History: the previous version of kvm (unknown) and qemu-lite had an issue using virtio 1.0 version when it came to device hotplug, which led to the team to disable 1.0 version of virtio for hotplug (set disable-modern=on). Please check containers/virtcontainers@e99f6b2 for further info.

We have moved to QEMU4.0 and probably a newer version of KVM since the last time issue was noticed (2017). We should try and enable virtio 1.0 for pcie devices since there is probably nothing blocking us.