[libvirt-users] "virsh define" modify xml configuration file

hi: I upgrade my system from rhel 7.3 to 7.4. so libvirt upgrade to 3.2. I found command "virsh define vm.xml" sometimes modify "vm.xml". I thought the command will read vm.xml, not write to it. is this kind of behavior by design? for example vm.xml with the line <cpu mode='custom' match='exact'> will be replaced with <cpu mode='custom' match='exact' check='partial'> Regards, tbskyd