From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from [140.186.70.92] (port=48542 helo=eggs.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1OOR7l-0001qn-Rb
	for qemu-devel@nongnu.org; Tue, 15 Jun 2010 04:03:58 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69)
	(envelope-from <amit.shah@redhat.com>) id 1OOR7k-0007UN-BJ
	for qemu-devel@nongnu.org; Tue, 15 Jun 2010 04:03:57 -0400
Received: from mx1.redhat.com ([209.132.183.28]:36654)
	by eggs.gnu.org with esmtp (Exim 4.69)
	(envelope-from <amit.shah@redhat.com>) id 1OOR7k-0007UI-4j
	for qemu-devel@nongnu.org; Tue, 15 Jun 2010 04:03:56 -0400
Received: from int-mx08.intmail.prod.int.phx2.redhat.com
	(int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.21])
	by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o5F83tvV001691
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK)
	for <qemu-devel@nongnu.org>; Tue, 15 Jun 2010 04:03:55 -0400
Date: Tue, 15 Jun 2010 13:35:35 +0530
From: Amit Shah <amit.shah@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v2] net: Fix hotplug with pci_add
Message-ID: <20100615080535.GB20578@amit-laptop.redhat.com>
References: <356ef9bdde008d695e7c75dd1566222d6160d4b6.1276011638.git.amit.shah@redhat.com>
	<m3zkz55vsz.fsf@blackfin.pond.sub.org>
	<20100608172525.GB10305@amit-laptop.redhat.com>
	<m3pr00pv89.fsf@blackfin.pond.sub.org>
	<20100609095811.GB20595@amit-laptop.redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20100609095811.GB20595@amit-laptop.redhat.com>
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Markus Armbruster <armbru@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>, Gerd Hoffmann <kraxel@redhat.com>, qemu list <qemu-devel@nongnu.org>

On (Wed) Jun 09 2010 [15:28:11], Amit Shah wrote:
> > Let me rephrase: Behavior changes for -net types without an init()
> > method.  The only one without an init() method is "none".  Before,
> > net_client_init() succeeded for it.  Now it fails.  What's the impact of
> > that change?  And why does it make sense?
> 
> It makes sense because we don't actually initialise anything. We don't
> place anything in the nd_table[] array. That means callers shouldn't
> poke in the array for any values. Returning -1 makes sense for that
> reason. If we continued to return 0, callers might just assume that init
> was successful and that nd_table[0] was set up for use appropriately.
> 
> The thing is that the code doesn't go this far in case of '-net none'
> anyway. This was just a potential bug lurking around for any new -net
> method which didn't have an init.

Hm, I only tested -net none from the monitor, using pci_add. Looks like
I skipped testing it from the cmd line. I did that today and found out
the VM doesn't start. I've sent a patch to revert to the original
behaviour of returning 0, and we'll have to find another way of fixing
the 'success or index' return problem.

		Amit