From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Rhett Aultman Subject: Domain suspend mechanism Date: Thu, 10 Nov 2005 15:20:01 -0500 Message-ID: <4373AB71.7060903@cise.ufl.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Xen Developers: My name is Rhett Aultman, and I'm a Ph.D student at the University of Florida. I'm taking a class which studies virtual machines, and I'm using Xen for my term project. Specifically, I'm attempting to implement a "wake on LAN" feature in Xen, whereby a domain can be suspended and later restarted if a network packet arrives and would be delivered to the domain had it been running. At the moment, I'm trying to understand how the domain suspension mechanism works. I am fairly sure the codebase I'm using is a recent copy of Xen 3.0 unstable, if that helps. I've found that most of the process of saving a domain to an image file is in the libxc library function called xc_linux_save( ) or something similar, but the actual events going on during suspension do not yet make sense to me. It seems there's a utility function called suspend_and_state( ), and it seems to suspend a target domain...but the only way it seems to do so is by sending the string "suspend" via standard out. How this works, and how the target domain receives the message, I do not understand. Additionally, if anyone here has any advice or opinions on how a "wake on LAN" feature might be implemented, I'm all ears. I've noted that the Xen hypervisor doesn't manage much of the mechanics of a domain's saving and restoration, so the process of bubbling up the information that a packet has arrived for a suspended domain will be...interesting. I'm a total rookie with your codebase, so any advice you could provide would help me. -- Rhett.