Re: [Qemu-devel] [PATCH V3] Support logging xen-guest console

[Alexander Graf <agraf@suse.de>]

On 06/30/2011 11:39 AM, Chun Yan Liu wrote:
> On Thursday, June 30, 2011 03:58:57 PM Alexander Graf wrote:
>> On 30.06.2011, at 09:08, Chunyan Liu wrote:
>>> Add code to support logging xen-domU console, as what xenconsoled does.
>>> To enable logging, set environment variable XENCONSOLED_TRACE=guest and
>>> XENCONSOLED_LOGDIR=<specified directory>, log file will be saved in
>>> <specified directory>.
>> In fact, this whole thing looks as if you're merely trying to reimplement
>> "tee" on the xenconsole output. Wouldn't it make more sense to do this in
>> the char layer? So we could do:
>>
>>    -xenconsole tee:stdio,file:/tmp/xen.log
>>
>> or similar? That's probably a lot more useful than a random Xen specific
>> hack.
>>
> Thanks, Alex.  It IS something like "tee". But IMO, change in xen_console.c
> and change in char layer are just different time points, do not have essential
> difference. Change in xen_console.c is trying to backup output data into log
> file before sending to char device, change in char device is trying to
> dupicate data from char device to log file. Correct me if I'm wrong.

Sure, the outcome is the same though, no? We get the output data in both 
a file and the char backend.


Alex