Re: Problems with APIC on versions 4.9 and later (4.8 works)

[Jan Beulich <jbeulich@xxxxxxxx>]

On 01.02.2021 15:46, Claudemir Todo Bom wrote:
> Tested first without the debug patch and with following parameters:

And this test was all three of the non-debugging patches?

> xen: dom0_mem=1024M,max:2048M dom0_max_vcpus=4 dom0_vcpus_pin=true smt=true
> kernel: loglevel=3
> 
> same behaviour as before... black screen right after the xen messages.
> 
> adding earlyprintk=xen to the kernel command line is sufficient to
> make it boot, I can imagine this can be happening because Xen is not
> releasing console to the kernel at that moment.

If the answer to the above question is "yes", then I start
suspecting this to be a different problem. I'm not sure I
see a way to debug this without having access to any output
(i.e. neither video nor serial). Without "earlyprintk=xen"
and instead with "vga=keep watchdog" on the Xen command
line, is there anything helpful (without or if need be with
the debugging patch in place)?

> The system worked well (with earlyprintk=xen), tested with the "yes
> stress test" mentioned before on a guest and on dom0.
> 
> Then, I installed the debug patch and booted it again, it also needed
> the earlyprintk=xen parameter on the kernel command line. I've also
> added console_timestamps=boot to the xen command line in order to get
> the time of the messages.
> 
> I'm attaching the outputs of "xl dmesg" and "dmesg" on this message.
> 
> Think it is almost done! WIll wait for the next round of tests!

As per above, not sure if there's going to be one. Thanks
for your patient testing!

Jan