libvirt users - Jul 2013 - Changing CPU cache size of guest

Hi everybody,

Using libvirt 1.0.0 how does one change the L2 cache size of the virtual
CPU?  I can change the CPU model but the cache size never changes:

<cpu mode='host-passthrough'/>
<model>Nehalem</model>

OR

<cpu match='exact' mode='custom'/>
<model>Nehalem</model>

Is there a qemu requirement?

-- 
peter matulis

On 07/19/2013 09:34 AM, Peter Matulis wrote:
> Hi everybody,
> 
> Using libvirt 1.0.0 how does one change the L2 cache size of the virtual
> CPU?  I can change the CPU model but the cache size never changes:
> 
> <cpu mode='host-passthrough'/>
> <model>Nehalem</model>
> 
> OR
> 
> <cpu match='exact' mode='custom'/>
> <model>Nehalem</model>
> 
> Is there a qemu requirement?
As far as I know, qemu does not expose a command line option that lets
you determine the size of the L2 cache that the guest will see; as long
as qemu doesn't have the knob, then libvirt can't expose the knob in
XML.  So yes, you'd have to implement it in qemu first.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org