Description of problem:

When we configure vCPU pinning in Nova by setting 'vcpu_pin_set' option
in nova.conf. Currently "emulatorpin" libvirt option gets configured to same physical CPU's on which vCPU's are already pinned.

This stops guest from booting and require manual tweaking of libvirt
xml file. Till we have this feature BZ 1298079, we need to manually restart
instance to test KVM/RT with OSP. 

When we try to manually restart instance, Nova shuts it down by saying:

<nova-compute.log>
Instance shutdown by itself. Calling the stop API. Current vm_state: active, current task_state: None, original DB power_state: 1, current VM power_state: 4 
</nova-compute.log>

We tried to set option 'sync_power_state_interval=-1' in 'nova.conf' to avoid
nova taking any action if it finds power_state out of sync. But it looks like this feature is not yet in Nova-RT package.

Version-Release number of selected component (if applicable):

openstack-nova-2015.1.1-1.el7ost.rt2.noarch.rpm

How reproducible:


Steps to Reproduce:
1. kill running Qemu INSTANCE.
2. Immediately start instance with "virsh start INSTANCE"

Actual results:
2' Nova automatically shut-downs VM instance.


Expected results:
1] Instance should start running.

2] If 'sync_power_state_interval=-1' is configured in 'nova.conf' file, Nova should not take any action to change actual virtual machine power state.


Additional info:

Upstream link for this feature is:
https://review.openstack.org/#/c/291804/