Created attachment 1169530 [details]
host vdsm and libvirtd log

Description of problem:
CPU QoS does not work

Version-Release number of selected component (if applicable):
rhevm-4.0.0.4-0.1.el7ev.noarch
vdsm-4.18.3-0.el7ev.x86_64
libvirt-1.2.17-13.el7_2.5.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Create CPU QoS on datacenter with the limit 10
2. Create   profile with above QoS
3. Create VM with number of CPU equal to number of CPU's on the host_1 and with above CPU profile
4. Start VM on the host_1
5. Load VM CPU to 100%

Actual results:
Host CPU also has load 100%

Expected results:
Host CPU has load 10%

Additional info:
I can see via virsh that we send correct quota
<name>golden_env_mixed_virtio_0</name>
  <uuid>cbe701c0-f395-4b90-a67f-a461057f4638</uuid>
  <metadata xmlns:ovirt="http://ovirt.org/vm/tune/1.0">
    <ovirt:qos xmlns:ovirt="http://ovirt.org/vm/tune/1.0">
        <ovirt:vcpuLimit>10</ovirt:vcpuLimit>
</ovirt:qos>
  </metadata>
but from some reason values under cgroups are not updated:
# cat /sys/fs/cgroup/cpu\,cpuacct/machine.slice/machine-qemu\\x2d128\\x2dgoldenenvmixedvirtio0.scope/vcpu0/cpu.cfs_period_us 
100000
# cat /sys/fs/cgroup/cpu\,cpuacct/machine.slice/machine-qemu\\x2d128\\x2dgoldenenvmixedvirtio0.scope/vcpu0/cpu.cfs_quota_us 
-1