdr->hdr_len);
1667     virtio_tswap16s(vdev, &hdr->gso_size);
1668     virtio_tswap16s(vdev, &hdr->csum_start);
1669     virtio_tswap16s(vdev, &hdr->csum_offset);
1670 }
1671 
1672 /* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
1673  * it never finds out that the packets don't have valid checksums.  This
1674  * causes dhclient to get upset.  Fedora's carried a patch for ages to
1675  * fix this with Xen but it hasn't appeared in an upstream release of
1676  * dhclient yet.
1677  *
1678  * To avoid breaking existing guests, we catch udp packets and add
1679  * checksums.  This is terrible but it's better than hacking the guest
1680  * kernels.
1681  *
1682  * N.B. if we introduce a zero-copy API, this operation is no longer free so
1683  * we should provide a mechanism to disable it to avoid polluting the host
1684  * cache.
1685  */
1686 static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
1687                                         uint8_t *buf, size_t size)
1688 {
1689     if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
1690         (size > 27 && size < 1500) && /* normal sized MTU */
1691         (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
1692         (buf[23] == 17) && /* ip.protocol == UDP */
1693         (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
1694         net_checksum_calculate(buf, size, CSUM_UDP);
1695         hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
1696     }
1697 }
1698 
1699 static void receive_header(VirtIONet *n, const struct iovec *iov, int iov_cnt,
1700                            const void *buf, size_t size)
1701 {
1702     if (n->has_vnet_hdr) {
1703         /* FIXME this cast is evil */
1704         void *wbuf = (void *)buf;
1705         work_around_broken_dhclient(wbuf, wbuf + n->host_hdr_len,
1706                                     size - n->host_hdr_len);
1707 
1708         if (n->needs_vnet_hdr_swap) {
1709             virtio_net_hdr_swap(VIRTIO_DEVICE(n), wbuf);
1710         }
1711         iov_from_buf(iov, iov_cnt, 0, buf, sizeof(struct virtio_net_hdr));
1712     } else {
1713         struct virtio_net_hdr hdr = {
1714             .flags = 0,
1715             .gso_type = VIRTIO_NET_HDR_GSO_NONE
1716         };
1717         iov_from_buf(iov, iov_cnt, 0, &hdr, sizeof hdr);
1718     }
1719 }
1720 
1721 static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
1722 {
1723     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
1724     static const uint8_t vlan[] = {0x81, 0x00};
1725     uint8_t *ptr = (uint8_t *)buf;
1726     int i;
1727 
1728     if (n->promisc)
1729         return 1;
1730 
1731     ptr += n->host_hdr_len;
1732 
1733     if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
1734         int vid = lduw_be_p(ptr + 14) & 0xfff;
1735         if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
1736             return 0;
1737     }
1738 
1739     if (ptr[0] & 1) { // multicast
1740         if (!memcmp(ptr, bcast, sizeof(bcast))) {
1741             return !n->nobcast;
1742         } else if (n->nomulti) {
1743             return 0;
1744         } else if (n->allmulti || n->mac_table.multi_overflow) {
1745             return 1;
1746         }
1747 
1748         for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
1749             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
1750                 return 1;
1751             }
1752         }
1753     } else { // unicast
1754         if (n->nouni) {
1755             return 0;
1756         } else if (n->alluni || n->mac_table.uni_overflow) {
1757             return 1;
1758         } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
1759             return 1;
1760         }
1761 
1762         for (i = 0; i < n->mac_table.first_multi; i++) {
1763             if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
1764                 return 1;
1765             }
1766         }
1767     }
1768 
1769     return 0;
1770 }
1771 
1772 static uint8_t virtio_net_get_hash_type(bool hasip4,
1773                                         bool hasip6,
1774                                         EthL4HdrProto l4hdr_proto,
1775                                         uint32_t types)
1776 {
1777     if (hasip4) {
1778         switch (l4hdr_proto) {
1779         case ETH_L4_HDR_PROTO_TCP:
1780             if (types & VIRTIO_NET_RSS_HASH_TYPE_TCPv4) {
1781                 return NetPktRssIpV4Tcp;
1782             }
1783             break;
1784 
1785         case ETH_L4_HDR_PROTO_UDP:
1786             if (types & VIRTIO_NET_RSS_HASH_TYPE_UDPv4) {
1787                 return NetPktRssIpV4Udp;
1788             }
1789             break;
1790 
1791         default:
1792             break;
1793         }
1794 
1795         if (types & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
1796             return NetPktRssIpV4;
1797         }
1798     } else if (hasip6) {
1799         switch (l4hdr_proto) {
1800         case ETH_L4_HDR_PROTO_TCP:
1801             if (types & VIRTIO_NET_RSS_HASH_TYPE_TCP_EX) {
1802                 return NetPktRssIpV6TcpEx;
1803             }
1804             if (types & VIRTIO_NET_RSS_HASH_TYPE_TCPv6) {
1805                 return NetPktRssIpV6Tcp;
1806             }
1807             break;
1808 
1809         case ETH_L4_HDR_PROTO_UDP:
1810             if (types & VIRTIO_NET_RSS_HASH_TYPE_UDP_EX) {
1811                 return NetPktRssIpV6UdpEx;
1812             }
1813             if (types & VIRTIO_NET_RSS_HASH_TYPE_UDPv6) {
1814                 return NetPktRssIpV6Udp;
1815             }
1816             break;
1817 
1818         default:
1819             break;
1820         }
1821 
1822         if (types & VIRTIO_NET_RSS_HASH_TYPE_IP_EX) {
1823             return NetPktRssIpV6Ex;
1824         }
1825         if (types & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
1826             return NetPktRssIpV6;
1827         }
1828     }
1829     return 0xff;
1830 }
1831 
1832 static void virtio_set_packet_hash(const uint8_t *buf, uint8_t report,
1833                                    uint32_t hash)
1834 {
1835     struct virtio_net_hdr_v1_hash *hdr = (void *)buf;
1836     hdr->hash_value = hash;
1837     hdr->hash_report = report;
1838 }
1839 
1840 static int virtio_net_process_rss(NetClientState *nc, const uint8_t *buf,
1841                                   size_t size)
1842 {
1843     VirtIONet *n = qemu_get_nic_opaque(nc);
1844     unsigned int index = nc->queue_index, new_index = index;
1845     struct NetRxPkt *pkt = n->rx_pkt;
1846     uint8_t net_hash_type;
1847     uint32_t hash;
1848     bool hasip4, hasip6;
1849     EthL4HdrProto l4hdr_proto;
1850     static const uint8_t reports[NetPktRssIpV6UdpEx + 1] = {
1851         VIRTIO_NET_HASH_REPORT_IPv4,
1852         VIRTIO_NET_HASH_REPORT_TCPv4,
1853         VIRTIO_NET_HASH_REPORT_TCPv6,
1854         VIRTIO_NET_HASH_REPORT_IPv6,
1855         VIRTIO_NET_HASH_REPORT_IPv6_EX,
1856         VIRTIO_NET_HASH_REPORT_TCPv6_EX,
1857         VIRTIO_NET_HASH_REPORT_UDPv4,
1858         VIRTIO_NET_HASH_REPORT_UDPv6,
1859         VIRTIO_NET_HASH_REPORT_UDPv6_EX
1860     };
1861     struct iovec iov = {
1862         .iov_base = (void *)buf,
1863         .iov_len = size
1864     };
1865 
1866     net_rx_pkt_set_protocols(pkt, &iov, 1, n->host_hdr_len);
1867     net_rx_pkt_get_protocols(pkt, &hasip4, &hasip6, &l4hdr_proto);
1868     net_hash_type = virtio_net_get_hash_type(hasip4, hasip6, l4hdr_proto,
1869                                              n->rss_data.hash_types);
1870     if (net_hash_type > NetPktRssIpV6UdpEx) {
1871         if (n->rss_data.populate_hash) {
1872             virtio_set_packet_hash(buf, VIRTIO_NET_HASH_REPORT_NONE, 0);
1873         }
1874         return n->rss_data.redirect ? n->rss_data.default_queue : -1;
1875     }
1876 
1877     hash = net_rx_pkt_calc_rss_hash(pkt, net_hash_type, n->rss_data.key);
1878 
1879     if (n->rss_data.populate_hash) {
1880         virtio_set_packet_hash(buf, reports[net_hash_type], hash);
1881     }
1882 
1883     if (n->rss_data.redirect) {
1884         new_index = hash & (n->rss_data.indirections_len - 1);
1885         new_index = n->rss_data.indirections_table[new_index];
1886     }
1887 
1888     return (index == new_index) ? -1 : new_index;
1889 }
1890 
1891 static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
1892                                       size_t size, bool no_rss)
1893 {
1894     VirtIONet *n = qemu_get_nic_opaque(nc);
1895     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
1896     VirtIODevice *vdev = VIRTIO_DEVICE(n);
1897     VirtQueueElement *elems[VIRTQUEUE_MAX_SIZE];
1898     size_t lens[VIRTQUEUE_MAX_SIZE];
1899     struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE];
1900     struct virtio_net_hdr_mrg_rxbuf mhdr;
1901     unsigned mhdr_cnt = 0;
1902     size_t offset, i, guest_offset, j;
1903     ssize_t err;
1904 
1905     if (!virtio_net_can_receive(nc)) {
1906         return -1;
1907     }
1908 
1909     if (!no_rss && n->rss_data.enabled && n->rss_data.enabled_software_rss) {
1910         int index = virtio_net_process_rss(nc, buf, size);
1911         if (index >= 0) {
1912             NetClientState *nc2 = qemu_get_subqueue(n->nic, index);
1913             return virtio_net_receive_rcu(nc2, buf, size, true);
1914         }
1915     }
1916 
1917     /* hdr_len refers to the header we supply to the guest */
1918     if (!virtio_net_has_buffers(q, size + n->guest_hdr_len - n->host_hdr_len)) {
1919         return 0;
1920     }
1921 
1922     if (!receive_filter(n, buf, size))
1923         return size;
1924 
1925     offset = i = 0;
1926 
1927     while (offset < size) {
1928         VirtQueueElement *elem;
1929         int len, total;
1930         const struct iovec *sg;
1931 
1932         total = 0;
1933 
1934         if (i == VIRTQUEUE_MAX_SIZE) {
1935             virtio_error(vdev, "virtio-net unexpected long buffer chain");
1936             err = size;
1937             goto err;
1938         }
1939 
1940         elem = virtqueue_pop(q->rx_vq, sizeof(VirtQueueElement));
1941         if (!elem) {
1942             if (i) {
1943                 virtio_error(vdev, "virtio-net unexpected empty queue: "
1944                              "i %zd mergeable %d offset %zd, size %zd, "
1945                              "guest hdr len %zd, host hdr len %zd "
1946                              "guest features 0x%" PRIx64,
1947                              i, n->mergeable_rx_bufs, offset, size,
1948                              n->guest_hdr_len, n->host_hdr_len,
1949                              vdev->guest_features);
1950             }
1951             err = -1;
1952             goto err;
1953         }
1954 
1955         if (elem->in_num < 1) {
1956             virtio_error(vdev,
1957                          "virtio-net receive queue contains no in buffers");
1958             virtqueue_detach_element(q->rx_vq, elem, 0);
1959             g_free(elem);
1960             err = -1;
1961             goto err;
1962         }
1963 
1964         sg = elem->in_sg;
1965         if (i == 0) {
1966             assert(offset == 0);
1967             if (n->mergeable_rx_bufs) {
1968                 mhdr_cnt = iov_copy(mhdr_sg, ARRAY_SIZE(mhdr_sg),
1969                                     sg, elem->in_num,
1970                                     offsetof(typeof(mhdr), num_buffers),
1971                                     sizeof(mhdr.num_buffers));
1972             }
1973 
1974             receive_header(n, sg, elem->in_num, buf, size);
1975             if (n->rss_data.populate_hash) {
1976                 offset = sizeof(mhdr);
1977                 iov_from_buf(sg, elem->in_num, offset,
1978                              buf + offset, n->host_hdr_len - sizeof(mhdr));
1979             }
1980             offset = n->host_hdr_len;
1981             total += n->guest_hdr_len;
1982             guest_offset = n->guest_hdr_len;
1983         } else {
1984             guest_offset = 0;
1985         }
1986 
1987         /* copy in packet.  ugh */
1988         len = iov_from_buf(sg, elem->in_num, guest_offset,
1989                            buf + offset, size - offset);
1990         total += len;
1991         offset += len;
1992         /* If buffers can't be merged, at this point we
1993          * must have consumed the complete packet.
1994          * Otherwise, drop it. */
1995         if (!n->mergeable_rx_bufs && offset < size) {
1996             virtqueue_unpop(q->rx_vq, elem, total);
1997             g_free(elem);
1998             err = size;
1999             goto err;
2000         }
2001 
2002         elems[i] = elem;
2003         lens[i] = total;
2004         i++;
2005     }
2006 
2007     if (mhdr_cnt) {
2008         virtio_stw_p(vdev, &mhdr.num_buffers, i);
2009         iov_from_buf(mhdr_sg, mhdr_cnt,
2010                      0,
2011                      &mhdr.num_buffers, sizeof mhdr.num_buffers);
2012     }
2013 
2014     for (j = 0; j < i; j++) {
2015         /* signal other side */
2016         virtqueue_fill(q->rx_vq, elems[j], lens[j], j);
2017         g_free(elems[j]);
2018     }
2019 
2020     virtqueue_flush(q->rx_vq, i);
2021     virtio_notify(vdev, q->rx_vq);
2022 
2023     return size;
2024 
2025 err:
2026     for (j = 0; j < i; j++) {
2027         virtqueue_detach_element(q->rx_vq, elems[j], lens[j]);
2028         g_free(elems[j]);
2029     }
2030 
2031     return err;
2032 }
2033 
2034 static ssize_t virtio_net_do_receive(NetClientState *nc, const uint8_t *buf,
2035                                   size_t size)
2036 {
2037     RCU_READ_LOCK_GUARD();
2038 
2039     return virtio_net_receive_rcu(nc, buf, size, false);
2040 }
2041 
2042 static void virtio_net_rsc_extract_unit4(VirtioNetRscChain *chain,
2043                                          const uint8_t *buf,
2044                                          VirtioNetRscUnit *unit)
2045 {
2046     uint16_t ip_hdrlen;
2047     struct ip_header *ip;
2048 
2049     ip = (struct ip_header *)(buf + chain->n->guest_hdr_len
2050                               + sizeof(struct eth_header));
2051     unit->ip = (void *)ip;
2052     ip_hdrlen = (ip->ip_ver_len & 0xF) << 2;
2053     unit->ip_plen = &ip->ip_len;
2054     unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip) + ip_hdrlen);
2055     unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000) >> 10;
2056     unit->payload = htons(*unit->ip_plen) - ip_hdrlen - unit->tcp_hdrlen;
2057 }
2058 
2059 static void virtio_net_rsc_extract_unit6(VirtioNetRscChain *chain,
2060                                          const uint8_t *buf,
2061                                          VirtioNetRscUnit *unit)
2062 {
2063     struct ip6_header *ip6;
2064 
2065     ip6 = (struct ip6_header *)(buf + chain->n->guest_hdr_len
2066                                  + sizeof(struct eth_header));
2067     unit->ip = ip6;
2068     unit->ip_plen = &(ip6->ip6_ctlun.ip6_un1.ip6_un1_plen);
2069     unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip)
2070                                         + sizeof(struct ip6_header));
2071     unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000) >> 10;
2072 
2073     /* There is a difference between payload length in ipv4 and v6,
2074        ip header is excluded in ipv6 */
2075     unit->payload = htons(*unit->ip_plen) - unit->tcp_hdrlen;
2076 }
2077 
2078 static size_t virtio_net_rsc_drain_seg(VirtioNetRscChain *chain,
2079                                        VirtioNetRscSeg *seg)
2080 {
2081     int ret;
2082     struct virtio_net_hdr_v1 *h;
2083 
2084     h = (struct virtio_net_hdr_v1 *)seg->buf;
2085     h->flags = 0;
2086     h->gso_type = VIRTIO_NET_HDR_GSO_NONE;
2087 
2088     if (seg->is_coalesced) {
2089         h->rsc.segments = seg->packets;
2090         h->rsc.dup_acks = seg->dup_ack;
2091         h->flags = VIRTIO_NET_HDR_F_RSC_INFO;
2092         if (chain->proto == ETH_P_IP) {
2093             h->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2094         } else {
2095             h->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2096         }
2097     }
2098 
2099     ret = virtio_net_do_receive(seg->nc, seg->buf, seg->size);
2100     QTAILQ_REMOVE(&chain->buffers, seg, next);
2101     g_free(seg->buf);
2102     g_free(seg);
2103 
2104     return ret;
2105 }
2106 
2107 static void virtio_net_rsc_purge(void *opq)
2108 {
2109     VirtioNetRscSeg *seg, *rn;
2110     VirtioNetRscChain *chain = (VirtioNetRscChain *)opq;
2111 
2112     QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn) {
2113         if (virtio_net_rsc_drain_seg(chain, seg) == 0) {
2114             chain->stat.purge_failed++;
2115             continue;
2116         }
2117     }
2118 
2119     chain->stat.timer++;
2120     if (!QTAILQ_EMPTY(&chain->buffers)) {
2121         timer_mod(chain->drain_timer,
2122               qemu_clock_get_ns(QEMU_CLOCK_HOST) + chain->n->rsc_timeout);
2123     }
2124 }
2125 
2126 static void virtio_net_rsc_cleanup(VirtIONet *n)
2127 {
2128     VirtioNetRscChain *chain, *rn_chain;
2129     VirtioNetRscSeg *seg, *rn_seg;
2130 
2131     QTAILQ_FOREACH_SAFE(chain, &n->rsc_chains, next, rn_chain) {
2132         QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn_seg) {
2133             QTAILQ_REMOVE(&chain->buffers, seg, next);
2134             g_free(seg->buf);
2135             g_free(seg);
2136         }
2137 
2138         timer_free(chain->drain_timer);
2139         QTAILQ_REMOVE(&n->rsc_chains, chain, next);
2140         g_free(chain);
2141     }
2142 }
2143 
2144 static void virtio_net_rsc_cache_buf(VirtioNetRscChain *chain,
2145                                      NetClientState *nc,
2146                                      const uint8_t *buf, size_t size)
2147 {
2148     uint16_t hdr_len;
2149     VirtioNetRscSeg *seg;
2150 
2151     hdr_len = chain->n->guest_hdr_len;
2152     seg = g_new(VirtioNetRscSeg, 1);
2153     seg->buf = g_malloc(hdr_len + sizeof(struct eth_header)
2154         + sizeof(struct ip6_header) + VIRTIO_NET_MAX_TCP_PAYLOAD);
2155     memcpy(seg->buf, buf, size);
2156     seg->size = size;
2157     seg->packets = 1;
2158     seg->dup_ack = 0;
2159     seg->is_coalesced = 0;
2160     seg->nc = nc;
2161 
2162     QTAILQ_INSERT_TAIL(&chain->buffers, seg, next);
2163     chain->stat.cache++;
2164 
2165     switch (chain->proto) {
2166     case ETH_P_IP:
2167         virtio_net_rsc_extract_unit4(chain, seg->buf, &seg->unit);
2168         break;
2169     case ETH_P_IPV6:
2170         virtio_net_rsc_extract_unit6(chain, seg->buf, &seg->unit);
2171         break;
2172     default:
2173         g_assert_not_reached();
2174     }
2175 }
2176 
2177 static int32_t virtio_net_rsc_handle_ack(VirtioNetRscChain *chain,
2178                                          VirtioNetRscSeg *seg,
2179                                          const uint8_t *buf,
2180                                          struct tcp_header *n_tcp,
2181                                          struct tcp_header *o_tcp)
2182 {
2183     uint32_t nack, oack;
2184     uint16_t nwin, owin;
2185 
2186     nack = htonl(n_tcp->th_ack);
2187     nwin = htons(n_tcp->th_win);
2188     oack = htonl(o_tcp->th_ack);
2189     owin = htons(o_tcp->th_win);
2190 
2191     if ((nack - oack) >= VIRTIO_NET_MAX_TCP_PAYLOAD) {
2192         chain->stat.ack_out_of_win++;
2193         return RSC_FINAL;
2194     } else if (nack == oack) {
2195         /* duplicated ack or window probe */
2196         if (nwin == owin) {
2197             /* duplicated ack, add dup ack count due to whql test up to 1 */
2198             chain->stat.dup_ack++;
2199             return RSC_FINAL;
2200         } else {
2201             /* Coalesce window update */
2202             o_tcp->th_win = n_tcp->th_win;
2203             chain->stat.win_update++;
2204             return RSC_COALESCE;
2205         }
2206     } else {
2207         /* pure ack, go to 'C', finalize*/
2208         chain->stat.pure_ack++;
2209         return RSC_FINAL;
2210     }
2211 }
2212 
2213 static int32_t virtio_net_rsc_coalesce_data(VirtioNetRscChain *chain,
2214                                             VirtioNetRscSeg *seg,
2215                                             const uint8_t *buf,
2216                                             VirtioNetRscUnit *n_unit)
2217 {
2218     void *data;
2219     uint16_t o_ip_len;
2220     uint32_t nseq, oseq;
2221     VirtioNetRscUnit *o_unit;
2222 
2223     o_unit = &seg->unit;
2224     o_ip_len = htons(*o_unit->ip_plen);
2225     nseq = htonl(n_unit->tcp->th_seq);
2226     oseq = htonl(o_unit->tcp->th_seq);
2227 
2228     /* out of order or retransmitted. */
2229     if ((nseq - oseq) > VIRTIO_NET_MAX_TCP_PAYLOAD) {
2230         chain->stat.data_out_of_win++;
2231         return RSC_FINAL;
2232     }
2233 
2234     data = ((uint8_t *)n_unit->tcp) + n_unit->tcp_hdrlen;
2235     if (nseq == oseq) {
2236         if ((o_unit->payload == 0) && n_unit->payload) {
2237             /* From no payload to payload, normal case, not a dup ack or etc */
2238             chain->stat.data_after_pure_ack++;
2239             goto coalesce;
2240         } else {
2241             return virtio_net_rsc_handle_ack(chain, seg, buf,
2242                                              n_unit->tcp, o_unit->tcp);
2243         }
2244     } else if ((nseq - oseq) != o_unit->payload) {
2245         /* Not a consistent packet, out of order */
2246         chain->stat.data_out_of_order++;
2247         return RSC_FINAL;
2248     } else {
2249 coalesce:
2250         if ((o_ip_len + n_unit->payload) > chain->max_payload) {
2251             chain->stat.over_size++;
2252             return RSC_FINAL;
2253         }
2254 
2255         /* Here comes the right data, the payload length in v4/v6 is different,
2256            so use the field value to update and record the new data len */
2257         o_unit->payload += n_unit->payload; /* update new data len */
2258 
2259         /* update field in ip header */
2260         *o_unit->ip_plen = htons(o_ip_len + n_unit->payload);
2261 
2262         /* Bring 'PUSH' big, the whql test guide says 'PUSH' can be coalesced
2263            for windows guest, while this may change the behavior for linux
2264            guest (only if it uses RSC feature). */
2265         o_unit->tcp->th_offset_flags = n_unit->tcp->th_offset_flags;
2266 
2267         o_unit->tcp->th_ack = n_unit->tcp->th_ack;
2268         o_unit->tcp->th_win = n_unit->tcp->th_win;
2269 
2270         memmove(seg->buf + seg->size, data, n_unit->payload);
2271         seg->size += n_unit->payload;
2272         seg->packets++;
2273         chain->stat.coalesced++;
2274         return RSC_COALESCE;
2275     }
2276 }
2277 
2278 static int32_t virtio_net_rsc_coalesce4(VirtioNetRscChain *chain,
2279                                         VirtioNetRscSeg *seg,
2280                                         const uint8_t *buf, size_t size,
2281                                         VirtioNetRscUnit *unit)
2282 {
2283     struct ip_header *ip1, *ip2;
2284 
2285     ip1 = (struct ip_header *)(unit->ip);
2286     ip2 = (struct ip_header *)(seg->unit.ip);
2287     if ((ip1->ip_src ^ ip2->ip_src) || (ip1->ip_dst ^ ip2->ip_dst)
2288         || (unit->tcp->th_sport ^ seg->unit.tcp->th_sport)
2289         || (unit->tcp->th_dport ^ seg->unit.tcp->th_dport)) {
2290         chain->stat.no_match++;
2291         return RSC_NO_MATCH;
2292     }
2293 
2294     return virtio_net_rsc_coalesce_data(chain, seg, buf, unit);
2295 }
2296 
2297 static int32_t virtio_net_rsc_coalesce6(VirtioNetRscChain *chain,
2298                                         VirtioNetRscSeg *seg,
2299                                         const uint8_t *buf, size_t size,
2300                                         VirtioNetRscUnit *unit)
2301 {
2302     struct ip6_header *ip1, *ip2;
2303 
2304     ip1 = (struct ip6_header *)(unit->ip);
2305     ip2 = (struct ip6_header *)(seg->unit.ip);
2306     if (memcmp(&ip1->ip6_src, &ip2->ip6_src, sizeof(struct in6_address))
2307         || memcmp(&ip1->ip6_dst, &ip2->ip6_dst, sizeof(struct in6_address))
2308         || (unit->tcp->th_sport ^ seg->unit.tcp->th_sport)
2309         || (unit->tcp->th_dport ^ seg->unit.tcp->th_dport)) {
2310             chain->stat.no_match++;
2311             return RSC_NO_MATCH;
2312     }
2313 
2314     return virtio_net_rsc_coalesce_data(chain, seg, buf, unit);
2315 }
2316 
2317 /* Packets with 'SYN' should bypass, other flag should be sent after drain
2318  * to prevent out of order */
2319 static int virtio_net_rsc_tcp_ctrl_check(VirtioNetRscChain *chain,
2320                                          struct tcp_header *tcp)
2321 {
2322     uint16_t tcp_hdr;
2323     uint16_t tcp_flag;
2324 
2325     tcp_flag = htons(tcp->th_offset_flags);
2326     tcp_hdr = (tcp_flag & VIRTIO_NET_TCP_HDR_LENGTH) >> 10;
2327     tcp_flag &= VIRTIO_NET_TCP_FLAG;
2328     if (tcp_flag & TH_SYN) {
2329         chain->stat.tcp_syn++;
2330         return RSC_BYPASS;
2331     }
2332 
2333     if (tcp_flag & (TH_FIN | TH_URG | TH_RST | TH_ECE | TH_CWR)) {
2334         chain->stat.tcp_ctrl_drain++;
2335         return RSC_FINAL;
2336     }
2337 
2338     if (tcp_hdr > sizeof(struct tcp_header)) {
2339         chain->stat.tcp_all_opt++;
2340         return RSC_FINAL;
2341     }
2342 
2343     return RSC_CANDIDATE;
2344 }
2345 
2346 static size_t virtio_net_rsc_do_coalesce(VirtioNetRscChain *chain,
2347                                          NetClientState *nc,
2348                                          const uint8_t *buf, size_t size,
2349                                          VirtioNetRscUnit *unit)
2350 {
2351     int ret;
2352     VirtioNetRscSeg *seg, *nseg;
2353 
2354     if (QTAILQ_EMPTY(&chain->buffers)) {
2355         chain->stat.empty_cache++;
2356         virtio_net_rsc_cache_buf(chain, nc, buf, size);
2357         timer_mod(chain->drain_timer,
2358               qemu_clock_get_ns(QEMU_CLOCK_HOST) + chain->n->rsc_timeout);
2359         return size;
2360     }
2361 
2362     QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) {
2363         if (chain->proto == ETH_P_IP) {
2364             ret = virtio_net_rsc_coalesce4(chain, seg, buf, size, unit);
2365         } else {
2366             ret = virtio_net_rsc_coalesce6(chain, seg, buf, size, unit);
2367         }
2368 
2369         if (ret == RSC_FINAL) {
2370             if (virtio_net_rsc_drain_seg(chain, seg) == 0) {
2371                 /* Send failed */
2372                 chain->stat.final_failed++;
2373                 return 0;
2374             }
2375 
2376             /* Send current packet */
2377             return virtio_net_do_receive(nc, buf, size);
2378         } else if (ret == RSC_NO_MATCH) {
2379             continue;
2380         } else {
2381             /* Coalesced, mark coalesced flag to tell calc cksum for ipv4 */
2382             seg->is_coalesced = 1;
2383             return size;
2384         }
2385     }
2386 
2387     chain->stat.no_match_cache++;
2388     virtio_net_rsc_cache_buf(chain, nc, buf, size);
2389     return size;
2390 }
2391 
2392 /* Drain a connection data, this is to avoid out of order segments */
2393 static size_t virtio_net_rsc_drain_flow(VirtioNetRscChain *chain,
2394                                         NetClientState *nc,
2395                                         const uint8_t *buf, size_t size,
2396                                         uint16_t ip_start, uint16_t ip_size,
2397                                         uint16_t tcp_port)
2398 {
2399     VirtioNetRscSeg *seg, *nseg;
2400     uint32_t ppair1, ppair2;
2401 
2402     ppair1 = *(uint32_t *)(buf + tcp_port);
2403     QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) {
2404         ppair2 = *(uint32_t *)(seg->buf + tcp_port);
2405         if (memcmp(buf + ip_start, seg->buf + ip_start, ip_size)
2406             || (ppair1 != ppair2)) {
2407             continue;
2408         }
2409         if (virtio_net_rsc_drain_seg(chain, seg) == 0) {
2410             chain->stat.drain_failed++;
2411         }
2412 
2413         break;
2414     }
2415 
2416     return virtio_net_do_receive(nc, buf, size);
2417 }
2418 
2419 static int32_t virtio_net_rsc_sanity_check4(VirtioNetRscChain *chain,
2420                                             struct ip_header *ip,
2421                                             const uint8_t *buf, size_t size)
2422 {
2423     uint16_t ip_len;
2424 
2425     /* Not an ipv4 packet */
2426     if (((ip->ip_ver_len & 0xF0) >> 4) != IP_HEADER_VERSION_4) {
2427         chain->stat.ip_option++;
2428         return RSC_BYPASS;
2429     }
2430 
2431     /* Don't handle packets with ip option */
2432     if ((ip->ip_ver_len & 0xF) != VIRTIO_NET_IP4_HEADER_LENGTH) {
2433         chain->stat.ip_option++;
2434         return RSC_BYPASS;
2435     }
2436 
2437     if (ip->ip_p != IPPROTO_TCP) {
2438         chain->stat.bypass_not_tcp++;
2439         return RSC_BYPASS;
2440     }
2441 
2442     /* Don't handle packets with ip fragment */
2443     if (!(htons(ip->ip_off) & IP_DF)) {
2444         chain->stat.ip_frag++;
2445         return RSC_BYPASS;
2446     }
2447 
2448     /* Don't handle packets with ecn flag */
2449     if (IPTOS_ECN(ip->ip_tos)) {
2450         chain->stat.ip_ecn++;
2451         return RSC_BYPASS;
2452     }
2453 
2454     ip_len = htons(ip->ip_len);
2455     if (ip_len < (sizeof(struct ip_header) + sizeof(struct tcp_header))
2456         || ip_len > (size - chain->n->guest_hdr_len -
2457                      sizeof(struct eth_header))) {
2458         chain->stat.ip_hacked++;
2459         return RSC_BYPASS;
2460     }
2461 
2462     return RSC_CANDIDATE;
2463 }
2464 
2465 static size_t virtio_net_rsc_receive4(VirtioNetRscChain *chain,
2466                                       NetClientState *nc,
2467                                       const uint8_t *buf, size_t size)
2468 {
2469     int32_t ret;
2470     uint16_t hdr_len;
2471     VirtioNetRscUnit unit;
2472 
2473     hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len;
2474 
2475     if (size < (hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header)
2476         + sizeof(struct tcp_header))) {
2477         chain->stat.bypass_not_tcp++;
2478         return virtio_net_do_receive(nc, buf, size);
2479     }
2480 
2481     virtio_net_rsc_extract_unit4(chain, buf, &unit);
2482     if (virtio_net_rsc_sanity_check4(chain, unit.ip, buf, size)
2483         != RSC_CANDIDATE) {
2484         return virtio_net_do_receive(nc, buf, size);
2485     }
2486 
2487     ret = virtio_net_rsc_tcp_ctrl_check(chain, unit.tcp);
2488     if (ret == RSC_BYPASS) {
2489         return virtio_net_do_receive(nc, buf, size);
2490     } else if (ret == RSC_FINAL) {
2491         return virtio_net_rsc_drain_flow(chain, nc, buf, size,
2492                 ((hdr_len + sizeof(struct eth_header)) + 12),
2493                 VIRTIO_NET_IP4_ADDR_SIZE,
2494                 hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header));
2495     }
2496 
2497     return virtio_net_rsc_do_coalesce(chain, nc, buf, size, &unit);
2498 }
2499 
2500 static int32_t virtio_net_rsc_sanity_check6(VirtioNetRscChain *chain,
2501                                             struct ip6_header *ip6,
2502                                             const uint8_t *buf, size_t size)
2503 {
2504     uint16_t ip_len;
2505 
2506     if (((ip6->ip6_ctlun.ip6_un1.ip6_un1_flow & 0xF0) >> 4)
2507         != IP_HEADER_VERSION_6) {
2508         return RSC_BYPASS;
2509     }
2510 
2511     /* Both option and protocol is checked in this */
2512     if (ip6->ip6_ctlun.ip6_un1.ip6_un1_nxt != IPPROTO_TCP) {
2513         chain->stat.bypass_not_tcp++;
2514         return RSC_BYPASS;
2515     }
2516 
2517     ip_len = htons(ip6->ip6_ctlun.ip6_un1.ip6_un1_plen);
2518     if (ip_len < sizeof(struct tcp_header) ||
2519         ip_len > (size - chain->n->guest_hdr_len - sizeof(struct eth_header)
2520                   - sizeof(struct ip6_header))) {
2521         chain->stat.ip_hacked++;
2522         return RSC_BYPASS;
2523     }
2524 
2525     /* Don't handle packets with ecn flag */
2526     if (IP6_ECN(ip6->ip6_ctlun.ip6_un3.ip6_un3_ecn)) {
2527         chain->stat.ip_ecn++;
2528         return RSC_BYPASS;
2529     }
2530 
2531     return RSC_CANDIDATE;
2532 }
2533 
2534 static size_t virtio_net_rsc_receive6(void *opq, NetClientState *nc,
2535                                       const uint8_t *buf, size_t size)
2536 {
2537     int32_t ret;
2538     uint16_t hdr_len;
2539     VirtioNetRscChain *chain;
2540     VirtioNetRscUnit unit;
2541 
2542     chain = opq;
2543     hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len;
2544 
2545     if (size < (hdr_len + sizeof(struct eth_header) + sizeof(struct ip6_header)
2546         + sizeof(tcp_header))) {
2547         return virtio_net_do_receive(nc, buf, size);
2548     }
2549 
2550     virtio_net_rsc_extract_unit6(chain, buf, &unit);
2551     if (RSC_CANDIDATE != virtio_net_rsc_sanity_check6(chain,
2552                                                  unit.ip, buf, size)) {
2553         return virtio_net_do_receive(nc, buf, size);
2554     }
2555 
2556     ret = virtio_net_rsc_tcp_ctrl_check(chain, unit.tcp);
2557     if (ret == RSC_BYPASS) {
2558         return virtio_net_do_receive(nc, buf, size);
2559     } else if (ret == RSC_FINAL) {
2560         return virtio_net_rsc_drain_flow(chain, nc, buf, size,
2561                 ((hdr_len + sizeof(struct eth_header)) + 8),
2562                 VIRTIO_NET_IP6_ADDR_SIZE,
2563                 hdr_len + sizeof(struct eth_header)
2564                 + sizeof(struct ip6_header));
2565     }
2566 
2567     return virtio_net_rsc_do_coalesce(chain, nc, buf, size, &unit);
2568 }
2569 
2570 static VirtioNetRscChain *virtio_net_rsc_lookup_chain(VirtIONet *n,
2571                                                       NetClientState *nc,
2572                                                       uint16_t proto)
2573 {
2574     VirtioNetRscChain *chain;
2575 
2576     if ((proto != (uint16_t)ETH_P_IP) && (proto != (uint16_t)ETH_P_IPV6)) {
2577         return NULL;
2578     }
2579 
2580     QTAILQ_FOREACH(chain, &n->rsc_chains, next) {
2581         if (chain->proto == proto) {
2582             return chain;
2583         }
2584     }
2585 
2586     chain = g_malloc(sizeof(*chain));
2587     chain->n = n;
2588     chain->proto = proto;
2589     if (proto == (uint16_t)ETH_P_IP) {
2590         chain->max_payload = VIRTIO_NET_MAX_IP4_PAYLOAD;
2591         chain->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2592     } else {
2593         chain->max_payload = VIRTIO_NET_MAX_IP6_PAYLOAD;
2594         chain->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2595     }
2596     chain->drain_timer = timer_new_ns(QEMU_CLOCK_HOST,
2597                                       virtio_net_rsc_purge, chain);
2598     memset(&chain->stat, 0, sizeof(chain->stat));
2599 
2600     QTAILQ_INIT(&chain->buffers);
2601     QTAILQ_INSERT_TAIL(&n->rsc_chains, chain, next);
2602 
2603     return chain;
2604 }
2605 
2606 static ssize_t virtio_net_rsc_receive(NetClientState *nc,
2607                                       const uint8_t *buf,
2608                                       size_t size)
2609 {
2610     uint16_t proto;
2611     VirtioNetRscChain *chain;
2612     struct eth_header *eth;
2613     VirtIONet *n;
2614 
2615     n = qemu_get_nic_opaque(nc);
2616     if (size < (n->host_hdr_len + sizeof(struct eth_header))) {
2617         return virtio_net_do_receive(nc, buf, size);
2618     }
2619 
2620     eth = (struct eth_header *)(buf + n->guest_hdr_len);
2621     proto = htons(eth->h_proto);
2622 
2623     chain = virtio_net_rsc_lookup_chain(n, nc, proto);
2624     if (chain) {
2625         chain->stat.received++;
2626         if (proto == (uint16_t)ETH_P_IP && n->rsc4_enabled) {
2627             return virtio_net_rsc_receive4(chain, nc, buf, size);
2628         } else if (proto == (uint16_t)ETH_P_IPV6 && n->rsc6_enabled) {
2629             return virtio_net_rsc_receive6(chain, nc, buf, size);
2630         }
2631     }
2632     return virtio_net_do_receive(nc, buf, size);
2633 }
2634 
2635 static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf,
2636                                   size_t size)
2637 {
2638     VirtIONet *n = qemu_get_nic_opaque(nc);
2639     if ((n->rsc4_enabled || n->rsc6_enabled)) {
2640         return virtio_net_rsc_receive(nc, buf, size);
2641     } else {
2642         return virtio_net_do_receive(nc, buf, size);
2643     }
2644 }
2645 
2646 static int32_t virtio_net_flush_tx(VirtIONetQueue *q);
2647 
2648 static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
2649 {
2650     VirtIONet *n = qemu_get_nic_opaque(nc);
2651     VirtIONetQueue *q = virtio_net_get_subqueue(nc);
2652     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2653     int ret;
2654 
2655     virtqueue_push(q->tx_vq, q->async_tx.elem, 0);
2656     virtio_notify(vdev, q->tx_vq);
2657 
2658     g_free(q->async_tx.elem);
2659     q->async_tx.elem = NULL;
2660 
2661     virtio_queue_set_notification(q->tx_vq, 1);
2662     ret = virtio_net_flush_tx(q);
2663     if (ret >= n->tx_burst) {
2664         /*
2665          * the flush has been stopped by tx_burst
2666          * we will not receive notification for the
2667          * remainining part, so re-schedule
2668          */
2669         virtio_queue_set_notification(q->tx_vq, 0);
2670         if (q->tx_bh) {
2671             qemu_bh_schedule(q->tx_bh);
2672         } else {
2673             timer_mod(q->tx_timer,
2674                       qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
2675         }
2676         q->tx_waiting = 1;
2677     }
2678 }
2679 
2680 /* TX */
2681 static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
2682 {
2683     VirtIONet *n = q->n;
2684     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2685     VirtQueueElement *elem;
2686     int32_t num_packets = 0;
2687     int queue_index = vq2q(virtio_get_queue_index(q->tx_vq));
2688     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
2689         return num_packets;
2690     }
2691 
2692     if (q->async_tx.elem) {
2693         virtio_queue_set_notification(q->tx_vq, 0);
2694         return num_packets;
2695     }
2696 
2697     for (;;) {
2698         ssize_t ret;
2699         unsigned int out_num;
2700         struct iovec sg[VIRTQUEUE_MAX_SIZE], sg2[VIRTQUEUE_MAX_SIZE + 1], *out_sg;
2701         struct virtio_net_hdr_v1_hash vhdr;
2702 
2703         elem = virtqueue_pop(q->tx_vq, sizeof(VirtQueueElement));
2704         if (!elem) {
2705             break;
2706         }
2707 
2708         out_num = elem->out_num;
2709         out_sg = elem->out_sg;
2710         if (out_num < 1) {
2711             virtio_error(vdev, "virtio-net header not in first element");
2712             virtqueue_detach_element(q->tx_vq, elem, 0);
2713             g_free(elem);
2714             return -EINVAL;
2715         }
2716 
2717         if (n->has_vnet_hdr) {
2718             if (iov_to_buf(out_sg, out_num, 0, &vhdr, n->guest_hdr_len) <
2719                 n->guest_hdr_len) {
2720                 virtio_error(vdev, "virtio-net header incorrect");
2721                 virtqueue_detach_element(q->tx_vq, elem, 0);
2722                 g_free(elem);
2723                 return -EINVAL;
2724             }
2725             if (n->needs_vnet_hdr_swap) {
2726                 virtio_net_hdr_swap(vdev, (void *) &vhdr);
2727                 sg2[0].iov_base = &vhdr;
2728                 sg2[0].iov_len = n->guest_hdr_len;
2729                 out_num = iov_copy(&sg2[1], ARRAY_SIZE(sg2) - 1,
2730                                    out_sg, out_num,
2731                                    n->guest_hdr_len, -1);
2732                 if (out_num == VIRTQUEUE_MAX_SIZE) {
2733                     goto drop;
2734                 }
2735                 out_num += 1;
2736                 out_sg = sg2;
2737             }
2738         }
2739         /*
2740          * If host wants to see the guest header as is, we can
2741          * pass it on unchanged. Otherwise, copy just the parts
2742          * that host is interested in.
2743          */
2744         assert(n->host_hdr_len <= n->guest_hdr_len);
2745         if (n->host_hdr_len != n->guest_hdr_len) {
2746             unsigned sg_num = iov_copy(sg, ARRAY_SIZE(sg),
2747                                        out_sg, out_num,
2748                                        0, n->host_hdr_len);
2749             sg_num += iov_copy(sg + sg_num, ARRAY_SIZE(sg) - sg_num,
2750                              out_sg, out_num,
2751                              n->guest_hdr_len, -1);
2752             out_num = sg_num;
2753             out_sg = sg;
2754         }
2755 
2756         ret = qemu_sendv_packet_async(qemu_get_subqueue(n->nic, queue_index),
2757                                       out_sg, out_num, virtio_net_tx_complete);
2758         if (ret == 0) {
2759             virtio_queue_set_notification(q->tx_vq, 0);
2760             q->async_tx.elem = elem;
2761             return -EBUSY;
2762         }
2763 
2764 drop:
2765         virtqueue_push(q->tx_vq, elem, 0);
2766         virtio_notify(vdev, q->tx_vq);
2767         g_free(elem);
2768 
2769         if (++num_packets >= n->tx_burst) {
2770             break;
2771         }
2772     }
2773     return num_packets;
2774 }
2775 
2776 static void virtio_net_tx_timer(void *opaque);
2777 
2778 static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
2779 {
2780     VirtIONet *n = VIRTIO_NET(vdev);
2781     VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
2782 
2783     if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) {
2784         virtio_net_drop_tx_queue_data(vdev, vq);
2785         return;
2786     }
2787 
2788     /* This happens when device was stopped but VCPU wasn't. */
2789     if (!vdev->vm_running) {
2790         q->tx_waiting = 1;
2791         return;
2792     }
2793 
2794     if (q->tx_waiting) {
2795         /* We already have queued packets, immediately flush */
2796         timer_del(q->tx_timer);
2797         virtio_net_tx_timer(q);
2798     } else {
2799         /* re-arm timer to flush it (and more) on next tick */
2800         timer_mod(q->tx_timer,
2801                   qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
2802         q->tx_waiting = 1;
2803         virtio_queue_set_notification(vq, 0);
2804     }
2805 }
2806 
2807 static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
2808 {
2809     VirtIONet *n = VIRTIO_NET(vdev);
2810     VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
2811 
2812     if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) {
2813         virtio_net_drop_tx_queue_data(vdev, vq);
2814         return;
2815     }
2816 
2817     if (unlikely(q->tx_waiting)) {
2818         return;
2819     }
2820     q->tx_waiting = 1;
2821     /* This happens when device was stopped but VCPU wasn't. */
2822     if (!vdev->vm_running) {
2823         return;
2824     }
2825     virtio_queue_set_notification(vq, 0);
2826     qemu_bh_schedule(q->tx_bh);
2827 }
2828 
2829 static void virtio_net_tx_timer(void *opaque)
2830 {
2831     VirtIONetQueue *q = opaque;
2832     VirtIONet *n = q->n;
2833     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2834     int ret;
2835 
2836     /* This happens when device was stopped but BH wasn't. */
2837     if (!vdev->vm_running) {
2838         /* Make sure tx waiting is set, so we'll run when restarted. */
2839         assert(q->tx_waiting);
2840         return;
2841     }
2842 
2843     q->tx_waiting = 0;
2844 
2845     /* Just in case the driver is not ready on more */
2846     if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
2847         return;
2848     }
2849 
2850     ret = virtio_net_flush_tx(q);
2851     if (ret == -EBUSY || ret == -EINVAL) {
2852         return;
2853     }
2854     /*
2855      * If we flush a full burst of packets, assume there are
2856      * more coming and immediately rearm
2857      */
2858     if (ret >= n->tx_burst) {
2859         q->tx_waiting = 1;
2860         timer_mod(q->tx_timer,
2861                   qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
2862         return;
2863     }
2864     /*
2865      * If less than a full burst, re-enable notification and flush
2866      * anything that may have come in while we weren't looking.  If
2867      * we find something, assume the guest is still active and rearm
2868      */
2869     virtio_queue_set_notification(q->tx_vq, 1);
2870     ret = virtio_net_flush_tx(q);
2871     if (ret > 0) {
2872         virtio_queue_set_notification(q->tx_vq, 0);
2873         q->tx_waiting = 1;
2874         timer_mod(q->tx_timer,
2875                   qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
2876     }
2877 }
2878 
2879 static void virtio_net_tx_bh(void *opaque)
2880 {
2881     VirtIONetQueue *q = opaque;
2882     VirtIONet *n = q->n;
2883     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2884     int32_t ret;
2885 
2886     /* This happens when device was stopped but BH wasn't. */
2887     if (!vdev->vm_running) {
2888         /* Make sure tx waiting is set, so we'll run when restarted. */
2889         assert(q->tx_waiting);
2890         return;
2891     }
2892 
2893     q->tx_waiting = 0;
2894 
2895     /* Just in case the driver is not ready on more */
2896     if (unlikely(!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK))) {
2897         return;
2898     }
2899 
2900     ret = virtio_net_flush_tx(q);
2901     if (ret == -EBUSY || ret == -EINVAL) {
2902         return; /* Notification re-enable handled by tx_complete or device
2903                  * broken */
2904     }
2905 
2906     /* If we flush a full burst of packets, assume there are
2907      * more coming and immediately reschedule */
2908     if (ret >= n->tx_burst) {
2909         qemu_bh_schedule(q->tx_bh);
2910         q->tx_waiting = 1;
2911         return;
2912     }
2913 
2914     /* If less than a full burst, re-enable notification and flush
2915      * anything that may have come in while we weren't looking.  If
2916      * we find something, assume the guest is still active and reschedule */
2917     virtio_queue_set_notification(q->tx_vq, 1);
2918     ret = virtio_net_flush_tx(q);
2919     if (ret == -EINVAL) {
2920         return;
2921     } else if (ret > 0) {
2922         virtio_queue_set_notification(q->tx_vq, 0);
2923         qemu_bh_schedule(q->tx_bh);
2924         q->tx_waiting = 1;
2925     }
2926 }
2927 
2928 static void virtio_net_add_queue(VirtIONet *n, int index)
2929 {
2930     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2931 
2932     n->vqs[index].rx_vq = virtio_add_queue(vdev, n->net_conf.rx_queue_size,
2933                                            virtio_net_handle_rx);
2934 
2935     if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
2936         n->vqs[index].tx_vq =
2937             virtio_add_queue(vdev, n->net_conf.tx_queue_size,
2938                              virtio_net_handle_tx_timer);
2939         n->vqs[index].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
2940                                               virtio_net_tx_timer,
2941                                               &n->vqs[index]);
2942     } else {
2943         n->vqs[index].tx_vq =
2944             virtio_add_queue(vdev, n->net_conf.tx_queue_size,
2945                              virtio_net_handle_tx_bh);
2946         n->vqs[index].tx_bh = qemu_bh_new_guarded(virtio_net_tx_bh, &n->vqs[index],
2947                                                   &DEVICE(vdev)->mem_reentrancy_guard);
2948     }
2949 
2950     n->vqs[index].tx_waiting = 0;
2951     n->vqs[index].n = n;
2952 }
2953 
2954 static void virtio_net_del_queue(VirtIONet *n, int index)
2955 {
2956     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2957     VirtIONetQueue *q = &n->vqs[index];
2958     NetClientState *nc = qemu_get_subqueue(n->nic, index);
2959 
2960     qemu_purge_queued_packets(nc);
2961 
2962     virtio_del_queue(vdev, index * 2);
2963     if (q->tx_timer) {
2964         timer_free(q->tx_timer);
2965         q->tx_timer = NULL;
2966     } else {
2967         qemu_bh_delete(q->tx_bh);
2968         q->tx_bh = NULL;
2969     }
2970     q->tx_waiting = 0;
2971     virtio_del_queue(vdev, index * 2 + 1);
2972 }
2973 
2974 static void virtio_net_change_num_queue_pairs(VirtIONet *n, int new_max_queue_pairs)
2975 {
2976     VirtIODevice *vdev = VIRTIO_DEVICE(n);
2977     int old_num_queues = virtio_get_num_queues(vdev);
2978     int new_num_queues = new_max_queue_pairs * 2 + 1;
2979     int i;
2980 
2981     assert(old_num_queues >= 3);
2982     assert(old_num_queues % 2 == 1);
2983 
2984     if (old_num_queues == new_num_queues) {
2985         return;
2986     }
2987 
2988     /*
2989      * We always need to remove and add ctrl vq if
2990      * old_num_queues != new_num_queues. Remove ctrl_vq first,
2991      * and then we only enter one of the following two loops.
2992      */
2993     virtio_del_queue(vdev, old_num_queues - 1);
2994 
2995     for (i = new_num_queues - 1; i < old_num_queues - 1; i += 2) {
2996         /* new_num_queues < old_num_queues */
2997         virtio_net_del_queue(n, i / 2);
2998     }
2999 
3000     for (i = old_num_queues - 1; i < new_num_queues - 1; i += 2) {
3001         /* new_num_queues > old_num_queues */
3002         virtio_net_add_queue(n, i / 2);
3003     }
3004 
3005     /* add ctrl_vq last */
3006     n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
3007 }
3008 
3009 static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue)
3010 {
3011     int max = multiqueue ? n->max_queue_pairs : 1;
3012 
3013     n->multiqueue = multiqueue;
3014     virtio_net_change_num_queue_pairs(n, max);
3015 
3016     virtio_net_set_queue_pairs(n);
3017 }
3018 
3019 static int virtio_net_post_load_device(void *opaque, int version_id)
3020 {
3021     VirtIONet *n = opaque;
3022     VirtIODevice *vdev = VIRTIO_DEVICE(n);
3023     int i, link_down;
3024 
3025     trace_virtio_net_post_load_device();
3026     virtio_net_set_mrg_rx_bufs(n, n->mergeable_rx_bufs,
3027                                virtio_vdev_has_feature(vdev,
3028                                                        VIRTIO_F_VERSION_1),
3029                                virtio_vdev_has_feature(vdev,
3030                                                        VIRTIO_NET_F_HASH_REPORT));
3031 
3032     /* MAC_TABLE_ENTRIES may be different from the saved image */
3033     if (n->mac_table.in_use > MAC_TABLE_ENTRIES) {
3034         n->mac_table.in_use = 0;
3035     }
3036 
3037     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
3038         n->curr_guest_offloads = virtio_net_supported_guest_offloads(n);
3039     }
3040 
3041     /*
3042      * curr_guest_offloads will be later overwritten by the
3043      * virtio_set_features_nocheck call done from the virtio_load.
3044      * Here we make sure it is preserved and restored accordingly
3045      * in the virtio_net_post_load_virtio callback.
3046      */
3047     n->saved_guest_offloads = n->curr_guest_offloads;
3048 
3049     virtio_net_set_queue_pairs(n);
3050 
3051     /* Find the first multicast entry in the saved MAC filter */
3052     for (i = 0; i < n->mac_table.in_use; i++) {
3053         if (n->mac_table.macs[i * ETH_ALEN] & 1) {
3054             break;
3055         }
3056     }
3057     n->mac_table.first_multi = i;
3058 
3059     /* nc.link_down can't be migrated, so infer link_down according
3060      * to link status bit in n->status */
3061     link_down = (n->status & VIRTIO_NET_S_LINK_UP) == 0;
3062     for (i = 0; i < n->max_queue_pairs; i++) {
3063         qemu_get_subqueue(n->nic, i)->link_down = link_down;
3064     }
3065 
3066     if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) &&
3067         virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
3068         qemu_announce_timer_reset(&n->announce_timer, migrate_announce_params(),
3069                                   QEMU_CLOCK_VIRTUAL,
3070                                   virtio_net_announce_timer, n);
3071         if (n->announce_timer.round) {
3072             timer_mod(n->announce_timer.tm,
3073                       qemu_clock_get_ms(n->announce_timer.type));
3074         } else {
3075             qemu_announce_timer_del(&n->announce_timer, false);
3076         }
3077     }
3078 
3079     if (n->rss_data.enabled) {
3080         n->rss_data.enabled_software_rss = n->rss_data.populate_hash;
3081         if (!n->rss_data.populate_hash) {
3082             if (!virtio_net_attach_epbf_rss(n)) {
3083                 if (get_vhost_net(qemu_get_queue(n->nic)->peer)) {
3084                     warn_report("Can't post-load eBPF RSS for vhost");
3085                 } else {
3086                     warn_report("Can't post-load eBPF RSS - "
3087                                 "fallback to software RSS");
3088                     n->rss_data.enabled_software_rss = true;
3089                 }
3090             }
3091         }
3092 
3093         trace_virtio_net_rss_enable(n->rss_data.hash_types,
3094                                     n->rss_data.indirections_len,
3095                                     sizeof(n->rss_data.key));
3096     } else {
3097         trace_virtio_net_rss_disable();
3098     }
3099     return 0;
3100 }
3101 
3102 static int virtio_net_post_load_virtio(VirtIODevice *vdev)
3103 {
3104     VirtIONet *n = VIRTIO_NET(vdev);
3105     /*
3106      * The actual needed state is now in saved_guest_offloads,
3107      * see virtio_net_post_load_device for detail.
3108      * Restore it back and apply the desired offloads.
3109      */
3110     n->curr_guest_offloads = n->saved_guest_offloads;
3111     if (peer_has_vnet_hdr(n)) {
3112         virtio_net_apply_guest_offloads(n);
3113     }
3114 
3115     return 0;
3116 }
3117 
3118 /* tx_waiting field of a VirtIONetQueue */
3119 static const VMStateDescription vmstate_virtio_net_queue_tx_waiting = {
3120     .name = "virtio-net-queue-tx_waiting",
3121     .fields = (const VMStateField[]) {
3122         VMSTATE_UINT32(tx_waiting, VirtIONetQueue),
3123         VMSTATE_END_OF_LIST()
3124    },
3125 };
3126 
3127 static bool max_queue_pairs_gt_1(void *opaque, int version_id)
3128 {
3129     return VIRTIO_NET(opaque)->max_queue_pairs > 1;
3130 }
3131 
3132 static bool has_ctrl_guest_offloads(void *opaque, int version_id)
3133 {
3134     return virtio_vdev_has_feature(VIRTIO_DEVICE(opaque),
3135                                    VIRTIO_NET_F_CTRL_GUEST_OFFLOADS);
3136 }
3137 
3138 static bool mac_table_fits(void *opaque, int version_id)
3139 {
3140     return VIRTIO_NET(opaque)->mac_table.in_use <= MAC_TABLE_ENTRIES;
3141 }
3142 
3143 static bool mac_table_doesnt_fit(void *opaque, int version_id)
3144 {
3145     return !mac_table_fits(opaque, version_id);
3146 }
3147 
3148 /* This temporary type is shared by all the WITH_TMP methods
3149  * although only some fields are used by each.
3150  */
3151 struct VirtIONetMigTmp {
3152     VirtIONet      *parent;
3153     VirtIONetQueue *vqs_1;
3154     uint16_t        curr_queue_pairs_1;
3155     uint8_t         has_ufo;
3156     uint32_t        has_vnet_hdr;
3157 };
3158 
3159 /* The 2nd and subsequent tx_waiting flags are loaded later than
3160  * the 1st entry in the queue_pairs and only if there's more than one
3161  * entry.  We use the tmp mechanism to calculate a temporary
3162  * pointer and count and also validate the count.
3163  */
3164 
3165 static int virtio_net_tx_waiting_pre_save(void *opaque)
3166 {
3167     struct VirtIONetMigTmp *tmp = opaque;
3168 
3169     tmp->vqs_1 = tmp->parent->vqs + 1;
3170     tmp->curr_queue_pairs_1 = tmp->parent->curr_queue_pairs - 1;
3171     if (tmp->parent->curr_queue_pairs == 0) {
3172         tmp->curr_queue_pairs_1 = 0;
3173     }
3174 
3175     return 0;
3176 }
3177 
3178 static int virtio_net_tx_waiting_pre_load(void *opaque)
3179 {
3180     struct VirtIONetMigTmp *tmp = opaque;
3181 
3182     /* Reuse the pointer setup from save */
3183     virtio_net_tx_waiting_pre_save(opaque);
3184 
3185     if (tmp->parent->curr_queue_pairs > tmp->parent->max_queue_pairs) {
3186         error_report("virtio-net: curr_queue_pairs %x > max_queue_pairs %x",
3187             tmp->parent->curr_queue_pairs, tmp->parent->max_queue_pairs);
3188 
3189         return -EINVAL;
3190     }
3191 
3192     return 0; /* all good */
3193 }
3194 
3195 static const VMStateDescription vmstate_virtio_net_tx_waiting = {
3196     .name      = "virtio-net-tx_waiting",
3197     .pre_load  = virtio_net_tx_waiting_pre_load,
3198     .pre_save  = virtio_net_tx_waiting_pre_save,
3199     .fields    = (const VMStateField[]) {
3200         VMSTATE_STRUCT_VARRAY_POINTER_UINT16(vqs_1, struct VirtIONetMigTmp,
3201                                      curr_queue_pairs_1,
3202                                      vmstate_virtio_net_queue_tx_waiting,
3203                                      struct VirtIONetQueue),
3204         VMSTATE_END_OF_LIST()
3205     },
3206 };
3207 
3208 /* the 'has_ufo' flag is just tested; if the incoming stream has the
3209  * flag set we need to check that we have it
3210  */
3211 static int virtio_net_ufo_post_load(void *opaque, int version_id)
3212 {
3213     struct VirtIONetMigTmp *tmp = opaque;
3214 
3215     if (tmp->has_ufo && !peer_has_ufo(tmp->parent)) {
3216         error_report("virtio-net: saved image requires TUN_F_UFO support");
3217         return -EINVAL;
3218     }
3219 
3220     return 0;
3221 }
3222 
3223 static int virtio_net_ufo_pre_save(void *opaque)
3224 {
3225     struct VirtIONetMigTmp *tmp = opaque;
3226 
3227     tmp->has_ufo = tmp->parent->has_ufo;
3228 
3229     return 0;
3230 }
3231 
3232 static const VMStateDescription vmstate_virtio_net_has_ufo = {
3233     .name      = "virtio-net-ufo",
3234     .post_load = virtio_net_ufo_post_load,
3235     .pre_save  = virtio_net_ufo_pre_save,
3236     .fields    = (const VMStateField[]) {
3237         VMSTATE_UINT8(has_ufo, struct VirtIONetMigTmp),
3238         VMSTATE_END_OF_LIST()
3239     },
3240 };
3241 
3242 /* the 'has_vnet_hdr' flag is just tested; if the incoming stream has the
3243  * flag set we need to check that we have it
3244  */
3245 static int virtio_net_vnet_post_load(void *opaque, int version_id)
3246 {
3247     struct VirtIONetMigTmp *tmp = opaque;
3248 
3249     if (tmp->has_vnet_hdr && !peer_has_vnet_hdr(tmp->parent)) {
3250         error_report("virtio-net: saved image requires vnet_hdr=on");
3251         return -EINVAL;
3252     }
3253 
3254     return 0;
3255 }
3256 
3257 static int virtio_net_vnet_pre_save(void *opaque)
3258 {
3259     struct VirtIONetMigTmp *tmp = opaque;
3260 
3261     tmp->has_vnet_hdr = tmp->parent->has_vnet_hdr;
3262 
3263     return 0;
3264 }
3265 
3266 static const VMStateDescription vmstate_virtio_net_has_vnet = {
3267     .name      = "virtio-net-vnet",
3268     .post_load = virtio_net_vnet_post_load,
3269     .pre_save  = virtio_net_vnet_pre_save,
3270     .fields    = (const VMStateField[]) {
3271         VMSTATE_UINT32(has_vnet_hdr, struct VirtIONetMigTmp),
3272         VMSTATE_END_OF_LIST()
3273     },
3274 };
3275 
3276 static bool virtio_net_rss_needed(void *opaque)
3277 {
3278     return VIRTIO_NET(opaque)->rss_data.enabled;
3279 }
3280 
3281 static const VMStateDescription vmstate_virtio_net_rss = {
3282     .name      = "virtio-net-device/rss",
3283     .version_id = 1,
3284     .minimum_version_id = 1,
3285     .needed = virtio_net_rss_needed,
3286     .fields = (const VMStateField[]) {
3287         VMSTATE_BOOL(rss_data.enabled, VirtIONet),
3288         VMSTATE_BOOL(rss_data.redirect, VirtIONet),
3289         VMSTATE_BOOL(rss_data.populate_hash, VirtIONet),
3290         VMSTATE_UINT32(rss_data.hash_types, VirtIONet),
3291         VMSTATE_UINT16(rss_data.indirections_len, VirtIONet),
3292         VMSTATE_UINT16(rss_data.default_queue, VirtIONet),
3293         VMSTATE_UINT8_ARRAY(rss_data.key, VirtIONet,
3294                             VIRTIO_NET_RSS_MAX_KEY_SIZE),
3295         VMSTATE_VARRAY_UINT16_ALLOC(rss_data.indirections_table, VirtIONet,
3296                                     rss_data.indirections_len, 0,
3297                                     vmstate_info_uint16, uint16_t),
3298         VMSTATE_END_OF_LIST()
3299     },
3300 };
3301 
3302 static const VMStateDescription vmstate_virtio_net_device = {
3303     .name = "virtio-net-device",
3304     .version_id = VIRTIO_NET_VM_VERSION,
3305     .minimum_version_id = VIRTIO_NET_VM_VERSION,
3306     .post_load = virtio_net_post_load_device,
3307     .fields = (const VMStateField[]) {
3308         VMSTATE_UINT8_ARRAY(mac, VirtIONet, ETH_ALEN),
3309         VMSTATE_STRUCT_POINTER(vqs, VirtIONet,
3310                                vmstate_virtio_net_queue_tx_waiting,
3311                                VirtIONetQueue),
3312         VMSTATE_UINT32(mergeable_rx_bufs, VirtIONet),
3313         VMSTATE_UINT16(status, VirtIONet),
3314         VMSTATE_UINT8(promisc, VirtIONet),
3315         VMSTATE_UINT8(allmulti, VirtIONet),
3316         VMSTATE_UINT32(mac_table.in_use, VirtIONet),
3317 
3318         /* Guarded pair: If it fits we load it, else we throw it away
3319          * - can happen if source has a larger MAC table.; post-load
3320          *  sets flags in this case.
3321          */
3322         VMSTATE_VBUFFER_MULTIPLY(mac_table.macs, VirtIONet,
3323                                 0, mac_table_fits, mac_table.in_use,
3324                                  ETH_ALEN),
3325         VMSTATE_UNUSED_VARRAY_UINT32(VirtIONet, mac_table_doesnt_fit, 0,
3326                                      mac_table.in_use, ETH_ALEN),
3327 
3328         /* Note: This is an array of uint32's that's always been saved as a
3329          * buffer; hold onto your endiannesses; it's actually used as a bitmap
3330          * but based on the uint.
3331          */
3332         VMSTATE_BUFFER_POINTER_UNSAFE(vlans, VirtIONet, 0, MAX_VLAN >> 3),
3333         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
3334                          vmstate_virtio_net_has_vnet),
3335         VMSTATE_UINT8(mac_table.multi_overflow, VirtIONet),
3336         VMSTATE_UINT8(mac_table.uni_overflow, VirtIONet),
3337         VMSTATE_UINT8(alluni, VirtIONet),
3338         VMSTATE_UINT8(nomulti, VirtIONet),
3339         VMSTATE_UINT8(nouni, VirtIONet),
3340         VMSTATE_UINT8(nobcast, VirtIONet),
3341         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
3342                          vmstate_virtio_net_has_ufo),
3343         VMSTATE_SINGLE_TEST(max_queue_pairs, VirtIONet, max_queue_pairs_gt_1, 0,
3344                             vmstate_info_uint16_equal, uint16_t),
3345         VMSTATE_UINT16_TEST(curr_queue_pairs, VirtIONet, max_queue_pairs_gt_1),
3346         VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
3347                          vmstate_virtio_net_tx_waiting),
3348         VMSTATE_UINT64_TEST(curr_guest_offloads, VirtIONet,
3349                             has_ctrl_guest_offloads),
3350         VMSTATE_END_OF_LIST()
3351     },
3352     .subsections = (const VMStateDescription * const []) {
3353         &vmstate_virtio_net_rss,
3354         NULL
3355     }
3356 };
3357 
3358 static NetClientInfo net_virtio_info = {
3359     .type = NET_CLIENT_DRIVER_NIC,
3360     .size = sizeof(NICState),
3361     .can_receive = virtio_net_can_receive,
3362     .receive = virtio_net_receive,
3363     .link_status_changed = virtio_net_set_link_status,
3364     .query_rx_filter = virtio_net_query_rxfilter,
3365     .announce = virtio_net_announce,
3366 };
3367 
3368 static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
3369 {
3370     VirtIONet *n = VIRTIO_NET(vdev);
3371     NetClientState *nc;
3372     assert(n->vhost_started);
3373     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ) && idx == 2) {
3374         /* Must guard against invalid features and bogus queue index
3375          * from being set by malicious guest, or penetrated through
3376          * buggy migration stream.
3377          */
3378         if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
3379             qemu_log_mask(LOG_GUEST_ERROR,
3380                           "%s: bogus vq index ignored\n", __func__);
3381             return false;
3382         }
3383         nc = qemu_get_subqueue(n->nic, n->max_queue_pairs);
3384     } else {
3385         nc = qemu_get_subqueue(n->nic, vq2q(idx));
3386     }
3387     /*
3388      * Add the check for configure interrupt, Use VIRTIO_CONFIG_IRQ_IDX -1
3389      * as the macro of configure interrupt's IDX, If this driver does not
3390      * support, the function will return false
3391      */
3392 
3393     if (idx == VIRTIO_CONFIG_IRQ_IDX) {
3394         return vhost_net_config_pending(get_vhost_net(nc->peer));
3395     }
3396     return vhost_net_virtqueue_pending(get_vhost_net(nc->peer), idx);
3397 }
3398 
3399 static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
3400                                            bool mask)
3401 {
3402     VirtIONet *n = VIRTIO_NET(vdev);
3403     NetClientState *nc;
3404     assert(n->vhost_started);
3405     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ) && idx == 2) {
3406         /* Must guard against invalid features and bogus queue index
3407          * from being set by malicious guest, or penetrated through
3408          * buggy migration stream.
3409          */
3410         if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
3411             qemu_log_mask(LOG_GUEST_ERROR,
3412                           "%s: bogus vq index ignored\n", __func__);
3413             return;
3414         }
3415         nc = qemu_get_subqueue(n->nic, n->max_queue_pairs);
3416     } else {
3417         nc = qemu_get_subqueue(n->nic, vq2q(idx));
3418     }
3419     /*
3420      *Add the check for configure interrupt, Use VIRTIO_CONFIG_IRQ_IDX -1
3421      * as the macro of configure interrupt's IDX, If this driver does not
3422      * support, the function will return
3423      */
3424 
3425     if (idx == VIRTIO_CONFIG_IRQ_IDX) {
3426         vhost_net_config_mask(get_vhost_net(nc->peer), vdev, mask);
3427         return;
3428     }
3429     vhost_net_virtqueue_mask(get_vhost_net(nc->peer), vdev, idx, mask);
3430 }
3431 
3432 static void virtio_net_set_config_size(VirtIONet *n, uint64_t host_features)
3433 {
3434     virtio_add_feature(&host_features, VIRTIO_NET_F_MAC);
3435 
3436     n->config_size = virtio_get_config_size(&cfg_size_params, host_features);
3437 }
3438 
3439 void virtio_net_set_netclient_name(VirtIONet *n, const char *name,
3440                                    const char *type)
3441 {
3442     /*
3443      * The name can be NULL, the netclient name will be type.x.
3444      */
3445     assert(type != NULL);
3446 
3447     g_free(n->netclient_name);
3448     g_free(n->netclient_type);
3449     n->netclient_name = g_strdup(name);
3450     n->netclient_type = g_strdup(type);
3451 }
3452 
3453 static bool failover_unplug_primary(VirtIONet *n, DeviceState *dev)
3454 {
3455     HotplugHandler *hotplug_ctrl;
3456     PCIDevice *pci_dev;
3457     Error *err = NULL;
3458 
3459     hotplug_ctrl = qdev_get_hotplug_handler(dev);
3460     if (hotplug_ctrl) {
3461         pci_dev = PCI_DEVICE(dev);
3462         pci_dev->partially_hotplugged = true;
3463         hotplug_handler_unplug_request(hotplug_ctrl, dev, &err);
3464         if (err) {
3465             error_report_err(err);
3466             return false;
3467         }
3468     } else {
3469         return false;
3470     }
3471     return true;
3472 }
3473 
3474 static bool failover_replug_primary(VirtIONet *n, DeviceState *dev,
3475                                     Error **errp)
3476 {
3477     Error *err = NULL;
3478     HotplugHandler *hotplug_ctrl;
3479     PCIDevice *pdev = PCI_DEVICE(dev);
3480     BusState *primary_bus;
3481 
3482     if (!pdev->partially_hotplugged) {
3483         return true;
3484     }
3485     primary_bus = dev->parent_bus;
3486     if (!primary_bus) {
3487         error_setg(errp, "virtio_net: couldn't find primary bus");
3488         return false;
3489     }
3490     qdev_set_parent_bus(dev, primary_bus, &error_abort);
3491     qatomic_set(&n->failover_primary_hidden, false);
3492     hotplug_ctrl = qdev_get_hotplug_handler(dev);
3493     if (hotplug_ctrl) {
3494         hotplug_handler_pre_plug(hotplug_ctrl, dev, &err);
3495         if (err) {
3496             goto out;
3497         }
3498         hotplug_handler_plug(hotplug_ctrl, dev, &err);
3499     }
3500     pdev->partially_hotplugged = false;
3501 
3502 out:
3503     error_propagate(errp, err);
3504     return !err;
3505 }
3506 
3507 static void virtio_net_handle_migration_primary(VirtIONet *n, MigrationState *s)
3508 {
3509     bool should_be_hidden;
3510     Error *err = NULL;
3511     DeviceState *dev = failover_find_primary_device(n);
3512 
3513     if (!dev) {
3514         return;
3515     }
3516 
3517     should_be_hidden = qatomic_read(&n->failover_primary_hidden);
3518 
3519     if (migration_in_setup(s) && !should_be_hidden) {
3520         if (failover_unplug_primary(n, dev)) {
3521             vmstate_unregister(VMSTATE_IF(dev), qdev_get_vmsd(dev), dev);
3522             qapi_event_send_unplug_primary(dev->id);
3523             qatomic_set(&n->failover_primary_hidden, true);
3524         } else {
3525             warn_report("couldn't unplug primary device");
3526         }
3527     } else if (migration_has_failed(s)) {
3528         /* We already unplugged the device let's plug it back */
3529         if (!failover_replug_primary(n, dev, &err)) {
3530             if (err) {
3531                 error_report_err(err);
3532             }
3533         }
3534     }
3535 }
3536 
3537 static void virtio_net_migration_state_notifier(Notifier *notifier, void *data)
3538 {
3539     MigrationState *s = data;
3540     VirtIONet *n = container_of(notifier, VirtIONet, migration_state);
3541     virtio_net_handle_migration_primary(n, s);
3542 }
3543 
3544 static bool failover_hide_primary_device(DeviceListener *listener,
3545                                          const QDict *device_opts,
3546                                          bool from_json,
3547                                          Error **errp)
3548 {
3549     VirtIONet *n = container_of(listener, VirtIONet, primary_listener);
3550     const char *standby_id;
3551 
3552     if (!device_opts) {
3553         return false;
3554     }
3555 
3556     if (!qdict_haskey(device_opts, "failover_pair_id")) {
3557         return false;
3558     }
3559 
3560     if (!qdict_haskey(device_opts, "id")) {
3561         error_setg(errp, "Device with failover_pair_id needs to have id");
3562         return false;
3563     }
3564 
3565     standby_id = qdict_get_str(device_opts, "failover_pair_id");
3566     if (g_strcmp0(standby_id, n->netclient_name) != 0) {
3567         return false;
3568     }
3569 
3570     /*
3571      * The hide helper can be called several times for a given device.
3572      * Check there is only one primary for a virtio-net device but
3573      * don't duplicate the qdict several times if it's called for the same
3574      * device.
3575      */
3576     if (n->primary_opts) {
3577         const char *old, *new;
3578         /* devices with failover_pair_id always have an id */
3579         old = qdict_get_str(n->primary_opts, "id");
3580         new = qdict_get_str(device_opts, "id");
3581         if (strcmp(old, new) != 0) {
3582             error_setg(errp, "Cannot attach more than one primary device to "
3583                        "'%s': '%s' and '%s'", n->netclient_name, old, new);
3584             return false;
3585         }
3586     } else {
3587         n->primary_opts = qdict_clone_shallow(device_opts);
3588         n->primary_opts_from_json = from_json;
3589     }
3590 
3591     /* failover_primary_hidden is set during feature negotiation */
3592     return qatomic_read(&n->failover_primary_hidden);
3593 }
3594 
3595 static void virtio_net_device_realize(DeviceState *dev, Error **errp)
3596 {
3597     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
3598     VirtIONet *n = VIRTIO_NET(dev);
3599     NetClientState *nc;
3600     int i;
3601 
3602     if (n->net_conf.mtu) {
3603         n->host_features |= (1ULL << VIRTIO_NET_F_MTU);
3604     }
3605 
3606     if (n->net_conf.duplex_str) {
3607         if (strncmp(n->net_conf.duplex_str, "half", 5) == 0) {
3608             n->net_conf.duplex = DUPLEX_HALF;
3609         } else if (strncmp(n->net_conf.duplex_str, "full", 5) == 0) {
3610             n->net_conf.duplex = DUPLEX_FULL;
3611         } else {
3612             error_setg(errp, "'duplex' must be 'half' or 'full'");
3613             return;
3614         }
3615         n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
3616     } else {
3617         n->net_conf.duplex = DUPLEX_UNKNOWN;
3618     }
3619 
3620     if (n->net_conf.speed < SPEED_UNKNOWN) {
3621         error_setg(errp, "'speed' must be between 0 and INT_MAX");
3622         return;
3623     }
3624     if (n->net_conf.speed >= 0) {
3625         n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
3626     }
3627 
3628     if (n->failover) {
3629         n->primary_listener.hide_device = failover_hide_primary_device;
3630         qatomic_set(&n->failover_primary_hidden, true);
3631         device_listener_register(&n->primary_listener);
3632         migration_add_notifier(&n->migration_state,
3633                                virtio_net_migration_state_notifier);
3634         n->host_features |= (1ULL << VIRTIO_NET_F_STANDBY);
3635     }
3636 
3637     virtio_net_set_config_size(n, n->host_features);
3638     virtio_init(vdev, VIRTIO_ID_NET, n->config_size);
3639 
3640     /*
3641      * We set a lower limit on RX queue size to what it always was.
3642      * Guests that want a smaller ring can always resize it without
3643      * help from us (using virtio 1 and up).
3644      */
3645     if (n->net_conf.rx_queue_size < VIRTIO_NET_RX_QUEUE_MIN_SIZE ||
3646         n->net_conf.rx_queue_size > VIRTQUEUE_MAX_SIZE ||
3647         !is_power_of_2(n->net_conf.rx_queue_size)) {
3648         error_setg(errp, "Invalid rx_queue_size (= %" PRIu16 "), "
3649                    "must be a power of 2 between %d and %d.",
3650                    n->net_conf.rx_queue_size, VIRTIO_NET_RX_QUEUE_MIN_SIZE,
3651                    VIRTQUEUE_MAX_SIZE);
3652         virtio_cleanup(vdev);
3653         return;
3654     }
3655 
3656     if (n->net_conf.tx_queue_size < VIRTIO_NET_TX_QUEUE_MIN_SIZE ||
3657         n->net_conf.tx_queue_size > virtio_net_max_tx_queue_size(n) ||
3658         !is_power_of_2(n->net_conf.tx_queue_size)) {
3659         error_setg(errp, "Invalid tx_queue_size (= %" PRIu16 "), "
3660                    "must be a power of 2 between %d and %d",
3661                    n->net_conf.tx_queue_size, VIRTIO_NET_TX_QUEUE_MIN_SIZE,
3662                    virtio_net_max_tx_queue_size(n));
3663         virtio_cleanup(vdev);
3664         return;
3665     }
3666 
3667     n->max_ncs = MAX(n->nic_conf.peers.queues, 1);
3668 
3669     /*
3670      * Figure out the datapath queue pairs since the backend could
3671      * provide control queue via peers as well.
3672      */
3673     if (n->nic_conf.peers.queues) {
3674         for (i = 0; i < n->max_ncs; i++) {
3675             if (n->nic_conf.peers.ncs[i]->is_datapath) {
3676                 ++n->max_queue_pairs;
3677             }
3678         }
3679     }
3680     n->max_queue_pairs = MAX(n->max_queue_pairs, 1);
3681 
3682     if (n->max_queue_pairs * 2 + 1 > VIRTIO_QUEUE_MAX) {
3683         error_setg(errp, "Invalid number of queue pairs (= %" PRIu32 "), "
3684                    "must be a positive integer less than %d.",
3685                    n->max_queue_pairs, (VIRTIO_QUEUE_MAX - 1) / 2);
3686         virtio_cleanup(vdev);
3687         return;
3688     }
3689     n->vqs = g_new0(VirtIONetQueue, n->max_queue_pairs);
3690     n->curr_queue_pairs = 1;
3691     n->tx_timeout = n->net_conf.txtimer;
3692 
3693     if (n->net_conf.tx && strcmp(n->net_conf.tx, "timer")
3694                        && strcmp(n->net_conf.tx, "bh")) {
3695         warn_report("virtio-net: "
3696                     "Unknown option tx=%s, valid options: \"timer\" \"bh\"",
3697                     n->net_conf.tx);
3698         error_printf("Defaulting to \"bh\"");
3699     }
3700 
3701     n->net_conf.tx_queue_size = MIN(virtio_net_max_tx_queue_size(n),
3702                                     n->net_conf.tx_queue_size);
3703 
3704     for (i = 0; i < n->max_queue_pairs; i++) {
3705         virtio_net_add_queue(n, i);
3706     }
3707 
3708     n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
3709     qemu_macaddr_default_if_unset(&n->nic_conf.macaddr);
3710     memcpy(&n->mac[0], &n->nic_conf.macaddr, sizeof(n->mac));
3711     n->status = VIRTIO_NET_S_LINK_UP;
3712     qemu_announce_timer_reset(&n->announce_timer, migrate_announce_params(),
3713                               QEMU_CLOCK_VIRTUAL,
3714                               virtio_net_announce_timer, n);
3715     n->announce_timer.round = 0;
3716 
3717     if (n->netclient_type) {
3718         /*
3719          * Happen when virtio_net_set_netclient_name has been called.
3720          */
3721         n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
3722                               n->netclient_type, n->netclient_name,
3723                               &dev->mem_reentrancy_guard, n);
3724     } else {
3725         n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
3726                               object_get_typename(OBJECT(dev)), dev->id,
3727                               &dev->mem_reentrancy_guard, n);
3728     }
3729 
3730     for (i = 0; i < n->max_queue_pairs; i++) {
3731         n->nic->ncs[i].do_not_pad = true;
3732     }
3733 
3734     peer_test_vnet_hdr(n);
3735     if (peer_has_vnet_hdr(n)) {
3736         for (i = 0; i < n->max_queue_pairs; i++) {
3737             qemu_using_vnet_hdr(qemu_get_subqueue(n->nic, i)->peer, true);
3738         }
3739         n->host_hdr_len = sizeof(struct virtio_net_hdr);
3740     } else {
3741         n->host_hdr_len = 0;
3742     }
3743 
3744     qemu_format_nic_info_str(qemu_get_queue(n->nic), n->nic_conf.macaddr.a);
3745 
3746     n->vqs[0].tx_waiting = 0;
3747     n->tx_burst = n->net_conf.txburst;
3748     virtio_net_set_mrg_rx_bufs(n, 0, 0, 0);
3749     n->promisc = 1; /* for compatibility */
3750 
3751     n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
3752 
3753     n->vlans = g_malloc0(MAX_VLAN >> 3);
3754 
3755     nc = qemu_get_queue(n->nic);
3756     nc->rxfilter_notify_enabled = 1;
3757 
3758    if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
3759         struct virtio_net_config netcfg = {};
3760         memcpy(&netcfg.mac, &n->nic_conf.macaddr, ETH_ALEN);
3761         vhost_net_set_config(get_vhost_net(nc->peer),
3762             (uint8_t *)&netcfg, 0, ETH_ALEN, VHOST_SET_CONFIG_TYPE_FRONTEND);
3763     }
3764     QTAILQ_INIT(&n->rsc_chains);
3765     n->qdev = dev;
3766 
3767     net_rx_pkt_init(&n->rx_pkt);
3768 
3769     if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS)) {
3770         virtio_net_load_ebpf(n);
3771     }
3772 }
3773 
3774 static void virtio_net_device_unrealize(DeviceState *dev)
3775 {
3776     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
3777     VirtIONet *n = VIRTIO_NET(dev);
3778     int i, max_queue_pairs;
3779 
3780     if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS)) {
3781         virtio_net_unload_ebpf(n);
3782     }
3783 
3784     /* This will stop vhost backend if appropriate. */
3785     virtio_net_set_status(vdev, 0);
3786 
3787     g_free(n->netclient_name);
3788     n->netclient_name = NULL;
3789     g_free(n->netclient_type);
3790     n->netclient_type = NULL;
3791 
3792     g_free(n->mac_table.macs);
3793     g_free(n->vlans);
3794 
3795     if (n->failover) {
3796         qobject_unref(n->primary_opts);
3797         device_listener_unregister(&n->primary_listener);
3798         migration_remove_notifier(&n->migration_state);
3799     } else {
3800         assert(n->primary_opts == NULL);
3801     }
3802 
3803     max_queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
3804     for (i = 0; i < max_queue_pairs; i++) {
3805         virtio_net_del_queue(n, i);
3806     }
3807     /* delete also control vq */
3808     virtio_del_queue(vdev, max_queue_pairs * 2);
3809     qemu_announce_timer_del(&n->announce_timer, false);
3810     g_free(n->vqs);
3811     qemu_del_nic(n->nic);
3812     virtio_net_rsc_cleanup(n);
3813     g_free(n->rss_data.indirections_table);
3814     net_rx_pkt_uninit(n->rx_pkt);
3815     virtio_cleanup(vdev);
3816 }
3817 
3818 static void virtio_net_instance_init(Object *obj)
3819 {
3820     VirtIONet *n = VIRTIO_NET(obj);
3821 
3822     /*
3823      * The default config_size is sizeof(struct virtio_net_config).
3824      * Can be overridden with virtio_net_set_config_size.
3825      */
3826     n->config_size = sizeof(struct virtio_net_config);
3827     device_add_bootindex_property(obj, &n->nic_conf.bootindex,
3828                                   "bootindex", "/ethernet-phy@0",
3829                                   DEVICE(n));
3830 
3831     ebpf_rss_init(&n->ebpf_rss);
3832 }
3833 
3834 static int virtio_net_pre_save(void *opaque)
3835 {
3836     VirtIONet *n = opaque;
3837 
3838     /* At this point, backend must be stopped, otherwise
3839      * it might keep writing to memory. */
3840     assert(!n->vhost_started);
3841 
3842     return 0;
3843 }
3844 
3845 static bool primary_unplug_pending(void *opaque)
3846 {
3847     DeviceState *dev = opaque;
3848     DeviceState *primary;
3849     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
3850     VirtIONet *n = VIRTIO_NET(vdev);
3851 
3852     if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
3853         return false;
3854     }
3855     primary = failover_find_primary_device(n);
3856     return primary ? primary->pending_deleted_event : false;
3857 }
3858 
3859 static bool dev_unplug_pending(void *opaque)
3860 {
3861     DeviceState *dev = opaque;
3862     VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev);
3863 
3864     return vdc->primary_unplug_pending(dev);
3865 }
3866 
3867 static struct vhost_dev *virtio_net_get_vhost(VirtIODevice *vdev)
3868 {
3869     VirtIONet *n = VIRTIO_NET(vdev);
3870     NetClientState *nc = qemu_get_queue(n->nic);
3871     struct vhost_net *net = get_vhost_net(nc->peer);
3872     return &net->dev;
3873 }
3874 
3875 static const VMStateDescription vmstate_virtio_net = {
3876     .name = "virtio-net",
3877     .minimum_version_id = VIRTIO_NET_VM_VERSION,
3878     .version_id = VIRTIO_NET_VM_VERSION,
3879     .fields = (const VMStateField[]) {
3880         VMSTATE_VIRTIO_DEVICE,
3881         VMSTATE_END_OF_LIST()
3882     },
3883     .pre_save = virtio_net_pre_save,
3884     .dev_unplug_pending = dev_unplug_pending,
3885 };
3886 
3887 static Property virtio_net_properties[] = {
3888     DEFINE_PROP_BIT64("csum", VirtIONet, host_features,
3889                     VIRTIO_NET_F_CSUM, true),
3890     DEFINE_PROP_BIT64("guest_csum", VirtIONet, host_features,
3891                     VIRTIO_NET_F_GUEST_CSUM, true),
3892     DEFINE_PROP_BIT64("gso", VirtIONet, host_features, VIRTIO_NET_F_GSO, true),
3893     DEFINE_PROP_BIT64("guest_tso4", VirtIONet, host_features,
3894                     VIRTIO_NET_F_GUEST_TSO4, true),
3895     DEFINE_PROP_BIT64("guest_tso6", VirtIONet, host_features,
3896                     VIRTIO_NET_F_GUEST_TSO6, true),
3897     DEFINE_PROP_BIT64("guest_ecn", VirtIONet, host_features,
3898                     VIRTIO_NET_F_GUEST_ECN, true),
3899     DEFINE_PROP_BIT64("guest_ufo", VirtIONet, host_features,
3900                     VIRTIO_NET_F_GUEST_UFO, true),
3901     DEFINE_PROP_BIT64("guest_announce", VirtIONet, host_features,
3902                     VIRTIO_NET_F_GUEST_ANNOUNCE, true),
3903     DEFINE_PROP_BIT64("host_tso4", VirtIONet, host_features,
3904                     VIRTIO_NET_F_HOST_TSO4, true),
3905     DEFINE_PROP_BIT64("host_tso6", VirtIONet, host_features,
3906                     VIRTIO_NET_F_HOST_TSO6, true),
3907     DEFINE_PROP_BIT64("host_ecn", VirtIONet, host_features,
3908                     VIRTIO_NET_F_HOST_ECN, true),
3909     DEFINE_PROP_BIT64("host_ufo", VirtIONet, host_features,
3910                     VIRTIO_NET_F_HOST_UFO, true),
3911     DEFINE_PROP_BIT64("mrg_rxbuf", VirtIONet, host_features,
3912                     VIRTIO_NET_F_MRG_RXBUF, true),
3913     DEFINE_PROP_BIT64("status", VirtIONet, host_features,
3914                     VIRTIO_NET_F_STATUS, true),
3915     DEFINE_PROP_BIT64("ctrl_vq", VirtIONet, host_features,
3916                     VIRTIO_NET_F_CTRL_VQ, true),
3917     DEFINE_PROP_BIT64("ctrl_rx", VirtIONet, host_features,
3918                     VIRTIO_NET_F_CTRL_RX, true),
3919     DEFINE_PROP_BIT64("ctrl_vlan", VirtIONet, host_features,
3920                     VIRTIO_NET_F_CTRL_VLAN, true),
3921     DEFINE_PROP_BIT64("ctrl_rx_extra", VirtIONet, host_features,
3922                     VIRTIO_NET_F_CTRL_RX_EXTRA, true),
3923     DEFINE_PROP_BIT64("ctrl_mac_addr", VirtIONet, host_features,
3924                     VIRTIO_NET_F_CTRL_MAC_ADDR, true),
3925     DEFINE_PROP_BIT64("ctrl_guest_offloads", VirtIONet, host_features,
3926                     VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, true),
3927     DEFINE_PROP_BIT64("mq", VirtIONet, host_features, VIRTIO_NET_F_MQ, false),
3928     DEFINE_PROP_BIT64("rss", VirtIONet, host_features,
3929                     VIRTIO_NET_F_RSS, false),
3930     DEFINE_PROP_BIT64("hash", VirtIONet, host_features,
3931                     VIRTIO_NET_F_HASH_REPORT, false),
3932     DEFINE_PROP_BIT64("guest_rsc_ext", VirtIONet, host_features,
3933                     VIRTIO_NET_F_RSC_EXT, false),
3934     DEFINE_PROP_UINT32("rsc_interval", VirtIONet, rsc_timeout,
3935                        VIRTIO_NET_RSC_DEFAULT_INTERVAL),
3936     DEFINE_NIC_PROPERTIES(VirtIONet, nic_conf),
3937     DEFINE_PROP_UINT32("x-txtimer", VirtIONet, net_conf.txtimer,
3938                        TX_TIMER_INTERVAL),
3939     DEFINE_PROP_INT32("x-txburst", VirtIONet, net_conf.txburst, TX_BURST),
3940     DEFINE_PROP_STRING("tx", VirtIONet, net_conf.tx),
3941     DEFINE_PROP_UINT16("rx_queue_size", VirtIONet, net_conf.rx_queue_size,
3942                        VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE),
3943     DEFINE_PROP_UINT16("tx_queue_size", VirtIONet, net_conf.tx_queue_size,
3944                        VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE),
3945     DEFINE_PROP_UINT16("host_mtu", VirtIONet, net_conf.mtu, 0),
3946     DEFINE_PROP_BOOL("x-mtu-bypass-backend", VirtIONet, mtu_bypass_backend,
3947                      true),
3948     DEFINE_PROP_INT32("speed", VirtIONet, net_conf.speed, SPEED_UNKNOWN),
3949     DEFINE_PROP_STRING("duplex", VirtIONet, net_conf.duplex_str),
3950     DEFINE_PROP_BOOL("failover", VirtIONet, failover, false),
3951     DEFINE_PROP_BIT64("guest_uso4", VirtIONet, host_features,
3952                       VIRTIO_NET_F_GUEST_USO4, true),
3953     DEFINE_PROP_BIT64("guest_uso6", VirtIONet, host_features,
3954                       VIRTIO_NET_F_GUEST_USO6, true),
3955     DEFINE_PROP_BIT64("host_uso", VirtIONet, host_features,
3956                       VIRTIO_NET_F_HOST_USO, true),
3957     DEFINE_PROP_END_OF_LIST(),
3958 };
3959 
3960 static void virtio_net_class_init(ObjectClass *klass, void *data)
3961 {
3962     DeviceClass *dc = DEVICE_CLASS(klass);
3963     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
3964 
3965     device_class_set_props(dc, virtio_net_properties);
3966     dc->vmsd = &vmstate_virtio_net;
3967     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
3968     vdc->realize = virtio_net_device_realize;
3969     vdc->unrealize = virtio_net_device_unrealize;
3970     vdc->get_config = virtio_net_get_config;
3971     vdc->set_config = virtio_net_set_config;
3972     vdc->get_features = virtio_net_get_features;
3973     vdc->set_features = virtio_net_set_features;
3974     vdc->bad_features = virtio_net_bad_features;
3975     vdc->reset = virtio_net_reset;
3976     vdc->queue_reset = virtio_net_queue_reset;
3977     vdc->queue_enable = virtio_net_queue_enable;
3978     vdc->set_status = virtio_net_set_status;
3979     vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
3980     vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;
3981     vdc->legacy_features |= (0x1 << VIRTIO_NET_F_GSO);
3982     vdc->post_load = virtio_net_post_load_virtio;
3983     vdc->vmsd = &vmstate_virtio_net_device;
3984     vdc->primary_unplug_pending = primary_unplug_pending;
3985     vdc->get_vhost = virtio_net_get_vhost;
3986     vdc->toggle_device_iotlb = vhost_toggle_device_iotlb;
3987 }
3988 
3989 static const TypeInfo virtio_net_info = {
3990     .name = TYPE_VIRTIO_NET,
3991     .parent = TYPE_VIRTIO_DEVICE,
3992     .instance_size = sizeof(VirtIONet),
3993     .instance_init = virtio_net_instance_init,
3994     .class_init = virtio_net_class_init,
3995 };
3996 
3997 static void virtio_register_types(void)
3998 {
3999     type_register_static(&virtio_net_info);
4000 }
4001 
4002 type_init(virtio_register_types)
4003