Re: [PATCH 0/3] Introduce xensock socket and implement sockback and sockfront drivers

[David Vrabel <david.vrabel@citrix.com>]

On 08/08/14 12:32, Oleksandr Dmytryshyn wrote:
> Next series of the patches adds new socket support: xensock.
> Those sockets will be used for the xen-sock frontend/backend
> drivers. Those drivers will allow to connect via xensock
> sockets (in this case dom0/domD sockets can be used for the
> server application and domU sockets can be used for the
> client application). Those sockets are similar to the TCP sockets.
> But there are some limitations. Xensock sockets
> ignore an address and can act only as the stream
> sockets. Only one xensock socket can be opened in the frontend
> side and it will be connected with the single xensock socket
> in the backend side (this link is created automatically by
> frontend and backend driver).

We only want one generic socket-based interdomain communication
mechanism in the kernel and this proposal is lacking in several areas.

* It does not use the existing support for interdomain sockets (AF_VSOCK).

* It it not suitable for a channel between two mutually untrusting peers.

* The single channel to one other domain is insufficient.  Each domain
must be able to support connections to many other domains.

See also a previous discussion.

http://lists.xen.org/archives/html/xen-devel/2013-06/msg01123.html

But note the document has not been updated following the feedback from
that thread.

There is a userspace prototype available:

http://xenbits.xen.org/gitweb/?p=people/dvrabel/idc-prototype.git;a=summary

David