xref: /qemu/net/vhost-vdpa.c (revision 62845d32)
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/migration.h"
30 #include "migration/misc.h"
31 #include "hw/virtio/vhost.h"
32 #include "trace.h"
33 
34 /* Todo:need to add the multiqueue support here */
35 typedef struct VhostVDPAState {
36     NetClientState nc;
37     struct vhost_vdpa vhost_vdpa;
38     NotifierWithReturn migration_state;
39     VHostNetState *vhost_net;
40 
41     /* Control commands shadow buffers */
42     void *cvq_cmd_out_buffer;
43     virtio_net_ctrl_ack *status;
44 
45     /* The device always have SVQ enabled */
46     bool always_svq;
47 
48     /* The device can isolate CVQ in its own ASID */
49     bool cvq_isolated;
50 
51     bool started;
52 } VhostVDPAState;
53 
54 /*
55  * The array is sorted alphabetically in ascending order,
56  * with the exception of VHOST_INVALID_FEATURE_BIT,
57  * which should always be the last entry.
58  */
59 const int vdpa_feature_bits[] = {
60     VIRTIO_F_ANY_LAYOUT,
61     VIRTIO_F_IOMMU_PLATFORM,
62     VIRTIO_F_NOTIFY_ON_EMPTY,
63     VIRTIO_F_RING_PACKED,
64     VIRTIO_F_RING_RESET,
65     VIRTIO_F_VERSION_1,
66     VIRTIO_NET_F_CSUM,
67     VIRTIO_NET_F_CTRL_GUEST_OFFLOADS,
68     VIRTIO_NET_F_CTRL_MAC_ADDR,
69     VIRTIO_NET_F_CTRL_RX,
70     VIRTIO_NET_F_CTRL_RX_EXTRA,
71     VIRTIO_NET_F_CTRL_VLAN,
72     VIRTIO_NET_F_CTRL_VQ,
73     VIRTIO_NET_F_GSO,
74     VIRTIO_NET_F_GUEST_CSUM,
75     VIRTIO_NET_F_GUEST_ECN,
76     VIRTIO_NET_F_GUEST_TSO4,
77     VIRTIO_NET_F_GUEST_TSO6,
78     VIRTIO_NET_F_GUEST_UFO,
79     VIRTIO_NET_F_GUEST_USO4,
80     VIRTIO_NET_F_GUEST_USO6,
81     VIRTIO_NET_F_HASH_REPORT,
82     VIRTIO_NET_F_HOST_ECN,
83     VIRTIO_NET_F_HOST_TSO4,
84     VIRTIO_NET_F_HOST_TSO6,
85     VIRTIO_NET_F_HOST_UFO,
86     VIRTIO_NET_F_HOST_USO,
87     VIRTIO_NET_F_MQ,
88     VIRTIO_NET_F_MRG_RXBUF,
89     VIRTIO_NET_F_MTU,
90     VIRTIO_NET_F_RSS,
91     VIRTIO_NET_F_STATUS,
92     VIRTIO_RING_F_EVENT_IDX,
93     VIRTIO_RING_F_INDIRECT_DESC,
94 
95     /* VHOST_INVALID_FEATURE_BIT should always be the last entry */
96     VHOST_INVALID_FEATURE_BIT
97 };
98 
99 /** Supported device specific feature bits with SVQ */
100 static const uint64_t vdpa_svq_device_features =
101     BIT_ULL(VIRTIO_NET_F_CSUM) |
102     BIT_ULL(VIRTIO_NET_F_GUEST_CSUM) |
103     BIT_ULL(VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) |
104     BIT_ULL(VIRTIO_NET_F_MTU) |
105     BIT_ULL(VIRTIO_NET_F_MAC) |
106     BIT_ULL(VIRTIO_NET_F_GUEST_TSO4) |
107     BIT_ULL(VIRTIO_NET_F_GUEST_TSO6) |
108     BIT_ULL(VIRTIO_NET_F_GUEST_ECN) |
109     BIT_ULL(VIRTIO_NET_F_GUEST_UFO) |
110     BIT_ULL(VIRTIO_NET_F_HOST_TSO4) |
111     BIT_ULL(VIRTIO_NET_F_HOST_TSO6) |
112     BIT_ULL(VIRTIO_NET_F_HOST_ECN) |
113     BIT_ULL(VIRTIO_NET_F_HOST_UFO) |
114     BIT_ULL(VIRTIO_NET_F_MRG_RXBUF) |
115     BIT_ULL(VIRTIO_NET_F_STATUS) |
116     BIT_ULL(VIRTIO_NET_F_CTRL_VQ) |
117     BIT_ULL(VIRTIO_NET_F_CTRL_RX) |
118     BIT_ULL(VIRTIO_NET_F_CTRL_VLAN) |
119     BIT_ULL(VIRTIO_NET_F_CTRL_RX_EXTRA) |
120     BIT_ULL(VIRTIO_NET_F_MQ) |
121     BIT_ULL(VIRTIO_F_ANY_LAYOUT) |
122     BIT_ULL(VIRTIO_NET_F_CTRL_MAC_ADDR) |
123     /* VHOST_F_LOG_ALL is exposed by SVQ */
124     BIT_ULL(VHOST_F_LOG_ALL) |
125     BIT_ULL(VIRTIO_NET_F_HASH_REPORT) |
126     BIT_ULL(VIRTIO_NET_F_RSS) |
127     BIT_ULL(VIRTIO_NET_F_RSC_EXT) |
128     BIT_ULL(VIRTIO_NET_F_STANDBY) |
129     BIT_ULL(VIRTIO_NET_F_SPEED_DUPLEX);
130 
131 #define VHOST_VDPA_NET_CVQ_ASID 1
132 
133 VHostNetState *vhost_vdpa_get_vhost_net(NetClientState *nc)
134 {
135     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
136     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
137     return s->vhost_net;
138 }
139 
140 static size_t vhost_vdpa_net_cvq_cmd_len(void)
141 {
142     /*
143      * MAC_TABLE_SET is the ctrl command that produces the longer out buffer.
144      * In buffer is always 1 byte, so it should fit here
145      */
146     return sizeof(struct virtio_net_ctrl_hdr) +
147            2 * sizeof(struct virtio_net_ctrl_mac) +
148            MAC_TABLE_ENTRIES * ETH_ALEN;
149 }
150 
151 static size_t vhost_vdpa_net_cvq_cmd_page_len(void)
152 {
153     return ROUND_UP(vhost_vdpa_net_cvq_cmd_len(), qemu_real_host_page_size());
154 }
155 
156 static bool vhost_vdpa_net_valid_svq_features(uint64_t features, Error **errp)
157 {
158     uint64_t invalid_dev_features =
159         features & ~vdpa_svq_device_features &
160         /* Transport are all accepted at this point */
161         ~MAKE_64BIT_MASK(VIRTIO_TRANSPORT_F_START,
162                          VIRTIO_TRANSPORT_F_END - VIRTIO_TRANSPORT_F_START);
163 
164     if (invalid_dev_features) {
165         error_setg(errp, "vdpa svq does not work with features 0x%" PRIx64,
166                    invalid_dev_features);
167         return false;
168     }
169 
170     return vhost_svq_valid_features(features, errp);
171 }
172 
173 static int vhost_vdpa_net_check_device_id(struct vhost_net *net)
174 {
175     uint32_t device_id;
176     int ret;
177     struct vhost_dev *hdev;
178 
179     hdev = (struct vhost_dev *)&net->dev;
180     ret = hdev->vhost_ops->vhost_get_device_id(hdev, &device_id);
181     if (device_id != VIRTIO_ID_NET) {
182         return -ENOTSUP;
183     }
184     return ret;
185 }
186 
187 static int vhost_vdpa_add(NetClientState *ncs, void *be,
188                           int queue_pair_index, int nvqs)
189 {
190     VhostNetOptions options;
191     struct vhost_net *net = NULL;
192     VhostVDPAState *s;
193     int ret;
194 
195     options.backend_type = VHOST_BACKEND_TYPE_VDPA;
196     assert(ncs->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
197     s = DO_UPCAST(VhostVDPAState, nc, ncs);
198     options.net_backend = ncs;
199     options.opaque      = be;
200     options.busyloop_timeout = 0;
201     options.nvqs = nvqs;
202 
203     net = vhost_net_init(&options);
204     if (!net) {
205         error_report("failed to init vhost_net for queue");
206         goto err_init;
207     }
208     s->vhost_net = net;
209     ret = vhost_vdpa_net_check_device_id(net);
210     if (ret) {
211         goto err_check;
212     }
213     return 0;
214 err_check:
215     vhost_net_cleanup(net);
216     g_free(net);
217 err_init:
218     return -1;
219 }
220 
221 static void vhost_vdpa_cleanup(NetClientState *nc)
222 {
223     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
224 
225     /*
226      * If a peer NIC is attached, do not cleanup anything.
227      * Cleanup will happen as a part of qemu_cleanup() -> net_cleanup()
228      * when the guest is shutting down.
229      */
230     if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) {
231         return;
232     }
233     munmap(s->cvq_cmd_out_buffer, vhost_vdpa_net_cvq_cmd_page_len());
234     munmap(s->status, vhost_vdpa_net_cvq_cmd_page_len());
235     if (s->vhost_net) {
236         vhost_net_cleanup(s->vhost_net);
237         g_free(s->vhost_net);
238         s->vhost_net = NULL;
239     }
240     if (s->vhost_vdpa.index != 0) {
241         return;
242     }
243     qemu_close(s->vhost_vdpa.shared->device_fd);
244     g_free(s->vhost_vdpa.shared);
245 }
246 
247 /** Dummy SetSteeringEBPF to support RSS for vhost-vdpa backend  */
248 static bool vhost_vdpa_set_steering_ebpf(NetClientState *nc, int prog_fd)
249 {
250     return true;
251 }
252 
253 static bool vhost_vdpa_has_vnet_hdr(NetClientState *nc)
254 {
255     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
256 
257     return true;
258 }
259 
260 static bool vhost_vdpa_has_ufo(NetClientState *nc)
261 {
262     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
263     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
264     uint64_t features = 0;
265     features |= (1ULL << VIRTIO_NET_F_HOST_UFO);
266     features = vhost_net_get_features(s->vhost_net, features);
267     return !!(features & (1ULL << VIRTIO_NET_F_HOST_UFO));
268 
269 }
270 
271 static bool vhost_vdpa_check_peer_type(NetClientState *nc, ObjectClass *oc,
272                                        Error **errp)
273 {
274     const char *driver = object_class_get_name(oc);
275 
276     if (!g_str_has_prefix(driver, "virtio-net-")) {
277         error_setg(errp, "vhost-vdpa requires frontend driver virtio-net-*");
278         return false;
279     }
280 
281     return true;
282 }
283 
284 /** Dummy receive in case qemu falls back to userland tap networking */
285 static ssize_t vhost_vdpa_receive(NetClientState *nc, const uint8_t *buf,
286                                   size_t size)
287 {
288     return size;
289 }
290 
291 
292 /** From any vdpa net client, get the netclient of the i-th queue pair */
293 static VhostVDPAState *vhost_vdpa_net_get_nc_vdpa(VhostVDPAState *s, int i)
294 {
295     NICState *nic = qemu_get_nic(s->nc.peer);
296     NetClientState *nc_i = qemu_get_peer(nic->ncs, i);
297 
298     return DO_UPCAST(VhostVDPAState, nc, nc_i);
299 }
300 
301 static VhostVDPAState *vhost_vdpa_net_first_nc_vdpa(VhostVDPAState *s)
302 {
303     return vhost_vdpa_net_get_nc_vdpa(s, 0);
304 }
305 
306 static void vhost_vdpa_net_log_global_enable(VhostVDPAState *s, bool enable)
307 {
308     struct vhost_vdpa *v = &s->vhost_vdpa;
309     VirtIONet *n;
310     VirtIODevice *vdev;
311     int data_queue_pairs, cvq, r;
312 
313     /* We are only called on the first data vqs and only if x-svq is not set */
314     if (s->vhost_vdpa.shadow_vqs_enabled == enable) {
315         return;
316     }
317 
318     vdev = v->dev->vdev;
319     n = VIRTIO_NET(vdev);
320     if (!n->vhost_started) {
321         return;
322     }
323 
324     data_queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
325     cvq = virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) ?
326                                   n->max_ncs - n->max_queue_pairs : 0;
327     /*
328      * TODO: vhost_net_stop does suspend, get_base and reset. We can be smarter
329      * in the future and resume the device if read-only operations between
330      * suspend and reset goes wrong.
331      */
332     vhost_net_stop(vdev, n->nic->ncs, data_queue_pairs, cvq);
333 
334     /* Start will check migration setup_or_active to configure or not SVQ */
335     r = vhost_net_start(vdev, n->nic->ncs, data_queue_pairs, cvq);
336     if (unlikely(r < 0)) {
337         error_report("unable to start vhost net: %s(%d)", g_strerror(-r), -r);
338     }
339 }
340 
341 static int vdpa_net_migration_state_notifier(NotifierWithReturn *notifier,
342                                              MigrationEvent *e, Error **errp)
343 {
344     VhostVDPAState *s = container_of(notifier, VhostVDPAState, migration_state);
345 
346     if (e->type == MIG_EVENT_PRECOPY_SETUP) {
347         vhost_vdpa_net_log_global_enable(s, true);
348     } else if (e->type == MIG_EVENT_PRECOPY_FAILED) {
349         vhost_vdpa_net_log_global_enable(s, false);
350     }
351     return 0;
352 }
353 
354 static void vhost_vdpa_net_data_start_first(VhostVDPAState *s)
355 {
356     struct vhost_vdpa *v = &s->vhost_vdpa;
357 
358     migration_add_notifier(&s->migration_state,
359                            vdpa_net_migration_state_notifier);
360     if (v->shadow_vqs_enabled) {
361         v->shared->iova_tree = vhost_iova_tree_new(v->shared->iova_range.first,
362                                                    v->shared->iova_range.last);
363     }
364 }
365 
366 static int vhost_vdpa_net_data_start(NetClientState *nc)
367 {
368     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
369     struct vhost_vdpa *v = &s->vhost_vdpa;
370 
371     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
372 
373     if (s->always_svq ||
374         migration_is_setup_or_active(migrate_get_current()->state)) {
375         v->shadow_vqs_enabled = true;
376     } else {
377         v->shadow_vqs_enabled = false;
378     }
379 
380     if (v->index == 0) {
381         v->shared->shadow_data = v->shadow_vqs_enabled;
382         vhost_vdpa_net_data_start_first(s);
383         return 0;
384     }
385 
386     return 0;
387 }
388 
389 static int vhost_vdpa_net_data_load(NetClientState *nc)
390 {
391     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
392     struct vhost_vdpa *v = &s->vhost_vdpa;
393     bool has_cvq = v->dev->vq_index_end % 2;
394 
395     if (has_cvq) {
396         return 0;
397     }
398 
399     for (int i = 0; i < v->dev->nvqs; ++i) {
400         vhost_vdpa_set_vring_ready(v, i + v->dev->vq_index);
401     }
402     return 0;
403 }
404 
405 static void vhost_vdpa_net_client_stop(NetClientState *nc)
406 {
407     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
408     struct vhost_dev *dev;
409 
410     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
411 
412     if (s->vhost_vdpa.index == 0) {
413         migration_remove_notifier(&s->migration_state);
414     }
415 
416     dev = s->vhost_vdpa.dev;
417     if (dev->vq_index + dev->nvqs == dev->vq_index_end) {
418         g_clear_pointer(&s->vhost_vdpa.shared->iova_tree,
419                         vhost_iova_tree_delete);
420     }
421 }
422 
423 static NetClientInfo net_vhost_vdpa_info = {
424         .type = NET_CLIENT_DRIVER_VHOST_VDPA,
425         .size = sizeof(VhostVDPAState),
426         .receive = vhost_vdpa_receive,
427         .start = vhost_vdpa_net_data_start,
428         .load = vhost_vdpa_net_data_load,
429         .stop = vhost_vdpa_net_client_stop,
430         .cleanup = vhost_vdpa_cleanup,
431         .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
432         .has_ufo = vhost_vdpa_has_ufo,
433         .check_peer_type = vhost_vdpa_check_peer_type,
434         .set_steering_ebpf = vhost_vdpa_set_steering_ebpf,
435 };
436 
437 static int64_t vhost_vdpa_get_vring_group(int device_fd, unsigned vq_index,
438                                           Error **errp)
439 {
440     struct vhost_vring_state state = {
441         .index = vq_index,
442     };
443     int r = ioctl(device_fd, VHOST_VDPA_GET_VRING_GROUP, &state);
444 
445     if (unlikely(r < 0)) {
446         r = -errno;
447         error_setg_errno(errp, errno, "Cannot get VQ %u group", vq_index);
448         return r;
449     }
450 
451     return state.num;
452 }
453 
454 static int vhost_vdpa_set_address_space_id(struct vhost_vdpa *v,
455                                            unsigned vq_group,
456                                            unsigned asid_num)
457 {
458     struct vhost_vring_state asid = {
459         .index = vq_group,
460         .num = asid_num,
461     };
462     int r;
463 
464     trace_vhost_vdpa_set_address_space_id(v, vq_group, asid_num);
465 
466     r = ioctl(v->shared->device_fd, VHOST_VDPA_SET_GROUP_ASID, &asid);
467     if (unlikely(r < 0)) {
468         error_report("Can't set vq group %u asid %u, errno=%d (%s)",
469                      asid.index, asid.num, errno, g_strerror(errno));
470     }
471     return r;
472 }
473 
474 static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr)
475 {
476     VhostIOVATree *tree = v->shared->iova_tree;
477     DMAMap needle = {
478         /*
479          * No need to specify size or to look for more translations since
480          * this contiguous chunk was allocated by us.
481          */
482         .translated_addr = (hwaddr)(uintptr_t)addr,
483     };
484     const DMAMap *map = vhost_iova_tree_find_iova(tree, &needle);
485     int r;
486 
487     if (unlikely(!map)) {
488         error_report("Cannot locate expected map");
489         return;
490     }
491 
492     r = vhost_vdpa_dma_unmap(v->shared, v->address_space_id, map->iova,
493                              map->size + 1);
494     if (unlikely(r != 0)) {
495         error_report("Device cannot unmap: %s(%d)", g_strerror(r), r);
496     }
497 
498     vhost_iova_tree_remove(tree, *map);
499 }
500 
501 /** Map CVQ buffer. */
502 static int vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, void *buf, size_t size,
503                                   bool write)
504 {
505     DMAMap map = {};
506     int r;
507 
508     map.translated_addr = (hwaddr)(uintptr_t)buf;
509     map.size = size - 1;
510     map.perm = write ? IOMMU_RW : IOMMU_RO,
511     r = vhost_iova_tree_map_alloc(v->shared->iova_tree, &map);
512     if (unlikely(r != IOVA_OK)) {
513         error_report("Cannot map injected element");
514         return r;
515     }
516 
517     r = vhost_vdpa_dma_map(v->shared, v->address_space_id, map.iova,
518                            vhost_vdpa_net_cvq_cmd_page_len(), buf, !write);
519     if (unlikely(r < 0)) {
520         goto dma_map_err;
521     }
522 
523     return 0;
524 
525 dma_map_err:
526     vhost_iova_tree_remove(v->shared->iova_tree, map);
527     return r;
528 }
529 
530 static int vhost_vdpa_net_cvq_start(NetClientState *nc)
531 {
532     VhostVDPAState *s, *s0;
533     struct vhost_vdpa *v;
534     int64_t cvq_group;
535     int r;
536     Error *err = NULL;
537 
538     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
539 
540     s = DO_UPCAST(VhostVDPAState, nc, nc);
541     v = &s->vhost_vdpa;
542 
543     s0 = vhost_vdpa_net_first_nc_vdpa(s);
544     v->shadow_vqs_enabled = s0->vhost_vdpa.shadow_vqs_enabled;
545     s->vhost_vdpa.address_space_id = VHOST_VDPA_GUEST_PA_ASID;
546 
547     if (v->shared->shadow_data) {
548         /* SVQ is already configured for all virtqueues */
549         goto out;
550     }
551 
552     /*
553      * If we early return in these cases SVQ will not be enabled. The migration
554      * will be blocked as long as vhost-vdpa backends will not offer _F_LOG.
555      */
556     if (!vhost_vdpa_net_valid_svq_features(v->dev->features, NULL)) {
557         return 0;
558     }
559 
560     if (!s->cvq_isolated) {
561         return 0;
562     }
563 
564     cvq_group = vhost_vdpa_get_vring_group(v->shared->device_fd,
565                                            v->dev->vq_index_end - 1,
566                                            &err);
567     if (unlikely(cvq_group < 0)) {
568         error_report_err(err);
569         return cvq_group;
570     }
571 
572     r = vhost_vdpa_set_address_space_id(v, cvq_group, VHOST_VDPA_NET_CVQ_ASID);
573     if (unlikely(r < 0)) {
574         return r;
575     }
576 
577     v->shadow_vqs_enabled = true;
578     s->vhost_vdpa.address_space_id = VHOST_VDPA_NET_CVQ_ASID;
579 
580 out:
581     if (!s->vhost_vdpa.shadow_vqs_enabled) {
582         return 0;
583     }
584 
585     /*
586      * If other vhost_vdpa already have an iova_tree, reuse it for simplicity,
587      * whether CVQ shares ASID with guest or not, because:
588      * - Memory listener need access to guest's memory addresses allocated in
589      *   the IOVA tree.
590      * - There should be plenty of IOVA address space for both ASID not to
591      *   worry about collisions between them.  Guest's translations are still
592      *   validated with virtio virtqueue_pop so there is no risk for the guest
593      *   to access memory that it shouldn't.
594      *
595      * To allocate a iova tree per ASID is doable but it complicates the code
596      * and it is not worth it for the moment.
597      */
598     if (!v->shared->iova_tree) {
599         v->shared->iova_tree = vhost_iova_tree_new(v->shared->iova_range.first,
600                                                    v->shared->iova_range.last);
601     }
602 
603     r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer,
604                                vhost_vdpa_net_cvq_cmd_page_len(), false);
605     if (unlikely(r < 0)) {
606         return r;
607     }
608 
609     r = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, s->status,
610                                vhost_vdpa_net_cvq_cmd_page_len(), true);
611     if (unlikely(r < 0)) {
612         vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer);
613     }
614 
615     return r;
616 }
617 
618 static void vhost_vdpa_net_cvq_stop(NetClientState *nc)
619 {
620     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
621 
622     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
623 
624     if (s->vhost_vdpa.shadow_vqs_enabled) {
625         vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer);
626         vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->status);
627     }
628 
629     vhost_vdpa_net_client_stop(nc);
630 }
631 
632 static ssize_t vhost_vdpa_net_cvq_add(VhostVDPAState *s,
633                                     const struct iovec *out_sg, size_t out_num,
634                                     const struct iovec *in_sg, size_t in_num)
635 {
636     VhostShadowVirtqueue *svq = g_ptr_array_index(s->vhost_vdpa.shadow_vqs, 0);
637     int r;
638 
639     r = vhost_svq_add(svq, out_sg, out_num, in_sg, in_num, NULL);
640     if (unlikely(r != 0)) {
641         if (unlikely(r == -ENOSPC)) {
642             qemu_log_mask(LOG_GUEST_ERROR, "%s: No space on device queue\n",
643                           __func__);
644         }
645     }
646 
647     return r;
648 }
649 
650 /*
651  * Convenience wrapper to poll SVQ for multiple control commands.
652  *
653  * Caller should hold the BQL when invoking this function, and should take
654  * the answer before SVQ pulls by itself when BQL is released.
655  */
656 static ssize_t vhost_vdpa_net_svq_poll(VhostVDPAState *s, size_t cmds_in_flight)
657 {
658     VhostShadowVirtqueue *svq = g_ptr_array_index(s->vhost_vdpa.shadow_vqs, 0);
659     return vhost_svq_poll(svq, cmds_in_flight);
660 }
661 
662 static void vhost_vdpa_net_load_cursor_reset(VhostVDPAState *s,
663                                              struct iovec *out_cursor,
664                                              struct iovec *in_cursor)
665 {
666     /* reset the cursor of the output buffer for the device */
667     out_cursor->iov_base = s->cvq_cmd_out_buffer;
668     out_cursor->iov_len = vhost_vdpa_net_cvq_cmd_page_len();
669 
670     /* reset the cursor of the in buffer for the device */
671     in_cursor->iov_base = s->status;
672     in_cursor->iov_len = vhost_vdpa_net_cvq_cmd_page_len();
673 }
674 
675 /*
676  * Poll SVQ for multiple pending control commands and check the device's ack.
677  *
678  * Caller should hold the BQL when invoking this function.
679  *
680  * @s: The VhostVDPAState
681  * @len: The length of the pending status shadow buffer
682  */
683 static ssize_t vhost_vdpa_net_svq_flush(VhostVDPAState *s, size_t len)
684 {
685     /* device uses a one-byte length ack for each control command */
686     ssize_t dev_written = vhost_vdpa_net_svq_poll(s, len);
687     if (unlikely(dev_written != len)) {
688         return -EIO;
689     }
690 
691     /* check the device's ack */
692     for (int i = 0; i < len; ++i) {
693         if (s->status[i] != VIRTIO_NET_OK) {
694             return -EIO;
695         }
696     }
697     return 0;
698 }
699 
700 static ssize_t vhost_vdpa_net_load_cmd(VhostVDPAState *s,
701                                        struct iovec *out_cursor,
702                                        struct iovec *in_cursor, uint8_t class,
703                                        uint8_t cmd, const struct iovec *data_sg,
704                                        size_t data_num)
705 {
706     const struct virtio_net_ctrl_hdr ctrl = {
707         .class = class,
708         .cmd = cmd,
709     };
710     size_t data_size = iov_size(data_sg, data_num), cmd_size;
711     struct iovec out, in;
712     ssize_t r;
713     unsigned dummy_cursor_iov_cnt;
714     VhostShadowVirtqueue *svq = g_ptr_array_index(s->vhost_vdpa.shadow_vqs, 0);
715 
716     assert(data_size < vhost_vdpa_net_cvq_cmd_page_len() - sizeof(ctrl));
717     cmd_size = sizeof(ctrl) + data_size;
718     if (vhost_svq_available_slots(svq) < 2 ||
719         iov_size(out_cursor, 1) < cmd_size) {
720         /*
721          * It is time to flush all pending control commands if SVQ is full
722          * or control commands shadow buffers are full.
723          *
724          * We can poll here since we've had BQL from the time
725          * we sent the descriptor.
726          */
727         r = vhost_vdpa_net_svq_flush(s, in_cursor->iov_base -
728                                      (void *)s->status);
729         if (unlikely(r < 0)) {
730             return r;
731         }
732 
733         vhost_vdpa_net_load_cursor_reset(s, out_cursor, in_cursor);
734     }
735 
736     /* pack the CVQ command header */
737     iov_from_buf(out_cursor, 1, 0, &ctrl, sizeof(ctrl));
738     /* pack the CVQ command command-specific-data */
739     iov_to_buf(data_sg, data_num, 0,
740                out_cursor->iov_base + sizeof(ctrl), data_size);
741 
742     /* extract the required buffer from the cursor for output */
743     iov_copy(&out, 1, out_cursor, 1, 0, cmd_size);
744     /* extract the required buffer from the cursor for input */
745     iov_copy(&in, 1, in_cursor, 1, 0, sizeof(*s->status));
746 
747     r = vhost_vdpa_net_cvq_add(s, &out, 1, &in, 1);
748     if (unlikely(r < 0)) {
749         return r;
750     }
751 
752     /* iterate the cursors */
753     dummy_cursor_iov_cnt = 1;
754     iov_discard_front(&out_cursor, &dummy_cursor_iov_cnt, cmd_size);
755     dummy_cursor_iov_cnt = 1;
756     iov_discard_front(&in_cursor, &dummy_cursor_iov_cnt, sizeof(*s->status));
757 
758     return 0;
759 }
760 
761 static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n,
762                                    struct iovec *out_cursor,
763                                    struct iovec *in_cursor)
764 {
765     if (virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
766         const struct iovec data = {
767             .iov_base = (void *)n->mac,
768             .iov_len = sizeof(n->mac),
769         };
770         ssize_t r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
771                                             VIRTIO_NET_CTRL_MAC,
772                                             VIRTIO_NET_CTRL_MAC_ADDR_SET,
773                                             &data, 1);
774         if (unlikely(r < 0)) {
775             return r;
776         }
777     }
778 
779     /*
780      * According to VirtIO standard, "The device MUST have an
781      * empty MAC filtering table on reset.".
782      *
783      * Therefore, there is no need to send this CVQ command if the
784      * driver also sets an empty MAC filter table, which aligns with
785      * the device's defaults.
786      *
787      * Note that the device's defaults can mismatch the driver's
788      * configuration only at live migration.
789      */
790     if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_RX) ||
791         n->mac_table.in_use == 0) {
792         return 0;
793     }
794 
795     uint32_t uni_entries = n->mac_table.first_multi,
796              uni_macs_size = uni_entries * ETH_ALEN,
797              mul_entries = n->mac_table.in_use - uni_entries,
798              mul_macs_size = mul_entries * ETH_ALEN;
799     struct virtio_net_ctrl_mac uni = {
800         .entries = cpu_to_le32(uni_entries),
801     };
802     struct virtio_net_ctrl_mac mul = {
803         .entries = cpu_to_le32(mul_entries),
804     };
805     const struct iovec data[] = {
806         {
807             .iov_base = &uni,
808             .iov_len = sizeof(uni),
809         }, {
810             .iov_base = n->mac_table.macs,
811             .iov_len = uni_macs_size,
812         }, {
813             .iov_base = &mul,
814             .iov_len = sizeof(mul),
815         }, {
816             .iov_base = &n->mac_table.macs[uni_macs_size],
817             .iov_len = mul_macs_size,
818         },
819     };
820     ssize_t r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
821                                         VIRTIO_NET_CTRL_MAC,
822                                         VIRTIO_NET_CTRL_MAC_TABLE_SET,
823                                         data, ARRAY_SIZE(data));
824     if (unlikely(r < 0)) {
825         return r;
826     }
827 
828     return 0;
829 }
830 
831 static int vhost_vdpa_net_load_rss(VhostVDPAState *s, const VirtIONet *n,
832                                    struct iovec *out_cursor,
833                                    struct iovec *in_cursor, bool do_rss)
834 {
835     struct virtio_net_rss_config cfg = {};
836     ssize_t r;
837     g_autofree uint16_t *table = NULL;
838 
839     /*
840      * According to VirtIO standard, "Initially the device has all hash
841      * types disabled and reports only VIRTIO_NET_HASH_REPORT_NONE.".
842      *
843      * Therefore, there is no need to send this CVQ command if the
844      * driver disables the all hash types, which aligns with
845      * the device's defaults.
846      *
847      * Note that the device's defaults can mismatch the driver's
848      * configuration only at live migration.
849      */
850     if (!n->rss_data.enabled ||
851         n->rss_data.hash_types == VIRTIO_NET_HASH_REPORT_NONE) {
852         return 0;
853     }
854 
855     table = g_malloc_n(n->rss_data.indirections_len,
856                        sizeof(n->rss_data.indirections_table[0]));
857     cfg.hash_types = cpu_to_le32(n->rss_data.hash_types);
858 
859     if (do_rss) {
860         /*
861          * According to VirtIO standard, "Number of entries in indirection_table
862          * is (indirection_table_mask + 1)".
863          */
864         cfg.indirection_table_mask = cpu_to_le16(n->rss_data.indirections_len -
865                                                  1);
866         cfg.unclassified_queue = cpu_to_le16(n->rss_data.default_queue);
867         for (int i = 0; i < n->rss_data.indirections_len; ++i) {
868             table[i] = cpu_to_le16(n->rss_data.indirections_table[i]);
869         }
870         cfg.max_tx_vq = cpu_to_le16(n->curr_queue_pairs);
871     } else {
872         /*
873          * According to VirtIO standard, "Field reserved MUST contain zeroes.
874          * It is defined to make the structure to match the layout of
875          * virtio_net_rss_config structure, defined in 5.1.6.5.7.".
876          *
877          * Therefore, we need to zero the fields in
878          * struct virtio_net_rss_config, which corresponds to the
879          * `reserved` field in struct virtio_net_hash_config.
880          *
881          * Note that all other fields are zeroed at their definitions,
882          * except for the `indirection_table` field, where the actual data
883          * is stored in the `table` variable to ensure compatibility
884          * with RSS case. Therefore, we need to zero the `table` variable here.
885          */
886         table[0] = 0;
887     }
888 
889     /*
890      * Considering that virtio_net_handle_rss() currently does not restore
891      * the hash key length parsed from the CVQ command sent from the guest
892      * into n->rss_data and uses the maximum key length in other code, so
893      * we also employ the maximum key length here.
894      */
895     cfg.hash_key_length = sizeof(n->rss_data.key);
896 
897     const struct iovec data[] = {
898         {
899             .iov_base = &cfg,
900             .iov_len = offsetof(struct virtio_net_rss_config,
901                                 indirection_table),
902         }, {
903             .iov_base = table,
904             .iov_len = n->rss_data.indirections_len *
905                        sizeof(n->rss_data.indirections_table[0]),
906         }, {
907             .iov_base = &cfg.max_tx_vq,
908             .iov_len = offsetof(struct virtio_net_rss_config, hash_key_data) -
909                        offsetof(struct virtio_net_rss_config, max_tx_vq),
910         }, {
911             .iov_base = (void *)n->rss_data.key,
912             .iov_len = sizeof(n->rss_data.key),
913         }
914     };
915 
916     r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
917                                 VIRTIO_NET_CTRL_MQ,
918                                 do_rss ? VIRTIO_NET_CTRL_MQ_RSS_CONFIG :
919                                 VIRTIO_NET_CTRL_MQ_HASH_CONFIG,
920                                 data, ARRAY_SIZE(data));
921     if (unlikely(r < 0)) {
922         return r;
923     }
924 
925     return 0;
926 }
927 
928 static int vhost_vdpa_net_load_mq(VhostVDPAState *s,
929                                   const VirtIONet *n,
930                                   struct iovec *out_cursor,
931                                   struct iovec *in_cursor)
932 {
933     struct virtio_net_ctrl_mq mq;
934     ssize_t r;
935 
936     if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_MQ)) {
937         return 0;
938     }
939 
940     mq.virtqueue_pairs = cpu_to_le16(n->curr_queue_pairs);
941     const struct iovec data = {
942         .iov_base = &mq,
943         .iov_len = sizeof(mq),
944     };
945     r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
946                                 VIRTIO_NET_CTRL_MQ,
947                                 VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET,
948                                 &data, 1);
949     if (unlikely(r < 0)) {
950         return r;
951     }
952 
953     if (virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_RSS)) {
954         /* load the receive-side scaling state */
955         r = vhost_vdpa_net_load_rss(s, n, out_cursor, in_cursor, true);
956         if (unlikely(r < 0)) {
957             return r;
958         }
959     } else if (virtio_vdev_has_feature(&n->parent_obj,
960                                        VIRTIO_NET_F_HASH_REPORT)) {
961         /* load the hash calculation state */
962         r = vhost_vdpa_net_load_rss(s, n, out_cursor, in_cursor, false);
963         if (unlikely(r < 0)) {
964             return r;
965         }
966     }
967 
968     return 0;
969 }
970 
971 static int vhost_vdpa_net_load_offloads(VhostVDPAState *s,
972                                         const VirtIONet *n,
973                                         struct iovec *out_cursor,
974                                         struct iovec *in_cursor)
975 {
976     uint64_t offloads;
977     ssize_t r;
978 
979     if (!virtio_vdev_has_feature(&n->parent_obj,
980                                  VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
981         return 0;
982     }
983 
984     if (n->curr_guest_offloads == virtio_net_supported_guest_offloads(n)) {
985         /*
986          * According to VirtIO standard, "Upon feature negotiation
987          * corresponding offload gets enabled to preserve
988          * backward compatibility.".
989          *
990          * Therefore, there is no need to send this CVQ command if the
991          * driver also enables all supported offloads, which aligns with
992          * the device's defaults.
993          *
994          * Note that the device's defaults can mismatch the driver's
995          * configuration only at live migration.
996          */
997         return 0;
998     }
999 
1000     offloads = cpu_to_le64(n->curr_guest_offloads);
1001     const struct iovec data = {
1002         .iov_base = &offloads,
1003         .iov_len = sizeof(offloads),
1004     };
1005     r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
1006                                 VIRTIO_NET_CTRL_GUEST_OFFLOADS,
1007                                 VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET,
1008                                 &data, 1);
1009     if (unlikely(r < 0)) {
1010         return r;
1011     }
1012 
1013     return 0;
1014 }
1015 
1016 static int vhost_vdpa_net_load_rx_mode(VhostVDPAState *s,
1017                                        struct iovec *out_cursor,
1018                                        struct iovec *in_cursor,
1019                                        uint8_t cmd,
1020                                        uint8_t on)
1021 {
1022     const struct iovec data = {
1023         .iov_base = &on,
1024         .iov_len = sizeof(on),
1025     };
1026     ssize_t r;
1027 
1028     r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
1029                                 VIRTIO_NET_CTRL_RX, cmd, &data, 1);
1030     if (unlikely(r < 0)) {
1031         return r;
1032     }
1033 
1034     return 0;
1035 }
1036 
1037 static int vhost_vdpa_net_load_rx(VhostVDPAState *s,
1038                                   const VirtIONet *n,
1039                                   struct iovec *out_cursor,
1040                                   struct iovec *in_cursor)
1041 {
1042     ssize_t r;
1043 
1044     if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_RX)) {
1045         return 0;
1046     }
1047 
1048     /*
1049      * According to virtio_net_reset(), device turns promiscuous mode
1050      * on by default.
1051      *
1052      * Additionally, according to VirtIO standard, "Since there are
1053      * no guarantees, it can use a hash filter or silently switch to
1054      * allmulti or promiscuous mode if it is given too many addresses.".
1055      * QEMU marks `n->mac_table.uni_overflow` if guest sets too many
1056      * non-multicast MAC addresses, indicating that promiscuous mode
1057      * should be enabled.
1058      *
1059      * Therefore, QEMU should only send this CVQ command if the
1060      * `n->mac_table.uni_overflow` is not marked and `n->promisc` is off,
1061      * which sets promiscuous mode on, different from the device's defaults.
1062      *
1063      * Note that the device's defaults can mismatch the driver's
1064      * configuration only at live migration.
1065      */
1066     if (!n->mac_table.uni_overflow && !n->promisc) {
1067         r = vhost_vdpa_net_load_rx_mode(s, out_cursor, in_cursor,
1068                                         VIRTIO_NET_CTRL_RX_PROMISC, 0);
1069         if (unlikely(r < 0)) {
1070             return r;
1071         }
1072     }
1073 
1074     /*
1075      * According to virtio_net_reset(), device turns all-multicast mode
1076      * off by default.
1077      *
1078      * According to VirtIO standard, "Since there are no guarantees,
1079      * it can use a hash filter or silently switch to allmulti or
1080      * promiscuous mode if it is given too many addresses.". QEMU marks
1081      * `n->mac_table.multi_overflow` if guest sets too many
1082      * non-multicast MAC addresses.
1083      *
1084      * Therefore, QEMU should only send this CVQ command if the
1085      * `n->mac_table.multi_overflow` is marked or `n->allmulti` is on,
1086      * which sets all-multicast mode on, different from the device's defaults.
1087      *
1088      * Note that the device's defaults can mismatch the driver's
1089      * configuration only at live migration.
1090      */
1091     if (n->mac_table.multi_overflow || n->allmulti) {
1092         r = vhost_vdpa_net_load_rx_mode(s, out_cursor, in_cursor,
1093                                         VIRTIO_NET_CTRL_RX_ALLMULTI, 1);
1094         if (unlikely(r < 0)) {
1095             return r;
1096         }
1097     }
1098 
1099     if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_RX_EXTRA)) {
1100         return 0;
1101     }
1102 
1103     /*
1104      * According to virtio_net_reset(), device turns all-unicast mode
1105      * off by default.
1106      *
1107      * Therefore, QEMU should only send this CVQ command if the driver
1108      * sets all-unicast mode on, different from the device's defaults.
1109      *
1110      * Note that the device's defaults can mismatch the driver's
1111      * configuration only at live migration.
1112      */
1113     if (n->alluni) {
1114         r = vhost_vdpa_net_load_rx_mode(s, out_cursor, in_cursor,
1115                                         VIRTIO_NET_CTRL_RX_ALLUNI, 1);
1116         if (r < 0) {
1117             return r;
1118         }
1119     }
1120 
1121     /*
1122      * According to virtio_net_reset(), device turns non-multicast mode
1123      * off by default.
1124      *
1125      * Therefore, QEMU should only send this CVQ command if the driver
1126      * sets non-multicast mode on, different from the device's defaults.
1127      *
1128      * Note that the device's defaults can mismatch the driver's
1129      * configuration only at live migration.
1130      */
1131     if (n->nomulti) {
1132         r = vhost_vdpa_net_load_rx_mode(s, out_cursor, in_cursor,
1133                                         VIRTIO_NET_CTRL_RX_NOMULTI, 1);
1134         if (r < 0) {
1135             return r;
1136         }
1137     }
1138 
1139     /*
1140      * According to virtio_net_reset(), device turns non-unicast mode
1141      * off by default.
1142      *
1143      * Therefore, QEMU should only send this CVQ command if the driver
1144      * sets non-unicast mode on, different from the device's defaults.
1145      *
1146      * Note that the device's defaults can mismatch the driver's
1147      * configuration only at live migration.
1148      */
1149     if (n->nouni) {
1150         r = vhost_vdpa_net_load_rx_mode(s, out_cursor, in_cursor,
1151                                         VIRTIO_NET_CTRL_RX_NOUNI, 1);
1152         if (r < 0) {
1153             return r;
1154         }
1155     }
1156 
1157     /*
1158      * According to virtio_net_reset(), device turns non-broadcast mode
1159      * off by default.
1160      *
1161      * Therefore, QEMU should only send this CVQ command if the driver
1162      * sets non-broadcast mode on, different from the device's defaults.
1163      *
1164      * Note that the device's defaults can mismatch the driver's
1165      * configuration only at live migration.
1166      */
1167     if (n->nobcast) {
1168         r = vhost_vdpa_net_load_rx_mode(s, out_cursor, in_cursor,
1169                                         VIRTIO_NET_CTRL_RX_NOBCAST, 1);
1170         if (r < 0) {
1171             return r;
1172         }
1173     }
1174 
1175     return 0;
1176 }
1177 
1178 static int vhost_vdpa_net_load_single_vlan(VhostVDPAState *s,
1179                                            const VirtIONet *n,
1180                                            struct iovec *out_cursor,
1181                                            struct iovec *in_cursor,
1182                                            uint16_t vid)
1183 {
1184     const struct iovec data = {
1185         .iov_base = &vid,
1186         .iov_len = sizeof(vid),
1187     };
1188     ssize_t r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor,
1189                                         VIRTIO_NET_CTRL_VLAN,
1190                                         VIRTIO_NET_CTRL_VLAN_ADD,
1191                                         &data, 1);
1192     if (unlikely(r < 0)) {
1193         return r;
1194     }
1195 
1196     return 0;
1197 }
1198 
1199 static int vhost_vdpa_net_load_vlan(VhostVDPAState *s,
1200                                     const VirtIONet *n,
1201                                     struct iovec *out_cursor,
1202                                     struct iovec *in_cursor)
1203 {
1204     int r;
1205 
1206     if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_VLAN)) {
1207         return 0;
1208     }
1209 
1210     for (int i = 0; i < MAX_VLAN >> 5; i++) {
1211         for (int j = 0; n->vlans[i] && j <= 0x1f; j++) {
1212             if (n->vlans[i] & (1U << j)) {
1213                 r = vhost_vdpa_net_load_single_vlan(s, n, out_cursor,
1214                                                     in_cursor, (i << 5) + j);
1215                 if (unlikely(r != 0)) {
1216                     return r;
1217                 }
1218             }
1219         }
1220     }
1221 
1222     return 0;
1223 }
1224 
1225 static int vhost_vdpa_net_cvq_load(NetClientState *nc)
1226 {
1227     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
1228     struct vhost_vdpa *v = &s->vhost_vdpa;
1229     const VirtIONet *n;
1230     int r;
1231     struct iovec out_cursor, in_cursor;
1232 
1233     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
1234 
1235     vhost_vdpa_set_vring_ready(v, v->dev->vq_index);
1236 
1237     if (v->shadow_vqs_enabled) {
1238         n = VIRTIO_NET(v->dev->vdev);
1239         vhost_vdpa_net_load_cursor_reset(s, &out_cursor, &in_cursor);
1240         r = vhost_vdpa_net_load_mac(s, n, &out_cursor, &in_cursor);
1241         if (unlikely(r < 0)) {
1242             return r;
1243         }
1244         r = vhost_vdpa_net_load_mq(s, n, &out_cursor, &in_cursor);
1245         if (unlikely(r)) {
1246             return r;
1247         }
1248         r = vhost_vdpa_net_load_offloads(s, n, &out_cursor, &in_cursor);
1249         if (unlikely(r)) {
1250             return r;
1251         }
1252         r = vhost_vdpa_net_load_rx(s, n, &out_cursor, &in_cursor);
1253         if (unlikely(r)) {
1254             return r;
1255         }
1256         r = vhost_vdpa_net_load_vlan(s, n, &out_cursor, &in_cursor);
1257         if (unlikely(r)) {
1258             return r;
1259         }
1260 
1261         /*
1262          * We need to poll and check all pending device's used buffers.
1263          *
1264          * We can poll here since we've had BQL from the time
1265          * we sent the descriptor.
1266          */
1267         r = vhost_vdpa_net_svq_flush(s, in_cursor.iov_base - (void *)s->status);
1268         if (unlikely(r)) {
1269             return r;
1270         }
1271     }
1272 
1273     for (int i = 0; i < v->dev->vq_index; ++i) {
1274         vhost_vdpa_set_vring_ready(v, i);
1275     }
1276 
1277     return 0;
1278 }
1279 
1280 static NetClientInfo net_vhost_vdpa_cvq_info = {
1281     .type = NET_CLIENT_DRIVER_VHOST_VDPA,
1282     .size = sizeof(VhostVDPAState),
1283     .receive = vhost_vdpa_receive,
1284     .start = vhost_vdpa_net_cvq_start,
1285     .load = vhost_vdpa_net_cvq_load,
1286     .stop = vhost_vdpa_net_cvq_stop,
1287     .cleanup = vhost_vdpa_cleanup,
1288     .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
1289     .has_ufo = vhost_vdpa_has_ufo,
1290     .check_peer_type = vhost_vdpa_check_peer_type,
1291     .set_steering_ebpf = vhost_vdpa_set_steering_ebpf,
1292 };
1293 
1294 /*
1295  * Forward the excessive VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command to
1296  * vdpa device.
1297  *
1298  * Considering that QEMU cannot send the entire filter table to the
1299  * vdpa device, it should send the VIRTIO_NET_CTRL_RX_PROMISC CVQ
1300  * command to enable promiscuous mode to receive all packets,
1301  * according to VirtIO standard, "Since there are no guarantees,
1302  * it can use a hash filter or silently switch to allmulti or
1303  * promiscuous mode if it is given too many addresses.".
1304  *
1305  * Since QEMU ignores MAC addresses beyond `MAC_TABLE_ENTRIES` and
1306  * marks `n->mac_table.x_overflow` accordingly, it should have
1307  * the same effect on the device model to receive
1308  * (`MAC_TABLE_ENTRIES` + 1) or more non-multicast MAC addresses.
1309  * The same applies to multicast MAC addresses.
1310  *
1311  * Therefore, QEMU can provide the device model with a fake
1312  * VIRTIO_NET_CTRL_MAC_TABLE_SET command with (`MAC_TABLE_ENTRIES` + 1)
1313  * non-multicast MAC addresses and (`MAC_TABLE_ENTRIES` + 1) multicast
1314  * MAC addresses. This ensures that the device model marks
1315  * `n->mac_table.uni_overflow` and `n->mac_table.multi_overflow`,
1316  * allowing all packets to be received, which aligns with the
1317  * state of the vdpa device.
1318  */
1319 static int vhost_vdpa_net_excessive_mac_filter_cvq_add(VhostVDPAState *s,
1320                                                        VirtQueueElement *elem,
1321                                                        struct iovec *out,
1322                                                        const struct iovec *in)
1323 {
1324     struct virtio_net_ctrl_mac mac_data, *mac_ptr;
1325     struct virtio_net_ctrl_hdr *hdr_ptr;
1326     uint32_t cursor;
1327     ssize_t r;
1328     uint8_t on = 1;
1329 
1330     /* parse the non-multicast MAC address entries from CVQ command */
1331     cursor = sizeof(*hdr_ptr);
1332     r = iov_to_buf(elem->out_sg, elem->out_num, cursor,
1333                    &mac_data, sizeof(mac_data));
1334     if (unlikely(r != sizeof(mac_data))) {
1335         /*
1336          * If the CVQ command is invalid, we should simulate the vdpa device
1337          * to reject the VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command
1338          */
1339         *s->status = VIRTIO_NET_ERR;
1340         return sizeof(*s->status);
1341     }
1342     cursor += sizeof(mac_data) + le32_to_cpu(mac_data.entries) * ETH_ALEN;
1343 
1344     /* parse the multicast MAC address entries from CVQ command */
1345     r = iov_to_buf(elem->out_sg, elem->out_num, cursor,
1346                    &mac_data, sizeof(mac_data));
1347     if (r != sizeof(mac_data)) {
1348         /*
1349          * If the CVQ command is invalid, we should simulate the vdpa device
1350          * to reject the VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command
1351          */
1352         *s->status = VIRTIO_NET_ERR;
1353         return sizeof(*s->status);
1354     }
1355     cursor += sizeof(mac_data) + le32_to_cpu(mac_data.entries) * ETH_ALEN;
1356 
1357     /* validate the CVQ command */
1358     if (iov_size(elem->out_sg, elem->out_num) != cursor) {
1359         /*
1360          * If the CVQ command is invalid, we should simulate the vdpa device
1361          * to reject the VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command
1362          */
1363         *s->status = VIRTIO_NET_ERR;
1364         return sizeof(*s->status);
1365     }
1366 
1367     /*
1368      * According to VirtIO standard, "Since there are no guarantees,
1369      * it can use a hash filter or silently switch to allmulti or
1370      * promiscuous mode if it is given too many addresses.".
1371      *
1372      * Therefore, considering that QEMU is unable to send the entire
1373      * filter table to the vdpa device, it should send the
1374      * VIRTIO_NET_CTRL_RX_PROMISC CVQ command to enable promiscuous mode
1375      */
1376     hdr_ptr = out->iov_base;
1377     out->iov_len = sizeof(*hdr_ptr) + sizeof(on);
1378 
1379     hdr_ptr->class = VIRTIO_NET_CTRL_RX;
1380     hdr_ptr->cmd = VIRTIO_NET_CTRL_RX_PROMISC;
1381     iov_from_buf(out, 1, sizeof(*hdr_ptr), &on, sizeof(on));
1382     r = vhost_vdpa_net_cvq_add(s, out, 1, in, 1);
1383     if (unlikely(r < 0)) {
1384         return r;
1385     }
1386 
1387     /*
1388      * We can poll here since we've had BQL from the time
1389      * we sent the descriptor.
1390      */
1391     r = vhost_vdpa_net_svq_poll(s, 1);
1392     if (unlikely(r < sizeof(*s->status))) {
1393         return r;
1394     }
1395     if (*s->status != VIRTIO_NET_OK) {
1396         return sizeof(*s->status);
1397     }
1398 
1399     /*
1400      * QEMU should also send a fake VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ
1401      * command to the device model, including (`MAC_TABLE_ENTRIES` + 1)
1402      * non-multicast MAC addresses and (`MAC_TABLE_ENTRIES` + 1)
1403      * multicast MAC addresses.
1404      *
1405      * By doing so, the device model can mark `n->mac_table.uni_overflow`
1406      * and `n->mac_table.multi_overflow`, enabling all packets to be
1407      * received, which aligns with the state of the vdpa device.
1408      */
1409     cursor = 0;
1410     uint32_t fake_uni_entries = MAC_TABLE_ENTRIES + 1,
1411              fake_mul_entries = MAC_TABLE_ENTRIES + 1,
1412              fake_cvq_size = sizeof(struct virtio_net_ctrl_hdr) +
1413                              sizeof(mac_data) + fake_uni_entries * ETH_ALEN +
1414                              sizeof(mac_data) + fake_mul_entries * ETH_ALEN;
1415 
1416     assert(fake_cvq_size < vhost_vdpa_net_cvq_cmd_page_len());
1417     out->iov_len = fake_cvq_size;
1418 
1419     /* pack the header for fake CVQ command */
1420     hdr_ptr = out->iov_base + cursor;
1421     hdr_ptr->class = VIRTIO_NET_CTRL_MAC;
1422     hdr_ptr->cmd = VIRTIO_NET_CTRL_MAC_TABLE_SET;
1423     cursor += sizeof(*hdr_ptr);
1424 
1425     /*
1426      * Pack the non-multicast MAC addresses part for fake CVQ command.
1427      *
1428      * According to virtio_net_handle_mac(), QEMU doesn't verify the MAC
1429      * addresses provided in CVQ command. Therefore, only the entries
1430      * field need to be prepared in the CVQ command.
1431      */
1432     mac_ptr = out->iov_base + cursor;
1433     mac_ptr->entries = cpu_to_le32(fake_uni_entries);
1434     cursor += sizeof(*mac_ptr) + fake_uni_entries * ETH_ALEN;
1435 
1436     /*
1437      * Pack the multicast MAC addresses part for fake CVQ command.
1438      *
1439      * According to virtio_net_handle_mac(), QEMU doesn't verify the MAC
1440      * addresses provided in CVQ command. Therefore, only the entries
1441      * field need to be prepared in the CVQ command.
1442      */
1443     mac_ptr = out->iov_base + cursor;
1444     mac_ptr->entries = cpu_to_le32(fake_mul_entries);
1445 
1446     /*
1447      * Simulating QEMU poll a vdpa device used buffer
1448      * for VIRTIO_NET_CTRL_MAC_TABLE_SET CVQ command
1449      */
1450     return sizeof(*s->status);
1451 }
1452 
1453 /**
1454  * Validate and copy control virtqueue commands.
1455  *
1456  * Following QEMU guidelines, we offer a copy of the buffers to the device to
1457  * prevent TOCTOU bugs.
1458  */
1459 static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
1460                                             VirtQueueElement *elem,
1461                                             void *opaque)
1462 {
1463     VhostVDPAState *s = opaque;
1464     size_t in_len;
1465     const struct virtio_net_ctrl_hdr *ctrl;
1466     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
1467     /* Out buffer sent to both the vdpa device and the device model */
1468     struct iovec out = {
1469         .iov_base = s->cvq_cmd_out_buffer,
1470     };
1471     /* in buffer used for device model */
1472     const struct iovec model_in = {
1473         .iov_base = &status,
1474         .iov_len = sizeof(status),
1475     };
1476     /* in buffer used for vdpa device */
1477     const struct iovec vdpa_in = {
1478         .iov_base = s->status,
1479         .iov_len = sizeof(*s->status),
1480     };
1481     ssize_t dev_written = -EINVAL;
1482 
1483     out.iov_len = iov_to_buf(elem->out_sg, elem->out_num, 0,
1484                              s->cvq_cmd_out_buffer,
1485                              vhost_vdpa_net_cvq_cmd_page_len());
1486 
1487     ctrl = s->cvq_cmd_out_buffer;
1488     if (ctrl->class == VIRTIO_NET_CTRL_ANNOUNCE) {
1489         /*
1490          * Guest announce capability is emulated by qemu, so don't forward to
1491          * the device.
1492          */
1493         dev_written = sizeof(status);
1494         *s->status = VIRTIO_NET_OK;
1495     } else if (unlikely(ctrl->class == VIRTIO_NET_CTRL_MAC &&
1496                         ctrl->cmd == VIRTIO_NET_CTRL_MAC_TABLE_SET &&
1497                         iov_size(elem->out_sg, elem->out_num) > out.iov_len)) {
1498         /*
1499          * Due to the size limitation of the out buffer sent to the vdpa device,
1500          * which is determined by vhost_vdpa_net_cvq_cmd_page_len(), excessive
1501          * MAC addresses set by the driver for the filter table can cause
1502          * truncation of the CVQ command in QEMU. As a result, the vdpa device
1503          * rejects the flawed CVQ command.
1504          *
1505          * Therefore, QEMU must handle this situation instead of sending
1506          * the CVQ command directly.
1507          */
1508         dev_written = vhost_vdpa_net_excessive_mac_filter_cvq_add(s, elem,
1509                                                             &out, &vdpa_in);
1510         if (unlikely(dev_written < 0)) {
1511             goto out;
1512         }
1513     } else {
1514         ssize_t r;
1515         r = vhost_vdpa_net_cvq_add(s, &out, 1, &vdpa_in, 1);
1516         if (unlikely(r < 0)) {
1517             dev_written = r;
1518             goto out;
1519         }
1520 
1521         /*
1522          * We can poll here since we've had BQL from the time
1523          * we sent the descriptor.
1524          */
1525         dev_written = vhost_vdpa_net_svq_poll(s, 1);
1526     }
1527 
1528     if (unlikely(dev_written < sizeof(status))) {
1529         error_report("Insufficient written data (%zu)", dev_written);
1530         goto out;
1531     }
1532 
1533     if (*s->status != VIRTIO_NET_OK) {
1534         goto out;
1535     }
1536 
1537     status = VIRTIO_NET_ERR;
1538     virtio_net_handle_ctrl_iov(svq->vdev, &model_in, 1, &out, 1);
1539     if (status != VIRTIO_NET_OK) {
1540         error_report("Bad CVQ processing in model");
1541     }
1542 
1543 out:
1544     in_len = iov_from_buf(elem->in_sg, elem->in_num, 0, &status,
1545                           sizeof(status));
1546     if (unlikely(in_len < sizeof(status))) {
1547         error_report("Bad device CVQ written length");
1548     }
1549     vhost_svq_push_elem(svq, elem, MIN(in_len, sizeof(status)));
1550     /*
1551      * `elem` belongs to vhost_vdpa_net_handle_ctrl_avail() only when
1552      * the function successfully forwards the CVQ command, indicated
1553      * by a non-negative value of `dev_written`. Otherwise, it still
1554      * belongs to SVQ.
1555      * This function should only free the `elem` when it owns.
1556      */
1557     if (dev_written >= 0) {
1558         g_free(elem);
1559     }
1560     return dev_written < 0 ? dev_written : 0;
1561 }
1562 
1563 static const VhostShadowVirtqueueOps vhost_vdpa_net_svq_ops = {
1564     .avail_handler = vhost_vdpa_net_handle_ctrl_avail,
1565 };
1566 
1567 /**
1568  * Probe if CVQ is isolated
1569  *
1570  * @device_fd         The vdpa device fd
1571  * @features          Features offered by the device.
1572  * @cvq_index         The control vq pair index
1573  *
1574  * Returns <0 in case of failure, 0 if false and 1 if true.
1575  */
1576 static int vhost_vdpa_probe_cvq_isolation(int device_fd, uint64_t features,
1577                                           int cvq_index, Error **errp)
1578 {
1579     uint64_t backend_features;
1580     int64_t cvq_group;
1581     uint8_t status = VIRTIO_CONFIG_S_ACKNOWLEDGE |
1582                      VIRTIO_CONFIG_S_DRIVER;
1583     int r;
1584 
1585     ERRP_GUARD();
1586 
1587     r = ioctl(device_fd, VHOST_GET_BACKEND_FEATURES, &backend_features);
1588     if (unlikely(r < 0)) {
1589         error_setg_errno(errp, errno, "Cannot get vdpa backend_features");
1590         return r;
1591     }
1592 
1593     if (!(backend_features & BIT_ULL(VHOST_BACKEND_F_IOTLB_ASID))) {
1594         return 0;
1595     }
1596 
1597     r = ioctl(device_fd, VHOST_VDPA_SET_STATUS, &status);
1598     if (unlikely(r)) {
1599         error_setg_errno(errp, -r, "Cannot set device status");
1600         goto out;
1601     }
1602 
1603     r = ioctl(device_fd, VHOST_SET_FEATURES, &features);
1604     if (unlikely(r)) {
1605         error_setg_errno(errp, -r, "Cannot set features");
1606         goto out;
1607     }
1608 
1609     status |= VIRTIO_CONFIG_S_FEATURES_OK;
1610     r = ioctl(device_fd, VHOST_VDPA_SET_STATUS, &status);
1611     if (unlikely(r)) {
1612         error_setg_errno(errp, -r, "Cannot set device status");
1613         goto out;
1614     }
1615 
1616     cvq_group = vhost_vdpa_get_vring_group(device_fd, cvq_index, errp);
1617     if (unlikely(cvq_group < 0)) {
1618         if (cvq_group != -ENOTSUP) {
1619             r = cvq_group;
1620             goto out;
1621         }
1622 
1623         /*
1624          * The kernel report VHOST_BACKEND_F_IOTLB_ASID if the vdpa frontend
1625          * support ASID even if the parent driver does not.  The CVQ cannot be
1626          * isolated in this case.
1627          */
1628         error_free(*errp);
1629         *errp = NULL;
1630         r = 0;
1631         goto out;
1632     }
1633 
1634     for (int i = 0; i < cvq_index; ++i) {
1635         int64_t group = vhost_vdpa_get_vring_group(device_fd, i, errp);
1636         if (unlikely(group < 0)) {
1637             r = group;
1638             goto out;
1639         }
1640 
1641         if (group == (int64_t)cvq_group) {
1642             r = 0;
1643             goto out;
1644         }
1645     }
1646 
1647     r = 1;
1648 
1649 out:
1650     status = 0;
1651     ioctl(device_fd, VHOST_VDPA_SET_STATUS, &status);
1652     return r;
1653 }
1654 
1655 static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
1656                                        const char *device,
1657                                        const char *name,
1658                                        int vdpa_device_fd,
1659                                        int queue_pair_index,
1660                                        int nvqs,
1661                                        bool is_datapath,
1662                                        bool svq,
1663                                        struct vhost_vdpa_iova_range iova_range,
1664                                        uint64_t features,
1665                                        VhostVDPAShared *shared,
1666                                        Error **errp)
1667 {
1668     NetClientState *nc = NULL;
1669     VhostVDPAState *s;
1670     int ret = 0;
1671     assert(name);
1672     int cvq_isolated = 0;
1673 
1674     if (is_datapath) {
1675         nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device,
1676                                  name);
1677     } else {
1678         cvq_isolated = vhost_vdpa_probe_cvq_isolation(vdpa_device_fd, features,
1679                                                       queue_pair_index * 2,
1680                                                       errp);
1681         if (unlikely(cvq_isolated < 0)) {
1682             return NULL;
1683         }
1684 
1685         nc = qemu_new_net_control_client(&net_vhost_vdpa_cvq_info, peer,
1686                                          device, name);
1687     }
1688     qemu_set_info_str(nc, TYPE_VHOST_VDPA);
1689     s = DO_UPCAST(VhostVDPAState, nc, nc);
1690 
1691     s->vhost_vdpa.index = queue_pair_index;
1692     s->always_svq = svq;
1693     s->migration_state.notify = NULL;
1694     s->vhost_vdpa.shadow_vqs_enabled = svq;
1695     if (queue_pair_index == 0) {
1696         vhost_vdpa_net_valid_svq_features(features,
1697                                           &s->vhost_vdpa.migration_blocker);
1698         s->vhost_vdpa.shared = g_new0(VhostVDPAShared, 1);
1699         s->vhost_vdpa.shared->device_fd = vdpa_device_fd;
1700         s->vhost_vdpa.shared->iova_range = iova_range;
1701         s->vhost_vdpa.shared->shadow_data = svq;
1702     } else if (!is_datapath) {
1703         s->cvq_cmd_out_buffer = mmap(NULL, vhost_vdpa_net_cvq_cmd_page_len(),
1704                                      PROT_READ | PROT_WRITE,
1705                                      MAP_SHARED | MAP_ANONYMOUS, -1, 0);
1706         s->status = mmap(NULL, vhost_vdpa_net_cvq_cmd_page_len(),
1707                          PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS,
1708                          -1, 0);
1709 
1710         s->vhost_vdpa.shadow_vq_ops = &vhost_vdpa_net_svq_ops;
1711         s->vhost_vdpa.shadow_vq_ops_opaque = s;
1712         s->cvq_isolated = cvq_isolated;
1713     }
1714     if (queue_pair_index != 0) {
1715         s->vhost_vdpa.shared = shared;
1716     }
1717 
1718     ret = vhost_vdpa_add(nc, (void *)&s->vhost_vdpa, queue_pair_index, nvqs);
1719     if (ret) {
1720         qemu_del_net_client(nc);
1721         return NULL;
1722     }
1723 
1724     return nc;
1725 }
1726 
1727 static int vhost_vdpa_get_features(int fd, uint64_t *features, Error **errp)
1728 {
1729     int ret = ioctl(fd, VHOST_GET_FEATURES, features);
1730     if (unlikely(ret < 0)) {
1731         error_setg_errno(errp, errno,
1732                          "Fail to query features from vhost-vDPA device");
1733     }
1734     return ret;
1735 }
1736 
1737 static int vhost_vdpa_get_max_queue_pairs(int fd, uint64_t features,
1738                                           int *has_cvq, Error **errp)
1739 {
1740     unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
1741     g_autofree struct vhost_vdpa_config *config = NULL;
1742     __virtio16 *max_queue_pairs;
1743     int ret;
1744 
1745     if (features & (1 << VIRTIO_NET_F_CTRL_VQ)) {
1746         *has_cvq = 1;
1747     } else {
1748         *has_cvq = 0;
1749     }
1750 
1751     if (features & (1 << VIRTIO_NET_F_MQ)) {
1752         config = g_malloc0(config_size + sizeof(*max_queue_pairs));
1753         config->off = offsetof(struct virtio_net_config, max_virtqueue_pairs);
1754         config->len = sizeof(*max_queue_pairs);
1755 
1756         ret = ioctl(fd, VHOST_VDPA_GET_CONFIG, config);
1757         if (ret) {
1758             error_setg(errp, "Fail to get config from vhost-vDPA device");
1759             return -ret;
1760         }
1761 
1762         max_queue_pairs = (__virtio16 *)&config->buf;
1763 
1764         return lduw_le_p(max_queue_pairs);
1765     }
1766 
1767     return 1;
1768 }
1769 
1770 int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
1771                         NetClientState *peer, Error **errp)
1772 {
1773     const NetdevVhostVDPAOptions *opts;
1774     uint64_t features;
1775     int vdpa_device_fd;
1776     g_autofree NetClientState **ncs = NULL;
1777     struct vhost_vdpa_iova_range iova_range;
1778     NetClientState *nc;
1779     int queue_pairs, r, i = 0, has_cvq = 0;
1780 
1781     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_VDPA);
1782     opts = &netdev->u.vhost_vdpa;
1783     if (!opts->vhostdev && !opts->vhostfd) {
1784         error_setg(errp,
1785                    "vhost-vdpa: neither vhostdev= nor vhostfd= was specified");
1786         return -1;
1787     }
1788 
1789     if (opts->vhostdev && opts->vhostfd) {
1790         error_setg(errp,
1791                    "vhost-vdpa: vhostdev= and vhostfd= are mutually exclusive");
1792         return -1;
1793     }
1794 
1795     if (opts->vhostdev) {
1796         vdpa_device_fd = qemu_open(opts->vhostdev, O_RDWR, errp);
1797         if (vdpa_device_fd == -1) {
1798             return -errno;
1799         }
1800     } else {
1801         /* has_vhostfd */
1802         vdpa_device_fd = monitor_fd_param(monitor_cur(), opts->vhostfd, errp);
1803         if (vdpa_device_fd == -1) {
1804             error_prepend(errp, "vhost-vdpa: unable to parse vhostfd: ");
1805             return -1;
1806         }
1807     }
1808 
1809     r = vhost_vdpa_get_features(vdpa_device_fd, &features, errp);
1810     if (unlikely(r < 0)) {
1811         goto err;
1812     }
1813 
1814     queue_pairs = vhost_vdpa_get_max_queue_pairs(vdpa_device_fd, features,
1815                                                  &has_cvq, errp);
1816     if (queue_pairs < 0) {
1817         qemu_close(vdpa_device_fd);
1818         return queue_pairs;
1819     }
1820 
1821     r = vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range);
1822     if (unlikely(r < 0)) {
1823         error_setg(errp, "vhost-vdpa: get iova range failed: %s",
1824                    strerror(-r));
1825         goto err;
1826     }
1827 
1828     if (opts->x_svq && !vhost_vdpa_net_valid_svq_features(features, errp)) {
1829         goto err;
1830     }
1831 
1832     ncs = g_malloc0(sizeof(*ncs) * queue_pairs);
1833 
1834     for (i = 0; i < queue_pairs; i++) {
1835         VhostVDPAShared *shared = NULL;
1836 
1837         if (i) {
1838             shared = DO_UPCAST(VhostVDPAState, nc, ncs[0])->vhost_vdpa.shared;
1839         }
1840         ncs[i] = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name,
1841                                      vdpa_device_fd, i, 2, true, opts->x_svq,
1842                                      iova_range, features, shared, errp);
1843         if (!ncs[i])
1844             goto err;
1845     }
1846 
1847     if (has_cvq) {
1848         VhostVDPAState *s0 = DO_UPCAST(VhostVDPAState, nc, ncs[0]);
1849         VhostVDPAShared *shared = s0->vhost_vdpa.shared;
1850 
1851         nc = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name,
1852                                  vdpa_device_fd, i, 1, false,
1853                                  opts->x_svq, iova_range, features, shared,
1854                                  errp);
1855         if (!nc)
1856             goto err;
1857     }
1858 
1859     return 0;
1860 
1861 err:
1862     if (i) {
1863         for (i--; i >= 0; i--) {
1864             qemu_del_net_client(ncs[i]);
1865         }
1866     }
1867 
1868     qemu_close(vdpa_device_fd);
1869 
1870     return -1;
1871 }
1872