xref: /openbmc/qemu/net/vhost-vdpa.c (revision bbc0543b)
1 /*
2  * vhost-vdpa.c
3  *
4  * Copyright(c) 2017-2018 Intel Corporation.
5  * Copyright(c) 2020 Red Hat, Inc.
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2 or later.
8  * See the COPYING file in the top-level directory.
9  *
10  */
11 
12 #include "qemu/osdep.h"
13 #include "clients.h"
14 #include "hw/virtio/virtio-net.h"
15 #include "net/vhost_net.h"
16 #include "net/vhost-vdpa.h"
17 #include "hw/virtio/vhost-vdpa.h"
18 #include "qemu/config-file.h"
19 #include "qemu/error-report.h"
20 #include "qemu/log.h"
21 #include "qemu/memalign.h"
22 #include "qemu/option.h"
23 #include "qapi/error.h"
24 #include <linux/vhost.h>
25 #include <sys/ioctl.h>
26 #include <err.h>
27 #include "standard-headers/linux/virtio_net.h"
28 #include "monitor/monitor.h"
29 #include "migration/misc.h"
30 #include "hw/virtio/vhost.h"
31 
32 /* Todo:need to add the multiqueue support here */
33 typedef struct VhostVDPAState {
34     NetClientState nc;
35     struct vhost_vdpa vhost_vdpa;
36     NotifierWithReturn migration_state;
37     VHostNetState *vhost_net;
38 
39     /* Control commands shadow buffers */
40     void *cvq_cmd_out_buffer;
41     virtio_net_ctrl_ack *status;
42 
43     /* The device always have SVQ enabled */
44     bool always_svq;
45 
46     /* The device can isolate CVQ in its own ASID */
47     bool cvq_isolated;
48 
49     bool started;
50 } VhostVDPAState;
51 
52 /*
53  * The array is sorted alphabetically in ascending order,
54  * with the exception of VHOST_INVALID_FEATURE_BIT,
55  * which should always be the last entry.
56  */
57 const int vdpa_feature_bits[] = {
58     VIRTIO_F_ANY_LAYOUT,
59     VIRTIO_F_IOMMU_PLATFORM,
60     VIRTIO_F_NOTIFY_ON_EMPTY,
61     VIRTIO_F_RING_PACKED,
62     VIRTIO_F_RING_RESET,
63     VIRTIO_F_VERSION_1,
64     VIRTIO_NET_F_CSUM,
65     VIRTIO_NET_F_CTRL_GUEST_OFFLOADS,
66     VIRTIO_NET_F_CTRL_MAC_ADDR,
67     VIRTIO_NET_F_CTRL_RX,
68     VIRTIO_NET_F_CTRL_RX_EXTRA,
69     VIRTIO_NET_F_CTRL_VLAN,
70     VIRTIO_NET_F_CTRL_VQ,
71     VIRTIO_NET_F_GSO,
72     VIRTIO_NET_F_GUEST_CSUM,
73     VIRTIO_NET_F_GUEST_ECN,
74     VIRTIO_NET_F_GUEST_TSO4,
75     VIRTIO_NET_F_GUEST_TSO6,
76     VIRTIO_NET_F_GUEST_UFO,
77     VIRTIO_NET_F_GUEST_USO4,
78     VIRTIO_NET_F_GUEST_USO6,
79     VIRTIO_NET_F_HASH_REPORT,
80     VIRTIO_NET_F_HOST_ECN,
81     VIRTIO_NET_F_HOST_TSO4,
82     VIRTIO_NET_F_HOST_TSO6,
83     VIRTIO_NET_F_HOST_UFO,
84     VIRTIO_NET_F_HOST_USO,
85     VIRTIO_NET_F_MQ,
86     VIRTIO_NET_F_MRG_RXBUF,
87     VIRTIO_NET_F_MTU,
88     VIRTIO_NET_F_RSS,
89     VIRTIO_NET_F_STATUS,
90     VIRTIO_RING_F_EVENT_IDX,
91     VIRTIO_RING_F_INDIRECT_DESC,
92 
93     /* VHOST_INVALID_FEATURE_BIT should always be the last entry */
94     VHOST_INVALID_FEATURE_BIT
95 };
96 
97 /** Supported device specific feature bits with SVQ */
98 static const uint64_t vdpa_svq_device_features =
99     BIT_ULL(VIRTIO_NET_F_CSUM) |
100     BIT_ULL(VIRTIO_NET_F_GUEST_CSUM) |
101     BIT_ULL(VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) |
102     BIT_ULL(VIRTIO_NET_F_MTU) |
103     BIT_ULL(VIRTIO_NET_F_MAC) |
104     BIT_ULL(VIRTIO_NET_F_GUEST_TSO4) |
105     BIT_ULL(VIRTIO_NET_F_GUEST_TSO6) |
106     BIT_ULL(VIRTIO_NET_F_GUEST_ECN) |
107     BIT_ULL(VIRTIO_NET_F_GUEST_UFO) |
108     BIT_ULL(VIRTIO_NET_F_HOST_TSO4) |
109     BIT_ULL(VIRTIO_NET_F_HOST_TSO6) |
110     BIT_ULL(VIRTIO_NET_F_HOST_ECN) |
111     BIT_ULL(VIRTIO_NET_F_HOST_UFO) |
112     BIT_ULL(VIRTIO_NET_F_MRG_RXBUF) |
113     BIT_ULL(VIRTIO_NET_F_STATUS) |
114     BIT_ULL(VIRTIO_NET_F_CTRL_VQ) |
115     BIT_ULL(VIRTIO_NET_F_CTRL_RX) |
116     BIT_ULL(VIRTIO_NET_F_CTRL_VLAN) |
117     BIT_ULL(VIRTIO_NET_F_CTRL_RX_EXTRA) |
118     BIT_ULL(VIRTIO_NET_F_MQ) |
119     BIT_ULL(VIRTIO_F_ANY_LAYOUT) |
120     BIT_ULL(VIRTIO_NET_F_CTRL_MAC_ADDR) |
121     /* VHOST_F_LOG_ALL is exposed by SVQ */
122     BIT_ULL(VHOST_F_LOG_ALL) |
123     BIT_ULL(VIRTIO_NET_F_HASH_REPORT) |
124     BIT_ULL(VIRTIO_NET_F_RSS) |
125     BIT_ULL(VIRTIO_NET_F_RSC_EXT) |
126     BIT_ULL(VIRTIO_NET_F_STANDBY) |
127     BIT_ULL(VIRTIO_NET_F_SPEED_DUPLEX);
128 
129 #define VHOST_VDPA_NET_CVQ_ASID 1
130 
131 VHostNetState *vhost_vdpa_get_vhost_net(NetClientState *nc)
132 {
133     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
134     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
135     return s->vhost_net;
136 }
137 
138 static size_t vhost_vdpa_net_cvq_cmd_len(void)
139 {
140     /*
141      * MAC_TABLE_SET is the ctrl command that produces the longer out buffer.
142      * In buffer is always 1 byte, so it should fit here
143      */
144     return sizeof(struct virtio_net_ctrl_hdr) +
145            2 * sizeof(struct virtio_net_ctrl_mac) +
146            MAC_TABLE_ENTRIES * ETH_ALEN;
147 }
148 
149 static size_t vhost_vdpa_net_cvq_cmd_page_len(void)
150 {
151     return ROUND_UP(vhost_vdpa_net_cvq_cmd_len(), qemu_real_host_page_size());
152 }
153 
154 static bool vhost_vdpa_net_valid_svq_features(uint64_t features, Error **errp)
155 {
156     uint64_t invalid_dev_features =
157         features & ~vdpa_svq_device_features &
158         /* Transport are all accepted at this point */
159         ~MAKE_64BIT_MASK(VIRTIO_TRANSPORT_F_START,
160                          VIRTIO_TRANSPORT_F_END - VIRTIO_TRANSPORT_F_START);
161 
162     if (invalid_dev_features) {
163         error_setg(errp, "vdpa svq does not work with features 0x%" PRIx64,
164                    invalid_dev_features);
165         return false;
166     }
167 
168     return vhost_svq_valid_features(features, errp);
169 }
170 
171 static int vhost_vdpa_net_check_device_id(struct vhost_net *net)
172 {
173     uint32_t device_id;
174     int ret;
175     struct vhost_dev *hdev;
176 
177     hdev = (struct vhost_dev *)&net->dev;
178     ret = hdev->vhost_ops->vhost_get_device_id(hdev, &device_id);
179     if (device_id != VIRTIO_ID_NET) {
180         return -ENOTSUP;
181     }
182     return ret;
183 }
184 
185 static int vhost_vdpa_add(NetClientState *ncs, void *be,
186                           int queue_pair_index, int nvqs)
187 {
188     VhostNetOptions options;
189     struct vhost_net *net = NULL;
190     VhostVDPAState *s;
191     int ret;
192 
193     options.backend_type = VHOST_BACKEND_TYPE_VDPA;
194     assert(ncs->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
195     s = DO_UPCAST(VhostVDPAState, nc, ncs);
196     options.net_backend = ncs;
197     options.opaque      = be;
198     options.busyloop_timeout = 0;
199     options.nvqs = nvqs;
200 
201     net = vhost_net_init(&options);
202     if (!net) {
203         error_report("failed to init vhost_net for queue");
204         goto err_init;
205     }
206     s->vhost_net = net;
207     ret = vhost_vdpa_net_check_device_id(net);
208     if (ret) {
209         goto err_check;
210     }
211     return 0;
212 err_check:
213     vhost_net_cleanup(net);
214     g_free(net);
215 err_init:
216     return -1;
217 }
218 
219 static void vhost_vdpa_cleanup(NetClientState *nc)
220 {
221     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
222 
223     /*
224      * If a peer NIC is attached, do not cleanup anything.
225      * Cleanup will happen as a part of qemu_cleanup() -> net_cleanup()
226      * when the guest is shutting down.
227      */
228     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
229         return;
230     }
231     munmap(s->cvq_cmd_out_buffer, vhost_vdpa_net_cvq_cmd_page_len());
232     munmap(s->status, vhost_vdpa_net_cvq_cmd_page_len());
233     if (s->vhost_net) {
234         vhost_net_cleanup(s->vhost_net);
235         g_free(s->vhost_net);
236         s->vhost_net = NULL;
237     }
238     if (s->vhost_vdpa.index != 0) {
239         return;
240     }
241     qemu_close(s->vhost_vdpa.shared->device_fd);
242     g_free(s->vhost_vdpa.shared);
243 }
244 
245 /** Dummy SetSteeringEBPF to support RSS for vhost-vdpa backend  */
246 static bool vhost_vdpa_set_steering_ebpf(NetClientState *nc, int prog_fd)
247 {
248     return true;
249 }
250 
251 static bool vhost_vdpa_has_vnet_hdr(NetClientState *nc)
252 {
253     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
254 
255     return true;
256 }
257 
258 static bool vhost_vdpa_has_ufo(NetClientState *nc)
259 {
260     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
261     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
262     uint64_t features = 0;
263     features |= (1ULL << VIRTIO_NET_F_HOST_UFO);
264     features = vhost_net_get_features(s->vhost_net, features);
265     return !!(features & (1ULL << VIRTIO_NET_F_HOST_UFO));
266 
267 }
268 
269 static bool vhost_vdpa_check_peer_type(NetClientState *nc, ObjectClass *oc,
270                                        Error **errp)
271 {
272     const char *driver = object_class_get_name(oc);
273 
274     if (!g_str_has_prefix(driver, "virtio-net-")) {
275         error_setg(errp, "vhost-vdpa requires frontend driver virtio-net-*");
276         return false;
277     }
278 
279     return true;
280 }
281 
282 /** Dummy receive in case qemu falls back to userland tap networking */
283 static ssize_t vhost_vdpa_receive(NetClientState *nc, const uint8_t *buf,
284                                   size_t size)
285 {
286     return size;
287 }
288 
289 static void vhost_vdpa_net_log_global_enable(VhostVDPAState *s, bool enable)
290 {
291     struct vhost_vdpa *v = &s->vhost_vdpa;
292     VirtIONet *n;
293     VirtIODevice *vdev;
294     int data_queue_pairs, cvq, r;
295 
296     /* We are only called on the first data vqs and only if x-svq is not set */
297     if (s->vhost_vdpa.shadow_vqs_enabled == enable) {
298         return;
299     }
300 
301     vdev = v->dev->vdev;
302     n = VIRTIO_NET(vdev);
303     if (!n->vhost_started) {
304         return;
305     }
306 
307     data_queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
308     cvq = virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) ?
309                                   n->max_ncs - n->max_queue_pairs : 0;
310     /*
311      * TODO: vhost_net_stop does suspend, get_base and reset. We can be smarter
312      * in the future and resume the device if read-only operations between
313      * suspend and reset goes wrong.
314      */
315     vhost_net_stop(vdev, n->nic->ncs, data_queue_pairs, cvq);
316 
317     /* Start will check migration setup_or_active to configure or not SVQ */
318     r = vhost_net_start(vdev, n->nic->ncs, data_queue_pairs, cvq);
319     if (unlikely(r < 0)) {
320         error_report("unable to start vhost net: %s(%d)", g_strerror(-r), -r);
321     }
322 }
323 
324 static int vdpa_net_migration_state_notifier(NotifierWithReturn *notifier,
325                                              MigrationEvent *e, Error **errp)
326 {
327     VhostVDPAState *s = container_of(notifier, VhostVDPAState, migration_state);
328 
329     if (e->type == MIG_EVENT_PRECOPY_SETUP) {
330         vhost_vdpa_net_log_global_enable(s, true);
331     } else if (e->type == MIG_EVENT_PRECOPY_FAILED) {
332         vhost_vdpa_net_log_global_enable(s, false);
333     }
334     return 0;
335 }
336 
337 static void vhost_vdpa_net_data_start_first(VhostVDPAState *s)
338 {
339     struct vhost_vdpa *v = &s->vhost_vdpa;
340 
341     migration_add_notifier(&s->migration_state,
342                            vdpa_net_migration_state_notifier);
343     if (v->shadow_vqs_enabled) {
344         v->shared->iova_tree = vhost_iova_tree_new(v->shared->iova_range.first,
345                                                    v->shared->iova_range.last);
346     }
347 }
348 
349 static int vhost_vdpa_net_data_start(NetClientState *nc)
350 {
351     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
352     struct vhost_vdpa *v = &s->vhost_vdpa;
353 
354     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
355 
356     if (s->always_svq ||
357         migration_is_setup_or_active()) {
358         v->shadow_vqs_enabled = true;
359     } else {
360         v->shadow_vqs_enabled = false;
361     }
362 
363     if (v->index == 0) {
364         v->shared->shadow_data = v->shadow_vqs_enabled;
365         vhost_vdpa_net_data_start_first(s);
366         return 0;
367     }
368 
369     return 0;
370 }
371 
372 static int vhost_vdpa_net_data_load(NetClientState *nc)
373 {
374     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
375     struct vhost_vdpa *v = &s->vhost_vdpa;
376     bool has_cvq = v->dev->vq_index_end % 2;
377 
378     if (has_cvq) {
379         return 0;
380     }
381 
382     for (int i = 0; i < v->dev->nvqs; ++i) {
383         vhost_vdpa_set_vring_ready(v, i + v->dev->vq_index);
384     }
385     return 0;
386 }
387 
388 static void vhost_vdpa_net_client_stop(NetClientState *nc)
389 {
390     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
391     struct vhost_dev *dev;
392 
393     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
394 
395     if (s->vhost_vdpa.index == 0) {
396         migration_remove_notifier(&s->migration_state);
397     }
398 
399     dev = s->vhost_vdpa.dev;
400     if (dev->vq_index + dev->nvqs == dev->vq_index_end) {
401         g_clear_pointer(&s->vhost_vdpa.shared->iova_tree,
402                         vhost_iova_tree_delete);
403     }
404 }
405 
406 static NetClientInfo net_vhost_vdpa_info = {
407         .type = NET_CLIENT_DRIVER_VHOST_VDPA,
408         .size = sizeof(VhostVDPAState),
409         .receive = vhost_vdpa_receive,
410         .start = vhost_vdpa_net_data_start,
411         .load = vhost_vdpa_net_data_load,
412         .stop = vhost_vdpa_net_client_stop,
413         .cleanup = vhost_vdpa_cleanup,
414         .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
415         .has_ufo = vhost_vdpa_has_ufo,
416         .check_peer_type = vhost_vdpa_check_peer_type,
417         .set_steering_ebpf = vhost_vdpa_set_steering_ebpf,
418 };
419 
420 static int64_t vhost_vdpa_get_vring_group(int device_fd, unsigned vq_index,
421                                           Error **errp)
422 {
423     struct vhost_vring_state state = {
424         .index = vq_index,
425     };
426     int r = ioctl(device_fd, VHOST_VDPA_GET_VRING_GROUP, &state);
427 
428     if (unlikely(r < 0)) {
429         r = -errno;
430         error_setg_errno(errp, errno, "Cannot get VQ %u group", vq_index);
431         return r;
432     }
433 
434     return state.num;
435 }
436 
437 static int vhost_vdpa_set_address_space_id(struct vhost_vdpa *v,
438                                            unsigned vq_group,
439                                            unsigned asid_num)
440 {
441     struct vhost_vring_state asid = {
442         .index = vq_group,
443         .num = asid_num,
444     };
445     int r;
446 
447     r = ioctl(v->shared->device_fd, VHOST_VDPA_SET_GROUP_ASID, &asid);
448     if (unlikely(r < 0)) {
449         error_report("Can't set vq group %u asid %u, errno=%d (%s)",
450                      asid.index, asid.num, errno, g_strerror(errno));
451     }
452     return r;
453 }
454 
455 static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr)
456 {
457     VhostIOVATree *tree = v->shared->iova_tree;
458     DMAMap needle = {
459         /*
460          * No need to specify size or to look for more translations since
461          * this contiguous chunk was allocated by us.
462          */
463         .translated_addr = (hwaddr)(uintptr_t)addr,
464     };
465     const DMAMap *map = vhost_iova_tree_find_iova(tree, &needle);
466     int r;
467 
468     if (unlikely(!map)) {
469         error_report("Cannot locate expected map");
470         return;
471     }
472 
473     r = vhost_vdpa_dma_unmap(v->shared, v->address_space_id, map->iova,
474                              map->size + 1);
475     if (unlikely(r != 0)) {
476         error_report("Device cannot unmap: %s(%d)", g_strerror(r), r);
477     }
478 
479     vhost_iova_tree_remove(tree, *map);
480 }
481 
482 /** Map CVQ buffer. */
483 static int vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, void *buf, size_t size,
484                                   bool write)
485 {
486     DMAMap map = {};
487     int r;
488 
489     map.translated_addr = (hwaddr)(uintptr_t)buf;
490     map.size = size - 1;
491     map.perm = write ? IOMMU_RW : IOMMU_RO,
492     r = vhost_iova_tree_map_alloc(v->shared->iova_tree, &map);
493     if (unlikely(r != IOVA_OK)) {
494         error_report("Cannot map injected element");
495         return r;
496     }
497 
498     r = vhost_vdpa_dma_map(v->shared, v->address_space_id, map.iova,
499                            vhost_vdpa_net_cvq_cmd_page_len(), buf, !write);
500     if (unlikely(r < 0)) {
501         goto dma_map_err;
502     }
503 
504     return 0;
505 
506 dma_map_err:
507     vhost_iova_tree_remove(v->shared->iova_tree, map);
508     return r;
509 }
510 
511 static int vhost_vdpa_net_cvq_start(NetClientState *nc)
512 {
513     VhostVDPAState *s;
514     struct vhost_vdpa *v;
515     int64_t cvq_group;
516     int r;
517     Error *err = NULL;
518 
519     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
520 
521     s = DO_UPCAST(VhostVDPAState, nc, nc);
522     v = &s->vhost_vdpa;
523 
524     v->shadow_vqs_enabled = v->shared->shadow_data;
525     s->vhost_vdpa.address_space_id = VHOST_VDPA_GUEST_PA_ASID;
526 
527     if (v->shared->shadow_data) {
528         /* SVQ is already configured for all virtqueues */
529         goto out;
530     }
531 
532     /*
533      * If we early return in these cases SVQ will not be enabled. The migration
534      * will be blocked as long as vhost-vdpa backends will not offer _F_LOG.
535      */
536     if (!vhost_vdpa_net_valid_svq_features(v->dev->features, NULL)) {
537         return 0;
538     }
539 
540     if (!s->cvq_isolated) {
541         return 0;
542     }
543 
544     cvq_group = vhost_vdpa_get_vring_group(v->shared->device_fd,
545                                            v->dev->vq_index_end - 1,
546                                            &err);
547     if (unlikely(cvq_group < 0)) {
548         error_report_err(err);
549         return cvq_group;
550     }
551 
552     r = vhost_vdpa_set_address_space_id(v, cvq_group, VHOST_VDPA_NET_CVQ_ASID);
553     if (unlikely(r < 0)) {
554         return r;
555     }
556 
557     v->shadow_vqs_enabled = true;
558     s->vhost_vdpa.address_space_id = VHOST_VDPA_NET_CVQ_ASID;
559 
560 out:
561     if (!s->vhost_vdpa.shadow_vqs_enabled) {
562         return 0;
563     }
564 
565     /*
566      * If other vhost_vdpa already have an iova_tree, reuse it for simplicity,
567      * whether CVQ shares ASID with guest or not, because:
568      * - Memory listener need access to guest's memory addresses allocated in
569      *   the IOVA tree.
570      * - There should be plenty of IOVA address space for both ASID not to
571      *   worry about collisions between them.  Guest's translations are still
572      *   validated with virtio virtqueue_pop so there is no risk for the guest
573      *   to access memory that it shouldn't.
574      *
575      * To allocate a iova tree per ASID is doable but it complicates the code
576      * and it is not worth it for the moment.
577      */
578     if (!v->shared->iova_tree) {
579         v->shared->iova_tree = vhost_iova_tree_new(v->shared->iova_range.first,
580                                                    v->shared->iova_range.last);
581     }
582 
583     r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer,
584                                vhost_vdpa_net_cvq_cmd_page_len(), false);
585     if (unlikely(r < 0)) {
586         return r;
587     }
588 
589     r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->status,
590                                vhost_vdpa_net_cvq_cmd_page_len(), true);
591     if (unlikely(r < 0)) {
592         vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer);
593     }
594 
595     return r;
596 }
597 
598 static void vhost_vdpa_net_cvq_stop(NetClientState *nc)
599 {
600     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
601 
602     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
603 
604     if (s->vhost_vdpa.shadow_vqs_enabled) {
605         vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer);
606         vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->status);
607     }
608 
609     vhost_vdpa_net_client_stop(nc);
610 }
611 
612 static ssize_t vhost_vdpa_net_cvq_add(VhostVDPAState *s,
613                                     const struct iovec *out_sg, size_t out_num,
614                                     const struct iovec *in_sg, size_t in_num)
615 {
616     VhostShadowVirtqueue *svq = g_ptr_array_index(s->vhost_vdpa.shadow_vqs, 0);
617     int r;
618 
619     r = vhost_svq_add(svq, out_sg, out_num, in_sg, in_num, NULL);
620     if (unlikely(r != 0)) {
621         if (unlikely(r == -ENOSPC)) {
622             qemu_log_mask(LOG_GUEST_ERROR, "%s: No space on device queue\n",
623                           __func__);
624         }
625     }
626 
627     return r;
628 }
629 
630 /*
631  * Convenience wrapper to poll SVQ for multiple control commands.
632  *
633  * Caller should hold the BQL when invoking this function, and should take
634  * the answer before SVQ pulls by itself when BQL is released.
635  */
636 static ssize_t vhost_vdpa_net_svq_poll(VhostVDPAState *s, size_t cmds_in_flight)
637 {
638     VhostShadowVirtqueue *svq = g_ptr_array_index(s->vhost_vdpa.shadow_vqs, 0);
639     return vhost_svq_poll(svq, cmds_in_flight);
640 }
641 
642 static void vhost_vdpa_net_load_cursor_reset(VhostVDPAState *s,
643                                              struct iovec *out_cursor,
644                                              struct iovec *in_cursor)
645 {
646     /* reset the cursor of the output buffer for the device */
647     out_cursor->iov_base = s->cvq_cmd_out_buffer;
648     out_cursor->iov_len = vhost_vdpa_net_cvq_cmd_page_len();
649 
650     /* reset the cursor of the in buffer for the device */
651     in_cursor->iov_base = s->status;
652     in_cursor->iov_len = vhost_vdpa_net_cvq_cmd_page_len();
653 }
654 
655 /*
656  * Poll SVQ for multiple pending control commands and check the device's ack.
657  *
658  * Caller should hold the BQL when invoking this function.
659  *
660  * @s: The VhostVDPAState
661  * @len: The length of the pending status shadow buffer
662  */
663 static ssize_t vhost_vdpa_net_svq_flush(VhostVDPAState *s, size_t len)
664 {
665     /* device uses a one-byte length ack for each control command */
666     ssize_t dev_written = vhost_vdpa_net_svq_poll(s, len);
667     if (unlikely(dev_written != len)) {
668         return -EIO;
669     }
670 
671     /* check the device's ack */
672     for (int i = 0; i < len; ++i) {
673         if (s->status[i] != VIRTIO_NET_OK) {
674             return -EIO;
675         }
676     }
677     return 0;
678 }
679 
680 static ssize_t vhost_vdpa_net_load_cmd(VhostVDPAState *s,
681                                        struct iovec *out_cursor,
682                                        struct iovec *in_cursor, uint8_t class,
683                                        uint8_t cmd, const struct iovec *data_sg,
684                                        size_t data_num)
685 {
686     const struct virtio_net_ctrl_hdr ctrl = {
687         .class = class,
688         .cmd = cmd,
689     };
690     size_t data_size = iov_size(data_sg, data_num), cmd_size;
691     struct iovec out, in;
692     ssize_t r;
693     unsigned dummy_cursor_iov_cnt;
694     VhostShadowVirtqueue *svq = g_ptr_array_index(s->vhost_vdpa.shadow_vqs, 0);
695 
696     assert(data_size < vhost_vdpa_net_cvq_cmd_page_len() - sizeof(ctrl));
697     cmd_size = sizeof(ctrl) + data_size;
698     if (vhost_svq_available_slots(svq) < 2 ||
699         iov_size(out_cursor, 1) < cmd_size) {
700         /*
701          * It is time to flush all pending control commands if SVQ is full
702          * or control commands shadow buffers are full.
703          *
704          * We can poll here since we've had BQL from the time
705          * we sent the descriptor.
706          */
707         r = vhost_vdpa_net_svq_flush(s, in_cursor->iov_base -
708                                      (void *)s->status);
709         if (unlikely(r < 0)) {
710             return r;
711         }
712 
713         vhost_vdpa_net_load_cursor_reset(s, out_cursor, in_cursor);
714     }
715 
716     /* pack the CVQ command header */
717     iov_from_buf(out_cursor, 1, 0, &ctrl, sizeof(ctrl));
718     /* pack the CVQ command command-specific-data */
719     iov_to_buf(data_sg, data_num, 0,
720                out_cursor->iov_base + sizeof(ctrl), data_size);
721 
722     /* extract the required buffer from the cursor for output */
723     iov_copy(&out, 1, out_cursor, 1, 0, cmd_size);
724     /* extract the required buffer from the cursor for input */
725     iov_copy(&in, 1, in_cursor, 1, 0, sizeof(*s->status));
726 
727     r = vhost_vdpa_net_cvq_add(s, &out, 1, &in, 1);
728     if (unlikely(r < 0)) {
729         return r;
730     }
731 
732     /* iterate the cursors */
733     dummy_cursor_iov_cnt = 1;
734     iov_discard_front(&out_cursor, &dummy_cursor_iov_cnt, cmd_size);
735     dummy_cursor_iov_cnt = 1;
736     iov_discard_front(&in_cursor, &dummy_cursor_iov_cnt, sizeof(*s->status));
737 
738     return 0;
739 }
740 
741 static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n,
742                                    struct iovec *out_cursor,
743                                    struct iovec *in_cursor)
744 {
745     if (virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
746         const struct iovec data = {
747             .iov_base = (void *)n->mac,
748             .iov_len = sizeof(n->mac),
749         };
750         ssize_t r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
751                                             VIRTIO_NET_CTRL_MAC,
752                                             VIRTIO_NET_CTRL_MAC_ADDR_SET,
753                                             &data, 1);
754         if (unlikely(r < 0)) {
755             return r;
756         }
757     }
758 
759     /*
760      * According to VirtIO standard, "The device MUST have an
761      * empty MAC filtering table on reset.".
762      *
763      * Therefore, there is no need to send this CVQ command if the
764      * driver also sets an empty MAC filter table, which aligns with
765      * the device's defaults.
766      *
767      * Note that the device's defaults can mismatch the driver's
768      * configuration only at live migration.
769      */
770     if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_RX) ||
771         n->mac_table.in_use == 0) {
772         return 0;
773     }
774 
775     uint32_t uni_entries = n->mac_table.first_multi,
776              uni_macs_size = uni_entries * ETH_ALEN,
777              mul_entries = n->mac_table.in_use - uni_entries,
778              mul_macs_size = mul_entries * ETH_ALEN;
779     struct virtio_net_ctrl_mac uni = {
780         .entries = cpu_to_le32(uni_entries),
781     };
782     struct virtio_net_ctrl_mac mul = {
783         .entries = cpu_to_le32(mul_entries),
784     };
785     const struct iovec data[] = {
786         {
787             .iov_base = &uni,
788             .iov_len = sizeof(uni),
789         }, {
790             .iov_base = n->mac_table.macs,
791             .iov_len = uni_macs_size,
792         }, {
793             .iov_base = &mul,
794             .iov_len = sizeof(mul),
795         }, {
796             .iov_base = &n->mac_table.macs[uni_macs_size],
797             .iov_len = mul_macs_size,
798         },
799     };
800     ssize_t r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
801                                         VIRTIO_NET_CTRL_MAC,
802                                         VIRTIO_NET_CTRL_MAC_TABLE_SET,
803                                         data, ARRAY_SIZE(data));
804     if (unlikely(r < 0)) {
805         return r;
806     }
807 
808     return 0;
809 }
810 
811 static int vhost_vdpa_net_load_rss(VhostVDPAState *s, const VirtIONet *n,
812                                    struct iovec *out_cursor,
813                                    struct iovec *in_cursor, bool do_rss)
814 {
815     struct virtio_net_rss_config cfg = {};
816     ssize_t r;
817     g_autofree uint16_t *table = NULL;
818 
819     /*
820      * According to VirtIO standard, "Initially the device has all hash
821      * types disabled and reports only VIRTIO_NET_HASH_REPORT_NONE.".
822      *
823      * Therefore, there is no need to send this CVQ command if the
824      * driver disables the all hash types, which aligns with
825      * the device's defaults.
826      *
827      * Note that the device's defaults can mismatch the driver's
828      * configuration only at live migration.
829      */
830     if (!n->rss_data.enabled ||
831         n->rss_data.hash_types == VIRTIO_NET_HASH_REPORT_NONE) {
832         return 0;
833     }
834 
835     table = g_malloc_n(n->rss_data.indirections_len,
836                        sizeof(n->rss_data.indirections_table[0]));
837     cfg.hash_types = cpu_to_le32(n->rss_data.hash_types);
838 
839     if (do_rss) {
840         /*
841          * According to VirtIO standard, "Number of entries in indirection_table
842          * is (indirection_table_mask + 1)".
843          */
844         cfg.indirection_table_mask = cpu_to_le16(n->rss_data.indirections_len -
845                                                  1);
846         cfg.unclassified_queue = cpu_to_le16(n->rss_data.default_queue);
847         for (int i = 0; i < n->rss_data.indirections_len; ++i) {
848             table[i] = cpu_to_le16(n->rss_data.indirections_table[i]);
849         }
850         cfg.max_tx_vq = cpu_to_le16(n->curr_queue_pairs);
851     } else {
852         /*
853          * According to VirtIO standard, "Field reserved MUST contain zeroes.
854          * It is defined to make the structure to match the layout of
855          * virtio_net_rss_config structure, defined in 5.1.6.5.7.".
856          *
857          * Therefore, we need to zero the fields in
858          * struct virtio_net_rss_config, which corresponds to the
859          * `reserved` field in struct virtio_net_hash_config.
860          *
861          * Note that all other fields are zeroed at their definitions,
862          * except for the `indirection_table` field, where the actual data
863          * is stored in the `table` variable to ensure compatibility
864          * with RSS case. Therefore, we need to zero the `table` variable here.
865          */
866         table[0] = 0;
867     }
868 
869     /*
870      * Considering that virtio_net_handle_rss() currently does not restore
871      * the hash key length parsed from the CVQ command sent from the guest
872      * into n->rss_data and uses the maximum key length in other code, so
873      * we also employ the maximum key length here.
874      */
875     cfg.hash_key_length = sizeof(n->rss_data.key);
876 
877     const struct iovec data[] = {
878         {
879             .iov_base = &cfg,
880             .iov_len = offsetof(struct virtio_net_rss_config,
881                                 indirection_table),
882         }, {
883             .iov_base = table,
884             .iov_len = n->rss_data.indirections_len *
885                        sizeof(n->rss_data.indirections_table[0]),
886         }, {
887             .iov_base = &cfg.max_tx_vq,
888             .iov_len = offsetof(struct virtio_net_rss_config, hash_key_data) -
889                        offsetof(struct virtio_net_rss_config, max_tx_vq),
890         }, {
891             .iov_base = (void *)n->rss_data.key,
892             .iov_len = sizeof(n->rss_data.key),
893         }
894     };
895 
896     r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
897                                 VIRTIO_NET_CTRL_MQ,
898                                 do_rss ? VIRTIO_NET_CTRL_MQ_RSS_CONFIG :
899                                 VIRTIO_NET_CTRL_MQ_HASH_CONFIG,
900                                 data, ARRAY_SIZE(data));
901     if (unlikely(r < 0)) {
902         return r;
903     }
904 
905     return 0;
906 }
907 
908 static int vhost_vdpa_net_load_mq(VhostVDPAState *s,
909                                   const VirtIONet *n,
910                                   struct iovec *out_cursor,
911                                   struct iovec *in_cursor)
912 {
913     struct virtio_net_ctrl_mq mq;
914     ssize_t r;
915 
916     if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_MQ)) {
917         return 0;
918     }
919 
920     mq.virtqueue_pairs = cpu_to_le16(n->curr_queue_pairs);
921     const struct iovec data = {
922         .iov_base = &mq,
923         .iov_len = sizeof(mq),
924     };
925     r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
926                                 VIRTIO_NET_CTRL_MQ,
927                                 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET,
928                                 &data, 1);
929     if (unlikely(r < 0)) {
930         return r;
931     }
932 
933     if (virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_RSS)) {
934         /* load the receive-side scaling state */
935         r = vhost_vdpa_net_load_rss(s, n, out_cursor, in_cursor, true);
936         if (unlikely(r < 0)) {
937             return r;
938         }
939     } else if (virtio_vdev_has_feature(&n->parent_obj,
940                                        VIRTIO_NET_F_HASH_REPORT)) {
941         /* load the hash calculation state */
942         r = vhost_vdpa_net_load_rss(s, n, out_cursor, in_cursor, false);
943         if (unlikely(r < 0)) {
944             return r;
945         }
946     }
947 
948     return 0;
949 }
950 
951 static int vhost_vdpa_net_load_offloads(VhostVDPAState *s,
952                                         const VirtIONet *n,
953                                         struct iovec *out_cursor,
954                                         struct iovec *in_cursor)
955 {
956     uint64_t offloads;
957     ssize_t r;
958 
959     if (!virtio_vdev_has_feature(&n->parent_obj,
960                                  VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
961         return 0;
962     }
963 
964     if (n->curr_guest_offloads == virtio_net_supported_guest_offloads(n)) {
965         /*
966          * According to VirtIO standard, "Upon feature negotiation
967          * corresponding offload gets enabled to preserve
968          * backward compatibility.".
969          *
970          * Therefore, there is no need to send this CVQ command if the
971          * driver also enables all supported offloads, which aligns with
972          * the device's defaults.
973          *
974          * Note that the device's defaults can mismatch the driver's
975          * configuration only at live migration.
976          */
977         return 0;
978     }
979 
980     offloads = cpu_to_le64(n->curr_guest_offloads);
981     const struct iovec data = {
982         .iov_base = &offloads,
983         .iov_len = sizeof(offloads),
984     };
985     r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
986                                 VIRTIO_NET_CTRL_GUEST_OFFLOADS,
987                                 VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET,
988                                 &data, 1);
989     if (unlikely(r < 0)) {
990         return r;
991     }
992 
993     return 0;
994 }
995 
996 static int vhost_vdpa_net_load_rx_mode(VhostVDPAState *s,
997                                        struct iovec *out_cursor,
998                                        struct iovec *in_cursor,
999                                        uint8_t cmd,
1000                                        uint8_t on)
1001 {
1002     const struct iovec data = {
1003         .iov_base = &on,
1004         .iov_len = sizeof(on),
1005     };
1006     ssize_t r;
1007 
1008     r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
1009                                 VIRTIO_NET_CTRL_RX, cmd, &data, 1);
1010     if (unlikely(r < 0)) {
1011         return r;
1012     }
1013 
1014     return 0;
1015 }
1016 
1017 static int vhost_vdpa_net_load_rx(VhostVDPAState *s,
1018                                   const VirtIONet *n,
1019                                   struct iovec *out_cursor,
1020                                   struct iovec *in_cursor)
1021 {
1022     ssize_t r;
1023 
1024     if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_RX)) {
1025         return 0;
1026     }
1027 
1028     /*
1029      * According to virtio_net_reset(), device turns promiscuous mode
1030      * on by default.
1031      *
1032      * Additionally, according to VirtIO standard, "Since there are
1033      * no guarantees, it can use a hash filter or silently switch to
1034      * allmulti or promiscuous mode if it is given too many addresses.".
1035      * QEMU marks `n->mac_table.uni_overflow` if guest sets too many
1036      * non-multicast MAC addresses, indicating that promiscuous mode
1037      * should be enabled.
1038      *
1039      * Therefore, QEMU should only send this CVQ command if the
1040      * `n->mac_table.uni_overflow` is not marked and `n->promisc` is off,
1041      * which sets promiscuous mode on, different from the device's defaults.
1042      *
1043      * Note that the device's defaults can mismatch the driver's
1044      * configuration only at live migration.
1045      */
1046     if (!n->mac_table.uni_overflow && !n->promisc) {
1047         r = vhost_vdpa_net_load_rx_mode(s, out_cursor, in_cursor,
1048                                         VIRTIO_NET_CTRL_RX_PROMISC, 0);
1049         if (unlikely(r < 0)) {
1050             return r;
1051         }
1052     }
1053 
1054     /*
1055      * According to virtio_net_reset(), device turns all-multicast mode
1056      * off by default.
1057      *
1058      * According to VirtIO standard, "Since there are no guarantees,
1059      * it can use a hash filter or silently switch to allmulti or
1060      * promiscuous mode if it is given too many addresses.". QEMU marks
1061      * `n->mac_table.multi_overflow` if guest sets too many
1062      * non-multicast MAC addresses.
1063      *
1064      * Therefore, QEMU should only send this CVQ command if the
1065      * `n->mac_table.multi_overflow` is marked or `n->allmulti` is on,
1066      * which sets all-multicast mode on, different from the device's defaults.
1067      *
1068      * Note that the device's defaults can mismatch the driver's
1069      * configuration only at live migration.
1070      */
1071     if (n->mac_table.multi_overflow || n->allmulti) {
1072         r = vhost_vdpa_net_load_rx_mode(s, out_cursor, in_cursor,
1073                                         VIRTIO_NET_CTRL_RX_ALLMULTI, 1);
1074         if (unlikely(r < 0)) {
1075             return r;
1076         }
1077     }
1078 
1079     if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_RX_EXTRA)) {
1080         return 0;
1081     }
1082 
1083     /*
1084      * According to virtio_net_reset(), device turns all-unicast mode
1085      * off by default.
1086      *
1087      * Therefore, QEMU should only send this CVQ command if the driver
1088      * sets all-unicast mode on, different from the device's defaults.
1089      *
1090      * Note that the device's defaults can mismatch the driver's
1091      * configuration only at live migration.
1092      */
1093     if (n->alluni) {
1094         r = vhost_vdpa_net_load_rx_mode(s, out_cursor, in_cursor,
1095                                         VIRTIO_NET_CTRL_RX_ALLUNI, 1);
1096         if (r < 0) {
1097             return r;
1098         }
1099     }
1100 
1101     /*
1102      * According to virtio_net_reset(), device turns non-multicast mode
1103      * off by default.
1104      *
1105      * Therefore, QEMU should only send this CVQ command if the driver
1106      * sets non-multicast mode on, different from the device's defaults.
1107      *
1108      * Note that the device's defaults can mismatch the driver's
1109      * configuration only at live migration.
1110      */
1111     if (n->nomulti) {
1112         r = vhost_vdpa_net_load_rx_mode(s, out_cursor, in_cursor,
1113                                         VIRTIO_NET_CTRL_RX_NOMULTI, 1);
1114         if (r < 0) {
1115             return r;
1116         }
1117     }
1118 
1119     /*
1120      * According to virtio_net_reset(), device turns non-unicast mode
1121      * off by default.
1122      *
1123      * Therefore, QEMU should only send this CVQ command if the driver
1124      * sets non-unicast mode on, different from the device's defaults.
1125      *
1126      * Note that the device's defaults can mismatch the driver's
1127      * configuration only at live migration.
1128      */
1129     if (n->nouni) {
1130         r = vhost_vdpa_net_load_rx_mode(s, out_cursor, in_cursor,
1131                                         VIRTIO_NET_CTRL_RX_NOUNI, 1);
1132         if (r < 0) {
1133             return r;
1134         }
1135     }
1136 
1137     /*
1138      * According to virtio_net_reset(), device turns non-broadcast mode
1139      * off by default.
1140      *
1141      * Therefore, QEMU should only send this CVQ command if the driver
1142      * sets non-broadcast mode on, different from the device's defaults.
1143      *
1144      * Note that the device's defaults can mismatch the driver's
1145      * configuration only at live migration.
1146      */
1147     if (n->nobcast) {
1148         r = vhost_vdpa_net_load_rx_mode(s, out_cursor, in_cursor,
1149                                         VIRTIO_NET_CTRL_RX_NOBCAST, 1);
1150         if (r < 0) {
1151             return r;
1152         }
1153     }
1154 
1155     return 0;
1156 }
1157 
1158 static int vhost_vdpa_net_load_single_vlan(VhostVDPAState *s,
1159                                            const VirtIONet *n,
1160                                            struct iovec *out_cursor,
1161                                            struct iovec *in_cursor,
1162                                            uint16_t vid)
1163 {
1164     const struct iovec data = {
1165         .iov_base = &vid,
1166         .iov_len = sizeof(vid),
1167     };
1168     ssize_t r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
1169                                         VIRTIO_NET_CTRL_VLAN,
1170                                         VIRTIO_NET_CTRL_VLAN_ADD,
1171                                         &data, 1);
1172     if (unlikely(r < 0)) {
1173         return r;
1174     }
1175 
1176     return 0;
1177 }
1178 
1179 static int vhost_vdpa_net_load_vlan(VhostVDPAState *s,
1180                                     const VirtIONet *n,
1181                                     struct iovec *out_cursor,
1182                                     struct iovec *in_cursor)
1183 {
1184     int r;
1185 
1186     if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_VLAN)) {
1187         return 0;
1188     }
1189 
1190     for (int i = 0; i < MAX_VLAN >> 5; i++) {
1191         for (int j = 0; n->vlans[i] && j <= 0x1f; j++) {
1192             if (n->vlans[i] & (1U << j)) {
1193                 r = vhost_vdpa_net_load_single_vlan(s, n, out_cursor,
1194                                                     in_cursor, (i << 5) + j);
1195                 if (unlikely(r != 0)) {
1196                     return r;
1197                 }
1198             }
1199         }
1200     }
1201 
1202     return 0;
1203 }
1204 
1205 static int vhost_vdpa_net_cvq_load(NetClientState *nc)
1206 {
1207     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
1208     struct vhost_vdpa *v = &s->vhost_vdpa;
1209     const VirtIONet *n;
1210     int r;
1211     struct iovec out_cursor, in_cursor;
1212 
1213     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
1214 
1215     vhost_vdpa_set_vring_ready(v, v->dev->vq_index);
1216 
1217     if (v->shadow_vqs_enabled) {
1218         n = VIRTIO_NET(v->dev->vdev);
1219         vhost_vdpa_net_load_cursor_reset(s, &out_cursor, &in_cursor);
1220         r = vhost_vdpa_net_load_mac(s, n, &out_cursor, &in_cursor);
1221         if (unlikely(r < 0)) {
1222             return r;
1223         }
1224         r = vhost_vdpa_net_load_mq(s, n, &out_cursor, &in_cursor);
1225         if (unlikely(r)) {
1226             return r;
1227         }
1228         r = vhost_vdpa_net_load_offloads(s, n, &out_cursor, &in_cursor);
1229         if (unlikely(r)) {
1230             return r;
1231         }
1232         r = vhost_vdpa_net_load_rx(s, n, &out_cursor, &in_cursor);
1233         if (unlikely(r)) {
1234             return r;
1235         }
1236         r = vhost_vdpa_net_load_vlan(s, n, &out_cursor, &in_cursor);
1237         if (unlikely(r)) {
1238             return r;
1239         }
1240 
1241         /*
1242          * We need to poll and check all pending device's used buffers.
1243          *
1244          * We can poll here since we've had BQL from the time
1245          * we sent the descriptor.
1246          */
1247         r = vhost_vdpa_net_svq_flush(s, in_cursor.iov_base - (void *)s->status);
1248         if (unlikely(r)) {
1249             return r;
1250         }
1251     }
1252 
1253     for (int i = 0; i < v->dev->vq_index; ++i) {
1254         vhost_vdpa_set_vring_ready(v, i);
1255     }
1256 
1257     return 0;
1258 }
1259 
1260 static NetClientInfo net_vhost_vdpa_cvq_info = {
1261     .type = NET_CLIENT_DRIVER_VHOST_VDPA,
1262     .size = sizeof(VhostVDPAState),
1263     .receive = vhost_vdpa_receive,
1264     .start = vhost_vdpa_net_cvq_start,
1265     .load = vhost_vdpa_net_cvq_load,
1266     .stop = vhost_vdpa_net_cvq_stop,
1267     .cleanup = vhost_vdpa_cleanup,
1268     .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
1269     .has_ufo = vhost_vdpa_has_ufo,
1270     .check_peer_type = vhost_vdpa_check_peer_type,
1271     .set_steering_ebpf = vhost_vdpa_set_steering_ebpf,
1272 };
1273 
1274 /*
1275  * Forward the excessive VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command to
1276  * vdpa device.
1277  *
1278  * Considering that QEMU cannot send the entire filter table to the
1279  * vdpa device, it should send the VIRTIO_NET_CTRL_RX_PROMISC CVQ
1280  * command to enable promiscuous mode to receive all packets,
1281  * according to VirtIO standard, "Since there are no guarantees,
1282  * it can use a hash filter or silently switch to allmulti or
1283  * promiscuous mode if it is given too many addresses.".
1284  *
1285  * Since QEMU ignores MAC addresses beyond `MAC_TABLE_ENTRIES` and
1286  * marks `n->mac_table.x_overflow` accordingly, it should have
1287  * the same effect on the device model to receive
1288  * (`MAC_TABLE_ENTRIES` + 1) or more non-multicast MAC addresses.
1289  * The same applies to multicast MAC addresses.
1290  *
1291  * Therefore, QEMU can provide the device model with a fake
1292  * VIRTIO_NET_CTRL_MAC_TABLE_SET command with (`MAC_TABLE_ENTRIES` + 1)
1293  * non-multicast MAC addresses and (`MAC_TABLE_ENTRIES` + 1) multicast
1294  * MAC addresses. This ensures that the device model marks
1295  * `n->mac_table.uni_overflow` and `n->mac_table.multi_overflow`,
1296  * allowing all packets to be received, which aligns with the
1297  * state of the vdpa device.
1298  */
1299 static int vhost_vdpa_net_excessive_mac_filter_cvq_add(VhostVDPAState *s,
1300                                                        VirtQueueElement *elem,
1301                                                        struct iovec *out,
1302                                                        const struct iovec *in)
1303 {
1304     struct virtio_net_ctrl_mac mac_data, *mac_ptr;
1305     struct virtio_net_ctrl_hdr *hdr_ptr;
1306     uint32_t cursor;
1307     ssize_t r;
1308     uint8_t on = 1;
1309 
1310     /* parse the non-multicast MAC address entries from CVQ command */
1311     cursor = sizeof(*hdr_ptr);
1312     r = iov_to_buf(elem->out_sg, elem->out_num, cursor,
1313                    &mac_data, sizeof(mac_data));
1314     if (unlikely(r != sizeof(mac_data))) {
1315         /*
1316          * If the CVQ command is invalid, we should simulate the vdpa device
1317          * to reject the VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command
1318          */
1319         *s->status = VIRTIO_NET_ERR;
1320         return sizeof(*s->status);
1321     }
1322     cursor += sizeof(mac_data) + le32_to_cpu(mac_data.entries) * ETH_ALEN;
1323 
1324     /* parse the multicast MAC address entries from CVQ command */
1325     r = iov_to_buf(elem->out_sg, elem->out_num, cursor,
1326                    &mac_data, sizeof(mac_data));
1327     if (r != sizeof(mac_data)) {
1328         /*
1329          * If the CVQ command is invalid, we should simulate the vdpa device
1330          * to reject the VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command
1331          */
1332         *s->status = VIRTIO_NET_ERR;
1333         return sizeof(*s->status);
1334     }
1335     cursor += sizeof(mac_data) + le32_to_cpu(mac_data.entries) * ETH_ALEN;
1336 
1337     /* validate the CVQ command */
1338     if (iov_size(elem->out_sg, elem->out_num) != cursor) {
1339         /*
1340          * If the CVQ command is invalid, we should simulate the vdpa device
1341          * to reject the VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command
1342          */
1343         *s->status = VIRTIO_NET_ERR;
1344         return sizeof(*s->status);
1345     }
1346 
1347     /*
1348      * According to VirtIO standard, "Since there are no guarantees,
1349      * it can use a hash filter or silently switch to allmulti or
1350      * promiscuous mode if it is given too many addresses.".
1351      *
1352      * Therefore, considering that QEMU is unable to send the entire
1353      * filter table to the vdpa device, it should send the
1354      * VIRTIO_NET_CTRL_RX_PROMISC CVQ command to enable promiscuous mode
1355      */
1356     hdr_ptr = out->iov_base;
1357     out->iov_len = sizeof(*hdr_ptr) + sizeof(on);
1358 
1359     hdr_ptr->class = VIRTIO_NET_CTRL_RX;
1360     hdr_ptr->cmd = VIRTIO_NET_CTRL_RX_PROMISC;
1361     iov_from_buf(out, 1, sizeof(*hdr_ptr), &on, sizeof(on));
1362     r = vhost_vdpa_net_cvq_add(s, out, 1, in, 1);
1363     if (unlikely(r < 0)) {
1364         return r;
1365     }
1366 
1367     /*
1368      * We can poll here since we've had BQL from the time
1369      * we sent the descriptor.
1370      */
1371     r = vhost_vdpa_net_svq_poll(s, 1);
1372     if (unlikely(r < sizeof(*s->status))) {
1373         return r;
1374     }
1375     if (*s->status != VIRTIO_NET_OK) {
1376         return sizeof(*s->status);
1377     }
1378 
1379     /*
1380      * QEMU should also send a fake VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ
1381      * command to the device model, including (`MAC_TABLE_ENTRIES` + 1)
1382      * non-multicast MAC addresses and (`MAC_TABLE_ENTRIES` + 1)
1383      * multicast MAC addresses.
1384      *
1385      * By doing so, the device model can mark `n->mac_table.uni_overflow`
1386      * and `n->mac_table.multi_overflow`, enabling all packets to be
1387      * received, which aligns with the state of the vdpa device.
1388      */
1389     cursor = 0;
1390     uint32_t fake_uni_entries = MAC_TABLE_ENTRIES + 1,
1391              fake_mul_entries = MAC_TABLE_ENTRIES + 1,
1392              fake_cvq_size = sizeof(struct virtio_net_ctrl_hdr) +
1393                              sizeof(mac_data) + fake_uni_entries * ETH_ALEN +
1394                              sizeof(mac_data) + fake_mul_entries * ETH_ALEN;
1395 
1396     assert(fake_cvq_size < vhost_vdpa_net_cvq_cmd_page_len());
1397     out->iov_len = fake_cvq_size;
1398 
1399     /* pack the header for fake CVQ command */
1400     hdr_ptr = out->iov_base + cursor;
1401     hdr_ptr->class = VIRTIO_NET_CTRL_MAC;
1402     hdr_ptr->cmd = VIRTIO_NET_CTRL_MAC_TABLE_SET;
1403     cursor += sizeof(*hdr_ptr);
1404 
1405     /*
1406      * Pack the non-multicast MAC addresses part for fake CVQ command.
1407      *
1408      * According to virtio_net_handle_mac(), QEMU doesn't verify the MAC
1409      * addresses provided in CVQ command. Therefore, only the entries
1410      * field need to be prepared in the CVQ command.
1411      */
1412     mac_ptr = out->iov_base + cursor;
1413     mac_ptr->entries = cpu_to_le32(fake_uni_entries);
1414     cursor += sizeof(*mac_ptr) + fake_uni_entries * ETH_ALEN;
1415 
1416     /*
1417      * Pack the multicast MAC addresses part for fake CVQ command.
1418      *
1419      * According to virtio_net_handle_mac(), QEMU doesn't verify the MAC
1420      * addresses provided in CVQ command. Therefore, only the entries
1421      * field need to be prepared in the CVQ command.
1422      */
1423     mac_ptr = out->iov_base + cursor;
1424     mac_ptr->entries = cpu_to_le32(fake_mul_entries);
1425 
1426     /*
1427      * Simulating QEMU poll a vdpa device used buffer
1428      * for VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command
1429      */
1430     return sizeof(*s->status);
1431 }
1432 
1433 /**
1434  * Validate and copy control virtqueue commands.
1435  *
1436  * Following QEMU guidelines, we offer a copy of the buffers to the device to
1437  * prevent TOCTOU bugs.
1438  */
1439 static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
1440                                             VirtQueueElement *elem,
1441                                             void *opaque)
1442 {
1443     VhostVDPAState *s = opaque;
1444     size_t in_len;
1445     const struct virtio_net_ctrl_hdr *ctrl;
1446     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
1447     /* Out buffer sent to both the vdpa device and the device model */
1448     struct iovec out = {
1449         .iov_base = s->cvq_cmd_out_buffer,
1450     };
1451     /* in buffer used for device model */
1452     const struct iovec model_in = {
1453         .iov_base = &status,
1454         .iov_len = sizeof(status),
1455     };
1456     /* in buffer used for vdpa device */
1457     const struct iovec vdpa_in = {
1458         .iov_base = s->status,
1459         .iov_len = sizeof(*s->status),
1460     };
1461     ssize_t dev_written = -EINVAL;
1462 
1463     out.iov_len = iov_to_buf(elem->out_sg, elem->out_num, 0,
1464                              s->cvq_cmd_out_buffer,
1465                              vhost_vdpa_net_cvq_cmd_page_len());
1466 
1467     ctrl = s->cvq_cmd_out_buffer;
1468     if (ctrl->class == VIRTIO_NET_CTRL_ANNOUNCE) {
1469         /*
1470          * Guest announce capability is emulated by qemu, so don't forward to
1471          * the device.
1472          */
1473         dev_written = sizeof(status);
1474         *s->status = VIRTIO_NET_OK;
1475     } else if (unlikely(ctrl->class == VIRTIO_NET_CTRL_MAC &&
1476                         ctrl->cmd == VIRTIO_NET_CTRL_MAC_TABLE_SET &&
1477                         iov_size(elem->out_sg, elem->out_num) > out.iov_len)) {
1478         /*
1479          * Due to the size limitation of the out buffer sent to the vdpa device,
1480          * which is determined by vhost_vdpa_net_cvq_cmd_page_len(), excessive
1481          * MAC addresses set by the driver for the filter table can cause
1482          * truncation of the CVQ command in QEMU. As a result, the vdpa device
1483          * rejects the flawed CVQ command.
1484          *
1485          * Therefore, QEMU must handle this situation instead of sending
1486          * the CVQ command directly.
1487          */
1488         dev_written = vhost_vdpa_net_excessive_mac_filter_cvq_add(s, elem,
1489                                                             &out, &vdpa_in);
1490         if (unlikely(dev_written < 0)) {
1491             goto out;
1492         }
1493     } else {
1494         ssize_t r;
1495         r = vhost_vdpa_net_cvq_add(s, &out, 1, &vdpa_in, 1);
1496         if (unlikely(r < 0)) {
1497             dev_written = r;
1498             goto out;
1499         }
1500 
1501         /*
1502          * We can poll here since we've had BQL from the time
1503          * we sent the descriptor.
1504          */
1505         dev_written = vhost_vdpa_net_svq_poll(s, 1);
1506     }
1507 
1508     if (unlikely(dev_written < sizeof(status))) {
1509         error_report("Insufficient written data (%zu)", dev_written);
1510         goto out;
1511     }
1512 
1513     if (*s->status != VIRTIO_NET_OK) {
1514         goto out;
1515     }
1516 
1517     status = VIRTIO_NET_ERR;
1518     virtio_net_handle_ctrl_iov(svq->vdev, &model_in, 1, &out, 1);
1519     if (status != VIRTIO_NET_OK) {
1520         error_report("Bad CVQ processing in model");
1521     }
1522 
1523 out:
1524     in_len = iov_from_buf(elem->in_sg, elem->in_num, 0, &status,
1525                           sizeof(status));
1526     if (unlikely(in_len < sizeof(status))) {
1527         error_report("Bad device CVQ written length");
1528     }
1529     vhost_svq_push_elem(svq, elem, MIN(in_len, sizeof(status)));
1530     /*
1531      * `elem` belongs to vhost_vdpa_net_handle_ctrl_avail() only when
1532      * the function successfully forwards the CVQ command, indicated
1533      * by a non-negative value of `dev_written`. Otherwise, it still
1534      * belongs to SVQ.
1535      * This function should only free the `elem` when it owns.
1536      */
1537     if (dev_written >= 0) {
1538         g_free(elem);
1539     }
1540     return dev_written < 0 ? dev_written : 0;
1541 }
1542 
1543 static const VhostShadowVirtqueueOps vhost_vdpa_net_svq_ops = {
1544     .avail_handler = vhost_vdpa_net_handle_ctrl_avail,
1545 };
1546 
1547 /**
1548  * Probe if CVQ is isolated
1549  *
1550  * @device_fd         The vdpa device fd
1551  * @features          Features offered by the device.
1552  * @cvq_index         The control vq pair index
1553  *
1554  * Returns <0 in case of failure, 0 if false and 1 if true.
1555  */
1556 static int vhost_vdpa_probe_cvq_isolation(int device_fd, uint64_t features,
1557                                           int cvq_index, Error **errp)
1558 {
1559     ERRP_GUARD();
1560     uint64_t backend_features;
1561     int64_t cvq_group;
1562     uint8_t status = VIRTIO_CONFIG_S_ACKNOWLEDGE |
1563                      VIRTIO_CONFIG_S_DRIVER;
1564     int r;
1565 
1566     r = ioctl(device_fd, VHOST_GET_BACKEND_FEATURES, &backend_features);
1567     if (unlikely(r < 0)) {
1568         error_setg_errno(errp, errno, "Cannot get vdpa backend_features");
1569         return r;
1570     }
1571 
1572     if (!(backend_features & BIT_ULL(VHOST_BACKEND_F_IOTLB_ASID))) {
1573         return 0;
1574     }
1575 
1576     r = ioctl(device_fd, VHOST_VDPA_SET_STATUS, &status);
1577     if (unlikely(r)) {
1578         error_setg_errno(errp, -r, "Cannot set device status");
1579         goto out;
1580     }
1581 
1582     r = ioctl(device_fd, VHOST_SET_FEATURES, &features);
1583     if (unlikely(r)) {
1584         error_setg_errno(errp, -r, "Cannot set features");
1585         goto out;
1586     }
1587 
1588     status |= VIRTIO_CONFIG_S_FEATURES_OK;
1589     r = ioctl(device_fd, VHOST_VDPA_SET_STATUS, &status);
1590     if (unlikely(r)) {
1591         error_setg_errno(errp, -r, "Cannot set device status");
1592         goto out;
1593     }
1594 
1595     cvq_group = vhost_vdpa_get_vring_group(device_fd, cvq_index, errp);
1596     if (unlikely(cvq_group < 0)) {
1597         if (cvq_group != -ENOTSUP) {
1598             r = cvq_group;
1599             goto out;
1600         }
1601 
1602         /*
1603          * The kernel report VHOST_BACKEND_F_IOTLB_ASID if the vdpa frontend
1604          * support ASID even if the parent driver does not.  The CVQ cannot be
1605          * isolated in this case.
1606          */
1607         error_free(*errp);
1608         *errp = NULL;
1609         r = 0;
1610         goto out;
1611     }
1612 
1613     for (int i = 0; i < cvq_index; ++i) {
1614         int64_t group = vhost_vdpa_get_vring_group(device_fd, i, errp);
1615         if (unlikely(group < 0)) {
1616             r = group;
1617             goto out;
1618         }
1619 
1620         if (group == (int64_t)cvq_group) {
1621             r = 0;
1622             goto out;
1623         }
1624     }
1625 
1626     r = 1;
1627 
1628 out:
1629     status = 0;
1630     ioctl(device_fd, VHOST_VDPA_SET_STATUS, &status);
1631     return r;
1632 }
1633 
1634 static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
1635                                        const char *device,
1636                                        const char *name,
1637                                        int vdpa_device_fd,
1638                                        int queue_pair_index,
1639                                        int nvqs,
1640                                        bool is_datapath,
1641                                        bool svq,
1642                                        struct vhost_vdpa_iova_range iova_range,
1643                                        uint64_t features,
1644                                        VhostVDPAShared *shared,
1645                                        Error **errp)
1646 {
1647     NetClientState *nc = NULL;
1648     VhostVDPAState *s;
1649     int ret = 0;
1650     assert(name);
1651     int cvq_isolated = 0;
1652 
1653     if (is_datapath) {
1654         nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device,
1655                                  name);
1656     } else {
1657         cvq_isolated = vhost_vdpa_probe_cvq_isolation(vdpa_device_fd, features,
1658                                                       queue_pair_index * 2,
1659                                                       errp);
1660         if (unlikely(cvq_isolated < 0)) {
1661             return NULL;
1662         }
1663 
1664         nc = qemu_new_net_control_client(&net_vhost_vdpa_cvq_info, peer,
1665                                          device, name);
1666     }
1667     qemu_set_info_str(nc, TYPE_VHOST_VDPA);
1668     s = DO_UPCAST(VhostVDPAState, nc, nc);
1669 
1670     s->vhost_vdpa.index = queue_pair_index;
1671     s->always_svq = svq;
1672     s->migration_state.notify = NULL;
1673     s->vhost_vdpa.shadow_vqs_enabled = svq;
1674     if (queue_pair_index == 0) {
1675         vhost_vdpa_net_valid_svq_features(features,
1676                                           &s->vhost_vdpa.migration_blocker);
1677         s->vhost_vdpa.shared = g_new0(VhostVDPAShared, 1);
1678         s->vhost_vdpa.shared->device_fd = vdpa_device_fd;
1679         s->vhost_vdpa.shared->iova_range = iova_range;
1680         s->vhost_vdpa.shared->shadow_data = svq;
1681     } else if (!is_datapath) {
1682         s->cvq_cmd_out_buffer = mmap(NULL, vhost_vdpa_net_cvq_cmd_page_len(),
1683                                      PROT_READ | PROT_WRITE,
1684                                      MAP_SHARED | MAP_ANONYMOUS, -1, 0);
1685         s->status = mmap(NULL, vhost_vdpa_net_cvq_cmd_page_len(),
1686                          PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS,
1687                          -1, 0);
1688 
1689         s->vhost_vdpa.shadow_vq_ops = &vhost_vdpa_net_svq_ops;
1690         s->vhost_vdpa.shadow_vq_ops_opaque = s;
1691         s->cvq_isolated = cvq_isolated;
1692     }
1693     if (queue_pair_index != 0) {
1694         s->vhost_vdpa.shared = shared;
1695     }
1696 
1697     ret = vhost_vdpa_add(nc, (void *)&s->vhost_vdpa, queue_pair_index, nvqs);
1698     if (ret) {
1699         qemu_del_net_client(nc);
1700         return NULL;
1701     }
1702 
1703     return nc;
1704 }
1705 
1706 static int vhost_vdpa_get_features(int fd, uint64_t *features, Error **errp)
1707 {
1708     int ret = ioctl(fd, VHOST_GET_FEATURES, features);
1709     if (unlikely(ret < 0)) {
1710         error_setg_errno(errp, errno,
1711                          "Fail to query features from vhost-vDPA device");
1712     }
1713     return ret;
1714 }
1715 
1716 static int vhost_vdpa_get_max_queue_pairs(int fd, uint64_t features,
1717                                           int *has_cvq, Error **errp)
1718 {
1719     unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
1720     g_autofree struct vhost_vdpa_config *config = NULL;
1721     __virtio16 *max_queue_pairs;
1722     int ret;
1723 
1724     if (features & (1 << VIRTIO_NET_F_CTRL_VQ)) {
1725         *has_cvq = 1;
1726     } else {
1727         *has_cvq = 0;
1728     }
1729 
1730     if (features & (1 << VIRTIO_NET_F_MQ)) {
1731         config = g_malloc0(config_size + sizeof(*max_queue_pairs));
1732         config->off = offsetof(struct virtio_net_config, max_virtqueue_pairs);
1733         config->len = sizeof(*max_queue_pairs);
1734 
1735         ret = ioctl(fd, VHOST_VDPA_GET_CONFIG, config);
1736         if (ret) {
1737             error_setg(errp, "Fail to get config from vhost-vDPA device");
1738             return -ret;
1739         }
1740 
1741         max_queue_pairs = (__virtio16 *)&config->buf;
1742 
1743         return lduw_le_p(max_queue_pairs);
1744     }
1745 
1746     return 1;
1747 }
1748 
1749 int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
1750                         NetClientState *peer, Error **errp)
1751 {
1752     ERRP_GUARD();
1753     const NetdevVhostVDPAOptions *opts;
1754     uint64_t features;
1755     int vdpa_device_fd;
1756     g_autofree NetClientState **ncs = NULL;
1757     struct vhost_vdpa_iova_range iova_range;
1758     NetClientState *nc;
1759     int queue_pairs, r, i = 0, has_cvq = 0;
1760 
1761     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_VDPA);
1762     opts = &netdev->u.vhost_vdpa;
1763     if (!opts->vhostdev && !opts->vhostfd) {
1764         error_setg(errp,
1765                    "vhost-vdpa: neither vhostdev= nor vhostfd= was specified");
1766         return -1;
1767     }
1768 
1769     if (opts->vhostdev && opts->vhostfd) {
1770         error_setg(errp,
1771                    "vhost-vdpa: vhostdev= and vhostfd= are mutually exclusive");
1772         return -1;
1773     }
1774 
1775     if (opts->vhostdev) {
1776         vdpa_device_fd = qemu_open(opts->vhostdev, O_RDWR, errp);
1777         if (vdpa_device_fd == -1) {
1778             return -errno;
1779         }
1780     } else {
1781         /* has_vhostfd */
1782         vdpa_device_fd = monitor_fd_param(monitor_cur(), opts->vhostfd, errp);
1783         if (vdpa_device_fd == -1) {
1784             error_prepend(errp, "vhost-vdpa: unable to parse vhostfd: ");
1785             return -1;
1786         }
1787     }
1788 
1789     r = vhost_vdpa_get_features(vdpa_device_fd, &features, errp);
1790     if (unlikely(r < 0)) {
1791         goto err;
1792     }
1793 
1794     queue_pairs = vhost_vdpa_get_max_queue_pairs(vdpa_device_fd, features,
1795                                                  &has_cvq, errp);
1796     if (queue_pairs < 0) {
1797         qemu_close(vdpa_device_fd);
1798         return queue_pairs;
1799     }
1800 
1801     r = vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range);
1802     if (unlikely(r < 0)) {
1803         error_setg(errp, "vhost-vdpa: get iova range failed: %s",
1804                    strerror(-r));
1805         goto err;
1806     }
1807 
1808     if (opts->x_svq && !vhost_vdpa_net_valid_svq_features(features, errp)) {
1809         goto err;
1810     }
1811 
1812     ncs = g_malloc0(sizeof(*ncs) * queue_pairs);
1813 
1814     for (i = 0; i < queue_pairs; i++) {
1815         VhostVDPAShared *shared = NULL;
1816 
1817         if (i) {
1818             shared = DO_UPCAST(VhostVDPAState, nc, ncs[0])->vhost_vdpa.shared;
1819         }
1820         ncs[i] = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name,
1821                                      vdpa_device_fd, i, 2, true, opts->x_svq,
1822                                      iova_range, features, shared, errp);
1823         if (!ncs[i])
1824             goto err;
1825     }
1826 
1827     if (has_cvq) {
1828         VhostVDPAState *s0 = DO_UPCAST(VhostVDPAState, nc, ncs[0]);
1829         VhostVDPAShared *shared = s0->vhost_vdpa.shared;
1830 
1831         nc = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name,
1832                                  vdpa_device_fd, i, 1, false,
1833                                  opts->x_svq, iova_range, features, shared,
1834                                  errp);
1835         if (!nc)
1836             goto err;
1837     }
1838 
1839     return 0;
1840 
1841 err:
1842     if (i) {
1843         for (i--; i >= 0; i--) {
1844             qemu_del_net_client(ncs[i]);
1845         }
1846     }
1847 
1848     qemu_close(vdpa_device_fd);
1849 
1850     return -1;
1851 }
1852