Description of problem:
The first hotplug a vcpu to rhel6.3 guest. after then do S4 inside guest. 
the last check guest vcpu number after resume from S4.  guest will lose vcpu of hotplugging.  Since S4 cause different behaviors of windows and rhel guests . So I open this bug. Another bug 808680 is about windows2008r2 guest.  

Version-Release number of selected component (if applicable):
# rpm -qa|grep qemu
qemu-kvm-0.12.1.2-2.267.el6.x86_64

# uname -r
2.6.32-259.el6.x86_64

guest kernel version:
2.6.32-251.el6.x86_64

How reproducible:
100%

Steps to Reproduce:
1.CLI
/usr/libexec/qemu-kvm -M rhel6.3.0 -cpu Opteron_G3,-kvmclock --enable-kvm -m 4G -smp 1,cores=4,sockets=40,threads=1,maxcpus=161 -name rhel6.3 -uuid ddcbfb49-3411-1701-3c36-6bdbc00bedbb -rtc base=utc,clock=host,driftfix=slew -boot c -drive file=/home/rhel6.3-64.qcow2.bak,if=none,id=ide,format=qcow2,cache=none,werror=stop,rerror=stop,boot=on -device ide-drive,drive=ide,id=drive-ide0-0-0,bootindex=1 -netdev tap,id=hostnet1 -device virtio-net-pci,netdev=hostnet1,id=net1,mac=32:12:50:a4:32:74 -spice port=5914,disable-ticketing -vga qxl -device sga -chardev socket,id=serial0,path=/var/test3,server,nowait -device isa-serial,chardev=serial0 -monitor unix:/tmp/monitor4,server,nowait -monitor stdio -qmp tcp:0:6667,server,nowait

2.hot plug a vcpu to guest
cpu_set 1 online

3.do S4 
echo disk >/sys/power/state

4. resume guest 
  
Actual results:
vcpu lost

Expected results:
vcpu don't lose

Additional info: