systemtap stapvirt tool

Daniel P. Berrangé
Thu, 07 Jul 2022 08:07:14 -0000

On Wed, Jul 06, 2022 at 05:25:32PM -0400, Stan Cox
wrote:
> 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?

I don't know - as best I can tell all your logic matches what is in
virsh console.

What libvirt version are you testing with, and have you tried a differnt
version ?

With regards,
Daniel
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