set custom loglevel for external libraries

[Jim Fehlig]

On 10/11/21 04:30, Olaf Hering wrote:
> 
> This question is still open:
> where should the libxl specific setting be specified?

Sorry for not responding to your earlier mail.

> Am Sun, 25 Jul 2021 10:17:49 +0200
> schrieb Olaf Hering <olaf at aepfle.de>:
> 
>> I think it is wrong to use internal libvirt values for internal libxentoollog values.

What is gained over the sparse mapping? Are values not covered actually useful 
in practice? Also, how are the values specified when using the xl tool? A quick 
peek at the code seems to imply using more 'v' options. E.g. 'xl -vvvv ...'.

>> There has to be a separate configuration setting to specify the various xentoollog_level values. It is just the question where to put such setting, and how to name it.

If such a setting is actually needed, then the proper place would be 
/etc/libvirt/libxl.conf. And IMO we should avoid creating a new name that could 
potentially confuse users. If 'xentoollog_level' is the common jargon in xen, we 
should stick with the same name.

>> I guess no other used library provides similar internal logging, this requirement is unique to libxenlight.so.

Good question, but I think you are right. It is unique to libxenlight.

Jim