[libvirt] How to config my VM to use KVM with libvirt?

[Daniel P. Berrange]

On Tue, Jul 21, 2009 at 09:46:17AM -0400, Jim Paris wrote:
> Daniel P. Berrange wrote:
> > On Tue, Jul 21, 2009 at 05:47:15PM +0900, Jun Koi wrote:
> > > Hi,
> > > 
> > > I have a VM running under libvirt, and it is currently run with
> > > -no-kvm option (I saw that in "ps" output).
> > > Now I want to run this VM with KVM. How can I reconfigure it for that?
> > > 
> > > I looked into its configuration file under /etc/libvirt/qemu, but
> > > didnt see any option to turn KVM on.
> > 
> > Run 'virsh edit GUEST'  and on the top <domain> element, change the
> > type attribute to be 'kvm' instead of 'qemu'.
> 
> Speaking of this, I've noticed that
> 
> <domain type='qemu'>
>   <os>
>     <type arch='i686' machine='pc'>hvm</type>
>   </os>
> </domain>
> 
> runs WITH kvm on an x86_64 system.  Is that intended?

No, its not intended !

> It seems that this comment in qemu_conf.c:
> 
>     /* Need to explicitly disable KVM if
>      * 1. Arch matches host arch
>      * 2. Guest domain is 'qemu'
>      * 3. The qemu binary has the -no-kvm flag
>      */
> 
> might need to expand #1 to consider i686 == x86_64?

I'm actually wondering why we bother with #1 at all. If the
binary has '-no-kvm' and the domain is 'qemu', then it should
be used no matter what arch.

Regards,
Daniel
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