1 // SPDX-License-Identifier: GPL-2.0-only
3 * common code for virtio vsock
5 * Copyright (C) 2013-2015 Red Hat, Inc.
6 * Author: Asias He <asias@redhat.com>
7 * Stefan Hajnoczi <stefanha@redhat.com>
9 #include <linux/spinlock.h>
10 #include <linux/module.h>
11 #include <linux/sched/signal.h>
12 #include <linux/ctype.h>
13 #include <linux/list.h>
14 #include <linux/virtio_vsock.h>
15 #include <uapi/linux/vsockmon.h>
18 #include <net/af_vsock.h>
20 #define CREATE_TRACE_POINTS
21 #include <trace/events/vsock_virtio_transport_common.h>
23 /* How long to wait for graceful shutdown of a connection */
24 #define VSOCK_CLOSE_TIMEOUT (8 * HZ)
26 /* Threshold for detecting small packets to copy */
27 #define GOOD_COPY_LEN 128
29 static const struct virtio_transport *
30 virtio_transport_get_ops(struct vsock_sock *vsk)
32 const struct vsock_transport *t = vsock_core_get_transport(vsk);
37 return container_of(t, struct virtio_transport, transport);
40 static bool virtio_transport_can_zcopy(const struct virtio_transport *t_ops,
41 struct virtio_vsock_pkt_info *info,
44 struct iov_iter *iov_iter;
49 iov_iter = &info->msg->msg_iter;
51 if (iov_iter->iov_offset)
54 /* We can't send whole iov. */
55 if (iov_iter->count > pkt_len)
58 /* Check that transport can send data in zerocopy mode. */
59 t_ops = virtio_transport_get_ops(info->vsk);
61 if (t_ops->can_msgzerocopy) {
62 int pages_to_send = iov_iter_npages(iov_iter, MAX_SKB_FRAGS);
64 /* +1 is for packet header. */
65 return t_ops->can_msgzerocopy(pages_to_send + 1);
71 static int virtio_transport_init_zcopy_skb(struct vsock_sock *vsk,
76 struct ubuf_info *uarg;
82 struct iov_iter *iter = &msg->msg_iter;
83 struct ubuf_info_msgzc *uarg_zc;
85 uarg = msg_zerocopy_realloc(sk_vsock(vsk),
91 uarg_zc = uarg_to_msgzc(uarg);
92 uarg_zc->zerocopy = zerocopy ? 1 : 0;
95 skb_zcopy_init(skb, uarg);
100 static int virtio_transport_fill_skb(struct sk_buff *skb,
101 struct virtio_vsock_pkt_info *info,
106 return __zerocopy_sg_from_iter(info->msg, NULL, skb,
107 &info->msg->msg_iter,
110 return memcpy_from_msg(skb_put(skb, len), info->msg, len);
113 static void virtio_transport_init_hdr(struct sk_buff *skb,
114 struct virtio_vsock_pkt_info *info,
121 struct virtio_vsock_hdr *hdr;
123 hdr = virtio_vsock_hdr(skb);
124 hdr->type = cpu_to_le16(info->type);
125 hdr->op = cpu_to_le16(info->op);
126 hdr->src_cid = cpu_to_le64(src_cid);
127 hdr->dst_cid = cpu_to_le64(dst_cid);
128 hdr->src_port = cpu_to_le32(src_port);
129 hdr->dst_port = cpu_to_le32(dst_port);
130 hdr->flags = cpu_to_le32(info->flags);
131 hdr->len = cpu_to_le32(payload_len);
132 hdr->buf_alloc = cpu_to_le32(0);
133 hdr->fwd_cnt = cpu_to_le32(0);
136 static void virtio_transport_copy_nonlinear_skb(const struct sk_buff *skb,
140 struct iov_iter iov_iter = { 0 };
147 iov_iter.iter_type = ITER_KVEC;
148 iov_iter.kvec = &kvec;
149 iov_iter.nr_segs = 1;
151 to_copy = min_t(size_t, len, skb->len);
153 skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset,
158 static struct sk_buff *virtio_transport_build_skb(void *opaque)
160 struct virtio_vsock_hdr *pkt_hdr;
161 struct sk_buff *pkt = opaque;
162 struct af_vsockmon_hdr *hdr;
166 /* A packet could be split to fit the RX buffer, so we can retrieve
167 * the payload length from the header and the buffer pointer taking
168 * care of the offset in the original packet.
170 pkt_hdr = virtio_vsock_hdr(pkt);
171 payload_len = pkt->len;
173 skb = alloc_skb(sizeof(*hdr) + sizeof(*pkt_hdr) + payload_len,
178 hdr = skb_put(skb, sizeof(*hdr));
180 /* pkt->hdr is little-endian so no need to byteswap here */
181 hdr->src_cid = pkt_hdr->src_cid;
182 hdr->src_port = pkt_hdr->src_port;
183 hdr->dst_cid = pkt_hdr->dst_cid;
184 hdr->dst_port = pkt_hdr->dst_port;
186 hdr->transport = cpu_to_le16(AF_VSOCK_TRANSPORT_VIRTIO);
187 hdr->len = cpu_to_le16(sizeof(*pkt_hdr));
188 memset(hdr->reserved, 0, sizeof(hdr->reserved));
190 switch (le16_to_cpu(pkt_hdr->op)) {
191 case VIRTIO_VSOCK_OP_REQUEST:
192 case VIRTIO_VSOCK_OP_RESPONSE:
193 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONNECT);
195 case VIRTIO_VSOCK_OP_RST:
196 case VIRTIO_VSOCK_OP_SHUTDOWN:
197 hdr->op = cpu_to_le16(AF_VSOCK_OP_DISCONNECT);
199 case VIRTIO_VSOCK_OP_RW:
200 hdr->op = cpu_to_le16(AF_VSOCK_OP_PAYLOAD);
202 case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
203 case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
204 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONTROL);
207 hdr->op = cpu_to_le16(AF_VSOCK_OP_UNKNOWN);
211 skb_put_data(skb, pkt_hdr, sizeof(*pkt_hdr));
214 if (skb_is_nonlinear(pkt)) {
215 void *data = skb_put(skb, payload_len);
217 virtio_transport_copy_nonlinear_skb(pkt, data, payload_len);
219 skb_put_data(skb, pkt->data, payload_len);
226 void virtio_transport_deliver_tap_pkt(struct sk_buff *skb)
228 if (virtio_vsock_skb_tap_delivered(skb))
231 vsock_deliver_tap(virtio_transport_build_skb, skb);
232 virtio_vsock_skb_set_tap_delivered(skb);
234 EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);
236 static u16 virtio_transport_get_type(struct sock *sk)
238 if (sk->sk_type == SOCK_STREAM)
239 return VIRTIO_VSOCK_TYPE_STREAM;
241 return VIRTIO_VSOCK_TYPE_SEQPACKET;
244 /* Returns new sk_buff on success, otherwise returns NULL. */
245 static struct sk_buff *virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *info,
253 struct vsock_sock *vsk;
257 skb_len = VIRTIO_VSOCK_SKB_HEADROOM;
260 skb_len += payload_len;
262 skb = virtio_vsock_alloc_skb(skb_len, GFP_KERNEL);
266 virtio_transport_init_hdr(skb, info, payload_len, src_cid, src_port,
271 /* If 'vsk' != NULL then payload is always present, so we
272 * will never call '__zerocopy_sg_from_iter()' below without
273 * setting skb owner in 'skb_set_owner_w()'. The only case
274 * when 'vsk' == NULL is VIRTIO_VSOCK_OP_RST control message
277 WARN_ON_ONCE(!(vsk && (info->msg && payload_len)) && zcopy);
279 /* Set owner here, because '__zerocopy_sg_from_iter()' uses
280 * owner of skb without check to update 'sk_wmem_alloc'.
283 skb_set_owner_w(skb, sk_vsock(vsk));
285 if (info->msg && payload_len > 0) {
288 err = virtio_transport_fill_skb(skb, info, payload_len, zcopy);
292 if (msg_data_left(info->msg) == 0 &&
293 info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) {
294 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
296 hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
298 if (info->msg->msg_flags & MSG_EOR)
299 hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
304 virtio_vsock_skb_set_reply(skb);
306 trace_virtio_transport_alloc_pkt(src_cid, src_port,
320 /* This function can only be used on connecting/connected sockets,
321 * since a socket assigned to a transport is required.
323 * Do not use on listener sockets!
325 static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
326 struct virtio_vsock_pkt_info *info)
328 u32 max_skb_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
329 u32 src_cid, src_port, dst_cid, dst_port;
330 const struct virtio_transport *t_ops;
331 struct virtio_vsock_sock *vvs;
332 u32 pkt_len = info->pkt_len;
333 bool can_zcopy = false;
337 info->type = virtio_transport_get_type(sk_vsock(vsk));
339 t_ops = virtio_transport_get_ops(vsk);
340 if (unlikely(!t_ops))
343 src_cid = t_ops->transport.get_local_cid();
344 src_port = vsk->local_addr.svm_port;
345 if (!info->remote_cid) {
346 dst_cid = vsk->remote_addr.svm_cid;
347 dst_port = vsk->remote_addr.svm_port;
349 dst_cid = info->remote_cid;
350 dst_port = info->remote_port;
355 /* virtio_transport_get_credit might return less than pkt_len credit */
356 pkt_len = virtio_transport_get_credit(vvs, pkt_len);
358 /* Do not send zero length OP_RW pkt */
359 if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
363 /* If zerocopy is not enabled by 'setsockopt()', we behave as
364 * there is no MSG_ZEROCOPY flag set.
366 if (!sock_flag(sk_vsock(vsk), SOCK_ZEROCOPY))
367 info->msg->msg_flags &= ~MSG_ZEROCOPY;
369 if (info->msg->msg_flags & MSG_ZEROCOPY)
370 can_zcopy = virtio_transport_can_zcopy(t_ops, info, pkt_len);
373 max_skb_len = min_t(u32, VIRTIO_VSOCK_MAX_PKT_BUF_SIZE,
374 (MAX_SKB_FRAGS * PAGE_SIZE));
383 skb_len = min(max_skb_len, rest_len);
385 skb = virtio_transport_alloc_skb(info, skb_len, can_zcopy,
393 /* We process buffer part by part, allocating skb on
394 * each iteration. If this is last skb for this buffer
395 * and MSG_ZEROCOPY mode is in use - we must allocate
396 * completion for the current syscall.
398 if (info->msg && info->msg->msg_flags & MSG_ZEROCOPY &&
399 skb_len == rest_len && info->op == VIRTIO_VSOCK_OP_RW) {
400 if (virtio_transport_init_zcopy_skb(vsk, skb,
408 virtio_transport_inc_tx_pkt(vvs, skb);
410 ret = t_ops->send_pkt(skb);
414 /* Both virtio and vhost 'send_pkt()' returns 'skb_len',
415 * but for reliability use 'ret' instead of 'skb_len'.
416 * Also if partial send happens (e.g. 'ret' != 'skb_len')
417 * somehow, we break this loop, but account such returned
418 * value in 'virtio_transport_put_credit()'.
422 if (WARN_ONCE(ret != skb_len,
423 "'send_pkt()' returns %i, but %zu expected\n",
428 virtio_transport_put_credit(vvs, rest_len);
430 /* Return number of bytes, if any data has been sent. */
431 if (rest_len != pkt_len)
432 ret = pkt_len - rest_len;
437 static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
440 if (vvs->rx_bytes + len > vvs->buf_alloc)
443 vvs->rx_bytes += len;
447 static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
450 vvs->rx_bytes -= len;
454 void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct sk_buff *skb)
456 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
458 spin_lock_bh(&vvs->rx_lock);
459 vvs->last_fwd_cnt = vvs->fwd_cnt;
460 hdr->fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
461 hdr->buf_alloc = cpu_to_le32(vvs->buf_alloc);
462 spin_unlock_bh(&vvs->rx_lock);
464 EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
466 u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit)
473 spin_lock_bh(&vvs->tx_lock);
474 ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
478 spin_unlock_bh(&vvs->tx_lock);
482 EXPORT_SYMBOL_GPL(virtio_transport_get_credit);
484 void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit)
489 spin_lock_bh(&vvs->tx_lock);
490 vvs->tx_cnt -= credit;
491 spin_unlock_bh(&vvs->tx_lock);
493 EXPORT_SYMBOL_GPL(virtio_transport_put_credit);
495 static int virtio_transport_send_credit_update(struct vsock_sock *vsk)
497 struct virtio_vsock_pkt_info info = {
498 .op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
502 return virtio_transport_send_pkt_info(vsk, &info);
506 virtio_transport_stream_do_peek(struct vsock_sock *vsk,
510 struct virtio_vsock_sock *vvs = vsk->trans;
515 spin_lock_bh(&vvs->rx_lock);
517 skb_queue_walk(&vvs->rx_queue, skb) {
521 if (bytes > skb->len)
524 spin_unlock_bh(&vvs->rx_lock);
526 /* sk_lock is held by caller so no one else can dequeue.
527 * Unlock rx_lock since skb_copy_datagram_iter() may sleep.
529 err = skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset,
530 &msg->msg_iter, bytes);
536 spin_lock_bh(&vvs->rx_lock);
542 spin_unlock_bh(&vvs->rx_lock);
553 virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
557 struct virtio_vsock_sock *vvs = vsk->trans;
558 size_t bytes, total = 0;
565 spin_lock_bh(&vvs->rx_lock);
567 if (WARN_ONCE(skb_queue_empty(&vvs->rx_queue) && vvs->rx_bytes,
568 "rx_queue is empty, but rx_bytes is non-zero\n")) {
569 spin_unlock_bh(&vvs->rx_lock);
573 while (total < len && !skb_queue_empty(&vvs->rx_queue)) {
574 skb = skb_peek(&vvs->rx_queue);
576 bytes = min_t(size_t, len - total,
577 skb->len - VIRTIO_VSOCK_SKB_CB(skb)->offset);
579 /* sk_lock is held by caller so no one else can dequeue.
580 * Unlock rx_lock since skb_copy_datagram_iter() may sleep.
582 spin_unlock_bh(&vvs->rx_lock);
584 err = skb_copy_datagram_iter(skb,
585 VIRTIO_VSOCK_SKB_CB(skb)->offset,
586 &msg->msg_iter, bytes);
590 spin_lock_bh(&vvs->rx_lock);
594 VIRTIO_VSOCK_SKB_CB(skb)->offset += bytes;
596 if (skb->len == VIRTIO_VSOCK_SKB_CB(skb)->offset) {
597 u32 pkt_len = le32_to_cpu(virtio_vsock_hdr(skb)->len);
599 virtio_transport_dec_rx_pkt(vvs, pkt_len);
600 __skb_unlink(skb, &vvs->rx_queue);
605 fwd_cnt_delta = vvs->fwd_cnt - vvs->last_fwd_cnt;
606 free_space = vvs->buf_alloc - fwd_cnt_delta;
607 low_rx_bytes = (vvs->rx_bytes <
608 sock_rcvlowat(sk_vsock(vsk), 0, INT_MAX));
610 spin_unlock_bh(&vvs->rx_lock);
612 /* To reduce the number of credit update messages,
613 * don't update credits as long as lots of space is available.
614 * Note: the limit chosen here is arbitrary. Setting the limit
615 * too high causes extra messages. Too low causes transmitter
616 * stalls. As stalls are in theory more expensive than extra
617 * messages, we set the limit to a high value. TODO: experiment
618 * with different values. Also send credit update message when
619 * number of bytes in rx queue is not enough to wake up reader.
622 (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE || low_rx_bytes))
623 virtio_transport_send_credit_update(vsk);
634 virtio_transport_seqpacket_do_peek(struct vsock_sock *vsk,
637 struct virtio_vsock_sock *vvs = vsk->trans;
641 spin_lock_bh(&vvs->rx_lock);
643 if (!vvs->msg_count) {
644 spin_unlock_bh(&vvs->rx_lock);
649 len = msg_data_left(msg);
651 skb_queue_walk(&vvs->rx_queue, skb) {
652 struct virtio_vsock_hdr *hdr;
659 if (bytes > skb->len)
662 spin_unlock_bh(&vvs->rx_lock);
664 /* sk_lock is held by caller so no one else can dequeue.
665 * Unlock rx_lock since skb_copy_datagram_iter() may sleep.
667 err = skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset,
668 &msg->msg_iter, bytes);
672 spin_lock_bh(&vvs->rx_lock);
676 hdr = virtio_vsock_hdr(skb);
678 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
679 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)
680 msg->msg_flags |= MSG_EOR;
686 spin_unlock_bh(&vvs->rx_lock);
691 static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
695 struct virtio_vsock_sock *vvs = vsk->trans;
696 int dequeued_len = 0;
697 size_t user_buf_len = msg_data_left(msg);
698 bool msg_ready = false;
701 spin_lock_bh(&vvs->rx_lock);
703 if (vvs->msg_count == 0) {
704 spin_unlock_bh(&vvs->rx_lock);
709 struct virtio_vsock_hdr *hdr;
712 skb = __skb_dequeue(&vvs->rx_queue);
715 hdr = virtio_vsock_hdr(skb);
716 pkt_len = (size_t)le32_to_cpu(hdr->len);
718 if (dequeued_len >= 0) {
719 size_t bytes_to_copy;
721 bytes_to_copy = min(user_buf_len, pkt_len);
726 /* sk_lock is held by caller so no one else can dequeue.
727 * Unlock rx_lock since skb_copy_datagram_iter() may sleep.
729 spin_unlock_bh(&vvs->rx_lock);
731 err = skb_copy_datagram_iter(skb, 0,
735 /* Copy of message failed. Rest of
736 * fragments will be freed without copy.
740 user_buf_len -= bytes_to_copy;
743 spin_lock_bh(&vvs->rx_lock);
746 if (dequeued_len >= 0)
747 dequeued_len += pkt_len;
750 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
754 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)
755 msg->msg_flags |= MSG_EOR;
758 virtio_transport_dec_rx_pkt(vvs, pkt_len);
762 spin_unlock_bh(&vvs->rx_lock);
764 virtio_transport_send_credit_update(vsk);
770 virtio_transport_stream_dequeue(struct vsock_sock *vsk,
772 size_t len, int flags)
774 if (flags & MSG_PEEK)
775 return virtio_transport_stream_do_peek(vsk, msg, len);
777 return virtio_transport_stream_do_dequeue(vsk, msg, len);
779 EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
782 virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk,
786 if (flags & MSG_PEEK)
787 return virtio_transport_seqpacket_do_peek(vsk, msg);
789 return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
791 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue);
794 virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
798 struct virtio_vsock_sock *vvs = vsk->trans;
800 spin_lock_bh(&vvs->tx_lock);
802 if (len > vvs->peer_buf_alloc) {
803 spin_unlock_bh(&vvs->tx_lock);
807 spin_unlock_bh(&vvs->tx_lock);
809 return virtio_transport_stream_enqueue(vsk, msg, len);
811 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_enqueue);
814 virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
816 size_t len, int flags)
820 EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
822 s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
824 struct virtio_vsock_sock *vvs = vsk->trans;
827 spin_lock_bh(&vvs->rx_lock);
828 bytes = vvs->rx_bytes;
829 spin_unlock_bh(&vvs->rx_lock);
833 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data);
835 u32 virtio_transport_seqpacket_has_data(struct vsock_sock *vsk)
837 struct virtio_vsock_sock *vvs = vsk->trans;
840 spin_lock_bh(&vvs->rx_lock);
841 msg_count = vvs->msg_count;
842 spin_unlock_bh(&vvs->rx_lock);
846 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_has_data);
848 static s64 virtio_transport_has_space(struct vsock_sock *vsk)
850 struct virtio_vsock_sock *vvs = vsk->trans;
853 bytes = (s64)vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
860 s64 virtio_transport_stream_has_space(struct vsock_sock *vsk)
862 struct virtio_vsock_sock *vvs = vsk->trans;
865 spin_lock_bh(&vvs->tx_lock);
866 bytes = virtio_transport_has_space(vsk);
867 spin_unlock_bh(&vvs->tx_lock);
871 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space);
873 int virtio_transport_do_socket_init(struct vsock_sock *vsk,
874 struct vsock_sock *psk)
876 struct virtio_vsock_sock *vvs;
878 vvs = kzalloc(sizeof(*vvs), GFP_KERNEL);
884 if (psk && psk->trans) {
885 struct virtio_vsock_sock *ptrans = psk->trans;
887 vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
890 if (vsk->buffer_size > VIRTIO_VSOCK_MAX_BUF_SIZE)
891 vsk->buffer_size = VIRTIO_VSOCK_MAX_BUF_SIZE;
893 vvs->buf_alloc = vsk->buffer_size;
895 spin_lock_init(&vvs->rx_lock);
896 spin_lock_init(&vvs->tx_lock);
897 skb_queue_head_init(&vvs->rx_queue);
901 EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init);
903 /* sk_lock held by the caller */
904 void virtio_transport_notify_buffer_size(struct vsock_sock *vsk, u64 *val)
906 struct virtio_vsock_sock *vvs = vsk->trans;
908 if (*val > VIRTIO_VSOCK_MAX_BUF_SIZE)
909 *val = VIRTIO_VSOCK_MAX_BUF_SIZE;
911 vvs->buf_alloc = *val;
913 virtio_transport_send_credit_update(vsk);
915 EXPORT_SYMBOL_GPL(virtio_transport_notify_buffer_size);
918 virtio_transport_notify_poll_in(struct vsock_sock *vsk,
920 bool *data_ready_now)
922 *data_ready_now = vsock_stream_has_data(vsk) >= target;
926 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in);
929 virtio_transport_notify_poll_out(struct vsock_sock *vsk,
931 bool *space_avail_now)
935 free_space = vsock_stream_has_space(vsk);
937 *space_avail_now = true;
938 else if (free_space == 0)
939 *space_avail_now = false;
943 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out);
945 int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
946 size_t target, struct vsock_transport_recv_notify_data *data)
950 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init);
952 int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
953 size_t target, struct vsock_transport_recv_notify_data *data)
957 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block);
959 int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
960 size_t target, struct vsock_transport_recv_notify_data *data)
964 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue);
966 int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
967 size_t target, ssize_t copied, bool data_read,
968 struct vsock_transport_recv_notify_data *data)
972 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue);
974 int virtio_transport_notify_send_init(struct vsock_sock *vsk,
975 struct vsock_transport_send_notify_data *data)
979 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init);
981 int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
982 struct vsock_transport_send_notify_data *data)
986 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block);
988 int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
989 struct vsock_transport_send_notify_data *data)
993 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue);
995 int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
996 ssize_t written, struct vsock_transport_send_notify_data *data)
1000 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue);
1002 u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk)
1004 return vsk->buffer_size;
1006 EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat);
1008 bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
1012 EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
1014 bool virtio_transport_stream_allow(u32 cid, u32 port)
1018 EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
1020 int virtio_transport_dgram_bind(struct vsock_sock *vsk,
1021 struct sockaddr_vm *addr)
1025 EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
1027 bool virtio_transport_dgram_allow(u32 cid, u32 port)
1031 EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
1033 int virtio_transport_connect(struct vsock_sock *vsk)
1035 struct virtio_vsock_pkt_info info = {
1036 .op = VIRTIO_VSOCK_OP_REQUEST,
1040 return virtio_transport_send_pkt_info(vsk, &info);
1042 EXPORT_SYMBOL_GPL(virtio_transport_connect);
1044 int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
1046 struct virtio_vsock_pkt_info info = {
1047 .op = VIRTIO_VSOCK_OP_SHUTDOWN,
1048 .flags = (mode & RCV_SHUTDOWN ?
1049 VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
1050 (mode & SEND_SHUTDOWN ?
1051 VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
1055 return virtio_transport_send_pkt_info(vsk, &info);
1057 EXPORT_SYMBOL_GPL(virtio_transport_shutdown);
1060 virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
1061 struct sockaddr_vm *remote_addr,
1067 EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
1070 virtio_transport_stream_enqueue(struct vsock_sock *vsk,
1074 struct virtio_vsock_pkt_info info = {
1075 .op = VIRTIO_VSOCK_OP_RW,
1081 return virtio_transport_send_pkt_info(vsk, &info);
1083 EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);
1085 void virtio_transport_destruct(struct vsock_sock *vsk)
1087 struct virtio_vsock_sock *vvs = vsk->trans;
1091 EXPORT_SYMBOL_GPL(virtio_transport_destruct);
1093 static int virtio_transport_reset(struct vsock_sock *vsk,
1094 struct sk_buff *skb)
1096 struct virtio_vsock_pkt_info info = {
1097 .op = VIRTIO_VSOCK_OP_RST,
1102 /* Send RST only if the original pkt is not a RST pkt */
1103 if (skb && le16_to_cpu(virtio_vsock_hdr(skb)->op) == VIRTIO_VSOCK_OP_RST)
1106 return virtio_transport_send_pkt_info(vsk, &info);
1109 /* Normally packets are associated with a socket. There may be no socket if an
1110 * attempt was made to connect to a socket that does not exist.
1112 static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
1113 struct sk_buff *skb)
1115 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1116 struct virtio_vsock_pkt_info info = {
1117 .op = VIRTIO_VSOCK_OP_RST,
1118 .type = le16_to_cpu(hdr->type),
1121 struct sk_buff *reply;
1123 /* Send RST only if the original pkt is not a RST pkt */
1124 if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST)
1130 reply = virtio_transport_alloc_skb(&info, 0, false,
1131 le64_to_cpu(hdr->dst_cid),
1132 le32_to_cpu(hdr->dst_port),
1133 le64_to_cpu(hdr->src_cid),
1134 le32_to_cpu(hdr->src_port));
1138 return t->send_pkt(reply);
1141 /* This function should be called with sk_lock held and SOCK_DONE set */
1142 static void virtio_transport_remove_sock(struct vsock_sock *vsk)
1144 struct virtio_vsock_sock *vvs = vsk->trans;
1146 /* We don't need to take rx_lock, as the socket is closing and we are
1149 __skb_queue_purge(&vvs->rx_queue);
1150 vsock_remove_sock(vsk);
1153 static void virtio_transport_wait_close(struct sock *sk, long timeout)
1156 DEFINE_WAIT_FUNC(wait, woken_wake_function);
1158 add_wait_queue(sk_sleep(sk), &wait);
1161 if (sk_wait_event(sk, &timeout,
1162 sock_flag(sk, SOCK_DONE), &wait))
1164 } while (!signal_pending(current) && timeout);
1166 remove_wait_queue(sk_sleep(sk), &wait);
1170 static void virtio_transport_do_close(struct vsock_sock *vsk,
1171 bool cancel_timeout)
1173 struct sock *sk = sk_vsock(vsk);
1175 sock_set_flag(sk, SOCK_DONE);
1176 vsk->peer_shutdown = SHUTDOWN_MASK;
1177 if (vsock_stream_has_data(vsk) <= 0)
1178 sk->sk_state = TCP_CLOSING;
1179 sk->sk_state_change(sk);
1181 if (vsk->close_work_scheduled &&
1182 (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
1183 vsk->close_work_scheduled = false;
1185 virtio_transport_remove_sock(vsk);
1187 /* Release refcnt obtained when we scheduled the timeout */
1192 static void virtio_transport_close_timeout(struct work_struct *work)
1194 struct vsock_sock *vsk =
1195 container_of(work, struct vsock_sock, close_work.work);
1196 struct sock *sk = sk_vsock(vsk);
1201 if (!sock_flag(sk, SOCK_DONE)) {
1202 (void)virtio_transport_reset(vsk, NULL);
1204 virtio_transport_do_close(vsk, false);
1207 vsk->close_work_scheduled = false;
1213 /* User context, vsk->sk is locked */
1214 static bool virtio_transport_close(struct vsock_sock *vsk)
1216 struct sock *sk = &vsk->sk;
1218 if (!(sk->sk_state == TCP_ESTABLISHED ||
1219 sk->sk_state == TCP_CLOSING))
1222 /* Already received SHUTDOWN from peer, reply with RST */
1223 if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) {
1224 (void)virtio_transport_reset(vsk, NULL);
1228 if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
1229 (void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
1231 if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
1232 virtio_transport_wait_close(sk, sk->sk_lingertime);
1234 if (sock_flag(sk, SOCK_DONE)) {
1239 INIT_DELAYED_WORK(&vsk->close_work,
1240 virtio_transport_close_timeout);
1241 vsk->close_work_scheduled = true;
1242 schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT);
1246 void virtio_transport_release(struct vsock_sock *vsk)
1248 struct sock *sk = &vsk->sk;
1249 bool remove_sock = true;
1251 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)
1252 remove_sock = virtio_transport_close(vsk);
1255 sock_set_flag(sk, SOCK_DONE);
1256 virtio_transport_remove_sock(vsk);
1259 EXPORT_SYMBOL_GPL(virtio_transport_release);
1262 virtio_transport_recv_connecting(struct sock *sk,
1263 struct sk_buff *skb)
1265 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1266 struct vsock_sock *vsk = vsock_sk(sk);
1270 switch (le16_to_cpu(hdr->op)) {
1271 case VIRTIO_VSOCK_OP_RESPONSE:
1272 sk->sk_state = TCP_ESTABLISHED;
1273 sk->sk_socket->state = SS_CONNECTED;
1274 vsock_insert_connected(vsk);
1275 sk->sk_state_change(sk);
1277 case VIRTIO_VSOCK_OP_INVALID:
1279 case VIRTIO_VSOCK_OP_RST:
1291 virtio_transport_reset(vsk, skb);
1292 sk->sk_state = TCP_CLOSE;
1294 sk_error_report(sk);
1299 virtio_transport_recv_enqueue(struct vsock_sock *vsk,
1300 struct sk_buff *skb)
1302 struct virtio_vsock_sock *vvs = vsk->trans;
1303 bool can_enqueue, free_pkt = false;
1304 struct virtio_vsock_hdr *hdr;
1307 hdr = virtio_vsock_hdr(skb);
1308 len = le32_to_cpu(hdr->len);
1310 spin_lock_bh(&vvs->rx_lock);
1312 can_enqueue = virtio_transport_inc_rx_pkt(vvs, len);
1318 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM)
1321 /* Try to copy small packets into the buffer of last packet queued,
1322 * to avoid wasting memory queueing the entire buffer with a small
1325 if (len <= GOOD_COPY_LEN && !skb_queue_empty(&vvs->rx_queue)) {
1326 struct virtio_vsock_hdr *last_hdr;
1327 struct sk_buff *last_skb;
1329 last_skb = skb_peek_tail(&vvs->rx_queue);
1330 last_hdr = virtio_vsock_hdr(last_skb);
1332 /* If there is space in the last packet queued, we copy the
1333 * new packet in its buffer. We avoid this if the last packet
1334 * queued has VIRTIO_VSOCK_SEQ_EOM set, because this is
1335 * delimiter of SEQPACKET message, so 'pkt' is the first packet
1338 if (skb->len < skb_tailroom(last_skb) &&
1339 !(le32_to_cpu(last_hdr->flags) & VIRTIO_VSOCK_SEQ_EOM)) {
1340 memcpy(skb_put(last_skb, skb->len), skb->data, skb->len);
1342 last_hdr->flags |= hdr->flags;
1343 le32_add_cpu(&last_hdr->len, len);
1348 __skb_queue_tail(&vvs->rx_queue, skb);
1351 spin_unlock_bh(&vvs->rx_lock);
1357 virtio_transport_recv_connected(struct sock *sk,
1358 struct sk_buff *skb)
1360 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1361 struct vsock_sock *vsk = vsock_sk(sk);
1364 switch (le16_to_cpu(hdr->op)) {
1365 case VIRTIO_VSOCK_OP_RW:
1366 virtio_transport_recv_enqueue(vsk, skb);
1367 vsock_data_ready(sk);
1369 case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
1370 virtio_transport_send_credit_update(vsk);
1372 case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
1373 sk->sk_write_space(sk);
1375 case VIRTIO_VSOCK_OP_SHUTDOWN:
1376 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
1377 vsk->peer_shutdown |= RCV_SHUTDOWN;
1378 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
1379 vsk->peer_shutdown |= SEND_SHUTDOWN;
1380 if (vsk->peer_shutdown == SHUTDOWN_MASK) {
1381 if (vsock_stream_has_data(vsk) <= 0 && !sock_flag(sk, SOCK_DONE)) {
1382 (void)virtio_transport_reset(vsk, NULL);
1383 virtio_transport_do_close(vsk, true);
1385 /* Remove this socket anyway because the remote peer sent
1386 * the shutdown. This way a new connection will succeed
1387 * if the remote peer uses the same source port,
1388 * even if the old socket is still unreleased, but now disconnected.
1390 vsock_remove_sock(vsk);
1392 if (le32_to_cpu(virtio_vsock_hdr(skb)->flags))
1393 sk->sk_state_change(sk);
1395 case VIRTIO_VSOCK_OP_RST:
1396 virtio_transport_do_close(vsk, true);
1408 virtio_transport_recv_disconnecting(struct sock *sk,
1409 struct sk_buff *skb)
1411 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1412 struct vsock_sock *vsk = vsock_sk(sk);
1414 if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST)
1415 virtio_transport_do_close(vsk, true);
1419 virtio_transport_send_response(struct vsock_sock *vsk,
1420 struct sk_buff *skb)
1422 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1423 struct virtio_vsock_pkt_info info = {
1424 .op = VIRTIO_VSOCK_OP_RESPONSE,
1425 .remote_cid = le64_to_cpu(hdr->src_cid),
1426 .remote_port = le32_to_cpu(hdr->src_port),
1431 return virtio_transport_send_pkt_info(vsk, &info);
1434 static bool virtio_transport_space_update(struct sock *sk,
1435 struct sk_buff *skb)
1437 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1438 struct vsock_sock *vsk = vsock_sk(sk);
1439 struct virtio_vsock_sock *vvs = vsk->trans;
1440 bool space_available;
1442 /* Listener sockets are not associated with any transport, so we are
1443 * not able to take the state to see if there is space available in the
1444 * remote peer, but since they are only used to receive requests, we
1445 * can assume that there is always space available in the other peer.
1450 /* buf_alloc and fwd_cnt is always included in the hdr */
1451 spin_lock_bh(&vvs->tx_lock);
1452 vvs->peer_buf_alloc = le32_to_cpu(hdr->buf_alloc);
1453 vvs->peer_fwd_cnt = le32_to_cpu(hdr->fwd_cnt);
1454 space_available = virtio_transport_has_space(vsk);
1455 spin_unlock_bh(&vvs->tx_lock);
1456 return space_available;
1459 /* Handle server socket */
1461 virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
1462 struct virtio_transport *t)
1464 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1465 struct vsock_sock *vsk = vsock_sk(sk);
1466 struct vsock_sock *vchild;
1470 if (le16_to_cpu(hdr->op) != VIRTIO_VSOCK_OP_REQUEST) {
1471 virtio_transport_reset_no_sock(t, skb);
1475 if (sk_acceptq_is_full(sk)) {
1476 virtio_transport_reset_no_sock(t, skb);
1480 child = vsock_create_connected(sk);
1482 virtio_transport_reset_no_sock(t, skb);
1486 sk_acceptq_added(sk);
1488 lock_sock_nested(child, SINGLE_DEPTH_NESTING);
1490 child->sk_state = TCP_ESTABLISHED;
1492 vchild = vsock_sk(child);
1493 vsock_addr_init(&vchild->local_addr, le64_to_cpu(hdr->dst_cid),
1494 le32_to_cpu(hdr->dst_port));
1495 vsock_addr_init(&vchild->remote_addr, le64_to_cpu(hdr->src_cid),
1496 le32_to_cpu(hdr->src_port));
1498 ret = vsock_assign_transport(vchild, vsk);
1499 /* Transport assigned (looking at remote_addr) must be the same
1500 * where we received the request.
1502 if (ret || vchild->transport != &t->transport) {
1503 release_sock(child);
1504 virtio_transport_reset_no_sock(t, skb);
1509 if (virtio_transport_space_update(child, skb))
1510 child->sk_write_space(child);
1512 vsock_insert_connected(vchild);
1513 vsock_enqueue_accept(sk, child);
1514 virtio_transport_send_response(vchild, skb);
1516 release_sock(child);
1518 sk->sk_data_ready(sk);
1522 static bool virtio_transport_valid_type(u16 type)
1524 return (type == VIRTIO_VSOCK_TYPE_STREAM) ||
1525 (type == VIRTIO_VSOCK_TYPE_SEQPACKET);
1528 /* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
1531 void virtio_transport_recv_pkt(struct virtio_transport *t,
1532 struct sk_buff *skb)
1534 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1535 struct sockaddr_vm src, dst;
1536 struct vsock_sock *vsk;
1538 bool space_available;
1540 vsock_addr_init(&src, le64_to_cpu(hdr->src_cid),
1541 le32_to_cpu(hdr->src_port));
1542 vsock_addr_init(&dst, le64_to_cpu(hdr->dst_cid),
1543 le32_to_cpu(hdr->dst_port));
1545 trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
1546 dst.svm_cid, dst.svm_port,
1547 le32_to_cpu(hdr->len),
1548 le16_to_cpu(hdr->type),
1549 le16_to_cpu(hdr->op),
1550 le32_to_cpu(hdr->flags),
1551 le32_to_cpu(hdr->buf_alloc),
1552 le32_to_cpu(hdr->fwd_cnt));
1554 if (!virtio_transport_valid_type(le16_to_cpu(hdr->type))) {
1555 (void)virtio_transport_reset_no_sock(t, skb);
1559 /* The socket must be in connected or bound table
1560 * otherwise send reset back
1562 sk = vsock_find_connected_socket(&src, &dst);
1564 sk = vsock_find_bound_socket(&dst);
1566 (void)virtio_transport_reset_no_sock(t, skb);
1571 if (virtio_transport_get_type(sk) != le16_to_cpu(hdr->type)) {
1572 (void)virtio_transport_reset_no_sock(t, skb);
1577 if (!skb_set_owner_sk_safe(skb, sk)) {
1578 WARN_ONCE(1, "receiving vsock socket has sk_refcnt == 0\n");
1586 /* Check if sk has been closed before lock_sock */
1587 if (sock_flag(sk, SOCK_DONE)) {
1588 (void)virtio_transport_reset_no_sock(t, skb);
1594 space_available = virtio_transport_space_update(sk, skb);
1596 /* Update CID in case it has changed after a transport reset event */
1597 if (vsk->local_addr.svm_cid != VMADDR_CID_ANY)
1598 vsk->local_addr.svm_cid = dst.svm_cid;
1600 if (space_available)
1601 sk->sk_write_space(sk);
1603 switch (sk->sk_state) {
1605 virtio_transport_recv_listen(sk, skb, t);
1609 virtio_transport_recv_connecting(sk, skb);
1612 case TCP_ESTABLISHED:
1613 virtio_transport_recv_connected(sk, skb);
1616 virtio_transport_recv_disconnecting(sk, skb);
1620 (void)virtio_transport_reset_no_sock(t, skb);
1627 /* Release refcnt obtained when we fetched this socket out of the
1628 * bound or connected list.
1636 EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
1638 /* Remove skbs found in a queue that have a vsk that matches.
1640 * Each skb is freed.
1642 * Returns the count of skbs that were reply packets.
1644 int virtio_transport_purge_skbs(void *vsk, struct sk_buff_head *queue)
1646 struct sk_buff_head freeme;
1647 struct sk_buff *skb, *tmp;
1650 skb_queue_head_init(&freeme);
1652 spin_lock_bh(&queue->lock);
1653 skb_queue_walk_safe(queue, skb, tmp) {
1654 if (vsock_sk(skb->sk) != vsk)
1657 __skb_unlink(skb, queue);
1658 __skb_queue_tail(&freeme, skb);
1660 if (virtio_vsock_skb_reply(skb))
1663 spin_unlock_bh(&queue->lock);
1665 __skb_queue_purge(&freeme);
1669 EXPORT_SYMBOL_GPL(virtio_transport_purge_skbs);
1671 int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t recv_actor)
1673 struct virtio_vsock_sock *vvs = vsk->trans;
1674 struct sock *sk = sk_vsock(vsk);
1675 struct sk_buff *skb;
1679 spin_lock_bh(&vvs->rx_lock);
1680 /* Use __skb_recv_datagram() for race-free handling of the receive. It
1681 * works for types other than dgrams.
1683 skb = __skb_recv_datagram(sk, &vvs->rx_queue, MSG_DONTWAIT, &off, &err);
1684 spin_unlock_bh(&vvs->rx_lock);
1689 return recv_actor(sk, skb);
1691 EXPORT_SYMBOL_GPL(virtio_transport_read_skb);
1693 int virtio_transport_notify_set_rcvlowat(struct vsock_sock *vsk, int val)
1695 struct virtio_vsock_sock *vvs = vsk->trans;
1698 spin_lock_bh(&vvs->rx_lock);
1700 /* If number of available bytes is less than new SO_RCVLOWAT value,
1701 * kick sender to send more data, because sender may sleep in its
1702 * 'send()' syscall waiting for enough space at our side. Also
1703 * don't send credit update when peer already knows actual value -
1704 * such transmission will be useless.
1706 send_update = (vvs->rx_bytes < val) &&
1707 (vvs->fwd_cnt != vvs->last_fwd_cnt);
1709 spin_unlock_bh(&vvs->rx_lock);
1714 err = virtio_transport_send_credit_update(vsk);
1721 EXPORT_SYMBOL_GPL(virtio_transport_notify_set_rcvlowat);
1723 MODULE_LICENSE("GPL v2");
1724 MODULE_AUTHOR("Asias He");
1725 MODULE_DESCRIPTION("common code for virtio vsock");