Re: [Qemu-devel] PMON2000 compilation and kernel question

[BALATON Zoltan]

Hello,

On Mon, 18 Mar 2019, John Snow wrote:
> On 3/6/19 11:01 AM, Andrew Randrianasulu wrote:
> > > This could be some missing or buggy emulation. Maybe if you can get some debug 
> > > logs from kernel that could tell what it's doing. Usually at least -d 
> > > unimp,guest_errors options are recommended for debugging but if nothing is 
> > > printed then it's harder to find out what's causing the hang.
> >
> > This was kernel dying in ata subsystem:
>
> I'm very late to the party here; but you could try enabling tracing for

No you're not late, we still haven't figured it out. Thanks for your interest.

> the ATA code and that might give a better picture as to what's going wrong;
>
> warning that if you enable every last trace it does get QUITE chatty (it
> includes data IO dumps) but it might give us a better picture.
>
> See hw/ide/trace-events and try enabling everything except the events
> labeled "verbose" as a first step.

I'm attaching logs of a command like this:

qemu-system-mips64el -M fulong2e -vga std -kernel vmlinuz -append 
'console=ttyS0'
-cdrom debian-8.11.0-mipsel-netinst.iso -serial stdio
-d guest_errors,unimp,trace:'ide*',trace:'bmdma*',trace:'cd*'

with repeated lines replaced with "count line" as in uniq -c -u and 
removed things not related to ide for brevity. (The -vga std is needed to 
avoid a kernel oops before it touches ide which is discussed here: 
http://lists.nongnu.org/archive/html/qemu-devel/2019-03/msg05169.html)

It looks like that PIO mode works but DMA doesn't. I've reproduced similar 
issue on another platform with via-ide and Andrew reported similar with 
the pmon formware on mips so it can be a bug in via-ide which might be 
something I did not implement correctly when trying to change it to 
emulate PCI native mode. Unfortunately I don't know what might be missing 
or wrong not knowing how bmdma works so if you can tell from the log or 
have some insight it is greatly appreciated.

Thank you,
BALATON Zoltan

fu-ide-uniq.log.xz
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