Re: [Qemu-devel] qemu-ppc (prep) crashes with NetBSD guest

[Gerd Hoffmann <kraxel@redhat.com>]

  Hi,

>> # qemu-system-ppc -nographic -M prep -m 128M -hda hda.qcow2 -cdrom 
>> NetBSD-6.1-prep.iso -serial ... -kernel sysinst_com0.fs
>> 
>> There seems to be a connection between the amount of RAM chosen
>> and the point where the crash happens. With 128M, qemu will crash
>> when the installer extracts some of the earlier packages, with 256M
>> the crash will happen later when extracting. Each one is
>> reproducible at the exact point of installation. And the amount of
>> bytes extracted could be the amount of RAM minus some number. (64M
>> and >256MB won't boot at all, so I could not finish
>> installation...)

>> Would be great if someone (also with a current qemu) could have a 
>> look, as I did not even manage to get a core file...
> 
> Gerd, this seems to be vbe related and you're the only person I know
> who might have a clue what's going on there :). Based on where the
> VGA code was crashing I came up with the following patch, but I'd
> assume the underlying issue is somewhere else.

Most likely it's somewhere else, yes.  I put my money on someone writing
random yunk into the vga's mmio bar, maybe due to netbsd not detecting
memory correctly.

What does 'info mtree' in the monitor print?

If you append '-global VGA.mmio=0' to the qemu command line, does that
change behavior?

cheers,
  Gerd