[CentOS-virt] How does KVM handle multiple cores?

Thu Nov 11 03:29:34 UTC 2010
MargoAndTodd <margoandtodd at gmail.com>

On 11/10/2010 06:59 PM, MargoAndTodd wrote:
> Hi All,
> How does KVM handle multiple cores.  I have an x5650 with 6 real cores
> that presents itself to my OS as 12 virtual cores (hyperthreading).
> Does KVM see 6 or 12 cores.
> And, can I tell KVM how many cores I want it to use?
> Am I misunderstanding how KVM works?
> What I am after is if my guest is 100% busy, I still
> want some power left over for my host.
> Many thanks,
> -T

Found this is the manual page:
       -smp n
            Simulate an SMP system with n CPUs. On the PC target,
            up to 255.   CPUs are supported.

Okay, not very informative.  On my x5650 would that be a
maximum of 6 or 12 processors?