1 // SPDX-License-Identifier: GPL-2.0-only
3 * virtio transport for vsock
5 * Copyright (C) 2013-2015 Red Hat, Inc.
6 * Author: Asias He <asias@redhat.com>
7 * Stefan Hajnoczi <stefanha@redhat.com>
9 * Some of the code is take from Gerd Hoffmann <kraxel@redhat.com>'s
10 * early virtio-vsock proof-of-concept bits.
12 #include <linux/spinlock.h>
13 #include <linux/module.h>
14 #include <linux/list.h>
15 #include <linux/atomic.h>
16 #include <linux/virtio.h>
17 #include <linux/virtio_ids.h>
18 #include <linux/virtio_config.h>
19 #include <linux/virtio_vsock.h>
21 #include <linux/mutex.h>
22 #include <net/af_vsock.h>
24 static struct workqueue_struct *virtio_vsock_workqueue;
25 static struct virtio_vsock __rcu *the_virtio_vsock;
26 static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */
27 static struct virtio_transport virtio_transport; /* forward declaration */
30 struct virtio_device *vdev;
31 struct virtqueue *vqs[VSOCK_VQ_MAX];
33 /* Virtqueue processing is deferred to a workqueue */
34 struct work_struct tx_work;
35 struct work_struct rx_work;
36 struct work_struct event_work;
38 /* The following fields are protected by tx_lock. vqs[VSOCK_VQ_TX]
39 * must be accessed with tx_lock held.
44 struct work_struct send_pkt_work;
45 struct sk_buff_head send_pkt_queue;
47 atomic_t queued_replies;
49 /* The following fields are protected by rx_lock. vqs[VSOCK_VQ_RX]
50 * must be accessed with rx_lock held.
57 /* The following fields are protected by event_lock.
58 * vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held.
60 struct mutex event_lock;
62 struct virtio_vsock_event event_list[8];
67 /* These fields are used only in tx path in function
68 * 'virtio_transport_send_pkt_work()', so to save
69 * stack space in it, place both of them here. Each
70 * pointer from 'out_sgs' points to the corresponding
71 * element in 'out_bufs' - this is initialized in
72 * 'virtio_vsock_probe()'. Both fields are protected
73 * by 'tx_lock'. +1 is needed for packet header.
75 struct scatterlist *out_sgs[MAX_SKB_FRAGS + 1];
76 struct scatterlist out_bufs[MAX_SKB_FRAGS + 1];
79 static u32 virtio_transport_get_local_cid(void)
81 struct virtio_vsock *vsock;
85 vsock = rcu_dereference(the_virtio_vsock);
91 ret = vsock->guest_cid;
98 virtio_transport_send_pkt_work(struct work_struct *work)
100 struct virtio_vsock *vsock =
101 container_of(work, struct virtio_vsock, send_pkt_work);
102 struct virtqueue *vq;
104 bool restart_rx = false;
106 mutex_lock(&vsock->tx_lock);
111 vq = vsock->vqs[VSOCK_VQ_TX];
114 int ret, in_sg = 0, out_sg = 0;
115 struct scatterlist **sgs;
119 skb = virtio_vsock_skb_dequeue(&vsock->send_pkt_queue);
123 virtio_transport_deliver_tap_pkt(skb);
124 reply = virtio_vsock_skb_reply(skb);
125 sgs = vsock->out_sgs;
126 sg_init_one(sgs[out_sg], virtio_vsock_hdr(skb),
127 sizeof(*virtio_vsock_hdr(skb)));
130 if (!skb_is_nonlinear(skb)) {
132 sg_init_one(sgs[out_sg], skb->data, skb->len);
136 struct skb_shared_info *si;
139 /* If skb is nonlinear, then its buffer must contain
140 * only header and nothing more. Data is stored in
143 WARN_ON_ONCE(skb_headroom(skb) != sizeof(*virtio_vsock_hdr(skb)));
145 si = skb_shinfo(skb);
147 for (i = 0; i < si->nr_frags; i++) {
148 skb_frag_t *skb_frag = &si->frags[i];
151 /* We will use 'page_to_virt()' for the userspace page
152 * here, because virtio or dma-mapping layers will call
153 * 'virt_to_phys()' later to fill the buffer descriptor.
154 * We don't touch memory at "virtual" address of this page.
156 va = page_to_virt(skb_frag->bv_page);
157 sg_init_one(sgs[out_sg],
158 va + skb_frag->bv_offset,
164 ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, skb, GFP_KERNEL);
165 /* Usually this means that there is no more space available in
169 virtio_vsock_skb_queue_head(&vsock->send_pkt_queue, skb);
174 struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
177 val = atomic_dec_return(&vsock->queued_replies);
179 /* Do we now have resources to resume rx processing? */
180 if (val + 1 == virtqueue_get_vring_size(rx_vq))
191 mutex_unlock(&vsock->tx_lock);
194 queue_work(virtio_vsock_workqueue, &vsock->rx_work);
198 virtio_transport_send_pkt(struct sk_buff *skb)
200 struct virtio_vsock_hdr *hdr;
201 struct virtio_vsock *vsock;
204 hdr = virtio_vsock_hdr(skb);
207 vsock = rcu_dereference(the_virtio_vsock);
214 if (le64_to_cpu(hdr->dst_cid) == vsock->guest_cid) {
220 if (virtio_vsock_skb_reply(skb))
221 atomic_inc(&vsock->queued_replies);
223 virtio_vsock_skb_queue_tail(&vsock->send_pkt_queue, skb);
224 queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
232 virtio_transport_cancel_pkt(struct vsock_sock *vsk)
234 struct virtio_vsock *vsock;
238 vsock = rcu_dereference(the_virtio_vsock);
244 cnt = virtio_transport_purge_skbs(vsk, &vsock->send_pkt_queue);
247 struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
250 new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
251 if (new_cnt + cnt >= virtqueue_get_vring_size(rx_vq) &&
252 new_cnt < virtqueue_get_vring_size(rx_vq))
253 queue_work(virtio_vsock_workqueue, &vsock->rx_work);
263 static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
265 int total_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE + VIRTIO_VSOCK_SKB_HEADROOM;
266 struct scatterlist pkt, *p;
267 struct virtqueue *vq;
271 vq = vsock->vqs[VSOCK_VQ_RX];
274 skb = virtio_vsock_alloc_skb(total_len, GFP_KERNEL);
278 memset(skb->head, 0, VIRTIO_VSOCK_SKB_HEADROOM);
279 sg_init_one(&pkt, virtio_vsock_hdr(skb), total_len);
281 ret = virtqueue_add_sgs(vq, &p, 0, 1, skb, GFP_KERNEL);
288 } while (vq->num_free);
289 if (vsock->rx_buf_nr > vsock->rx_buf_max_nr)
290 vsock->rx_buf_max_nr = vsock->rx_buf_nr;
294 static void virtio_transport_tx_work(struct work_struct *work)
296 struct virtio_vsock *vsock =
297 container_of(work, struct virtio_vsock, tx_work);
298 struct virtqueue *vq;
301 vq = vsock->vqs[VSOCK_VQ_TX];
302 mutex_lock(&vsock->tx_lock);
311 virtqueue_disable_cb(vq);
312 while ((skb = virtqueue_get_buf(vq, &len)) != NULL) {
316 } while (!virtqueue_enable_cb(vq));
319 mutex_unlock(&vsock->tx_lock);
322 queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
325 /* Is there space left for replies to rx packets? */
326 static bool virtio_transport_more_replies(struct virtio_vsock *vsock)
328 struct virtqueue *vq = vsock->vqs[VSOCK_VQ_RX];
331 smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
332 val = atomic_read(&vsock->queued_replies);
334 return val < virtqueue_get_vring_size(vq);
337 /* event_lock must be held */
338 static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock,
339 struct virtio_vsock_event *event)
341 struct scatterlist sg;
342 struct virtqueue *vq;
344 vq = vsock->vqs[VSOCK_VQ_EVENT];
346 sg_init_one(&sg, event, sizeof(*event));
348 return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL);
351 /* event_lock must be held */
352 static void virtio_vsock_event_fill(struct virtio_vsock *vsock)
356 for (i = 0; i < ARRAY_SIZE(vsock->event_list); i++) {
357 struct virtio_vsock_event *event = &vsock->event_list[i];
359 virtio_vsock_event_fill_one(vsock, event);
362 virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
365 static void virtio_vsock_reset_sock(struct sock *sk)
367 /* vmci_transport.c doesn't take sk_lock here either. At least we're
368 * under vsock_table_lock so the sock cannot disappear while we're
372 sk->sk_state = TCP_CLOSE;
373 sk->sk_err = ECONNRESET;
377 static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock)
379 struct virtio_device *vdev = vsock->vdev;
382 vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid),
383 &guest_cid, sizeof(guest_cid));
384 vsock->guest_cid = le64_to_cpu(guest_cid);
387 /* event_lock must be held */
388 static void virtio_vsock_event_handle(struct virtio_vsock *vsock,
389 struct virtio_vsock_event *event)
391 switch (le32_to_cpu(event->id)) {
392 case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET:
393 virtio_vsock_update_guest_cid(vsock);
394 vsock_for_each_connected_socket(&virtio_transport.transport,
395 virtio_vsock_reset_sock);
400 static void virtio_transport_event_work(struct work_struct *work)
402 struct virtio_vsock *vsock =
403 container_of(work, struct virtio_vsock, event_work);
404 struct virtqueue *vq;
406 vq = vsock->vqs[VSOCK_VQ_EVENT];
408 mutex_lock(&vsock->event_lock);
410 if (!vsock->event_run)
414 struct virtio_vsock_event *event;
417 virtqueue_disable_cb(vq);
418 while ((event = virtqueue_get_buf(vq, &len)) != NULL) {
419 if (len == sizeof(*event))
420 virtio_vsock_event_handle(vsock, event);
422 virtio_vsock_event_fill_one(vsock, event);
424 } while (!virtqueue_enable_cb(vq));
426 virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
428 mutex_unlock(&vsock->event_lock);
431 static void virtio_vsock_event_done(struct virtqueue *vq)
433 struct virtio_vsock *vsock = vq->vdev->priv;
437 queue_work(virtio_vsock_workqueue, &vsock->event_work);
440 static void virtio_vsock_tx_done(struct virtqueue *vq)
442 struct virtio_vsock *vsock = vq->vdev->priv;
446 queue_work(virtio_vsock_workqueue, &vsock->tx_work);
449 static void virtio_vsock_rx_done(struct virtqueue *vq)
451 struct virtio_vsock *vsock = vq->vdev->priv;
455 queue_work(virtio_vsock_workqueue, &vsock->rx_work);
458 static bool virtio_transport_can_msgzerocopy(int bufs_num)
460 struct virtio_vsock *vsock;
465 vsock = rcu_dereference(the_virtio_vsock);
467 struct virtqueue *vq = vsock->vqs[VSOCK_VQ_TX];
469 /* Check that tx queue is large enough to keep whole
470 * data to send. This is needed, because when there is
471 * not enough free space in the queue, current skb to
472 * send will be reinserted to the head of tx list of
473 * the socket to retry transmission later, so if skb
474 * is bigger than whole queue, it will be reinserted
475 * again and again, thus blocking other skbs to be sent.
476 * Each page of the user provided buffer will be added
477 * as a single buffer to the tx virtqueue, so compare
478 * number of pages against maximum capacity of the queue.
480 if (bufs_num <= vq->num_max)
489 static bool virtio_transport_msgzerocopy_allow(void)
494 static bool virtio_transport_seqpacket_allow(u32 remote_cid);
496 static struct virtio_transport virtio_transport = {
498 .module = THIS_MODULE,
500 .get_local_cid = virtio_transport_get_local_cid,
502 .init = virtio_transport_do_socket_init,
503 .destruct = virtio_transport_destruct,
504 .release = virtio_transport_release,
505 .connect = virtio_transport_connect,
506 .shutdown = virtio_transport_shutdown,
507 .cancel_pkt = virtio_transport_cancel_pkt,
509 .dgram_bind = virtio_transport_dgram_bind,
510 .dgram_dequeue = virtio_transport_dgram_dequeue,
511 .dgram_enqueue = virtio_transport_dgram_enqueue,
512 .dgram_allow = virtio_transport_dgram_allow,
514 .stream_dequeue = virtio_transport_stream_dequeue,
515 .stream_enqueue = virtio_transport_stream_enqueue,
516 .stream_has_data = virtio_transport_stream_has_data,
517 .stream_has_space = virtio_transport_stream_has_space,
518 .stream_rcvhiwat = virtio_transport_stream_rcvhiwat,
519 .stream_is_active = virtio_transport_stream_is_active,
520 .stream_allow = virtio_transport_stream_allow,
522 .seqpacket_dequeue = virtio_transport_seqpacket_dequeue,
523 .seqpacket_enqueue = virtio_transport_seqpacket_enqueue,
524 .seqpacket_allow = virtio_transport_seqpacket_allow,
525 .seqpacket_has_data = virtio_transport_seqpacket_has_data,
527 .msgzerocopy_allow = virtio_transport_msgzerocopy_allow,
529 .notify_poll_in = virtio_transport_notify_poll_in,
530 .notify_poll_out = virtio_transport_notify_poll_out,
531 .notify_recv_init = virtio_transport_notify_recv_init,
532 .notify_recv_pre_block = virtio_transport_notify_recv_pre_block,
533 .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue,
534 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
535 .notify_send_init = virtio_transport_notify_send_init,
536 .notify_send_pre_block = virtio_transport_notify_send_pre_block,
537 .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue,
538 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
539 .notify_buffer_size = virtio_transport_notify_buffer_size,
541 .read_skb = virtio_transport_read_skb,
544 .send_pkt = virtio_transport_send_pkt,
545 .can_msgzerocopy = virtio_transport_can_msgzerocopy,
548 static bool virtio_transport_seqpacket_allow(u32 remote_cid)
550 struct virtio_vsock *vsock;
551 bool seqpacket_allow;
553 seqpacket_allow = false;
555 vsock = rcu_dereference(the_virtio_vsock);
557 seqpacket_allow = vsock->seqpacket_allow;
560 return seqpacket_allow;
563 static void virtio_transport_rx_work(struct work_struct *work)
565 struct virtio_vsock *vsock =
566 container_of(work, struct virtio_vsock, rx_work);
567 struct virtqueue *vq;
569 vq = vsock->vqs[VSOCK_VQ_RX];
571 mutex_lock(&vsock->rx_lock);
577 virtqueue_disable_cb(vq);
582 if (!virtio_transport_more_replies(vsock)) {
583 /* Stop rx until the device processes already
584 * pending replies. Leave rx virtqueue
585 * callbacks disabled.
590 skb = virtqueue_get_buf(vq, &len);
596 /* Drop short/long packets */
597 if (unlikely(len < sizeof(struct virtio_vsock_hdr) ||
598 len > virtio_vsock_skb_len(skb))) {
603 virtio_vsock_skb_rx_put(skb);
604 virtio_transport_deliver_tap_pkt(skb);
605 virtio_transport_recv_pkt(&virtio_transport, skb);
607 } while (!virtqueue_enable_cb(vq));
610 if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2)
611 virtio_vsock_rx_fill(vsock);
612 mutex_unlock(&vsock->rx_lock);
615 static int virtio_vsock_vqs_init(struct virtio_vsock *vsock)
617 struct virtio_device *vdev = vsock->vdev;
618 static const char * const names[] = {
623 vq_callback_t *callbacks[] = {
624 virtio_vsock_rx_done,
625 virtio_vsock_tx_done,
626 virtio_vsock_event_done,
630 ret = virtio_find_vqs(vdev, VSOCK_VQ_MAX, vsock->vqs, callbacks, names,
635 virtio_vsock_update_guest_cid(vsock);
637 virtio_device_ready(vdev);
642 static void virtio_vsock_vqs_start(struct virtio_vsock *vsock)
644 mutex_lock(&vsock->tx_lock);
645 vsock->tx_run = true;
646 mutex_unlock(&vsock->tx_lock);
648 mutex_lock(&vsock->rx_lock);
649 virtio_vsock_rx_fill(vsock);
650 vsock->rx_run = true;
651 mutex_unlock(&vsock->rx_lock);
653 mutex_lock(&vsock->event_lock);
654 virtio_vsock_event_fill(vsock);
655 vsock->event_run = true;
656 mutex_unlock(&vsock->event_lock);
658 /* virtio_transport_send_pkt() can queue packets once
659 * the_virtio_vsock is set, but they won't be processed until
660 * vsock->tx_run is set to true. We queue vsock->send_pkt_work
661 * when initialization finishes to send those packets queued
663 * We don't need to queue the other workers (rx, event) because
664 * as long as we don't fill the queues with empty buffers, the
665 * host can't send us any notification.
667 queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
670 static void virtio_vsock_vqs_del(struct virtio_vsock *vsock)
672 struct virtio_device *vdev = vsock->vdev;
675 /* Reset all connected sockets when the VQs disappear */
676 vsock_for_each_connected_socket(&virtio_transport.transport,
677 virtio_vsock_reset_sock);
679 /* Stop all work handlers to make sure no one is accessing the device,
680 * so we can safely call virtio_reset_device().
682 mutex_lock(&vsock->rx_lock);
683 vsock->rx_run = false;
684 mutex_unlock(&vsock->rx_lock);
686 mutex_lock(&vsock->tx_lock);
687 vsock->tx_run = false;
688 mutex_unlock(&vsock->tx_lock);
690 mutex_lock(&vsock->event_lock);
691 vsock->event_run = false;
692 mutex_unlock(&vsock->event_lock);
694 /* Flush all device writes and interrupts, device will not use any
697 virtio_reset_device(vdev);
699 mutex_lock(&vsock->rx_lock);
700 while ((skb = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX])))
702 mutex_unlock(&vsock->rx_lock);
704 mutex_lock(&vsock->tx_lock);
705 while ((skb = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX])))
707 mutex_unlock(&vsock->tx_lock);
709 virtio_vsock_skb_queue_purge(&vsock->send_pkt_queue);
711 /* Delete virtqueues and flush outstanding callbacks if any */
712 vdev->config->del_vqs(vdev);
715 static int virtio_vsock_probe(struct virtio_device *vdev)
717 struct virtio_vsock *vsock = NULL;
721 ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
725 /* Only one virtio-vsock device per guest is supported */
726 if (rcu_dereference_protected(the_virtio_vsock,
727 lockdep_is_held(&the_virtio_vsock_mutex))) {
732 vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
740 vsock->rx_buf_nr = 0;
741 vsock->rx_buf_max_nr = 0;
742 atomic_set(&vsock->queued_replies, 0);
744 mutex_init(&vsock->tx_lock);
745 mutex_init(&vsock->rx_lock);
746 mutex_init(&vsock->event_lock);
747 skb_queue_head_init(&vsock->send_pkt_queue);
748 INIT_WORK(&vsock->rx_work, virtio_transport_rx_work);
749 INIT_WORK(&vsock->tx_work, virtio_transport_tx_work);
750 INIT_WORK(&vsock->event_work, virtio_transport_event_work);
751 INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
753 if (virtio_has_feature(vdev, VIRTIO_VSOCK_F_SEQPACKET))
754 vsock->seqpacket_allow = true;
758 ret = virtio_vsock_vqs_init(vsock);
762 for (i = 0; i < ARRAY_SIZE(vsock->out_sgs); i++)
763 vsock->out_sgs[i] = &vsock->out_bufs[i];
765 rcu_assign_pointer(the_virtio_vsock, vsock);
766 virtio_vsock_vqs_start(vsock);
768 mutex_unlock(&the_virtio_vsock_mutex);
774 mutex_unlock(&the_virtio_vsock_mutex);
778 static void virtio_vsock_remove(struct virtio_device *vdev)
780 struct virtio_vsock *vsock = vdev->priv;
782 mutex_lock(&the_virtio_vsock_mutex);
785 rcu_assign_pointer(the_virtio_vsock, NULL);
788 virtio_vsock_vqs_del(vsock);
790 /* Other works can be queued before 'config->del_vqs()', so we flush
791 * all works before to free the vsock object to avoid use after free.
793 flush_work(&vsock->rx_work);
794 flush_work(&vsock->tx_work);
795 flush_work(&vsock->event_work);
796 flush_work(&vsock->send_pkt_work);
798 mutex_unlock(&the_virtio_vsock_mutex);
803 #ifdef CONFIG_PM_SLEEP
804 static int virtio_vsock_freeze(struct virtio_device *vdev)
806 struct virtio_vsock *vsock = vdev->priv;
808 mutex_lock(&the_virtio_vsock_mutex);
810 rcu_assign_pointer(the_virtio_vsock, NULL);
813 virtio_vsock_vqs_del(vsock);
815 mutex_unlock(&the_virtio_vsock_mutex);
820 static int virtio_vsock_restore(struct virtio_device *vdev)
822 struct virtio_vsock *vsock = vdev->priv;
825 mutex_lock(&the_virtio_vsock_mutex);
827 /* Only one virtio-vsock device per guest is supported */
828 if (rcu_dereference_protected(the_virtio_vsock,
829 lockdep_is_held(&the_virtio_vsock_mutex))) {
834 ret = virtio_vsock_vqs_init(vsock);
838 rcu_assign_pointer(the_virtio_vsock, vsock);
839 virtio_vsock_vqs_start(vsock);
842 mutex_unlock(&the_virtio_vsock_mutex);
845 #endif /* CONFIG_PM_SLEEP */
847 static struct virtio_device_id id_table[] = {
848 { VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID },
852 static unsigned int features[] = {
853 VIRTIO_VSOCK_F_SEQPACKET
856 static struct virtio_driver virtio_vsock_driver = {
857 .feature_table = features,
858 .feature_table_size = ARRAY_SIZE(features),
859 .driver.name = KBUILD_MODNAME,
860 .driver.owner = THIS_MODULE,
861 .id_table = id_table,
862 .probe = virtio_vsock_probe,
863 .remove = virtio_vsock_remove,
864 #ifdef CONFIG_PM_SLEEP
865 .freeze = virtio_vsock_freeze,
866 .restore = virtio_vsock_restore,
870 static int __init virtio_vsock_init(void)
874 virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0);
875 if (!virtio_vsock_workqueue)
878 ret = vsock_core_register(&virtio_transport.transport,
879 VSOCK_TRANSPORT_F_G2H);
883 ret = register_virtio_driver(&virtio_vsock_driver);
890 vsock_core_unregister(&virtio_transport.transport);
892 destroy_workqueue(virtio_vsock_workqueue);
896 static void __exit virtio_vsock_exit(void)
898 unregister_virtio_driver(&virtio_vsock_driver);
899 vsock_core_unregister(&virtio_transport.transport);
900 destroy_workqueue(virtio_vsock_workqueue);
903 module_init(virtio_vsock_init);
904 module_exit(virtio_vsock_exit);
905 MODULE_LICENSE("GPL v2");
906 MODULE_AUTHOR("Asias He");
907 MODULE_DESCRIPTION("virtio transport for vsock");
908 MODULE_DEVICE_TABLE(virtio, id_table);