virsh setcpus --live --guest generic 8

error: internal error: 'can-offline' missing in reply of guest-get-vcpus

$virsh qemu-agent-command generic '{"execute":"guest-get-vcpus"}' --pretty

{
"return": [
    {
        "online": true,
        "logical-id": 0
    },
    .
    .
    .
    {
        "online": true,
        "logical-id": 9
    }
]
}