---
fixes:
  - |
    Nova's use of libvirt's compareCPU() API has become error-prone as
    it doesn't take into account host hypervisor's capabilities.  With
    QEMU >=2.9 and libvirt >= 4.4.0, libvirt will do the right thing in
    terms of CPU comparison checks via a new replacement API,
    compareHypervisorCPU().  Nova satisfies the said minimum version
    requirements of QEMU and libvirt by a good margin.

    This change replaces the usage of older API, compareCPU(), with the
    new one, compareHypervisorCPU().