Re: [PATCH 13/17] Tools: hv: Implement the KVP verb - KVP_OP_SET_IP_INFO

[Ben Hutchings <ben@decadent.org.uk>]

On Mon, Jul 30, 2012 at 06:32:15PM +0000, KY Srinivasan wrote:
> 
> 
> > -----Original Message-----
> > From: Olaf Hering [mailto:olaf@aepfle.de]
> > Sent: Monday, July 30, 2012 2:03 PM
> > To: KY Srinivasan
> > Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org;
> > devel@linuxdriverproject.org; apw@canonical.com; netdev@vger.kernel.org;
> > ben@decadent.org.uk
> > Subject: Re: [PATCH 13/17] Tools: hv: Implement the KVP verb -
> > KVP_OP_SET_IP_INFO
> > 
> > On Tue, Jul 24, K. Y. Srinivasan wrote:
> > 
> > > +	/*
> > > +	 * Set the configuration for the specified interface with
> > > +	 * the information provided. Since there is no standard
> > > +	 * way to configure an interface, we will have an external
> > > +	 * script that does the job of configuring the interface and
> > > +	 * flushing the configuration.
> > > +	 *
> > > +	 * The parameters passed to this external script are:
> > > +	 * 1. A configuration file that has the specified configuration.
> > 
> > Maybe this should be written as 'A info file that has the requested
> > network configuration' or something like that.
> 
> That is the idea. This configuration file simply reflects all the
> information we have perhaps with some additional constant
> information. The script is free to ignore what it does not need. 
[...]

This does not strike me as a sensible interface.  If scripts are
'free to ignore' information then the KVP interface becomes unreliable
as a means for managing networking on Linux guests.  I would suggest
that at the least the script should be able to report that it did not
recognise some parts of the configuration.  This would be logged
and/or reported back to the hypervisor.

(This is separate from the issue of constant configuration lines;
for some distributions the script might recognise but ignore them
because they have no use on that distribution.  I don't see the
point in constant lines, but they don't seem to result in any
unreliability.)

Ben.

-- 
Ben Hutchings
We get into the habit of living before acquiring the habit of thinking.
                                                              - Albert Camus