---
features:
  - |
    Introduces ``[compute]/cpu_shared_set`` option for compute nodes.
    Some workloads run best when the hypervisor overhead processes
    (emulator threads in libvirt/QEMU) can be placed on different
    physical host CPUs than other guest CPU resources. This allows
    those workloads to prevent latency spikes for guest vCPU threads.

    To place a workload's emulator threads on a set of isolated
    physical CPUs, set the ``[compute]/cpu_shared_set`` configuration
    option to the set of host CPUs that should be used for best-effort
    CPU resources. Then set a flavor extra spec to
    ``hw:emulator_threads_policy=share`` to instruct nova to place
    that workload's emulator threads on that set of host CPUs.