Re: [FSL P50x0] KVM HV doesn't work anymore

On 20 May 21 at 01:07am, Nicholas Piggin wrote:

Excerpts from Christian Zigotzky's message of May 19, 2021 9:52 pm:

quoted

On 19 May 2021 at 09:57 am, Nicholas Piggin wrote:

quoted

Excerpts from Christian Zigotzky's message of May 17, 2021 7:42 pm:

quoted

On 17 May 2021 at 09:42am, Nicholas Piggin wrote:

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Excerpts from Christian Zigotzky's message of May 15, 2021 11:46 pm:

quoted

I tried it but it doesn't solve the issue. The uImage works without
KVM
HV in a virtual e5500 QEMU machine.

Any more progress with this? I would say that bisect might have just
been a bit unstable and maybe by chance some things did not crash so
it's pointing to the wrong patch.

Upstream merge of powerpc-5.13-1 was good and powerpc-5.13-2 was bad?

Between that looks like some KVM MMU rework. You could try the patch
before this one b1c5356e873c ("KVM: PPC: Convert to the gfn-based MMU
notifier callbacks"). That won't revert cleanly so just try run the
tree at that point. If it works, test the patch and see if it fails.

Thanks,
Nick

Hi Nick,

Thanks a lot for your answer. Yes, there is a little bit of progress.
The RC2 of kernel 5.13 successfully boots with -smp 3 in a virtual e5500
QEMU machine.
-smp 4 doesn't work anymore since the PowerPC updates 5.13-2. I used
-smp 4 before 5.13 because my FSL P5040 machine has 4 cores.

Could you please post a patch for reverting the commit before
b1c5356e873c ("KVM: PPC: Convert to the gfn-based MMU notifier callbacks")?

You could `git checkout b1c5356e873c~1`

Thanks,
Nick

Hi Nick,

Thanks for your answer. I checked out the commit b1c5356e873c~1 (HEAD is
now at d923ff258423 KVM: MIPS/MMU: Convert to the gfn-based MMU notifier
callbacks).
The kernel boots with '-smp 4' without any problems.
After that I patched with the probable first bad commit (KVM: PPC:
Convert to the gfn-based MMU notifier callbacks). The kernel also boots
with this patch. That means, this isn't the first bad commit.
Further information:
https://forum.hyperion-entertainment.com/viewtopic.php?p=53267#p53267

Hmm, okay that probably rules out those notifier changes then.

Can you remind me were you able to rule these out as suspects?

8f6cc75a97d1 powerpc: move norestart trap flag to bit 0
8dc7f0229b78 powerpc: remove partial register save logic
c45ba4f44f6b powerpc: clean up do_page_fault
d738ee8d56de powerpc/64e/interrupt: handle bad_page_fault in C
ceff77efa4f8 powerpc/64e/interrupt: Use new interrupt context tracking scheme
097157e16cf8 powerpc/64e/interrupt: reconcile irq soft-mask state in C
3db8aa10de9a powerpc/64e/interrupt: NMI save irq soft-mask state in C
0c2472de23ae powerpc/64e/interrupt: use new interrupt return
dc6231821a14 powerpc/interrupt: update common interrupt code for
4228b2c3d20e powerpc/64e/interrupt: always save nvgprs on interrupt
5a5a893c4ad8 powerpc/syscall: switch user_exit_irqoff and trace_hardirqs_off order

Thanks,
Nick

Hi Nick,

Thanks for your answer. Smp 4 still doesn't work on quad core e5500 
CPUs. I use -smp 3 currently. Shall I checkout the commits above (in 
your last answer) and test them? Do you prefer a commit for testing?

Thanks,
Christian