Description of problem:
boot guest with -smp 2,cores=1,threads=1,sockets=2, can not find the following info in /proc/cpuinfo: 
physical id, sibling, core id, cpu cores, apicid, initial apicid 

Version-Release number of selected component (if applicable):
qemu-kvm-0.12.1.2-2.160.el6.x86_64

How reproducible:
100%

Steps to Reproduce:
1. qemu-kvm -drive file='/home/images/RHEL-Server-6.0-32.qcow2',index=0,if=none,id=drive-ide0-0-0,media=disk,cache=none,format=qcow2,aio=native  \
-device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0  \
-device rtl8139,netdev=id4OXOGd,mac=9a:1e:2e:66:5f:5e,id=ndev00id4OXOGd,bus=pci.0,addr=0x3 -netdev tap,id=id4OXOGd,ifname='t0-154349-bu7b',script='/home/scripts/qemu-ifup-switch',downscript='no' -m 2048 \
-smp 2,cores=1,threads=1,sockets=2 -cpu cpu64-rhel6,+sse2,+x2apic \
-vnc :0 -rtc base=utc,clock=host,driftfix=none -M rhel6.1.0 -boot order=cdn,once=c,menu=off -usbdevice tablet -no-kvm-pit-reinjection -enable-kvm
2.
3.
  
Actual results:

"physical id, sibling, core id, cpu cores, apicid, initial apicid" info lost .

processor	: 1
vendor_id	: GenuineIntel
cpu family	: 6
model		: 13
model name	: QEMU Virtual CPU version (cpu64-rhel6)
stepping	: 3
cpu MHz		: 1995.154
cache size	: 4096 KB
fdiv_bug	: no
hlt_bug		: no
f00f_bug	: no
coma_bug	: no
fpu		: yes
fpu_exception	: yes
cpuid level	: 4
wp		: yes
flags		: fpu de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pse36 clflush mmx fxsr sse sse2 syscall nx lm unfair_spinlock pni cx16 x2apic hypervisor lahf_lm
bogomips	: 3990.30
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:


Expected results:


Additional info:

1. work well while boot guest with cores or threads > 1