DDS over virtio-vsock (AF_VSOCK)

[MatiasVara]

Hello, I worked on adding the AF_VSOCK as a new transport layer. This is an interesting use-case since clients can run on top of a guest OS without TCP/IP stack or network card. I am attaching the patches but this is much less than a PoC. It works for transmitting a string that says "Hello World" between two guests. This also requires socat in the host as a bridge. I think this work may inspire someone.

Regards,

cyclonedds-pub.xml.txt cyclonedds-sub.xml.txt patchforpublisher.patch.txt patchforsubscriber.patch.txt

[eboasson]

Thanks for suggesting this and showing that it can be made to do "something" fairly easily, @MatiasVara ! And I'm pretty sure this less-than-a-PoC bit works for a lot more than "Hello World" already, as just sending "Hello World" already requires quite a bit of stuff to work.

Never heard of the entire mechanism, but my first impression is that it would allow some interesting use cases with little effort. I don't have the time to dive into it right now, but I'll definitely leave upon the issue as a reminder to myself that something interesting can be done here and I will try to look into it with a bit more care to see how much work it would be to turn it into a viable PR. If it is not too much, perhaps you'd be willing to contribute it?

[MatiasVara]

I would love to contribute but I am having little time to do so. I am afraid that I did not give too many instructions to reproduce, I will add that soon (I think I have a video somewhere). I think a more serious implementation shall be based on udp. I think virtio-vsock just added support for this. However, this would still require some bridge in the host to forward packets between the guests. Note that virtio-vsock only allows communication from/to host. This is why I used socat as a proxy between the guests. A simpler approach would be to let the user define where the server is, i.e. without a discovery mechanism. This is what I did in my PoC. I simply rely on the tcp implementation.

[thijsmie]

We'd still love for you, MatiasVara, to contribute this, or someone else to pick this up. However, I am closing this now since it has been inactive for a while. If anyone wants to work on this, feel free to re-open/create a new ticket.

[MatiasVara]

@thijsmie I might start again to work on this on the coming months. Is someone interested? There have been some improvements in the virtio-vsock that would allow to:

1. use DGRAM instead of STREAM
2. communicate between VM thus removing the need of socat.

There is still the issue of discovering since vsock does not support something like BROADCASTING.

[thijsmie]

Hi there! Sounds good, and nice to know you are still interested! I am no longer affiliated with this project so maybe @eboasson can help you out where needed :)

[eboasson]

I am always here to help :)

And I can only second @thijsmie's comment, this would be a really neat. If you want to bounce ideas or need someone to think along, ping me here or on discord. If I don't respond within a reasonable time-frame, just try again ☺️

[MatiasVara]

@eboasson I would like to understand if there is a use-case in which using virtio-vsock as a transport layer may have benefits over virtio-net or other network card.