Re: [Xen-users] How to setup Xen guest

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

On Wed, 2016-01-20 at 05:20 +0000, Zhang, Chunyu wrote:
> hi peter
> > Peter Teoh schrieb:
> > 
> > > Now my question - same as before, is why is qemu-system-i386 running?
> > > And so it is emulating my 64-bit Ubuntu and CentOS?
> > 
> > qemu-system-i386 just emulates some *devices* you are using inside your
> > HVM. It does not need to emulate another CPU, since the code is simply 
> > run in another VM on your CPU. So it does not matter whether you use 
> > quemu-system-i386 or qemu-system-x86_64.

FYI as well as emulated devices the QEMU can also provide some PV backends,
specifically qdisk is the one used to provide a PV disk backend for qcow2
based images

In fact even on ARM the qemu binary (which only provides PV services, since
there is no HVM on ARM) is still called qemu-system-i386.

As you say the qemu in a Xen system does no processor emulation, only
device emulation, but QEMU can't be configured to have no CPU so we needed
to pick one.

> there are 2 qemuï
> - -xen-domid 0 -xen-attach -name dom0
> - -xen-domid 3
> 
> qemu domain 3 justÂÂemulates some *devices*ï
> but qemu domain0 is for whatï

It provides PV backends to dom0, specifically qdisk for loopback mount
(e.g. for running pygrub on a qcow2 image).

Ian.
=

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxx
http://lists.xen.org/xen-users