stapvirt seems to have a quite similar layout to virsh-console. All is fine for short packets: 1. Send file command to remote, stdin_event gets event stdin_event:1000 fd 0 events 0x1 stbuf_off 0 stbuf 0x7ffd0e99f848 termbuf_off 58 buf "file 926928 stap_1f18b4b" 2. stream_event gets event stream_event:1067 events 0x2 stbuf_off 0 stbuf 0x7ffd0e99f848 buf "file 926928 stap_1f18b4b" but stream_event is not triggered when kernel module is being sent in chunks 3. stdin_event reads first chunk of kernel module (which does virStreamEventUpdateCallback when it notices buffer contents) stdin_event:1000 fd 0 events 0x1 stbuf_off 0 stbuf 0x7ffd0e99f848 termbuf_off 1024 buf "^?ELF^B^A^A" 4. but stream_event is never triggered What triggers stream_event to be called such that the 2 case would be triggered but not the 4 case?