From mboxrd@z Thu Jan  1 00:00:00 1970
From: Anthony Liguori <anthony@codemonkey.ws>
Subject: Re: Qemu disaggregation in Xen environment
Date: Mon, 05 Mar 2012 16:20:56 -0600
Message-ID: <4F553C48.8070902@codemonkey.ws>
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To: Julien Grall <julien.grall@citrix.com>
Cc: xen-devel@lists.xensource.com, qemu-devel@nongnu.org, Stefano.Stabellini@eu.citrix.com, julian.pidancet@citrix.com
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On 02/28/2012 05:46 AM, Julien Grall wrote:
> 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...

Why would you want to do this?

Regards,

Anthony Liguori

>
> 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,
>
>