Re: systemtap stapvirt tool

I turned on: LIBVIRT_DEBUG=debug which shows the deviation, indicated by "->". The working case, stdin event followed by stream event is: stapvirt: ##### stdin_event:1000 fd 0 events 0x1 stbuf_off 0 stbuf 0x7fff259eecb8 termbuf_off 58 buf "file 926928 stap_b861775" 2022-07-07 17:20:55.565+0000: 353069: debug : virStreamEventUpdateCallback:1102 : stream=0x2013150, events=3 2022-07-07 17:20:55.565+0000: 353069: debug : virNetClientStreamEventTimerUpdate:86 : Check timer rx=(nil) cbEvents=3 2022-07-07 17:20:55.565+0000: 353069: debug : virNetClientStreamEventTimerUpdate:91 : Enabling event timer 2022-07-07 17:20:55.565+0000: 353069: info : virEventGLibTimeoutUpdate:395 : EVENT_GLIB_UPDATE_TIMEOUT: timer=1 interval=0 2022-07-07 17:20:55.565+0000: 353069: debug : virEventGLibTimeoutUpdate:406 : Update timeout data=0x2017e00 timer=1 interval=0 ms 2022-07-07 17:20:55.565+0000: 353069: debug : virEventRunDefaultImpl:341 : running default event implementation ->2022-07-07 17:20:55.565+0000: 353069: debug : virEventGLibTimeoutDispatch:303 : Dispatch timeout data=0x2017e00 cb=0x7fe5f98436a0 timer=1 opaque=0x200d170 2022-07-07 17:20:55.565+0000: 353069: info : virEventGLibTimeoutDispatch:306 : EVENT_GLIB_DISPATCH_TIMEOUT: timer=1 cb=0x7fe5f98436a0 opaque=0x200d170 2022-07-07 17:20:55.565+0000: 353069: debug : virNetClientStreamEventTimer:116 : Got Timer dispatch events=2 cbEvents=3 rx=(nil) stapvirt: ##### stream_event:1043 st 0x2013150 events 0x2 stbuf_off 0 stbuf 0x7fff259eecb8 The case where stream event is not hit is: stapvirt: ##### stdin_event:1000 fd 0 events 0x1 stbuf_off 0 stbuf 0x7fff259eecb8 termbuf_off 1024 buf "^?ELF^B^A^A" 2022-07-07 17:20:55.565+0000: 353069: debug : virStreamEventUpdateCallback:1102 : stream=0x2013150, events=3 2022-07-07 17:20:55.565+0000: 353069: debug : virNetClientStreamEventTimerUpdate:86 : Check timer rx=(nil) cbEvents=3 2022-07-07 17:20:55.565+0000: 353069: debug : virNetClientStreamEventTimerUpdate:91 : Enabling event timer 2022-07-07 17:20:55.565+0000: 353069: info : virEventGLibTimeoutUpdate:395 : EVENT_GLIB_UPDATE_TIMEOUT: timer=1 interval=0 2022-07-07 17:20:55.565+0000: 353069: debug : virEventGLibTimeoutUpdate:406 : Update timeout data=0x2017e00 timer=1 interval=0 ms 2022-07-07 17:20:55.566+0000: 353069: debug : virEventRunDefaultImpl:341 : running default event implementation -> 2022-07-07 17:20:55.566+0000: 353069: debug : virEventGLibHandleDispatch:113 : Dispatch handler data=0x201e600 watch=2 fd=0 events=1 opaque=0x7fff259ee8a0 2022-07-07 17:20:55.566+0000: 353069: info : virEventGLibHandleDispatch:116 : EVENT_GLIB_DISPATCH_HANDLE: watch=2 events=1 cb=0x4046e9 opaque=0x7fff259ee8a0 stapvirt: ##### stdin_event:975 fd 0 events 0x1 termbuf_off 1024 1024 Hits stream Doesn't hit stream ... ... virEventRunDefaultImpl:341 virEventRunDefaultImpl:341 virEventGLibHandleDispatch:113 virEventGLibTimeoutDispatch:303 virEventGLibTimeoutDispatch:306 virNetClientStreamEventTimer:116 virEventGLibHandleDispatch:116 stream_event stdin_event This is: libvirt-8.1.0-2.fc36.x86_64 I have not tried another version but will give that a shot.