[ovs-dev] [PATCH] vswitch.ovsschema: A new column, 'kmod_version' in Open_vSwitch table.

[Ben Pfaff]

On Wed, Oct 16, 2013 at 01:55:41PM -0700, Gurucharan Shetty wrote:
> The new column 'kmod_version' will be used by ovs-ctl to set the
> kernel module version that ovs-vswitchd will be interacting with.
> This column can be quite useful for remote systems to figure out
> any discrepancies in the kernel module version being used in all
> of the hypervisors under its domain.
> 
> Signed-off-by: Gurucharan Shetty <gshetty at nicira.com>

It would be better if we could avoid adding to the database columns
that assume some particular underlying datapath.  Right now most of
the OVS installations use the linux kernel datapath, but there are
exceptions already (e.g. FreeBSD/NetBSD and ASICs) and we'll probably
have more in the future (e.g. DPDK integration).

So to me that points to naming this something more like
"datapath_version", which is a more generic concept.  But once we do
that, it should become a per-Bridge concept.  And once we get to that
point, we've already got a suitable place to put it, the OFPST_DESC
message handled by handle_desc_stats_request() in ofproto.c.  Can we
put datapath-defined info into one of those fields, and for the Linux
datapath supply the module version in it?