Ok, problem is not with qemu-kvm-ev-2.3.0-31.el7.16.1 package, it is with systemd-networkd. I have installed openvswitch and all works ok. Then, my question, is why is it not possible to use systemd-networkd for configure virtual switches to use them with KVM guests in CentOS 7 (using for other things, they seem work ok)??

In Ubuntu, Arch and Debian there is no problem with systemd-networkd configured bridges for KVM guests.

Any idea why ??

Thanks.