Re: [Qemu-block] question： Does qemu-pr-helper have its own log files？

[Zhangbo (Oscar)]

>From: Stefan Hajnoczi [mailto:address@hidden
>Sent: Tuesday, April 23, 2019 9:57 PM
>On Tue, Apr 23, 2019 at 11:12:40AM +0800, Jie Wang wrote:
>>  Does qemu-pr-helper have its own log files？
>
>No, it does not.  qemu-pr-helper uses stderr for errors and there is not
>much output during normal operation.
>
>Check journalctl(1) for errors if you are launching it as a systemd
>service.
>
>Stefan

The error messages that sent to *stderr* are *not* captured by anyone, then
these error messages seems helpless.
It's different form qemu's log,  qemu's stderr logs are transferred to virtlogd,
that means these logs are finally written into disk.
Any further development plan?

We thought of:
1 logging into syslog, but the malicious guest may cause large amount of error
  messages to overflow the message log.
2 or, let virtlogd to redirect its logs. But if virtlogd get restarted, the 
helper's log would
  no longer be logged, because, unlike qemu, there's no qmp socket between 
  libvirtd and the helper, the channel between the helper and virtlogd could 
not be
  re-established.
3 or, let qemu to log the helper's log, seems a little odd and complex.
4 or, let the helper realize its own logging scheme and log into itself's 
logfile ?

What's your suggestion? Thanks!