0 should disable the timer, but start_hv_timer will recognize it as an
expired timer instead.
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
Reviewed-by: NWanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>