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Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 0/2] 40p: fix PCI interrupt routin
From: |
David Gibson |
Subject: |
Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 0/2] 40p: fix PCI interrupt routing |
Date: |
Thu, 20 Sep 2018 11:35:45 +1000 |
User-agent: |
Mutt/1.10.1 (2018-07-13) |
On Wed, Sep 19, 2018 at 04:47:36PM +0200, Roman Kapl wrote:
> Hi,
>
> On 09/19/2018 08:57 AM, Mark Cave-Ayland wrote:
> > On 18/09/2018 22:12, Mark Cave-Ayland wrote:
> >
> > > Roman, can you reproduce this locally at all? My setup is nothing
> > > special, just Debian Stretch on amd64.
>
> Ok, so I am able to reproduce it with your image and --enable-debug, but I
> was not able to find the root cause, just narrow it.
>
> It seems that the `dcbz` instruction is not emulated correctly (which may
> lead to some garbage in inittab?). However, if I manualy inline the
> `helper_dcbz_common` code into `helper dcbz`, it starts to work. I just
> literally copy it and add `int mmu_idx = env->dmmu_idx;` at the beginning.
> That could be related to the `--disable-debug` flag, since the compiler will
> inline the code when optimizations are enabled.
Ouch. That almost sounds like a compiler bug - have you tried with
some different compiler versions?
> If you have any debugging ideas, they would be welcome. Maybe there are some
> helper call limitations? Anyway, I will look at it again tomorrow.
>
> Apart from that, I've found some problems in my EPID patch, I will send a
> fix shortly. Namely the instructions are enabled outside of Booke206, one
> unrelated instruction had its opcode chcnaged by mistake and the slow path
> for dbczep is wrong. However, these problems are not related to the problem
> with your image.
>
> Thanks, Roman Kapl
>
> >
> > I've just realised that because this bug is still dependent upon queued
> > patches, it
> > would make sense for me to push a slightly modified version of David's
> > ppc-for-3.1
> > branch to github to help reproduce the issue. Below are the instructions on
> > how to
> > reproduce the bug locally:
> >
> >
> > 1) Grab the 40p test image from
> > http://www.juneau-lug.org/zImage.initrd.sandalfoot
> >
> > 2) Fetch my slightly-modified ppc-for-3.1 branch from
> > https://github.com/mcayland/qemu/tree/ppc-for-3.1-regression
> >
> > 3) Build QEMU with --enable-debug:
> >
> > ./configure --target-list=ppc-softmmu --enable-debug
> > make
> >
> > 4) Boot the 40p test image:
> >
> > ./ppc-softmmu/qemu-system-ppc -cdrom zImage.initrd.sandalfoot -boot d -M 40p
> >
> > You will see that the test image fails at the end of boot with messages
> > like this:
> >
> > Bad inittab entry:
> > Bad inittab entry:
> > No more tasks for init -- sleeping forever
> >
> > 5) Now remove the "target/ppc: add external PID support" patch from the
> > above branch:
> >
> > git checkout HEAD~1
> > make
> >
> > 6) Boot the 40p test image again:
> >
> > ./ppc-softmmu/qemu-system-ppc -cdrom zImage.initrd.sandalfoot -boot d -M 40p
> >
> > You will see that the test image now boots successfully to the "Please
> > press Enter to
> > activate this console" message.
> >
> >
> > ATB,
> >
> > Mark.
> >
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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- Re: [Qemu-devel] [PATCH v3 0/2] 40p: fix PCI interrupt routing, (continued)
- Re: [Qemu-devel] [PATCH v3 0/2] 40p: fix PCI interrupt routing, Hervé Poussineau, 2018/09/12
- Re: [Qemu-devel] [PATCH v3 0/2] 40p: fix PCI interrupt routing, David Gibson, 2018/09/16
- Re: [Qemu-devel] [PATCH v3 0/2] 40p: fix PCI interrupt routing, Mark Cave-Ayland, 2018/09/17
- Re: [Qemu-devel] [PATCH v3 0/2] 40p: fix PCI interrupt routing, Mark Cave-Ayland, 2018/09/18
- Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 0/2] 40p: fix PCI interrupt routing, Mark Cave-Ayland, 2018/09/19
- Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 0/2] 40p: fix PCI interrupt routing, Roman Kapl, 2018/09/19
- Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 0/2] 40p: fix PCI interrupt routing, Roman Kapl, 2018/09/19
- Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 0/2] 40p: fix PCI interrupt routing, Peter Maydell, 2018/09/19
- Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 0/2] 40p: fix PCI interrupt routing, Mark Cave-Ayland, 2018/09/19
- Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 0/2] 40p: fix PCI interrupt routing, Mark Cave-Ayland, 2018/09/19
- Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 0/2] 40p: fix PCI interrupt routing,
David Gibson <=