From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54402) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S2LWr-0002n5-B7 for qemu-devel@nongnu.org; Tue, 28 Feb 2012 06:47:43 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S2LWl-0003nu-3i for qemu-devel@nongnu.org; Tue, 28 Feb 2012 06:47:36 -0500 Received: from smtp.citrix.com ([66.165.176.89]:7227) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S2LWk-0003nD-Vh for qemu-devel@nongnu.org; Tue, 28 Feb 2012 06:47:31 -0500 Message-ID: <4F4CBE85.5000006@citrix.com> Date: Tue, 28 Feb 2012 11:46:13 +0000 From: Julien Grall MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Qemu disaggregation in Xen environment List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: xen-devel@lists.xensource.com, julian.pidancet@citrix.com, Stefano.Stabellini@eu.citrix.com Hello, In the current model, only one instance of qemu is running for each running HVM domain. We are looking at disaggregating qemu to have, for example, an instance to emulate only network controllers, another to emulate block devices, etc... Multiple instances of qemu would run for a single Xen domain. Each one would handle a subset of the hardware. Has someone already looked at it and potentially already submitted code for qemu ? The purpose of this e-mail is to start a discussion and gather opinions on how the qemu developers community would like to see it implemented. A couple of questions comes to mind: 1) How hard would it be to untangle "machine" specific (PC hardware) emulation from "device" specific emulation (PCI devices) ? 2) How can we achieve disaggregation from a configuration point of view. Currently, Xen toolstack starts qemu, and tells qemu which device to emulate using the command line. I've heard about a project for creating machine description configuration files for QEMU which could help greatly in dividing up which hardware to emulate in which instance of qemu. What is the status of this project ? Thank you for your answers, From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Qemu disaggregation in Xen environment Date: Tue, 28 Feb 2012 11:46:13 +0000 Message-ID: <4F4CBE85.5000006@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org To: qemu-devel@nongnu.org Cc: xen-devel@lists.xensource.com, julian.pidancet@citrix.com, Stefano.Stabellini@eu.citrix.com List-Id: xen-devel@lists.xenproject.org Hello, In the current model, only one instance of qemu is running for each running HVM domain. We are looking at disaggregating qemu to have, for example, an instance to emulate only network controllers, another to emulate block devices, etc... Multiple instances of qemu would run for a single Xen domain. Each one would handle a subset of the hardware. Has someone already looked at it and potentially already submitted code for qemu ? The purpose of this e-mail is to start a discussion and gather opinions on how the qemu developers community would like to see it implemented. A couple of questions comes to mind: 1) How hard would it be to untangle "machine" specific (PC hardware) emulation from "device" specific emulation (PCI devices) ? 2) How can we achieve disaggregation from a configuration point of view. Currently, Xen toolstack starts qemu, and tells qemu which device to emulate using the command line. I've heard about a project for creating machine description configuration files for QEMU which could help greatly in dividing up which hardware to emulate in which instance of qemu. What is the status of this project ? Thank you for your answers,