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

Arseniy Krasnov
2023-07-27T08:10:35Z

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@bytedance.com>
>>> ---
>>> 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@redhat.com> commented my patch with the same approach:

https://lore.kernel.org/netdev/lex6l5suez7azhirt22lidndtjomkbagfbpvvi5p7c2t7klzas@4l2qly7at37c/

Thanks, Arseniy

>
>>> 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