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

[Claudemir Todo Bom <claudemir@xxxxxxxxxxx>]

Em seg., 1 de fev. de 2021 às 12:09, Jan Beulich <jbeulich@xxxxxxxx> escreveu:
>
> 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?

Yes, all three 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)?

with "vga=text-80x25,keep watchdog" and without the earlyprintk,
system booted. I'm attaching the "xl dmesg" and "dmesg" outputs here.

>
> > 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!

I can live with the "earlyprintk=xen" or any other solution that makes
it boot. I'm pretty sure this problem will appear in tests of other
people with a setup that helps debug deeper.

Thank you for your work!

Best regards,
Claudemir

Attachment: xen-dmesg.txt
Description: Text document

Attachment: kernel-dmesg.txt
Description: Text document