virtio-win from isv:Rancher:Harvester:ExtraPackages:Dev project
Select Your Operating System
Add repository and install manually
For 15.7 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/isv:Rancher:Harvester:ExtraPackages:Dev/15.7/isv:Rancher:Harvester:ExtraPackages:Dev.repo zypper refresh zypper install virtio-win