This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-devel] [PATCH] xl: Special case tap/aio for disk validation

To: Jim Fehlig <jfehlig@xxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] xl: Special case tap/aio for disk validation
From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Date: Fri, 28 Jan 2011 17:51:30 +0000
Cc: Kamala Narasimhan <kamala.narasimhan@xxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>, "Kamala Narasimhan \(3P\)" <kamala.narasimhan@xxxxxxxxxx>, Stefano Stabellini <Stefano.Stabellini@xxxxxxxxxxxxx>
Delivery-date: Fri, 28 Jan 2011 09:50:42 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <4D42F437.7070107@xxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <4D407A06.1050902@xxxxxxxxx> <alpine.DEB.2.00.1101271506410.7277@kaball-desktop> <4D41EE90.5000907@xxxxxxxxx> <4D42E8B9.9060901@xxxxxxxxxx> <alpine.DEB.2.00.1101281623010.7277@kaball-desktop> <4D42F437.7070107@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Alpine 2.00 (DEB 1167 2008-08-23)
On Fri, 28 Jan 2011, Jim Fehlig wrote:
> Currently, IIUC, the external script is invoked by udev
> SUBSYSTEM=="xen-backend", KERNEL=="tap*", RUN+="/etc/xen/scripts/blktap
> $env{ACTION}"
> SUBSYSTEM=="xen-backend", KERNEL=="vbd*", RUN+="/etc/xen/scripts/block
> $env{ACTION}"
> The block script will delegate to a helper if needed, which configures
> the block device and writes some info (like resulting dev node) to
> xenstore.  xend and/or qemu then read the info and continue configuring
> the device from backend perspective.

When we add support for this to xl we are probably going to execute
these scripts directly. Having udev doing it for us doesn't simplify

> > It shouldn't be too difficult but still non-trivial at this point of the
> > release cycle.
> > Maybe users could work around the lack of support in 4.1 calling the
> > script themselves and using the name of the block device in the VM
> > config file directly?
> >   
> Yes, this is certainly a workaround.  One could argue this is the proper
> solution and remove support for external block scripts.  But this
> functionality has been around for years.

I think it is the best we can do for 4.1, given the timeframe available.

Xen-devel mailing list