---
features:
  - |
    A new hypervisor version weigher has been added to prefer selecting hosts
    with newer hypervisors installed. For the libvirt driver, this is the version
    of libvirt on the compute node not the version of qemu. As with all
    weighers this is enabled by default and its behavior can be modified using
    the new ``hypervisor_version_weight_multiplier`` config option in the
    ``filter_scheduler`` section.
upgrade:
  - |
    A new hypervisor version weigher has been added that will prefer selecting
    hosts with a newer hypervisor installed. This can help simplify rolling
    upgrades by preferring the already upgraded hosts when moving workloads around
    using live or cold migration. To restore the old behavior either remove
    the weigher from the list of enabled weighers or set
    ``[filter_scheduler] hypervisor_version_weight_multiplier=0``. The default
    value of the hypervisor_version_weight_multiplier is 1 so only a mild
    preference is given to new hosts, higher values will make the effect
    more pronounced and negative values will prefer older hosts.
