From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: event notification Date: Mon, 15 Mar 2010 19:25:26 -0400 Message-ID: <20100315232526.GA13116@phenom.dumpdata.com> References: <20100308164727.GA4568@phenom.dumpdata.com> <1268237356.11737.70451.camel@zakaz.uk.xensource.com> <1268293380.11261.53.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1268293380.11261.53.camel@localhost.localdomain> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ian Campbell Cc: ravi kerur , "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On Thu, Mar 11, 2010 at 07:43:00AM +0000, Ian Campbell wrote: > On Wed, 2010-03-10 at 23:20 +0000, ravi kerur wrote: > > Thanks Ian and Konrad. I thought monitoring udev events or xen store > > watch can be done from user-level apps. I am wondering can they be > > used from kernel modules as well? > > xenstore can. I don't think udev can. Of interest might be git commit dfecff0a8934996f381cb5a80c7220ad87830ae9 "commit dfecff0a8934996f381cb5a80c7220ad87830ae9 Author: Konrad Rzeszutek Wilk Date: Thu Nov 5 15:25:40 2009 -0500 xenbus_walk - walk XenStore keys, calling callback. This is quite similar to 'pci_walk_bus.' We walk the XenStore keys, starting at the initial path, calling the callback with each key that has a value. If the callback returns a negative value we stop, clean up, and return the value back. Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Jeremy Fitzhardinge " which you could use to get more details of your XenStore values. (this commit is in Jeremy's Xen tree git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git) > > Ian. > > > > > Thanks > > -RK > > > > On Wed, Mar 10, 2010 at 8:09 AM, Ian Campbell > > wrote: > > On Mon, 2010-03-08 at 16:47 +0000, Konrad Rzeszutek Wilk > > wrote: > > > On Sat, Mar 06, 2010 at 07:12:02PM -0800, ravi kerur wrote: > > > > Hi, > > > > > > > > Is there a mechanism available in Xen such that a kernel > > module in dom0 can > > > > register to it and when a VM(domU) is installed or deleted > > or suspend or > > > > resumed kernel module in domU can send notification to its > > counterpart in > > > > dom0. I have looked into xenbus mechanism used by PV > > drivers and it won't > > > > work for us. Inputs appreciated. > > > > > > You can listen on udev events and see when a vif device has > > been added. > > > Also you can add pieces to the dom0 kernel to send uevents > > when a device > > > is suspended and do something. > > > > > > Attached is a simple program to listen to all uevents.. > > > > > > Also if you are specifically interested in domain > > create/destruction > > (from the hypervisors PoV) then I think you can add a xenstore > > watch on > > "@releaseDomain" and "@introduceDomain". > > > > As far as the hypervisor is concerned things like migration or > > suspend/resume are just domain creation or destruction, the > > "illusion" > > of anything more is provided by the tools. > > > > If you are interested in the creation/suspension/migration/etc > > of > > domains at the toolstack level then it depends which toolstack > > you are > > targeting. > > > > > > > > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel