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virtio/vsock: add support for dgram
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This patch supports dgram in virtio and on the vhost side.

Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Bobby Eshleman <bobby.eshleman@bytedance.com>
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@beshleman @intel-lab-lkp
beshleman authored and intel-lab-lkp committed Aug 15, 2022
1 parent db4515c commit cbb332d
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Showing 6 changed files with 186 additions and 20 deletions.
2 changes: 1 addition & 1 deletion drivers/vhost/vsock.c
View file
Expand Up @@ -925,7 +925,7 @@ static int __init vhost_vsock_init(void)
int ret;

ret = vsock_core_register(&vhost_transport.transport,
VSOCK_TRANSPORT_F_H2G);
VSOCK_TRANSPORT_F_H2G | VSOCK_TRANSPORT_F_DGRAM);
if (ret < 0)
return ret;

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2 changes: 2 additions & 0 deletions include/net/af_vsock.h
View file
Expand Up @@ -78,6 +78,8 @@ struct vsock_sock {
s64 vsock_stream_has_data(struct vsock_sock *vsk);
s64 vsock_stream_has_space(struct vsock_sock *vsk);
struct sock *vsock_create_connected(struct sock *parent);
int vsock_bind_stream(struct vsock_sock *vsk,
struct sockaddr_vm *addr);

/**** TRANSPORT ****/

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1 change: 1 addition & 0 deletions include/uapi/linux/virtio_vsock.h
View file
Expand Up @@ -70,6 +70,7 @@ struct virtio_vsock_hdr {
enum virtio_vsock_type {
VIRTIO_VSOCK_TYPE_STREAM = 1,
VIRTIO_VSOCK_TYPE_SEQPACKET = 2,
VIRTIO_VSOCK_TYPE_DGRAM = 3,
};

enum virtio_vsock_op {
Expand Down
26 changes: 22 additions & 4 deletions net/vmw_vsock/af_vsock.c
View file
Expand Up @@ -675,6 +675,19 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
return 0;
}

int vsock_bind_stream(struct vsock_sock *vsk,
struct sockaddr_vm *addr)
{
int retval;

spin_lock_bh(&vsock_table_lock);
retval = __vsock_bind_connectible(vsk, addr);
spin_unlock_bh(&vsock_table_lock);

return retval;
}
EXPORT_SYMBOL(vsock_bind_stream);

static int __vsock_bind_dgram(struct vsock_sock *vsk,
struct sockaddr_vm *addr)
{
Expand Down Expand Up @@ -2371,11 +2384,16 @@ int vsock_core_register(const struct vsock_transport *t, int features)
}

if (features & VSOCK_TRANSPORT_F_DGRAM) {
if (t_dgram) {
err = -EBUSY;
goto err_busy;
/* TODO: always chose the G2H variant over others, support nesting later */
if (features & VSOCK_TRANSPORT_F_G2H) {
if (t_dgram)
pr_warn("virtio_vsock: t_dgram already set\n");
t_dgram = t;
}

if (!t_dgram) {
t_dgram = t;
}
t_dgram = t;
}

if (features & VSOCK_TRANSPORT_F_LOCAL) {
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2 changes: 1 addition & 1 deletion net/vmw_vsock/virtio_transport.c
View file
Expand Up @@ -850,7 +850,7 @@ static int __init virtio_vsock_init(void)
return -ENOMEM;

ret = vsock_core_register(&virtio_transport.transport,
VSOCK_TRANSPORT_F_G2H);
VSOCK_TRANSPORT_F_G2H | VSOCK_TRANSPORT_F_DGRAM);
if (ret)
goto out_wq;

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173 changes: 159 additions & 14 deletions net/vmw_vsock/virtio_transport_common.c
View file
Expand Up @@ -229,7 +229,9 @@ EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);

static u16 virtio_transport_get_type(struct sock *sk)
{
if (sk->sk_type == SOCK_STREAM)
if (sk->sk_type == SOCK_DGRAM)
return VIRTIO_VSOCK_TYPE_DGRAM;
else if (sk->sk_type == SOCK_STREAM)
return VIRTIO_VSOCK_TYPE_STREAM;
else
return VIRTIO_VSOCK_TYPE_SEQPACKET;
Expand Down Expand Up @@ -287,22 +289,29 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
vvs = vsk->trans;

/* we can send less than pkt_len bytes */
if (pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE)
pkt_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
if (pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
if (info->type != VIRTIO_VSOCK_TYPE_DGRAM)
pkt_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
else
return 0;
}

/* virtio_transport_get_credit might return less than pkt_len credit */
pkt_len = virtio_transport_get_credit(vvs, pkt_len);
if (info->type != VIRTIO_VSOCK_TYPE_DGRAM) {
/* virtio_transport_get_credit might return less than pkt_len credit */
pkt_len = virtio_transport_get_credit(vvs, pkt_len);

/* Do not send zero length OP_RW pkt */
if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
return pkt_len;
/* Do not send zero length OP_RW pkt */
if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
return pkt_len;
}

skb = virtio_transport_alloc_skb(info, pkt_len,
src_cid, src_port,
dst_cid, dst_port,
&err);
if (!skb) {
virtio_transport_put_credit(vvs, pkt_len);
if (info->type != VIRTIO_VSOCK_TYPE_DGRAM)
virtio_transport_put_credit(vvs, pkt_len);
return err;
}

Expand Down Expand Up @@ -586,6 +595,61 @@ virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk,
}
EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue);

static ssize_t
virtio_transport_dgram_do_dequeue(struct vsock_sock *vsk,
struct msghdr *msg, size_t len)
{
struct virtio_vsock_sock *vvs = vsk->trans;
struct sk_buff *skb;
size_t total = 0;
u32 free_space;
int err = -EFAULT;

spin_lock_bh(&vvs->rx_lock);
if (total < len && !skb_queue_empty_lockless(&vvs->rx_queue)) {
skb = __skb_dequeue(&vvs->rx_queue);

total = len;
if (total > skb->len - vsock_metadata(skb)->off)
total = skb->len - vsock_metadata(skb)->off;
else if (total < skb->len - vsock_metadata(skb)->off)
msg->msg_flags |= MSG_TRUNC;

/* sk_lock is held by caller so no one else can dequeue.
* Unlock rx_lock since memcpy_to_msg() may sleep.
*/
spin_unlock_bh(&vvs->rx_lock);

err = memcpy_to_msg(msg, skb->data + vsock_metadata(skb)->off, total);
if (err)
return err;

spin_lock_bh(&vvs->rx_lock);

virtio_transport_dec_rx_pkt(vvs, skb);
consume_skb(skb);
}

free_space = vvs->buf_alloc - (vvs->fwd_cnt - vvs->last_fwd_cnt);

spin_unlock_bh(&vvs->rx_lock);

if (total > 0 && msg->msg_name) {
/* Provide the address of the sender. */
DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);

vsock_addr_init(vm_addr, le64_to_cpu(vsock_hdr(skb)->src_cid),
le32_to_cpu(vsock_hdr(skb)->src_port));
msg->msg_namelen = sizeof(*vm_addr);
}
return total;
}

static s64 virtio_transport_dgram_has_data(struct vsock_sock *vsk)
{
return virtio_transport_stream_has_data(vsk);
}

int
virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
struct msghdr *msg,
Expand All @@ -611,7 +675,66 @@ virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
struct msghdr *msg,
size_t len, int flags)
{
return -EOPNOTSUPP;
struct sock *sk;
size_t err = 0;
long timeout;

DEFINE_WAIT(wait);

sk = &vsk->sk;
err = 0;

if (flags & MSG_OOB || flags & MSG_ERRQUEUE || flags & MSG_PEEK)
return -EOPNOTSUPP;

lock_sock(sk);

if (!len)
goto out;

timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);

while (1) {
s64 ready;

prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
ready = virtio_transport_dgram_has_data(vsk);

if (ready == 0) {
if (timeout == 0) {
err = -EAGAIN;
finish_wait(sk_sleep(sk), &wait);
break;
}

release_sock(sk);
timeout = schedule_timeout(timeout);
lock_sock(sk);

if (signal_pending(current)) {
err = sock_intr_errno(timeout);
finish_wait(sk_sleep(sk), &wait);
break;
} else if (timeout == 0) {
err = -EAGAIN;
finish_wait(sk_sleep(sk), &wait);
break;
}
} else {
finish_wait(sk_sleep(sk), &wait);

if (ready < 0) {
err = -ENOMEM;
goto out;
}

err = virtio_transport_dgram_do_dequeue(vsk, msg, len);
break;
}
}
out:
release_sock(sk);
return err;
}
EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);

Expand Down Expand Up @@ -819,13 +942,13 @@ EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
int virtio_transport_dgram_bind(struct vsock_sock *vsk,
struct sockaddr_vm *addr)
{
return -EOPNOTSUPP;
return vsock_bind_stream(vsk, addr);
}
EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);

bool virtio_transport_dgram_allow(u32 cid, u32 port)
{
return false;
return true;
}
EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);

Expand Down Expand Up @@ -861,7 +984,16 @@ virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
struct msghdr *msg,
size_t dgram_len)
{
return -EOPNOTSUPP;
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_RW,
.msg = msg,
.pkt_len = dgram_len,
.vsk = vsk,
.remote_cid = remote_addr->svm_cid,
.remote_port = remote_addr->svm_port,
};

return virtio_transport_send_pkt_info(vsk, &info);
}
EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);

Expand Down Expand Up @@ -1165,6 +1297,12 @@ virtio_transport_recv_connected(struct sock *sk,
struct virtio_vsock_hdr *hdr = vsock_hdr(skb);
int err = 0;

if (le16_to_cpu(vsock_hdr(skb)->type) == VIRTIO_VSOCK_TYPE_DGRAM) {
virtio_transport_recv_enqueue(vsk, skb);
sk->sk_data_ready(sk);
return err;
}

switch (le16_to_cpu(hdr->op)) {
case VIRTIO_VSOCK_OP_RW:
virtio_transport_recv_enqueue(vsk, skb);
Expand Down Expand Up @@ -1320,7 +1458,8 @@ virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
static bool virtio_transport_valid_type(u16 type)
{
return (type == VIRTIO_VSOCK_TYPE_STREAM) ||
(type == VIRTIO_VSOCK_TYPE_SEQPACKET);
(type == VIRTIO_VSOCK_TYPE_SEQPACKET) ||
(type == VIRTIO_VSOCK_TYPE_DGRAM);
}

/* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
Expand Down Expand Up @@ -1384,6 +1523,11 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
goto free_pkt;
}

if (sk->sk_type == SOCK_DGRAM) {
virtio_transport_recv_connected(sk, skb);
goto out;
}

space_available = virtio_transport_space_update(sk, skb);

/* Update CID in case it has changed after a transport reset event */
Expand Down Expand Up @@ -1415,6 +1559,7 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
break;
}

out:
release_sock(sk);

/* Release refcnt obtained when we fetched this socket out of the
Expand Down

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