[CentOS] question about upgrade qemu and libvirtd

Hi Team,
   I am not sure if I should put my question here, I have googled long
time, no explicit information found.

   Background:
      We need to support KVM encryption and decided to use LUKS.

      Refer to:https://libvirt.org/formatsecret.html#VolumeUsageType

      libvirtd and KVM should be able to support LUKS format disk directly.

      Unfortunately, seems that we need to use libvirt2.2+ and qemu
2.6+, because our current qemu-kvm version does not support luks
format:

      And our hypervisor's OS is CentOS 7.2 with libvirt 2.0 and qemu-kvm 1.5.3

    Question:
       Is there any safe way to upgrade to libvirt 2.2 and qemu 2.6?
       Safe way means: do not need to reboot hyper or VM, do not
impact VM types support .

     Any suggestion is welcome.

Thanks.