From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: KVM & Xen coexist? Date: Wed, 08 Nov 2006 11:32:06 +0200 Message-ID: <4551A416.1050701@qumranet.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Return-path: To: Jun Koi In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Jun Koi wrote: > hi, > > i guess this question should be in your FAQ: does KVM work with Xen? > in the other word, is it possible to run KVM on Xen machine? (i.e > loading KVM on Dom0 or DomU. obviously it does not work on DomU, but i > am not sure about Dom0 case). > Theoretically, you can run Xen for paravirtualization and kvm for full virtualization. Realistically, that's not trivial to accomplish: - Xen adds an additional addressing abstraction (machine addresses) that kvm has to be taught about - kvm uses privileged instructions which cannot be executed by a Xen guest (and would thus need assists) - VT returns to ring 0, and would need an assist to return to ring 1 where Linux (and kvm) lives - kvm wants to be pinned to a cpu while it's modifying VT state Another option is to use a small subset of kvm to run paravirtualized Xen guests on top of kvm (without Xen itself). -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642