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

[Chun Yan Liu]

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.

Thanks,
Chunyan