linux/net/vmw_vsock/virtio_transport.c
Jiyong Park 8e6ed96376 vsock: each transport cycles only on its own sockets
When iterating over sockets using vsock_for_each_connected_socket, make
sure that a transport filters out sockets that don't belong to the
transport.

There actually was an issue caused by this; in a nested VM
configuration, destroying the nested VM (which often involves the
closing of /dev/vhost-vsock if there was h2g connections to the nested
VM) kills not only the h2g connections, but also all existing g2h
connections to the (outmost) host which are totally unrelated.

Tested: Executed the following steps on Cuttlefish (Android running on a
VM) [1]: (1) Enter into an `adb shell` session - to have a g2h
connection inside the VM, (2) open and then close /dev/vhost-vsock by
`exec 3< /dev/vhost-vsock && exec 3<&-`, (3) observe that the adb
session is not reset.

[1] https://android.googlesource.com/device/google/cuttlefish/

Fixes: c0cfa2d8a7 ("vsock: add multi-transports support")
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jiyong Park <jiyong@google.com>
Link: https://lore.kernel.org/r/20220311020017.1509316-1-jiyong@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-11 23:14:19 -08:00

783 lines
19 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* virtio transport for vsock
*
* Copyright (C) 2013-2015 Red Hat, Inc.
* Author: Asias He <asias@redhat.com>
* Stefan Hajnoczi <stefanha@redhat.com>
*
* Some of the code is take from Gerd Hoffmann <kraxel@redhat.com>'s
* early virtio-vsock proof-of-concept bits.
*/
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/atomic.h>
#include <linux/virtio.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_config.h>
#include <linux/virtio_vsock.h>
#include <net/sock.h>
#include <linux/mutex.h>
#include <net/af_vsock.h>
static struct workqueue_struct *virtio_vsock_workqueue;
static struct virtio_vsock __rcu *the_virtio_vsock;
static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */
static struct virtio_transport virtio_transport; /* forward declaration */
struct virtio_vsock {
struct virtio_device *vdev;
struct virtqueue *vqs[VSOCK_VQ_MAX];
/* Virtqueue processing is deferred to a workqueue */
struct work_struct tx_work;
struct work_struct rx_work;
struct work_struct event_work;
/* The following fields are protected by tx_lock. vqs[VSOCK_VQ_TX]
* must be accessed with tx_lock held.
*/
struct mutex tx_lock;
bool tx_run;
struct work_struct send_pkt_work;
spinlock_t send_pkt_list_lock;
struct list_head send_pkt_list;
atomic_t queued_replies;
/* The following fields are protected by rx_lock. vqs[VSOCK_VQ_RX]
* must be accessed with rx_lock held.
*/
struct mutex rx_lock;
bool rx_run;
int rx_buf_nr;
int rx_buf_max_nr;
/* The following fields are protected by event_lock.
* vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held.
*/
struct mutex event_lock;
bool event_run;
struct virtio_vsock_event event_list[8];
u32 guest_cid;
bool seqpacket_allow;
};
static u32 virtio_transport_get_local_cid(void)
{
struct virtio_vsock *vsock;
u32 ret;
rcu_read_lock();
vsock = rcu_dereference(the_virtio_vsock);
if (!vsock) {
ret = VMADDR_CID_ANY;
goto out_rcu;
}
ret = vsock->guest_cid;
out_rcu:
rcu_read_unlock();
return ret;
}
static void
virtio_transport_send_pkt_work(struct work_struct *work)
{
struct virtio_vsock *vsock =
container_of(work, struct virtio_vsock, send_pkt_work);
struct virtqueue *vq;
bool added = false;
bool restart_rx = false;
mutex_lock(&vsock->tx_lock);
if (!vsock->tx_run)
goto out;
vq = vsock->vqs[VSOCK_VQ_TX];
for (;;) {
struct virtio_vsock_pkt *pkt;
struct scatterlist hdr, buf, *sgs[2];
int ret, in_sg = 0, out_sg = 0;
bool reply;
spin_lock_bh(&vsock->send_pkt_list_lock);
if (list_empty(&vsock->send_pkt_list)) {
spin_unlock_bh(&vsock->send_pkt_list_lock);
break;
}
pkt = list_first_entry(&vsock->send_pkt_list,
struct virtio_vsock_pkt, list);
list_del_init(&pkt->list);
spin_unlock_bh(&vsock->send_pkt_list_lock);
virtio_transport_deliver_tap_pkt(pkt);
reply = pkt->reply;
sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
sgs[out_sg++] = &hdr;
if (pkt->buf) {
sg_init_one(&buf, pkt->buf, pkt->len);
sgs[out_sg++] = &buf;
}
ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt, GFP_KERNEL);
/* Usually this means that there is no more space available in
* the vq
*/
if (ret < 0) {
spin_lock_bh(&vsock->send_pkt_list_lock);
list_add(&pkt->list, &vsock->send_pkt_list);
spin_unlock_bh(&vsock->send_pkt_list_lock);
break;
}
if (reply) {
struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
int val;
val = atomic_dec_return(&vsock->queued_replies);
/* Do we now have resources to resume rx processing? */
if (val + 1 == virtqueue_get_vring_size(rx_vq))
restart_rx = true;
}
added = true;
}
if (added)
virtqueue_kick(vq);
out:
mutex_unlock(&vsock->tx_lock);
if (restart_rx)
queue_work(virtio_vsock_workqueue, &vsock->rx_work);
}
static int
virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt)
{
struct virtio_vsock *vsock;
int len = pkt->len;
rcu_read_lock();
vsock = rcu_dereference(the_virtio_vsock);
if (!vsock) {
virtio_transport_free_pkt(pkt);
len = -ENODEV;
goto out_rcu;
}
if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid) {
virtio_transport_free_pkt(pkt);
len = -ENODEV;
goto out_rcu;
}
if (pkt->reply)
atomic_inc(&vsock->queued_replies);
spin_lock_bh(&vsock->send_pkt_list_lock);
list_add_tail(&pkt->list, &vsock->send_pkt_list);
spin_unlock_bh(&vsock->send_pkt_list_lock);
queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
out_rcu:
rcu_read_unlock();
return len;
}
static int
virtio_transport_cancel_pkt(struct vsock_sock *vsk)
{
struct virtio_vsock *vsock;
struct virtio_vsock_pkt *pkt, *n;
int cnt = 0, ret;
LIST_HEAD(freeme);
rcu_read_lock();
vsock = rcu_dereference(the_virtio_vsock);
if (!vsock) {
ret = -ENODEV;
goto out_rcu;
}
spin_lock_bh(&vsock->send_pkt_list_lock);
list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
if (pkt->vsk != vsk)
continue;
list_move(&pkt->list, &freeme);
}
spin_unlock_bh(&vsock->send_pkt_list_lock);
list_for_each_entry_safe(pkt, n, &freeme, list) {
if (pkt->reply)
cnt++;
list_del(&pkt->list);
virtio_transport_free_pkt(pkt);
}
if (cnt) {
struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
int new_cnt;
new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
if (new_cnt + cnt >= virtqueue_get_vring_size(rx_vq) &&
new_cnt < virtqueue_get_vring_size(rx_vq))
queue_work(virtio_vsock_workqueue, &vsock->rx_work);
}
ret = 0;
out_rcu:
rcu_read_unlock();
return ret;
}
static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
{
int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
struct virtio_vsock_pkt *pkt;
struct scatterlist hdr, buf, *sgs[2];
struct virtqueue *vq;
int ret;
vq = vsock->vqs[VSOCK_VQ_RX];
do {
pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
if (!pkt)
break;
pkt->buf = kmalloc(buf_len, GFP_KERNEL);
if (!pkt->buf) {
virtio_transport_free_pkt(pkt);
break;
}
pkt->buf_len = buf_len;
pkt->len = buf_len;
sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
sgs[0] = &hdr;
sg_init_one(&buf, pkt->buf, buf_len);
sgs[1] = &buf;
ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL);
if (ret) {
virtio_transport_free_pkt(pkt);
break;
}
vsock->rx_buf_nr++;
} while (vq->num_free);
if (vsock->rx_buf_nr > vsock->rx_buf_max_nr)
vsock->rx_buf_max_nr = vsock->rx_buf_nr;
virtqueue_kick(vq);
}
static void virtio_transport_tx_work(struct work_struct *work)
{
struct virtio_vsock *vsock =
container_of(work, struct virtio_vsock, tx_work);
struct virtqueue *vq;
bool added = false;
vq = vsock->vqs[VSOCK_VQ_TX];
mutex_lock(&vsock->tx_lock);
if (!vsock->tx_run)
goto out;
do {
struct virtio_vsock_pkt *pkt;
unsigned int len;
virtqueue_disable_cb(vq);
while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) {
virtio_transport_free_pkt(pkt);
added = true;
}
} while (!virtqueue_enable_cb(vq));
out:
mutex_unlock(&vsock->tx_lock);
if (added)
queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
}
/* Is there space left for replies to rx packets? */
static bool virtio_transport_more_replies(struct virtio_vsock *vsock)
{
struct virtqueue *vq = vsock->vqs[VSOCK_VQ_RX];
int val;
smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
val = atomic_read(&vsock->queued_replies);
return val < virtqueue_get_vring_size(vq);
}
/* event_lock must be held */
static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock,
struct virtio_vsock_event *event)
{
struct scatterlist sg;
struct virtqueue *vq;
vq = vsock->vqs[VSOCK_VQ_EVENT];
sg_init_one(&sg, event, sizeof(*event));
return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL);
}
/* event_lock must be held */
static void virtio_vsock_event_fill(struct virtio_vsock *vsock)
{
size_t i;
for (i = 0; i < ARRAY_SIZE(vsock->event_list); i++) {
struct virtio_vsock_event *event = &vsock->event_list[i];
virtio_vsock_event_fill_one(vsock, event);
}
virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
}
static void virtio_vsock_reset_sock(struct sock *sk)
{
/* vmci_transport.c doesn't take sk_lock here either. At least we're
* under vsock_table_lock so the sock cannot disappear while we're
* executing.
*/
sk->sk_state = TCP_CLOSE;
sk->sk_err = ECONNRESET;
sk_error_report(sk);
}
static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock)
{
struct virtio_device *vdev = vsock->vdev;
__le64 guest_cid;
vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid),
&guest_cid, sizeof(guest_cid));
vsock->guest_cid = le64_to_cpu(guest_cid);
}
/* event_lock must be held */
static void virtio_vsock_event_handle(struct virtio_vsock *vsock,
struct virtio_vsock_event *event)
{
switch (le32_to_cpu(event->id)) {
case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET:
virtio_vsock_update_guest_cid(vsock);
vsock_for_each_connected_socket(&virtio_transport.transport,
virtio_vsock_reset_sock);
break;
}
}
static void virtio_transport_event_work(struct work_struct *work)
{
struct virtio_vsock *vsock =
container_of(work, struct virtio_vsock, event_work);
struct virtqueue *vq;
vq = vsock->vqs[VSOCK_VQ_EVENT];
mutex_lock(&vsock->event_lock);
if (!vsock->event_run)
goto out;
do {
struct virtio_vsock_event *event;
unsigned int len;
virtqueue_disable_cb(vq);
while ((event = virtqueue_get_buf(vq, &len)) != NULL) {
if (len == sizeof(*event))
virtio_vsock_event_handle(vsock, event);
virtio_vsock_event_fill_one(vsock, event);
}
} while (!virtqueue_enable_cb(vq));
virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
out:
mutex_unlock(&vsock->event_lock);
}
static void virtio_vsock_event_done(struct virtqueue *vq)
{
struct virtio_vsock *vsock = vq->vdev->priv;
if (!vsock)
return;
queue_work(virtio_vsock_workqueue, &vsock->event_work);
}
static void virtio_vsock_tx_done(struct virtqueue *vq)
{
struct virtio_vsock *vsock = vq->vdev->priv;
if (!vsock)
return;
queue_work(virtio_vsock_workqueue, &vsock->tx_work);
}
static void virtio_vsock_rx_done(struct virtqueue *vq)
{
struct virtio_vsock *vsock = vq->vdev->priv;
if (!vsock)
return;
queue_work(virtio_vsock_workqueue, &vsock->rx_work);
}
static bool virtio_transport_seqpacket_allow(u32 remote_cid);
static struct virtio_transport virtio_transport = {
.transport = {
.module = THIS_MODULE,
.get_local_cid = virtio_transport_get_local_cid,
.init = virtio_transport_do_socket_init,
.destruct = virtio_transport_destruct,
.release = virtio_transport_release,
.connect = virtio_transport_connect,
.shutdown = virtio_transport_shutdown,
.cancel_pkt = virtio_transport_cancel_pkt,
.dgram_bind = virtio_transport_dgram_bind,
.dgram_dequeue = virtio_transport_dgram_dequeue,
.dgram_enqueue = virtio_transport_dgram_enqueue,
.dgram_allow = virtio_transport_dgram_allow,
.stream_dequeue = virtio_transport_stream_dequeue,
.stream_enqueue = virtio_transport_stream_enqueue,
.stream_has_data = virtio_transport_stream_has_data,
.stream_has_space = virtio_transport_stream_has_space,
.stream_rcvhiwat = virtio_transport_stream_rcvhiwat,
.stream_is_active = virtio_transport_stream_is_active,
.stream_allow = virtio_transport_stream_allow,
.seqpacket_dequeue = virtio_transport_seqpacket_dequeue,
.seqpacket_enqueue = virtio_transport_seqpacket_enqueue,
.seqpacket_allow = virtio_transport_seqpacket_allow,
.seqpacket_has_data = virtio_transport_seqpacket_has_data,
.notify_poll_in = virtio_transport_notify_poll_in,
.notify_poll_out = virtio_transport_notify_poll_out,
.notify_recv_init = virtio_transport_notify_recv_init,
.notify_recv_pre_block = virtio_transport_notify_recv_pre_block,
.notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue,
.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
.notify_send_init = virtio_transport_notify_send_init,
.notify_send_pre_block = virtio_transport_notify_send_pre_block,
.notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue,
.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
.notify_buffer_size = virtio_transport_notify_buffer_size,
},
.send_pkt = virtio_transport_send_pkt,
};
static bool virtio_transport_seqpacket_allow(u32 remote_cid)
{
struct virtio_vsock *vsock;
bool seqpacket_allow;
seqpacket_allow = false;
rcu_read_lock();
vsock = rcu_dereference(the_virtio_vsock);
if (vsock)
seqpacket_allow = vsock->seqpacket_allow;
rcu_read_unlock();
return seqpacket_allow;
}
static void virtio_transport_rx_work(struct work_struct *work)
{
struct virtio_vsock *vsock =
container_of(work, struct virtio_vsock, rx_work);
struct virtqueue *vq;
vq = vsock->vqs[VSOCK_VQ_RX];
mutex_lock(&vsock->rx_lock);
if (!vsock->rx_run)
goto out;
do {
virtqueue_disable_cb(vq);
for (;;) {
struct virtio_vsock_pkt *pkt;
unsigned int len;
if (!virtio_transport_more_replies(vsock)) {
/* Stop rx until the device processes already
* pending replies. Leave rx virtqueue
* callbacks disabled.
*/
goto out;
}
pkt = virtqueue_get_buf(vq, &len);
if (!pkt) {
break;
}
vsock->rx_buf_nr--;
/* Drop short/long packets */
if (unlikely(len < sizeof(pkt->hdr) ||
len > sizeof(pkt->hdr) + pkt->len)) {
virtio_transport_free_pkt(pkt);
continue;
}
pkt->len = len - sizeof(pkt->hdr);
virtio_transport_deliver_tap_pkt(pkt);
virtio_transport_recv_pkt(&virtio_transport, pkt);
}
} while (!virtqueue_enable_cb(vq));
out:
if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2)
virtio_vsock_rx_fill(vsock);
mutex_unlock(&vsock->rx_lock);
}
static int virtio_vsock_probe(struct virtio_device *vdev)
{
vq_callback_t *callbacks[] = {
virtio_vsock_rx_done,
virtio_vsock_tx_done,
virtio_vsock_event_done,
};
static const char * const names[] = {
"rx",
"tx",
"event",
};
struct virtio_vsock *vsock = NULL;
int ret;
ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
if (ret)
return ret;
/* Only one virtio-vsock device per guest is supported */
if (rcu_dereference_protected(the_virtio_vsock,
lockdep_is_held(&the_virtio_vsock_mutex))) {
ret = -EBUSY;
goto out;
}
vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
if (!vsock) {
ret = -ENOMEM;
goto out;
}
vsock->vdev = vdev;
ret = virtio_find_vqs(vsock->vdev, VSOCK_VQ_MAX,
vsock->vqs, callbacks, names,
NULL);
if (ret < 0)
goto out;
virtio_vsock_update_guest_cid(vsock);
vsock->rx_buf_nr = 0;
vsock->rx_buf_max_nr = 0;
atomic_set(&vsock->queued_replies, 0);
mutex_init(&vsock->tx_lock);
mutex_init(&vsock->rx_lock);
mutex_init(&vsock->event_lock);
spin_lock_init(&vsock->send_pkt_list_lock);
INIT_LIST_HEAD(&vsock->send_pkt_list);
INIT_WORK(&vsock->rx_work, virtio_transport_rx_work);
INIT_WORK(&vsock->tx_work, virtio_transport_tx_work);
INIT_WORK(&vsock->event_work, virtio_transport_event_work);
INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
mutex_lock(&vsock->tx_lock);
vsock->tx_run = true;
mutex_unlock(&vsock->tx_lock);
mutex_lock(&vsock->rx_lock);
virtio_vsock_rx_fill(vsock);
vsock->rx_run = true;
mutex_unlock(&vsock->rx_lock);
mutex_lock(&vsock->event_lock);
virtio_vsock_event_fill(vsock);
vsock->event_run = true;
mutex_unlock(&vsock->event_lock);
if (virtio_has_feature(vdev, VIRTIO_VSOCK_F_SEQPACKET))
vsock->seqpacket_allow = true;
vdev->priv = vsock;
rcu_assign_pointer(the_virtio_vsock, vsock);
mutex_unlock(&the_virtio_vsock_mutex);
return 0;
out:
kfree(vsock);
mutex_unlock(&the_virtio_vsock_mutex);
return ret;
}
static void virtio_vsock_remove(struct virtio_device *vdev)
{
struct virtio_vsock *vsock = vdev->priv;
struct virtio_vsock_pkt *pkt;
mutex_lock(&the_virtio_vsock_mutex);
vdev->priv = NULL;
rcu_assign_pointer(the_virtio_vsock, NULL);
synchronize_rcu();
/* Reset all connected sockets when the device disappear */
vsock_for_each_connected_socket(&virtio_transport.transport,
virtio_vsock_reset_sock);
/* Stop all work handlers to make sure no one is accessing the device,
* so we can safely call virtio_reset_device().
*/
mutex_lock(&vsock->rx_lock);
vsock->rx_run = false;
mutex_unlock(&vsock->rx_lock);
mutex_lock(&vsock->tx_lock);
vsock->tx_run = false;
mutex_unlock(&vsock->tx_lock);
mutex_lock(&vsock->event_lock);
vsock->event_run = false;
mutex_unlock(&vsock->event_lock);
/* Flush all device writes and interrupts, device will not use any
* more buffers.
*/
virtio_reset_device(vdev);
mutex_lock(&vsock->rx_lock);
while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX])))
virtio_transport_free_pkt(pkt);
mutex_unlock(&vsock->rx_lock);
mutex_lock(&vsock->tx_lock);
while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX])))
virtio_transport_free_pkt(pkt);
mutex_unlock(&vsock->tx_lock);
spin_lock_bh(&vsock->send_pkt_list_lock);
while (!list_empty(&vsock->send_pkt_list)) {
pkt = list_first_entry(&vsock->send_pkt_list,
struct virtio_vsock_pkt, list);
list_del(&pkt->list);
virtio_transport_free_pkt(pkt);
}
spin_unlock_bh(&vsock->send_pkt_list_lock);
/* Delete virtqueues and flush outstanding callbacks if any */
vdev->config->del_vqs(vdev);
/* Other works can be queued before 'config->del_vqs()', so we flush
* all works before to free the vsock object to avoid use after free.
*/
flush_work(&vsock->rx_work);
flush_work(&vsock->tx_work);
flush_work(&vsock->event_work);
flush_work(&vsock->send_pkt_work);
mutex_unlock(&the_virtio_vsock_mutex);
kfree(vsock);
}
static struct virtio_device_id id_table[] = {
{ VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID },
{ 0 },
};
static unsigned int features[] = {
VIRTIO_VSOCK_F_SEQPACKET
};
static struct virtio_driver virtio_vsock_driver = {
.feature_table = features,
.feature_table_size = ARRAY_SIZE(features),
.driver.name = KBUILD_MODNAME,
.driver.owner = THIS_MODULE,
.id_table = id_table,
.probe = virtio_vsock_probe,
.remove = virtio_vsock_remove,
};
static int __init virtio_vsock_init(void)
{
int ret;
virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0);
if (!virtio_vsock_workqueue)
return -ENOMEM;
ret = vsock_core_register(&virtio_transport.transport,
VSOCK_TRANSPORT_F_G2H);
if (ret)
goto out_wq;
ret = register_virtio_driver(&virtio_vsock_driver);
if (ret)
goto out_vci;
return 0;
out_vci:
vsock_core_unregister(&virtio_transport.transport);
out_wq:
destroy_workqueue(virtio_vsock_workqueue);
return ret;
}
static void __exit virtio_vsock_exit(void)
{
unregister_virtio_driver(&virtio_vsock_driver);
vsock_core_unregister(&virtio_transport.transport);
destroy_workqueue(virtio_vsock_workqueue);
}
module_init(virtio_vsock_init);
module_exit(virtio_vsock_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Asias He");
MODULE_DESCRIPTION("virtio transport for vsock");
MODULE_DEVICE_TABLE(virtio, id_table);