Re: [Xen-devel] Printing debug message from hypervisor

Grzegorz Miłoś
Tue, 10 Jun 2008 11:26:54 -0000

>> Which log are you looking at? Does ''xm dmesg'' show
anything more?
> dmesg dose''nt contain any of my messages!!!

I did really mean:
xm dmesg

>
>>
>>> code it seems like we cant directly use printk, because the guest
>>> checks the
>>> ''console I/O ring buffer after receving an event for the
same from
>>> hypervisor '' .  I chekced the functions of
drivers/char/console.c
>>> and it has
>>> the funciton printk which is does generate the event for console I/
>>> O but the
>>> console.h
>>
>> printk prototype is in lib.h (include/xen/lib.h)
>
>> Are you able to see _any_ output from the hypervisor at all? I
don''t
>> think printk in do_domctl will be any different.
> I get only the messages from xend and from xc_lib but none of the
> hypervisor printks'' are getting printed.
> Atleast i dont know where they are getting printed?? Is it in the
> xenstore..i think not!!!

Xen can be configured to output it''s messages on the serial line, and
it also puts it in a buffer (console ring) for Dom0''s attention, xm
dmesg should print all the hypervisors output.