[libvirt] Problem setting CPU topology

[Doug Goldstein]

On Sat, Jul 7, 2012 at 11:10 AM, Zeeshan Ali (Khattak)
<zeeshanak at gnome.org> wrote:
> Hi,
>    I'm trying to set exact CPU topology to qemu-kvm domains to match
> host's topology. In my case, host topology is: 1 socket, 2 cores and 2
> threads. If I set the XML like this:

<snip>

> The qemu commandline launched for this domain looks like this:
>
> /usr/bin/qemu-kvm -name fedora17-2 -S -M pc-0.15 -cpu
> core2duo,+lahf_lm,+rdtscp,+aes,+popcnt,+sse4.2,+sse4.1,+pdcm,+xtpr,+cx16,+tm2,+est,+smx,+vmx,+ds_cpl,+dtes64,+pclmuldq,+pbe,+tm,+ht,+ss,+acpi,+ds
> -enable-kvm -m 1152 -smp 4,sockets=1,cores=2,threads=2 -uuid

<snip>

>
> Despite the '-smp 4,sockets=1,cores=2,threads=2', I see only 1 CPU
> reported by '/proc/cpuinfo' in the guest F17 live.
>
> However, when I manually launch a very similar commandline,':
>
> /usr/bin/qemu-kvm -name fedora17-2 -M pc-0.15 -cpu
> core2duo,+lahf_lm,+rdtscp,+aes,+popcnt,+sse4.2,+sse4.1,+pdcm,+xtpr,+cx16,+tm2,+est,+smx,+vmx,+ds_cpl,+dtes64,+pclmuldq,+pbe,+tm,+ht,+ss,+acpi,+ds
> -m 1G -smp 4,cores=2,threads=2,sockets=1 -uuid
> c573342b-2876-05b8-098e-6d5314cab062 -nodefconfig -enable-kvm -cdrom
> /home/zeenix/ISOs/Fedora-17-i686-Live-Desktop.iso
>
> I see 4 CPUs reported by '/proc/cpuinfo in the guest. Any clues?

What version of qemu-kvm are you using? Sounds like a bug in
qemu-kvm's command line arg parsing code.


-- 
Doug Goldstein