[libvirt] Problem setting CPU topology

[Zeeshan Ali (Khattak)]

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:

<domain type='kvm'>
  ..
  <vcpu placement='static'>4</vcpu>
  <os>
    <type arch='i686' machine='pc-0.15'>hvm</type>
    <boot dev='hd'/>
  </os>
  <cpu mode='host-model'>
    <model fallback='allow'/>
    <topology sockets='1' cores='2' threads='2'/>
  </cpu>
..

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
c573342b-2876-05b8-098e-6d5314cab062 -nodefconfig -nodefaults -chardev
socket,id=charmonitor,path=/home/zeenix/.config/libvirt/qemu/lib/fedora17-2.monitor,server,nowait
-mon chardev=charmonitor,id=monitor,mode=control -rtc
base=utc,driftfix=slew -no-kvm-pit-reinjection -no-shutdown -no-acpi
-device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -device
virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5 -drive
file=/home/zeenix/.local/share/gnome-boxes/images/fedora17-2,if=none,id=drive-virtio-disk0,format=qcow2,cache=none
-device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x6,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1
-drive file=/extra-data/ISOs/Fedora-17-i686-Live-Desktop.iso,if=none,id=drive-ide0-1-0,readonly=on,format=raw
-device ide-cd,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0
-netdev user,id=hostnet0 -device
rtl8139,netdev=hostnet0,id=net0,mac=52:54:00:21:6f:6e,bus=pci.0,addr=0x3
-chardev pty,id=charserial0 -device
isa-serial,chardev=charserial0,id=serial0 -chardev
spicevmc,id=charchannel0,name=vdagent -device
virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.spice.0
-device usb-tablet,id=input0 -spice
port=5900,addr=127.0.0.1,disable-ticketing -vga qxl -global
qxl-vga.vram_size=67108864 -device AC97,id=sound0,bus=pci.0,addr=0x4
-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x7

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?

-- 
Regards,

Zeeshan Ali (Khattak)
FSF member#5124