@@ -11360,6 +11360,16 @@ S: Maintained
F: drivers/media/v4l2-core/videobuf2-*
F: include/media/videobuf2-*
+VIRTIO AND VHOST VSOCK DRIVER
+M: Stefan Hajnoczi <stefanha@redhat.com>
+L: kvm@vger.kernel.org
+L: virtualization@lists.linux-foundation.org
+L: netdev@vger.kernel.org
+S: Maintained
+F: include/linux/virtio_vsock.h
+F: include/uapi/linux/virtio_vsock.h
+F: net/vmw_vsock/virtio_transport_common.c
+
VIRTUAL SERIO DEVICE DRIVER
M: Stephen Chandler Paul <thatslyude@gmail.com>
S: Maintained
new file mode 100644
@@ -0,0 +1,167 @@
+#ifndef _LINUX_VIRTIO_VSOCK_H
+#define _LINUX_VIRTIO_VSOCK_H
+
+#include <uapi/linux/virtio_vsock.h>
+#include <linux/socket.h>
+#include <net/sock.h>
+#include <net/af_vsock.h>
+
+#define VIRTIO_VSOCK_DEFAULT_MIN_BUF_SIZE 128
+#define VIRTIO_VSOCK_DEFAULT_BUF_SIZE (1024 * 256)
+#define VIRTIO_VSOCK_DEFAULT_MAX_BUF_SIZE (1024 * 256)
+#define VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE (1024 * 4)
+#define VIRTIO_VSOCK_MAX_BUF_SIZE 0xFFFFFFFFUL
+#define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE (1024 * 64)
+#define VIRTIO_VSOCK_MAX_TX_BUF_SIZE (1024 * 1024 * 16)
+#define VIRTIO_VSOCK_MAX_DGRAM_SIZE (1024 * 64)
+
+enum {
+ VSOCK_VQ_CTRL = 0,
+ VSOCK_VQ_RX = 1, /* for host to guest data */
+ VSOCK_VQ_TX = 2, /* for guest to host data */
+ VSOCK_VQ_MAX = 3,
+};
+
+/* Per-socket state (accessed via vsk->trans) */
+struct virtio_vsock_sock {
+ struct vsock_sock *vsk;
+
+ /* Protected by lock_sock(sk_vsock(trans->vsk)) */
+ u32 buf_size;
+ u32 buf_size_min;
+ u32 buf_size_max;
+
+ struct mutex tx_lock;
+ struct mutex rx_lock;
+
+ /* Protected by tx_lock */
+ u32 tx_cnt;
+ u32 buf_alloc;
+ u32 peer_fwd_cnt;
+ u32 peer_buf_alloc;
+
+ /* Protected by rx_lock */
+ u32 fwd_cnt;
+ u32 rx_bytes;
+ struct list_head rx_queue;
+};
+
+struct virtio_vsock_pkt {
+ struct virtio_vsock_hdr hdr;
+ struct work_struct work;
+ struct list_head list;
+ void *buf;
+ u32 len;
+ u32 off;
+};
+
+struct virtio_vsock_pkt_info {
+ u32 remote_cid, remote_port;
+ struct msghdr *msg;
+ u32 pkt_len;
+ u16 type;
+ u16 op;
+ u32 flags;
+};
+
+struct virtio_transport {
+ /* This must be the first field */
+ struct vsock_transport transport;
+
+ /* Send packet for a specific socket */
+ int (*send_pkt)(struct vsock_sock *vsk,
+ struct virtio_vsock_pkt_info *info);
+
+ /* Send packet without a socket (e.g. RST). Prefer send_pkt() over
+ * send_pkt_no_sock() when a socket exists.
+ */
+ int (*send_pkt_no_sock)(struct virtio_vsock_pkt *pkt);
+};
+
+struct virtio_vsock_pkt *
+virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,
+ size_t len,
+ u32 src_cid,
+ u32 src_port,
+ u32 dst_cid,
+ u32 dst_port);
+ssize_t
+virtio_transport_stream_dequeue(struct vsock_sock *vsk,
+ struct msghdr *msg,
+ size_t len,
+ int type);
+int
+virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
+ struct msghdr *msg,
+ size_t len, int flags);
+
+s64 virtio_transport_stream_has_data(struct vsock_sock *vsk);
+s64 virtio_transport_stream_has_space(struct vsock_sock *vsk);
+
+int virtio_transport_do_socket_init(struct vsock_sock *vsk,
+ struct vsock_sock *psk);
+u64 virtio_transport_get_buffer_size(struct vsock_sock *vsk);
+u64 virtio_transport_get_min_buffer_size(struct vsock_sock *vsk);
+u64 virtio_transport_get_max_buffer_size(struct vsock_sock *vsk);
+void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val);
+void virtio_transport_set_min_buffer_size(struct vsock_sock *vsk, u64 val);
+void virtio_transport_set_max_buffer_size(struct vsock_sock *vs, u64 val);
+int
+virtio_transport_notify_poll_in(struct vsock_sock *vsk,
+ size_t target,
+ bool *data_ready_now);
+int
+virtio_transport_notify_poll_out(struct vsock_sock *vsk,
+ size_t target,
+ bool *space_available_now);
+
+int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
+ size_t target, struct vsock_transport_recv_notify_data *data);
+int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
+ size_t target, struct vsock_transport_recv_notify_data *data);
+int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
+ size_t target, struct vsock_transport_recv_notify_data *data);
+int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
+ size_t target, ssize_t copied, bool data_read,
+ struct vsock_transport_recv_notify_data *data);
+int virtio_transport_notify_send_init(struct vsock_sock *vsk,
+ struct vsock_transport_send_notify_data *data);
+int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
+ struct vsock_transport_send_notify_data *data);
+int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
+ struct vsock_transport_send_notify_data *data);
+int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
+ ssize_t written, struct vsock_transport_send_notify_data *data);
+
+u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk);
+bool virtio_transport_stream_is_active(struct vsock_sock *vsk);
+bool virtio_transport_stream_allow(u32 cid, u32 port);
+int virtio_transport_dgram_bind(struct vsock_sock *vsk,
+ struct sockaddr_vm *addr);
+bool virtio_transport_dgram_allow(u32 cid, u32 port);
+
+int virtio_transport_connect(struct vsock_sock *vsk);
+
+int virtio_transport_shutdown(struct vsock_sock *vsk, int mode);
+
+void virtio_transport_release(struct vsock_sock *vsk);
+
+ssize_t
+virtio_transport_stream_enqueue(struct vsock_sock *vsk,
+ struct msghdr *msg,
+ size_t len);
+int
+virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
+ struct sockaddr_vm *remote_addr,
+ struct msghdr *msg,
+ size_t len);
+
+void virtio_transport_destruct(struct vsock_sock *vsk);
+
+void virtio_transport_recv_pkt(struct virtio_vsock_pkt *pkt);
+void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt);
+void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt);
+u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 wanted);
+void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit);
+
+#endif /* _LINUX_VIRTIO_VSOCK_H */
new file mode 100644
@@ -0,0 +1,144 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM vsock
+
+#if !defined(_TRACE_VSOCK_VIRTIO_TRANSPORT_COMMON_H) || \
+ defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_VSOCK_VIRTIO_TRANSPORT_COMMON_H
+
+#include <linux/tracepoint.h>
+
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_TYPE_STREAM);
+
+#define show_type(val) \
+ __print_symbolic(val, { VIRTIO_VSOCK_TYPE_STREAM, "STREAM" })
+
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_INVALID);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_REQUEST);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_RESPONSE);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_RST);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_SHUTDOWN);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_RW);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_CREDIT_UPDATE);
+TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_CREDIT_REQUEST);
+
+#define show_op(val) \
+ __print_symbolic(val, \
+ { VIRTIO_VSOCK_OP_INVALID, "INVALID" }, \
+ { VIRTIO_VSOCK_OP_REQUEST, "REQUEST" }, \
+ { VIRTIO_VSOCK_OP_RESPONSE, "RESPONSE" }, \
+ { VIRTIO_VSOCK_OP_RST, "RST" }, \
+ { VIRTIO_VSOCK_OP_SHUTDOWN, "SHUTDOWN" }, \
+ { VIRTIO_VSOCK_OP_RW, "RW" }, \
+ { VIRTIO_VSOCK_OP_CREDIT_UPDATE, "CREDIT_UPDATE" }, \
+ { VIRTIO_VSOCK_OP_CREDIT_REQUEST, "CREDIT_REQUEST" })
+
+TRACE_EVENT(virtio_transport_alloc_pkt,
+ TP_PROTO(
+ __u32 src_cid, __u32 src_port,
+ __u32 dst_cid, __u32 dst_port,
+ __u32 len,
+ __u16 type,
+ __u16 op,
+ __u32 flags
+ ),
+ TP_ARGS(
+ src_cid, src_port,
+ dst_cid, dst_port,
+ len,
+ type,
+ op,
+ flags
+ ),
+ TP_STRUCT__entry(
+ __field(__u32, src_cid)
+ __field(__u32, src_port)
+ __field(__u32, dst_cid)
+ __field(__u32, dst_port)
+ __field(__u32, len)
+ __field(__u16, type)
+ __field(__u16, op)
+ __field(__u32, flags)
+ ),
+ TP_fast_assign(
+ __entry->src_cid = src_cid;
+ __entry->src_port = src_port;
+ __entry->dst_cid = dst_cid;
+ __entry->dst_port = dst_port;
+ __entry->len = len;
+ __entry->type = type;
+ __entry->op = op;
+ __entry->flags = flags;
+ ),
+ TP_printk("%u:%u -> %u:%u len=%u type=%s op=%s flags=%#x",
+ __entry->src_cid, __entry->src_port,
+ __entry->dst_cid, __entry->dst_port,
+ __entry->len,
+ show_type(__entry->type),
+ show_op(__entry->op),
+ __entry->flags)
+);
+
+TRACE_EVENT(virtio_transport_recv_pkt,
+ TP_PROTO(
+ __u32 src_cid, __u32 src_port,
+ __u32 dst_cid, __u32 dst_port,
+ __u32 len,
+ __u16 type,
+ __u16 op,
+ __u32 flags,
+ __u32 buf_alloc,
+ __u32 fwd_cnt
+ ),
+ TP_ARGS(
+ src_cid, src_port,
+ dst_cid, dst_port,
+ len,
+ type,
+ op,
+ flags,
+ buf_alloc,
+ fwd_cnt
+ ),
+ TP_STRUCT__entry(
+ __field(__u32, src_cid)
+ __field(__u32, src_port)
+ __field(__u32, dst_cid)
+ __field(__u32, dst_port)
+ __field(__u32, len)
+ __field(__u16, type)
+ __field(__u16, op)
+ __field(__u32, flags)
+ __field(__u32, buf_alloc)
+ __field(__u32, fwd_cnt)
+ ),
+ TP_fast_assign(
+ __entry->src_cid = src_cid;
+ __entry->src_port = src_port;
+ __entry->dst_cid = dst_cid;
+ __entry->dst_port = dst_port;
+ __entry->len = len;
+ __entry->type = type;
+ __entry->op = op;
+ __entry->flags = flags;
+ __entry->buf_alloc = buf_alloc;
+ __entry->fwd_cnt = fwd_cnt;
+ ),
+ TP_printk("%u:%u -> %u:%u len=%u type=%s op=%s flags=%#x "
+ "buf_alloc=%u fwd_cnt=%u",
+ __entry->src_cid, __entry->src_port,
+ __entry->dst_cid, __entry->dst_port,
+ __entry->len,
+ show_type(__entry->type),
+ show_op(__entry->op),
+ __entry->flags,
+ __entry->buf_alloc,
+ __entry->fwd_cnt)
+);
+
+#endif /* _TRACE_VSOCK_VIRTIO_TRANSPORT_COMMON_H */
+
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE vsock_virtio_transport_common
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
@@ -39,6 +39,7 @@
#define VIRTIO_ID_9P 9 /* 9p virtio console */
#define VIRTIO_ID_RPROC_SERIAL 11 /* virtio remoteproc serial link */
#define VIRTIO_ID_CAIF 12 /* Virtio caif */
+#define VIRTIO_ID_VSOCK 13 /* virtio vsock transport */
#define VIRTIO_ID_GPU 16 /* virtio GPU */
#define VIRTIO_ID_INPUT 18 /* virtio input */
new file mode 100644
@@ -0,0 +1,87 @@
+/*
+ * This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
+ * anyone can use the definitions to implement compatible drivers/servers:
+ *
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of IBM nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * Copyright (C) Red Hat, Inc., 2013-2015
+ * Copyright (C) Asias He <asias@redhat.com>, 2013
+ * Copyright (C) Stefan Hajnoczi <stefanha@redhat.com>, 2015
+ */
+
+#ifndef _UAPI_LINUX_VIRTIO_VSOCK_H
+#define _UAPI_LINUX_VIRTIO_VOSCK_H
+
+#include <linux/types.h>
+#include <linux/virtio_ids.h>
+#include <linux/virtio_config.h>
+
+struct virtio_vsock_config {
+ __le32 guest_cid;
+ __le32 max_virtqueue_pairs;
+};
+
+struct virtio_vsock_hdr {
+ __le32 src_cid;
+ __le32 src_port;
+ __le32 dst_cid;
+ __le32 dst_port;
+ __le32 len;
+ __le16 type; /* enum virtio_vsock_type */
+ __le16 op; /* enum virtio_vsock_op */
+ __le32 flags;
+ __le32 buf_alloc;
+ __le32 fwd_cnt;
+};
+
+enum virtio_vsock_type {
+ VIRTIO_VSOCK_TYPE_STREAM = 1,
+};
+
+enum virtio_vsock_op {
+ VIRTIO_VSOCK_OP_INVALID = 0,
+
+ /* Connect operations */
+ VIRTIO_VSOCK_OP_REQUEST = 1,
+ VIRTIO_VSOCK_OP_RESPONSE = 2,
+ VIRTIO_VSOCK_OP_RST = 3,
+ VIRTIO_VSOCK_OP_SHUTDOWN = 4,
+
+ /* To send payload */
+ VIRTIO_VSOCK_OP_RW = 5,
+
+ /* Tell the peer our credit info */
+ VIRTIO_VSOCK_OP_CREDIT_UPDATE = 6,
+ /* Request the peer to send the credit info to us */
+ VIRTIO_VSOCK_OP_CREDIT_REQUEST = 7,
+};
+
+/* VIRTIO_VSOCK_OP_SHUTDOWN flags values */
+enum virtio_vsock_shutdown {
+ VIRTIO_VSOCK_SHUTDOWN_RCV = 1,
+ VIRTIO_VSOCK_SHUTDOWN_SEND = 2,
+};
+
+#endif /* _UAPI_LINUX_VIRTIO_VSOCK_H */
new file mode 100644
@@ -0,0 +1,834 @@
+/*
+ * common code for virtio vsock
+ *
+ * Copyright (C) 2013-2015 Red Hat, Inc.
+ * Author: Asias He <asias@redhat.com>
+ * Stefan Hajnoczi <stefanha@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+#include <linux/module.h>
+#include <linux/ctype.h>
+#include <linux/list.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 <net/af_vsock.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/vsock_virtio_transport_common.h>
+
+static const struct virtio_transport *virtio_transport_get_ops(void)
+{
+ const struct vsock_transport *t = vsock_core_get_transport();
+
+ return container_of(t, struct virtio_transport, transport);
+}
+
+static int virtio_transport_send_pkt(struct vsock_sock *vsk,
+ struct virtio_vsock_pkt_info *info)
+{
+ return virtio_transport_get_ops()->send_pkt(vsk, info);
+}
+
+static int virtio_transport_send_pkt_no_sock(struct virtio_vsock_pkt *pkt)
+{
+ return virtio_transport_get_ops()->send_pkt_no_sock(pkt);
+}
+
+struct virtio_vsock_pkt *
+virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,
+ size_t len,
+ u32 src_cid,
+ u32 src_port,
+ u32 dst_cid,
+ u32 dst_port)
+{
+ struct virtio_vsock_pkt *pkt;
+ int err;
+
+ pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
+ if (!pkt)
+ return NULL;
+
+ pkt->hdr.type = cpu_to_le16(info->type);
+ pkt->hdr.op = cpu_to_le16(info->op);
+ pkt->hdr.src_cid = cpu_to_le32(src_cid);
+ pkt->hdr.src_port = cpu_to_le32(src_port);
+ pkt->hdr.dst_cid = cpu_to_le32(dst_cid);
+ pkt->hdr.dst_port = cpu_to_le32(dst_port);
+ pkt->hdr.flags = cpu_to_le32(info->flags);
+ pkt->len = len;
+ pkt->hdr.len = cpu_to_le32(len);
+
+ if (info->msg && len > 0) {
+ pkt->buf = kmalloc(len, GFP_KERNEL);
+ if (!pkt->buf)
+ goto out_pkt;
+ err = memcpy_from_msg(pkt->buf, info->msg, len);
+ if (err)
+ goto out;
+ }
+
+ trace_virtio_transport_alloc_pkt(src_cid, src_port,
+ dst_cid, dst_port,
+ len,
+ info->type,
+ info->op,
+ info->flags);
+
+ return pkt;
+
+out:
+ kfree(pkt->buf);
+out_pkt:
+ kfree(pkt);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_alloc_pkt);
+
+static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
+ struct virtio_vsock_pkt *pkt)
+{
+ vvs->rx_bytes += pkt->len;
+}
+
+static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
+ struct virtio_vsock_pkt *pkt)
+{
+ vvs->rx_bytes -= pkt->len;
+ vvs->fwd_cnt += pkt->len;
+}
+
+void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
+{
+ mutex_lock(&vvs->tx_lock);
+ pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
+ pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
+ mutex_unlock(&vvs->tx_lock);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
+
+u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit)
+{
+ u32 ret;
+
+ mutex_lock(&vvs->tx_lock);
+ ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
+ if (ret > credit)
+ ret = credit;
+ vvs->tx_cnt += ret;
+ mutex_unlock(&vvs->tx_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_get_credit);
+
+void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit)
+{
+ mutex_lock(&vvs->tx_lock);
+ vvs->tx_cnt -= credit;
+ mutex_unlock(&vvs->tx_lock);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_put_credit);
+
+static int virtio_transport_send_credit_update(struct vsock_sock *vsk,
+ int type,
+ struct virtio_vsock_hdr *hdr)
+{
+ struct virtio_vsock_pkt_info info = {
+ .op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
+ .type = type,
+ };
+
+ return virtio_transport_send_pkt(vsk, &info);
+}
+
+static ssize_t
+virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
+ struct msghdr *msg,
+ size_t len)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+ struct virtio_vsock_pkt *pkt;
+ size_t bytes, total = 0;
+ int err = -EFAULT;
+
+ mutex_lock(&vvs->rx_lock);
+ while (total < len &&
+ vvs->rx_bytes > 0 &&
+ !list_empty(&vvs->rx_queue)) {
+ pkt = list_first_entry(&vvs->rx_queue,
+ struct virtio_vsock_pkt, list);
+
+ bytes = len - total;
+ if (bytes > pkt->len - pkt->off)
+ bytes = pkt->len - pkt->off;
+
+ err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes);
+ if (err)
+ goto out;
+ total += bytes;
+ pkt->off += bytes;
+ if (pkt->off == pkt->len) {
+ virtio_transport_dec_rx_pkt(vvs, pkt);
+ list_del(&pkt->list);
+ virtio_transport_free_pkt(pkt);
+ }
+ }
+ mutex_unlock(&vvs->rx_lock);
+
+ /* Send a credit pkt to peer */
+ virtio_transport_send_credit_update(vsk, VIRTIO_VSOCK_TYPE_STREAM,
+ NULL);
+
+ return total;
+
+out:
+ mutex_unlock(&vvs->rx_lock);
+ if (total)
+ err = total;
+ return err;
+}
+
+ssize_t
+virtio_transport_stream_dequeue(struct vsock_sock *vsk,
+ struct msghdr *msg,
+ size_t len, int flags)
+{
+ if (flags & MSG_PEEK)
+ return -EOPNOTSUPP;
+
+ return virtio_transport_stream_do_dequeue(vsk, msg, len);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
+
+int
+virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
+ struct msghdr *msg,
+ size_t len, int flags)
+{
+ return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
+
+s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+ s64 bytes;
+
+ mutex_lock(&vvs->rx_lock);
+ bytes = vvs->rx_bytes;
+ mutex_unlock(&vvs->rx_lock);
+
+ return bytes;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data);
+
+static s64 virtio_transport_has_space(struct vsock_sock *vsk)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+ s64 bytes;
+
+ bytes = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
+ if (bytes < 0)
+ bytes = 0;
+
+ return bytes;
+}
+
+s64 virtio_transport_stream_has_space(struct vsock_sock *vsk)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+ s64 bytes;
+
+ mutex_lock(&vvs->tx_lock);
+ bytes = virtio_transport_has_space(vsk);
+ mutex_unlock(&vvs->tx_lock);
+
+ return bytes;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space);
+
+int virtio_transport_do_socket_init(struct vsock_sock *vsk,
+ struct vsock_sock *psk)
+{
+ struct virtio_vsock_sock *vvs;
+
+ vvs = kzalloc(sizeof(*vvs), GFP_KERNEL);
+ if (!vvs)
+ return -ENOMEM;
+
+ vsk->trans = vvs;
+ vvs->vsk = vsk;
+ if (psk) {
+ struct virtio_vsock_sock *ptrans = psk->trans;
+
+ vvs->buf_size = ptrans->buf_size;
+ vvs->buf_size_min = ptrans->buf_size_min;
+ vvs->buf_size_max = ptrans->buf_size_max;
+ vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
+ } else {
+ vvs->buf_size = VIRTIO_VSOCK_DEFAULT_BUF_SIZE;
+ vvs->buf_size_min = VIRTIO_VSOCK_DEFAULT_MIN_BUF_SIZE;
+ vvs->buf_size_max = VIRTIO_VSOCK_DEFAULT_MAX_BUF_SIZE;
+ }
+
+ vvs->buf_alloc = vvs->buf_size;
+
+ mutex_init(&vvs->rx_lock);
+ mutex_init(&vvs->tx_lock);
+ INIT_LIST_HEAD(&vvs->rx_queue);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init);
+
+u64 virtio_transport_get_buffer_size(struct vsock_sock *vsk)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+
+ return vvs->buf_size;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_get_buffer_size);
+
+u64 virtio_transport_get_min_buffer_size(struct vsock_sock *vsk)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+
+ return vvs->buf_size_min;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_get_min_buffer_size);
+
+u64 virtio_transport_get_max_buffer_size(struct vsock_sock *vsk)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+
+ return vvs->buf_size_max;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_get_max_buffer_size);
+
+void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+
+ if (val > VIRTIO_VSOCK_MAX_BUF_SIZE)
+ val = VIRTIO_VSOCK_MAX_BUF_SIZE;
+ if (val < vvs->buf_size_min)
+ vvs->buf_size_min = val;
+ if (val > vvs->buf_size_max)
+ vvs->buf_size_max = val;
+ vvs->buf_size = val;
+ vvs->buf_alloc = val;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_set_buffer_size);
+
+void virtio_transport_set_min_buffer_size(struct vsock_sock *vsk, u64 val)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+
+ if (val > VIRTIO_VSOCK_MAX_BUF_SIZE)
+ val = VIRTIO_VSOCK_MAX_BUF_SIZE;
+ if (val > vvs->buf_size)
+ vvs->buf_size = val;
+ vvs->buf_size_min = val;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_set_min_buffer_size);
+
+void virtio_transport_set_max_buffer_size(struct vsock_sock *vsk, u64 val)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+
+ if (val > VIRTIO_VSOCK_MAX_BUF_SIZE)
+ val = VIRTIO_VSOCK_MAX_BUF_SIZE;
+ if (val < vvs->buf_size)
+ vvs->buf_size = val;
+ vvs->buf_size_max = val;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_set_max_buffer_size);
+
+int
+virtio_transport_notify_poll_in(struct vsock_sock *vsk,
+ size_t target,
+ bool *data_ready_now)
+{
+ if (vsock_stream_has_data(vsk))
+ *data_ready_now = true;
+ else
+ *data_ready_now = false;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in);
+
+int
+virtio_transport_notify_poll_out(struct vsock_sock *vsk,
+ size_t target,
+ bool *space_avail_now)
+{
+ s64 free_space;
+
+ free_space = vsock_stream_has_space(vsk);
+ if (free_space > 0)
+ *space_avail_now = true;
+ else if (free_space == 0)
+ *space_avail_now = false;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out);
+
+int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
+ size_t target, struct vsock_transport_recv_notify_data *data)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init);
+
+int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
+ size_t target, struct vsock_transport_recv_notify_data *data)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block);
+
+int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
+ size_t target, struct vsock_transport_recv_notify_data *data)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue);
+
+int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
+ size_t target, ssize_t copied, bool data_read,
+ struct vsock_transport_recv_notify_data *data)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue);
+
+int virtio_transport_notify_send_init(struct vsock_sock *vsk,
+ struct vsock_transport_send_notify_data *data)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init);
+
+int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
+ struct vsock_transport_send_notify_data *data)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block);
+
+int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
+ struct vsock_transport_send_notify_data *data)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue);
+
+int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
+ ssize_t written, struct vsock_transport_send_notify_data *data)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue);
+
+u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+
+ return vvs->buf_size;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat);
+
+bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
+{
+ return true;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
+
+bool virtio_transport_stream_allow(u32 cid, u32 port)
+{
+ return true;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
+
+int virtio_transport_dgram_bind(struct vsock_sock *vsk,
+ struct sockaddr_vm *addr)
+{
+ return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
+
+bool virtio_transport_dgram_allow(u32 cid, u32 port)
+{
+ return false;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
+
+int virtio_transport_connect(struct vsock_sock *vsk)
+{
+ struct virtio_vsock_pkt_info info = {
+ .op = VIRTIO_VSOCK_OP_REQUEST,
+ .type = VIRTIO_VSOCK_TYPE_STREAM,
+ };
+
+ return virtio_transport_send_pkt(vsk, &info);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_connect);
+
+int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
+{
+ struct virtio_vsock_pkt_info info = {
+ .op = VIRTIO_VSOCK_OP_SHUTDOWN,
+ .type = VIRTIO_VSOCK_TYPE_STREAM,
+ .flags = (mode & RCV_SHUTDOWN ?
+ VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
+ (mode & SEND_SHUTDOWN ?
+ VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
+ };
+
+ return virtio_transport_send_pkt(vsk, &info);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_shutdown);
+
+void virtio_transport_release(struct vsock_sock *vsk)
+{
+ struct sock *sk = &vsk->sk;
+
+ /* Tell other side to terminate connection */
+ if (sk->sk_type == SOCK_STREAM &&
+ vsk->peer_shutdown != SHUTDOWN_MASK &&
+ sk->sk_state == SS_CONNECTED)
+ (void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_release);
+
+int
+virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
+ struct sockaddr_vm *remote_addr,
+ struct msghdr *msg,
+ size_t dgram_len)
+{
+ return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
+
+ssize_t
+virtio_transport_stream_enqueue(struct vsock_sock *vsk,
+ struct msghdr *msg,
+ size_t len)
+{
+ struct virtio_vsock_pkt_info info = {
+ .op = VIRTIO_VSOCK_OP_RW,
+ .type = VIRTIO_VSOCK_TYPE_STREAM,
+ .msg = msg,
+ .pkt_len = len,
+ };
+
+ return virtio_transport_send_pkt(vsk, &info);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);
+
+void virtio_transport_destruct(struct vsock_sock *vsk)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+
+ kfree(vvs);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_destruct);
+
+static int virtio_transport_send_reset(struct vsock_sock *vsk,
+ struct virtio_vsock_pkt *pkt)
+{
+ struct virtio_vsock_pkt_info info = {
+ .op = VIRTIO_VSOCK_OP_RST,
+ .type = VIRTIO_VSOCK_TYPE_STREAM,
+ };
+
+ /* Send RST only if the original pkt is not a RST pkt */
+ if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
+ return 0;
+
+ return virtio_transport_send_pkt(vsk, &info);
+}
+
+/* Normally packets are associated with a socket. There may be no socket if an
+ * attempt was made to connect to a socket that does not exist.
+ */
+static int virtio_transport_send_reset_no_sock(struct virtio_vsock_pkt *pkt)
+{
+ struct virtio_vsock_pkt_info info = {
+ .op = VIRTIO_VSOCK_OP_RST,
+ .type = le16_to_cpu(pkt->hdr.type),
+ };
+
+ /* Send RST only if the original pkt is not a RST pkt */
+ if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
+ return 0;
+
+ pkt = virtio_transport_alloc_pkt(&info, 0,
+ le32_to_cpu(pkt->hdr.dst_cid),
+ le32_to_cpu(pkt->hdr.dst_port),
+ le32_to_cpu(pkt->hdr.src_cid),
+ le32_to_cpu(pkt->hdr.src_port));
+ if (!pkt)
+ return -ENOMEM;
+
+ return virtio_transport_send_pkt_no_sock(pkt);
+}
+
+static int
+virtio_transport_recv_connecting(struct sock *sk,
+ struct virtio_vsock_pkt *pkt)
+{
+ struct vsock_sock *vsk = vsock_sk(sk);
+ int err;
+ int skerr;
+
+ switch (le16_to_cpu(pkt->hdr.op)) {
+ case VIRTIO_VSOCK_OP_RESPONSE:
+ sk->sk_state = SS_CONNECTED;
+ sk->sk_socket->state = SS_CONNECTED;
+ vsock_insert_connected(vsk);
+ sk->sk_state_change(sk);
+ break;
+ case VIRTIO_VSOCK_OP_INVALID:
+ break;
+ case VIRTIO_VSOCK_OP_RST:
+ skerr = ECONNRESET;
+ err = 0;
+ goto destroy;
+ default:
+ skerr = EPROTO;
+ err = -EINVAL;
+ goto destroy;
+ }
+ return 0;
+
+destroy:
+ virtio_transport_send_reset(vsk, pkt);
+ sk->sk_state = SS_UNCONNECTED;
+ sk->sk_err = skerr;
+ sk->sk_error_report(sk);
+ return err;
+}
+
+static int
+virtio_transport_recv_connected(struct sock *sk,
+ struct virtio_vsock_pkt *pkt)
+{
+ struct vsock_sock *vsk = vsock_sk(sk);
+ struct virtio_vsock_sock *vvs = vsk->trans;
+ int err = 0;
+
+ switch (le16_to_cpu(pkt->hdr.op)) {
+ case VIRTIO_VSOCK_OP_RW:
+ pkt->len = le32_to_cpu(pkt->hdr.len);
+ pkt->off = 0;
+
+ mutex_lock(&vvs->rx_lock);
+ virtio_transport_inc_rx_pkt(vvs, pkt);
+ list_add_tail(&pkt->list, &vvs->rx_queue);
+ mutex_unlock(&vvs->rx_lock);
+
+ sk->sk_data_ready(sk);
+ return err;
+ case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
+ sk->sk_write_space(sk);
+ break;
+ case VIRTIO_VSOCK_OP_SHUTDOWN:
+ if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
+ vsk->peer_shutdown |= RCV_SHUTDOWN;
+ if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
+ vsk->peer_shutdown |= SEND_SHUTDOWN;
+ if (vsk->peer_shutdown == SHUTDOWN_MASK &&
+ vsock_stream_has_data(vsk) <= 0)
+ sk->sk_state = SS_DISCONNECTING;
+ if (le32_to_cpu(pkt->hdr.flags))
+ sk->sk_state_change(sk);
+ break;
+ case VIRTIO_VSOCK_OP_RST:
+ sock_set_flag(sk, SOCK_DONE);
+ vsk->peer_shutdown = SHUTDOWN_MASK;
+ if (vsock_stream_has_data(vsk) <= 0)
+ sk->sk_state = SS_DISCONNECTING;
+ sk->sk_state_change(sk);
+ break;
+ default:
+ err = -EINVAL;
+ break;
+ }
+
+ virtio_transport_free_pkt(pkt);
+ return err;
+}
+
+static int
+virtio_transport_send_response(struct vsock_sock *vsk,
+ struct virtio_vsock_pkt *pkt)
+{
+ struct virtio_vsock_pkt_info info = {
+ .op = VIRTIO_VSOCK_OP_RESPONSE,
+ .type = VIRTIO_VSOCK_TYPE_STREAM,
+ .remote_cid = le32_to_cpu(pkt->hdr.src_cid),
+ .remote_port = le32_to_cpu(pkt->hdr.src_port),
+ };
+
+ return virtio_transport_send_pkt(vsk, &info);
+}
+
+/* Handle server socket */
+static int
+virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt)
+{
+ struct vsock_sock *vsk = vsock_sk(sk);
+ struct vsock_sock *vchild;
+ struct sock *child;
+
+ if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_REQUEST) {
+ virtio_transport_send_reset(vsk, pkt);
+ return -EINVAL;
+ }
+
+ if (sk_acceptq_is_full(sk)) {
+ virtio_transport_send_reset(vsk, pkt);
+ return -ENOMEM;
+ }
+
+ child = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL,
+ sk->sk_type, 0);
+ if (!child) {
+ virtio_transport_send_reset(vsk, pkt);
+ return -ENOMEM;
+ }
+
+ sk->sk_ack_backlog++;
+
+ lock_sock(child);
+
+ child->sk_state = SS_CONNECTED;
+
+ vchild = vsock_sk(child);
+ vsock_addr_init(&vchild->local_addr, le32_to_cpu(pkt->hdr.dst_cid),
+ le32_to_cpu(pkt->hdr.dst_port));
+ vsock_addr_init(&vchild->remote_addr, le32_to_cpu(pkt->hdr.src_cid),
+ le32_to_cpu(pkt->hdr.src_port));
+
+ vsock_insert_connected(vchild);
+ vsock_enqueue_accept(sk, child);
+ virtio_transport_send_response(vchild, pkt);
+
+ release_sock(child);
+
+ sk->sk_data_ready(sk);
+ return 0;
+}
+
+static void virtio_transport_space_update(struct sock *sk,
+ struct virtio_vsock_pkt *pkt)
+{
+ struct vsock_sock *vsk = vsock_sk(sk);
+ struct virtio_vsock_sock *vvs = vsk->trans;
+ bool space_available;
+
+ /* buf_alloc and fwd_cnt is always included in the hdr */
+ mutex_lock(&vvs->tx_lock);
+ vvs->peer_buf_alloc = le32_to_cpu(pkt->hdr.buf_alloc);
+ vvs->peer_fwd_cnt = le32_to_cpu(pkt->hdr.fwd_cnt);
+ space_available = virtio_transport_has_space(vsk);
+ mutex_unlock(&vvs->tx_lock);
+
+ if (space_available)
+ sk->sk_write_space(sk);
+}
+
+/* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
+ * lock.
+ */
+void virtio_transport_recv_pkt(struct virtio_vsock_pkt *pkt)
+{
+ struct sockaddr_vm src, dst;
+ struct vsock_sock *vsk;
+ struct sock *sk;
+
+ vsock_addr_init(&src, le32_to_cpu(pkt->hdr.src_cid),
+ le32_to_cpu(pkt->hdr.src_port));
+ vsock_addr_init(&dst, le32_to_cpu(pkt->hdr.dst_cid),
+ le32_to_cpu(pkt->hdr.dst_port));
+
+ trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
+ dst.svm_cid, dst.svm_port,
+ le32_to_cpu(pkt->hdr.len),
+ le16_to_cpu(pkt->hdr.type),
+ le16_to_cpu(pkt->hdr.op),
+ le32_to_cpu(pkt->hdr.flags),
+ le32_to_cpu(pkt->hdr.buf_alloc),
+ le32_to_cpu(pkt->hdr.fwd_cnt));
+
+ if (le16_to_cpu(pkt->hdr.type) != VIRTIO_VSOCK_TYPE_STREAM) {
+ (void)virtio_transport_send_reset_no_sock(pkt);
+ goto free_pkt;
+ }
+
+ /* The socket must be in connected or bound table
+ * otherwise send reset back
+ */
+ sk = vsock_find_connected_socket(&src, &dst);
+ if (!sk) {
+ sk = vsock_find_bound_socket(&dst);
+ if (!sk) {
+ (void)virtio_transport_send_reset_no_sock(pkt);
+ goto free_pkt;
+ }
+ }
+
+ vsk = vsock_sk(sk);
+
+ virtio_transport_space_update(sk, pkt);
+
+ lock_sock(sk);
+ switch (sk->sk_state) {
+ case VSOCK_SS_LISTEN:
+ virtio_transport_recv_listen(sk, pkt);
+ virtio_transport_free_pkt(pkt);
+ break;
+ case SS_CONNECTING:
+ virtio_transport_recv_connecting(sk, pkt);
+ virtio_transport_free_pkt(pkt);
+ break;
+ case SS_CONNECTED:
+ virtio_transport_recv_connected(sk, pkt);
+ break;
+ default:
+ virtio_transport_free_pkt(pkt);
+ break;
+ }
+ release_sock(sk);
+
+ /* Release refcnt obtained when we fetched this socket out of the
+ * bound or connected list.
+ */
+ sock_put(sk);
+ return;
+
+free_pkt:
+ virtio_transport_free_pkt(pkt);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
+
+void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
+{
+ kfree(pkt->buf);
+ kfree(pkt);
+}
+EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Asias He");
+MODULE_DESCRIPTION("common code for virtio vsock");