[libvirt] [Question] qemu cpu pinning

[KAMEZAWA Hiroyuki]

Hi,

When I run a VM(qemu-0.13) on my host with the latest libvirt,

I used following settings.
==
<domain type='kvm' id='1'>
  <name>RHEL6</name>
  <uuid>f7ad6bc3-e82a-1254-efb0-9e1a87d83d88</uuid>
  <memory>2048000</memory>
  <currentMemory>2048000</currentMemory>
  <vcpu cpuset='4-7'>2</vcpu>
==

I expected all works for this domain will be tied to cpu 4-7.

After minites, I checked the VM behavior and it shows
==
[root at bluextal src]# cat /cgroup/cpuacct/libvirt/qemu/RHEL6/cpuacct.usage_percpu
0 511342 3027636 94237 657712515 257104928 513463748303 252386161
==

Hmm, cpu 1,2,3 are used for some purpose.

All threads for this qemu may be following.
==
[root at bluextal src]# cat /cgroup/cpuacct/libvirt/qemu/RHEL6/tasks
25707
25727
25728
25729
==

And I found
==
[root at bluextal src]# grep Cpus /proc/25707/status
Cpus_allowed:   f0
Cpus_allowed_list:      4-7
[root at bluextal src]# grep Cpus /proc/25727/status
Cpus_allowed:   ff
Cpus_allowed_list:      0-7
[root at bluextal src]# grep Cpus /proc/25728/status
Cpus_allowed:   f0
Cpus_allowed_list:      4-7
[root at bluextal src]# grep Cpus /proc/25729/status
Cpus_allowed:   f0
Cpus_allowed_list:      4-7

==

Thread 25727 has no limitation. 

Is this an expected behavior and I need more setting in XML definition ?

Thanks,
-Kame