From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Logan Subject: Re: Where can I find some tutorial or manual on how to use xenstore? Date: Thu, 29 Jun 2006 14:53:26 +0100 Message-ID: <44A3DB56.2000509@symantec.com> References: <44A26331.6060200@symantec.com> <20060628130526.GC26663@leeni.uk.xensource.com> <44A28647.3010108@symantec.com> <20060628145724.GA27633@leeni.uk.xensource.com> <44A29E53.4000803@symantec.com> <20060628153219.GC27633@leeni.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20060628153219.GC27633@leeni.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ewan Mellor Cc: xen-devel@lists.xensource.com, jacobg@diku.dk, ushuanglily@gmail.com List-Id: xen-devel@lists.xenproject.org Ewan Mellor wrote: >On Wed, Jun 28, 2006 at 04:20:51PM +0100, Nick Logan wrote: > > > >>Ewan Mellor wrote: >> >> >> >>>On Wed, Jun 28, 2006 at 02:38:15PM +0100, Nick Logan wrote: >>> >>> >>> >>> >>> >>>>The driver was started outside of xend, using a varient of Jacob's >>>>buscreate program to set the necessary values in xenstore. As this a 3rd >>>>party driver, I'm looking for a solution that does not involve xm or >>>>xend changes, if that's possible. I'll take a look at the blktap patches >>>>to see if that helps. >>>> >>>> >>>> >>>> >>>Xend is explicitly bringing the devices back up on restore. If you >>>deliberately bypass it, then you are going to have to do that bringup >>>yourself. >>> >>>Ewan. >>> >>> >>> >>> >>I guessed that would be the case. The bringup for a restore would be >>quite straighforward but more complex for migration. Has anyone >>suggested hooks for xend to deal with 3rd party drivers so that it could >>initialise and restore devices that are supported by these drivers? >>This would enable new drivers to be implemented without changes to xend. >> >> > >One would have to write a device handler that parsed generic config, and then >passed it through to the store unaltered, and then have hotplug scripts that >could cope with this unparsed config. At the moment, the driver backends do >special-case things like generating a MAC address when none is supplied, >converting device names to their major:minor, that kind of thing. There isn't >a generic device path; adding one wouldn't be hard. > >Ewan. > > Can I just confirm what your proposal is: Add a generic device config to the xm config file that would contain the driver id, virtual device, physical device ..... Add a generic device handler to xend that would pass the unparsed generic config through to xenstore. Add a hotplug script that would parse the unparsed config in xenstore and start the driver. When saving a domain, xend would save the generic device config. xend would call restore for the generic devices. If that's correct, I'll find some time to investigate how this could done. Nick