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] Deficiencies in guest bootloader design

To: Anthony Liguori <aliguori@xxxxxxxxxx>
Subject: Re: [Xen-devel] Deficiencies in guest bootloader design
From: Ewan Mellor <ewan@xxxxxxxxxxxxx>
Date: Thu, 13 Apr 2006 16:36:17 +0100
Cc: Michael Paesold <mpaesold@xxxxxx>, Xen Devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Thu, 13 Apr 2006 08:36:38 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <443E6D3C.3080802@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/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <014901c65f06$a9501c80$d801a8c0@zaphod> <20060413151044.GB23641@xxxxxxxxxxxxxxxxxxxxxx> <443E6D3C.3080802@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.9i
On Thu, Apr 13, 2006 at 10:24:44AM -0500, Anthony Liguori wrote:

> Ewan Mellor wrote:
> >On Thu, Apr 13, 2006 at 04:29:23PM +0200, Michael Paesold wrote:
> >
> >  
> >>I have tried to use a dynamically activated block device with pygrub 
> >>(actually drbd, but could be enbd, nbd, or simply any vbd other than phy: 
> >>or file:). That does not work.
> >>
> >>The problem is that the bootloader is not called from Xend, after virtual 
> >>block devices are setup, but instead it is called directly from xm, i.e. 
> >>in xm/create.py.
> >>
> >>If I have looked correctly, (1) a bootloader cannot be used for devices 
> >>such as nbd: or enbd: devices, and (2) a bootloader cannot be used when 
> >>accessing Xend via XML-RPC (or libvirt or similar), because the whole 
> >>notion of a "bootloader" at domain creation time is only available in 
> >>"xm", but not in Xend.
> >>
> >>It should be fixable, since at least on guest *restart*, 
> >>xend/XendDomainInfo.py already uses the bootloader to re-extract the 
> >>kernel image from the vbd.
> >>
> >>Is there anyone working on bootloader improvements? If not, is a change 
> >>to move the bootloader stuff from xm to Xend acceptable? In that case I 
> >>could try to come up with a patch.
> >>    
> >
> >Certainly such a patch would be accepted.
> >  
> Just as a warning, it's not going to be simple to run something like 
> pygrub from Xend.  The reason it runs from xm now is that it needs to 
> interact with the user.  If it were launched from Xend, it need to find 
> a way to attach to a PTY that xenconsoled would use so that it can 
> display the text over the normal console before actually launching the 
> domain.
> It's certainly not impossible but it touches quite a few things.

So how _is_ the virtual frame buffer coming along?  ;-)


Xen-devel mailing list