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Date: Fri, 9 Apr 2010 22:06:51 +0100
From: Jamie Lokier <jamie@shareable.org>
Subject: Re: [Qemu-devel] Re: [libvirt] Libvirt debug API
Message-ID: <20100409210650.GA31666@shareable.org>
References: <4BBF2E93.3020508@redhat.com> <20100409142717.GA11875@redhat.com>
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To: "Daniel P. Berrange" <berrange@redhat.com>
Cc: Libvirt <libvir-list@redhat.com>, Jiri Denemark <jdenemar@redhat.com>, Chris Lalancette <clalance@redhat.com>, qemu-devel@nongnu.org

Daniel P. Berrange wrote:
> I think this alteration of existing args is faaaar too complex & fragile,
> and way overkill.

Would it not be simpler, for the target audience, for the config to
contain a one-line shell script to transform particular matched
arguments in any way that's wanted?

> If the arg that libvirt generates isn't what someone 
> needs, then remove the bit of the guest config responsible for that and
> add a complete extra arg, rather than munging the existing one.

Problem with that: You might want libvirt to think it has a device
that it's controlling, still show in the GUI, still tie up with the
rest of the stack, still do the management setup, but you just want to
change some qemu-specific parameters.  For example,
cache=somethingelse for block devices, iptables=tobedefined for net
devices, usbimplementation=hack for USB devices.

-- Jamie