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

[Bobby Eshleman]

On Thu, Jul 27, 2023 at 11:09:21AM +0300, Arseniy Krasnov wrote:
> 
> 
> On 26.07.2023 20:58, Bobby Eshleman wrote:
> > On Sat, Jul 22, 2023 at 11:45:29AM +0300, Arseniy Krasnov wrote:
> >>
> >>
> >> 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 <bobby.eshleman@xxxxxxxxxxxxx>
> >>> ---
> >>>  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.
> >>
> > 
> > Sounds okay with me, but this seems to go against the pattern
> > established by seqpacket. Any reason why?
> 
> Stefano Garzarella <sgarzare@xxxxxxxxxx> commented my patch with the same approach:
> 
> https://lore.kernel.org/netdev/lex6l5suez7azhirt22lidndtjomkbagfbpvvi5p7c2t7klzas@4l2qly7at37c/
> 
> Thanks, Arseniy
> 

Gotcha, sounds good.

Thanks,
Bobby
> 
> > 
> >>>  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
> > 
> > Thanks,
> > Bobby