Re: [RFC PATCH v9 14/19] virtio/vsock: enable SEQPACKET for transport

[Arseny Krasnov]

On 13.05.2021 15:49, Stefano Garzarella wrote:
> On Sat, May 08, 2021 at 07:36:14PM +0300, Arseny Krasnov wrote:
>> This adds
>> 1) SEQPACKET ops for virtio transport and 'seqpacket_allow()' callback.
>> 2) Handling of SEQPACKET bit: guest tries to negotiate it with vhost.
>>
>> Signed-off-by: Arseny Krasnov <arseny.krasnov@xxxxxxxxxxxxx>
>> ---
>> v8 -> v9:
>> 1) Move 'seqpacket_allow' to 'struct virtio_vsock'.
>>
>> net/vmw_vsock/virtio_transport.c | 25 +++++++++++++++++++++++++
>> 1 file changed, 25 insertions(+)
>>
>> diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
>> index 2700a63ab095..f714c16af65d 100644
>> --- a/net/vmw_vsock/virtio_transport.c
>> +++ b/net/vmw_vsock/virtio_transport.c
>> @@ -62,6 +62,7 @@ struct virtio_vsock {
>> 	struct virtio_vsock_event event_list[8];
>>
>> 	u32 guest_cid;
>> +	bool seqpacket_allow;
>> };
>>
>> static u32 virtio_transport_get_local_cid(void)
>> @@ -443,6 +444,8 @@ static void virtio_vsock_rx_done(struct virtqueue *vq)
>> 	queue_work(virtio_vsock_workqueue, &vsock->rx_work);
>> }
>>
>> +static bool virtio_transport_seqpacket_allow(u32 remote_cid);
>> +
>> static struct virtio_transport virtio_transport = {
>> 	.transport = {
>> 		.module                   = THIS_MODULE,
>> @@ -469,6 +472,10 @@ static struct virtio_transport virtio_transport = {
>> 		.stream_is_active         = virtio_transport_stream_is_active,
>> 		.stream_allow             = virtio_transport_stream_allow,
>>
>> +		.seqpacket_dequeue        = virtio_transport_seqpacket_dequeue,
>> +		.seqpacket_enqueue        = virtio_transport_seqpacket_enqueue,
>> +		.seqpacket_allow          = virtio_transport_seqpacket_allow,
>> +
>> 		.notify_poll_in           = virtio_transport_notify_poll_in,
>> 		.notify_poll_out          = virtio_transport_notify_poll_out,
>> 		.notify_recv_init         = virtio_transport_notify_recv_init,
>> @@ -485,6 +492,19 @@ static struct virtio_transport virtio_transport = {
>> 	.send_pkt = virtio_transport_send_pkt,
>> };
>>
>> +static bool virtio_transport_seqpacket_allow(u32 remote_cid)
>> +{
>> +	struct virtio_vsock *vsock;
>> +	bool seqpacket_allow;
>> +
>> +	rcu_read_lock();
>> +	vsock = rcu_dereference(the_virtio_vsock);
>> +	seqpacket_allow = vsock->seqpacket_allow;
>> +	rcu_read_unlock();
>> +
>> +	return seqpacket_allow;
>> +}
>> +
>> static void virtio_transport_rx_work(struct work_struct *work)
>> {
>> 	struct virtio_vsock *vsock =
>> @@ -612,6 +632,10 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
>> 	rcu_assign_pointer(the_virtio_vsock, vsock);
>>
>> 	mutex_unlock(&the_virtio_vsock_mutex);
>> +
>> +	if (vdev->features & (1ULL << VIRTIO_VSOCK_F_SEQPACKET))
> We should use virtio_has_feature() to check the device features.
>
>> +		vsock->seqpacket_allow = true;
> When we assign the_virtio_vsock pointer, we should already set all the 
> fields, so please move this code before the following block:
>
> 	# here
>
> 	vdev->priv = vsock;
> 	rcu_assign_pointer(the_virtio_vsock, vsock);
Ack
>
>