Provide new primitives used_empty/avail_empty and build poll_avail/poll_used on top of it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Useful to measure testing framework overhead. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>