Re: [PATCH 1/2] KVM: PPC: BookE: Disable preemption before loading guest FP and Altivec

[Christian Zigotzky <chzigotzky@xenosoft.de>]

On 02 November 2026 at 2:07 pm, Shrikanth Hegde <sshegde@linux.ibm.com> wrote:

Hi.

On 11/1/26 1:58 PM, Christian Zigotzky wrote:

Yes, I can help with testing.

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Thanks Christian.


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Hi all,

Ever since we enabled PREEMPT on our Nemo boards [1], we have been experiencing occasional problems with the kernel stack.

Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: srcu_gp_start_if_needed+0x534/0x538
Rebooting in 180 seconds..

We are using the following patches: [2] [3]

We have disabled PREEMPT with a patch [4] again, and since then our Nemo boards have been running perfectly once more.

As the problem with the kernel stack only occurs sporadically, bisection is impossible.

I hope you can fix the kernel stack issue.

Thanks,
Christian

[1] https://en.wikipedia.org/wiki/AmigaOne_X1000

[2] https://raw.githubusercontent.com/chzigotzky/kernels/refs/heads/main/patches/X1000/preempt_v1.patch

[3] https://raw.githubusercontent.com/chzigotzky/kernels/refs/heads/main/patches/X1000/kvm_powerpc.patch

[4] https://raw.githubusercontent.com/chzigotzky/kernels/refs/heads/main/patches/X1000/Kconfig.preempt.patch

[5] Kernel config: https://raw.githubusercontent.com/chzigotzky/kernels/31c064092e3aab0875c47d44838443c9515b2970/configs/x1000_defconfig