According to the docs, vcpupin will use either cgroups or sched_setaffinity to pin vcpu threads to cpus. How is this decision made? 

I observe differences even on different hosts featuring the same version of libvirtd (1.3.1): on one host vcpupin affects cpuset.cpus (cgroup), and on the other it affects vcpu threads affinity (observed through taskset). 

Thanks, 

Nikos