Hi UAnton,
In addition if you are using Centos7 try qemu-kvm-ev from the oVirt repo. And as addition try to enable ‘virtio-blk data plane’. But with the 'qemu-kvm-ev" I can’t achieve remarkable additional performance gain by enabling it. (you can enable the feature by adding an “XML tweaking script” in the remotes/vmm/kvm/deploy script, just before the XML is passed to virsh)
Kind Regards,
Anton Todorov