From mboxrd@z Thu Jan  1 00:00:00 1970
From: George Dunlap <george.dunlap@eu.citrix.com>
Subject: Re: RFC: removing hardcoded "modprobe blktap" in
	xencommons
Date: Mon, 15 Jul 2013 15:08:00 +0100
Message-ID: <51E40240.5010108@eu.citrix.com>
References: <20130712161255.GB4409@zion.uk.xensource.com>
	<51E3AD9C02000078000E4C9D@nat28.tlf.novell.com>
	<20130715073309.GA25286@zion.uk.xensource.com>
	<51E3C49502000078000E4D3D@nat28.tlf.novell.com>
	<20130715082656.GC25286@zion.uk.xensource.com>
	<51E3DE2A02000078000E4DCC@nat28.tlf.novell.com>
	<20130715093845.GA28802@zion.uk.xensource.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
In-Reply-To: <20130715093845.GA28802@zion.uk.xensource.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>, Jan Beulich <JBeulich@suse.com>, xen-devel@lists.xen.org
List-Id: xen-devel@lists.xenproject.org

On 15/07/13 10:38, Wei Liu wrote:
> On Mon, Jul 15, 2013 at 10:34:02AM +0100, Jan Beulich wrote:
>>>>> On 15.07.13 at 10:26, Wei Liu <wei.liu2@citrix.com> wrote:
>>> So my point is, if every driver follows the kernel convention
>>> (open(/dev/XYZ) would cause the module to load automatically) there then
>>> would be minimal changes to libxl. It is unmaintained kernel modules
>>> like blktap makes it not feasible to make things simplier.
>>>
>>> (Wild guess below, correct me if I'm wrong)
>>>
>>> Say, if we could make it just like open(blkback_char_dev), the loading
>>> is just a one-liner and doesn't need to be using libxl's AO interface.
>> Once again - most if not all backends don't fit that model - blktap
>> as said doesn't and neither blkback nor netback don't as they don't
>> create any /dev nodes.
>>
> OK, I get what you mean.
>
>> Backend module loading might be triggerable through xenstore
>> node watches...
>>
> Sure.

If we did something like this, we'd still have to have the modprobes in 
xencommons for older kernels; we'd just have to have a way to disable it 
for newer kernels.

  -George