qemu-ppc
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-ppc] macio ide question/bug report


From: Mark Cave-Ayland
Subject: Re: [Qemu-ppc] macio ide question/bug report
Date: Wed, 07 May 2014 18:37:00 +0100
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20131103 Icedove/17.0.10

On 07/05/14 18:00, BALATON Zoltan wrote:

On Wed, 7 May 2014, Mark Cave-Ayland wrote:
I'm not sure if your problem related to s->lba == -1 should be solved
just for macio or higher up in the block layer, but the block people
will be on qemu-devel and not qemu-ppc so you should definitely CC the
main list to get their feedback on this.

I think it's handled by the block layer but the translation in macio
breaks it and converts it to -4 which causes an error so probably it
should only be solved for macio. But I hope Alex can look at it and tell
for sure or maybe solve it.

Okay. So in that case it could just be a macio bug.

Those ISOs only boot for me with the default -M g3beige, but darwin is
a huge culprit for these unaligned accesses. My point was that if you
are making changes in this area, if you can still boot the darwin
images then that would be a good test that any changes you make are
working correctly :)

Ah, OK. They boot for me without a -M parameter with my changes (to the
point saying "available for installation:" and then empty as I did not
specify a hard disk image) too, but I was testing with -M mac99 as that
was what I changed. I think they still "work" as before.

But... the block patchset link I sent you has the potential to fix this anyway, since if the unaligned accesses can be passed directly up to the block layer then in theory this problem should go away as this whole chunk of code should no longer be required.

A good test for this would be to try reverting this patch: https://github.com/agraf/qemu/commit/063a333911f1bb09fcc1a4925c8ebf5c88fc2b63 which is Alex's original alignment fix. If you find with that with this patch reverted darwin boots as before, it means that the block alignment patches in core are working correctly and hopefully you may find that it fixes your MorphOS problem.

But again, you really should get this on qemu-devel to get the definitive answer from the block guys.


ATB,

Mark.




reply via email to

[Prev in Thread] Current Thread [Next in Thread]