Re: [PATCH 5/5] xen: Add V4V implementation

[Tim Deegan <tim@xen.org>]

At 13:43 +0100 on 13 Aug (1344865403), Jean Guyader wrote:
> Protocol isn't part of the namespace - I think that's
> where the confusion arises. The namespace is exclusively
> Port/Domain. Protocol is there to describe the content of
> _a particular message_ in the ring.

OK.  

In that case, I think the hypervisor shouldn't handle it at all.  That
can be done in the client drivers, and the V4V_PROTO definitions and
maybe packet format stuff can go in documentation.

> It is included in the hypercalls (rather than, say, being the first n
> bytes of all messages) to force all senders to use it.

I don't think that's very useful.  It just forces any V4V user who
doesn't need multiple protocols to make up a number for form's sake, and
since Xen doesn't do any checking on the field, it doesn't protect the
receiver from anything.

I guess what I'm saying is, either 'protocol' (or whatever name you give
it) is part of the v4v addressing, in which case it should be treated
properly and demuxed before port, or it's not, in which case it
needn't be in the interface at all.

Cheers,

Tim.