From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ligesh Subject: Re: Communicating with the domU from dom0 without Network Date: Wed, 9 Aug 2006 05:17:11 +0530 Message-ID: <20060808234711.GA25507@lxlabs.com> References: <20060807124015.GA3365@lxlabs.com> <20060807125754.GG3802@rhun.haifa.ibm.com> <20060807133130.GA4912@lxlabs.com> <20060807133203.GL3802@rhun.haifa.ibm.com> <20060807134906.GA5601@lxlabs.com> <44D767EF.4020003@epoch.ncsc.mil> <1155070472.5293.97.camel@lapbode42.lrr.in.tum.de> Reply-To: Ligesh Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1155070472.5293.97.camel@lapbode42.lrr.in.tum.de> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Daniel Stodden Cc: muli@il.ibm.com, xen-devel@lists.xensource.com, Michael LeMay List-Id: xen-devel@lists.xenproject.org Your arguments are valid in the case of domU-domU communication system, but not for dom0-domU. The dom0 will be, and should be aware of migrations and also there should be non-networking mechanism to manage and control every aspect of domU from dom0. This in my opinion, is a basic requirement. But I think ppp over serial port might be the exact thing what I was looking for. PPP doesn't provide domU-domU, but yes domU-domU actually defeats the entire purpose of Xen which is isolation, and also that Xen should be agnostic about the type of the OS running inside the domU. -- :: Ligesh :: http://ligesh.com On Tue, Aug 08, 2006 at 10:54:32PM +0200, Daniel Stodden wrote: > hi all. > > since you've explicitly asked for comments, here's mine. > > from a performance point of view, it is all obviously correct. get rid > of the tcp congestion/flow/reliability overhead. in a synchronous, > reliable environment like host-local domain intercommunication > infrastructure, as you propose, it is nothing but overhead, and should > speed up things a lot. plus it saves a whole bunch of memory. > > but there's a different point of view, which i would like to point out. > > if you think about the whole 'virtualization' thing, some of the > relevant literature is correct to point out that simple unix process is > nothing but a virtual machine. a 'process vm', in many respects quite > different from a system vm on top of a hypervisor, like xen, though it > already has a number of features which make up a virtual machine. > resource control and abstraction, as an example, being the most > prominent ones. such comparisons are especially daunting if you look at > a paravirtualizing, microkernel-style hypervisor design, like xen is > one. >