Nova Antelope / RHEL9 : failure to lauch VM because video model virtio is not supported

Hi, After upgrading a compute server from Yoga/EL8 to Antelope/EL9, I cannot start VM on it. nova-compute log says: ----  Failed to build and run instance: libvirt.libvirtError: unsupported configuration: domain configuration does not support video model 'virtio' ---- According to https://bugs.launchpad.net/nova/+bug/2018172, it seems the problem also existed when trying to deploy nova-compute Yoga/Zed on EL9 but what fixed the problem is not clear in the issue... Any idea about what could cause this problem and how to fix it? Best regards, Michel