libvirt users - Mar 2011 - using more than 1 core by a virtual machine

My virtual machine xml file has <vcpu>2</vcpu>  clause  while the
host has
2 physical cpus (cores).
Is this enough to cause a VM  running 2 endless loop threads  to use the 2 
 cores ?
In my case the VM running reports (cat /roc/cpuinfo) that it has 2 vcpus 
but it uses only 1 core (at a time)  because
the 'top' at the host shows 100%cpu   (out of total 200%)  used by the 
endless loop application 
Also virsh vcpuinfo <vm> shows only 1 CPU and 1 vcpu

any idea ?

thanks

Zvi Dubitzky 
Email:dubi at il.ibm.com

? 2011?03?17? 02:04, Zvi Dubitzky ??:
> My virtual machine xml file has<vcpu>2</vcpu>   clause  while
the host has
> 2 physical cpus (cores).
> Is this enough to cause a VM  running 2 endless loop threads  to use the 2
>   cores ?
> In my case the VM running reports (cat /roc/cpuinfo) that it has 2 vcpus
> but it uses only 1 core (at a time)  because
> the 'top' at the host shows 100%cpu   (out of total 200%)  used by
the
> endless loop application
> Also virsh vcpuinfo<vm>  shows only 1 CPU and 1 vcpu
Is it really only 1 vcpu is showed? it should be two, that's
strange if you specified two vcpus, but only 1 is showed.
and by default, if you don't specify "cpuset" in <vcpu>, it
uses
all the physical cpus, if I'm right, so you should be able to
see something like:

    CPU Affinity:   yy

Could you try specify "cpuset" explicitly like:

<vcpu cpuset="0,1">2</vcpu>

And see what it happens?

Regards
Osier