See also https://www.redhat.com/archives/libvir-list/2020-June/msg01232.html Before: $ uname -m s390x $ cat passthrough-cpu.xml <cpu check="none" mode="host-passthrough" /> $ virsh hypervisor-cpu-compare passthrough-cpu.xml error: Failed to compare hypervisor CPU with passthrough-cpu.xml error: internal error: unable to execute QEMU command 'query-cpu-model-comp arison': Invalid parameter type for 'modelb.name', expected: string After: $ virsh hypervisor-cpu-compare passthrough-cpu.xml CPU described in passthrough-cpu.xml is identical to the CPU provided by hy pervisor on the host Tim Wiederhake (1): qemu: substitute missing model name for host-passthrough src/qemu/qemu_driver.c | 9 +++++++++ 1 file changed, 9 insertions(+) -- 2.26.2