2xAMD Opteron 6128 with libvirt, Physical CPU 13 doesn't exist

Question

I need help with libvirt(?) problem.

Server specs:

• ProLiant DL165 G7
• 2x AMD Opteron(tm) Processor 6128

System:

• Debian GNU/Linux testing (wheezy)
• 3.2.0-3-amd64
• libvirt 0.9.12-5
• kvm 1:1.1.2+dfsg-2

$ grep processor /proc/cpuinfo | wc -l

16

$ virsh nodeinfo

setlocale: No such file or directory
CPU model:           x86_64
CPU(s):              16
CPU frequency:       800 MHz
CPU socket(s):       2
Core(s) per socket:  4
Thread(s) per core:  1
NUMA cell(s):        1
Memory size:         66114200 KiB

$ virsh capabilities

..
<topology>
      <cells num='4'>
        <cell id='0'>
          <cpus num='4'>
            <cpu id='0'/>
            <cpu id='1'/>
            <cpu id='2'/>
            <cpu id='3'/>
          </cpus>
        </cell>
        <cell id='1'>
          <cpus num='4'>
            <cpu id='4'/>
            <cpu id='5'/>
            <cpu id='6'/>
            <cpu id='7'/>
          </cpus>
        </cell>
        <cell id='2'>
          <cpus num='4'>
            <cpu id='12'/>
            <cpu id='13'/>
            <cpu id='14'/>
            <cpu id='15'/>
          </cpus>
        </cell>
        <cell id='3'>
          <cpus num='4'>
            <cpu id='8'/>
            <cpu id='9'/>
            <cpu id='10'/>
            <cpu id='11'/>
          </cpus>
        </cell>
      </cells>
    </topology>
..

$ virsh vcpupin vm 0 13,12,11,10,9,8,7,6,5

error: Physical CPU 13 doesn't exist.
error: cpulist: Invalid format.

Question?

Why my VM Guests use only first 8 CPUs and next 8 are idling?

$ for host in virsh list | awk '{print $2}'; do virsh vcpuinfo $host; done | grep ^CPU: | sort | uniq

CPU:            0
CPU:            1
CPU:            2
CPU:            3
CPU:            4
CPU:            5
CPU:            6
CPU:            7

Any ideas how to change it?

Answer 1

This is fast workaround of this problem:

for pid in `ps aux | grep '/usr/bin/kvm' | grep -v grep | awk '{print $2}'`; do taskset -p -c 0-15 $pid; done

But I decided to change operating system to Ubuntu and it works like a charm.