[ovs-dev] table features

[Ben Pfaff]

On Sat, Sep 20, 2014 at 01:27:49AM +0900, YAMAMOTO Takashi wrote:
> it seems master produces table-features with NXM_0, NXM_1,
> and even packet_regs for OF1.3.
> 
> i don't think it's a good idea to include NXM stuff
> because the OF standard doesn't seem to define how to parse them.
> (the size of OXM ids are class-dependant)

I think that there is a bug here: we should be careful to include only
NXM stuff that is not available via OXM.  But I don't think it makes
sense to include only standard fields.  That would defeat much of the
purpose of having an extensible match: it would make it more difficult
for controllers to find out what fields are supported.

The size of OXM ids is not class-dependent, except to the extent that
experimenter OXM ids are 64 bits and the rest are 32 bits.

> packet_regs seems like an OF1.5 stuff which should not be included
> when speaking OF1.3.

We can do that.

I recently posted a series that completely redoes OXM and NXM
handling.  Among other changes, it adds support for experimenter OXM.
I don't know whether it fixes this particular problem.