Subject: Re: [PATCH RFC net-next v5 13/14] virtio/vsock: implement datagram support

From: Arseniy Krasnov <[email-masked]>
Date: Sat, 22 Jul 2023 11:45:29 +0300

On 19.07.2023 03:50, Bobby Eshleman wrote:
> This commit implements datagram support for virtio/vsock by teaching
> virtio to use the general virtio transport ->dgram_addr_init() function
> and implementation a new version of ->dgram_allow().
> 
> Additionally, it drops virtio_transport_dgram_allow() as an exported
> symbol because it is no longer used in other transports.
> 
> Signed-off-by: Bobby Eshleman <[email-masked]>
> ---
>  include/linux/virtio_vsock.h            |  1 -
>  net/vmw_vsock/virtio_transport.c        | 24 +++++++++++++++++++++++-
>  net/vmw_vsock/virtio_transport_common.c |  6 ------
>  3 files changed, 23 insertions(+), 8 deletions(-)
> 
> diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
> index b3856b8a42b3..d0a4f08b12c1 100644
> --- a/include/linux/virtio_vsock.h
> +++ b/include/linux/virtio_vsock.h
> @@ -211,7 +211,6 @@ void virtio_transport_notify_buffer_size(struct vsock_sock *vsk, u64 *val);
>  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);
> -bool virtio_transport_dgram_allow(u32 cid, u32 port);
>  void virtio_transport_dgram_addr_init(struct sk_buff *skb,
>  				      struct sockaddr_vm *addr);
>  
> diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
> index ac2126c7dac5..713718861bd4 100644
> --- a/net/vmw_vsock/virtio_transport.c
> +++ b/net/vmw_vsock/virtio_transport.c
> @@ -63,6 +63,7 @@ struct virtio_vsock {
>  
>  	u32 guest_cid;
>  	bool seqpacket_allow;
> +	bool dgram_allow;
>  };
>  
>  static u32 virtio_transport_get_local_cid(void)
> @@ -413,6 +414,7 @@ static void virtio_vsock_rx_done(struct virtqueue *vq)
>  	queue_work(virtio_vsock_workqueue, &vsock->rx_work);
>  }
>  
> +static bool virtio_transport_dgram_allow(u32 cid, u32 port);

May be add body here? Without prototyping? Same for loopback and vhost.

>  static bool virtio_transport_seqpacket_allow(u32 remote_cid);
>  
>  static struct virtio_transport virtio_transport = {
> @@ -430,6 +432,7 @@ static struct virtio_transport virtio_transport = {
>  
>  		.dgram_enqueue            = virtio_transport_dgram_enqueue,
>  		.dgram_allow              = virtio_transport_dgram_allow,
> +		.dgram_addr_init          = virtio_transport_dgram_addr_init,
>  
>  		.stream_dequeue           = virtio_transport_stream_dequeue,
>  		.stream_enqueue           = virtio_transport_stream_enqueue,
> @@ -462,6 +465,21 @@ static struct virtio_transport virtio_transport = {
>  	.send_pkt = virtio_transport_send_pkt,
>  };
>  
> +static bool virtio_transport_dgram_allow(u32 cid, u32 port)
> +{
> +	struct virtio_vsock *vsock;
> +	bool dgram_allow;
> +
> +	dgram_allow = false;
> +	rcu_read_lock();
> +	vsock = rcu_dereference(the_virtio_vsock);
> +	if (vsock)
> +		dgram_allow = vsock->dgram_allow;
> +	rcu_read_unlock();
> +
> +	return dgram_allow;
> +}
> +
>  static bool virtio_transport_seqpacket_allow(u32 remote_cid)
>  {
>  	struct virtio_vsock *vsock;
> @@ -655,6 +673,9 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
>  	if (virtio_has_feature(vdev, VIRTIO_VSOCK_F_SEQPACKET))
>  		vsock->seqpacket_allow = true;
>  
> +	if (virtio_has_feature(vdev, VIRTIO_VSOCK_F_DGRAM))
> +		vsock->dgram_allow = true;
> +
>  	vdev->priv = vsock;
>  
>  	ret = virtio_vsock_vqs_init(vsock);
> @@ -747,7 +768,8 @@ static struct virtio_device_id id_table[] = {
>  };
>  
>  static unsigned int features[] = {
> -	VIRTIO_VSOCK_F_SEQPACKET
> +	VIRTIO_VSOCK_F_SEQPACKET,
> +	VIRTIO_VSOCK_F_DGRAM
>  };
>  
>  static struct virtio_driver virtio_vsock_driver = {
> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
> index 96118e258097..77898f5325cd 100644
> --- a/net/vmw_vsock/virtio_transport_common.c
> +++ b/net/vmw_vsock/virtio_transport_common.c
> @@ -783,12 +783,6 @@ bool virtio_transport_stream_allow(u32 cid, u32 port)
>  }
>  EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
>  
> -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 = {
> 

Thanks, Arseniy