ppc: hard lockup / hang in v5.17-rc1 under QEMU

[Michael Ellerman]

Miguel Ojeda <miguel.ojeda.sandonis at gmail.com> writes:
> Hi PPC folks,
>
> Our ppc64le CI deterministically triggers a hard lockup / hang under
> QEMU since v5.17-rc1 (upgrading from v5.16).
>
> Bisecting points to 0faf20a1ad16 ("powerpc/64s/interrupt: Don't enable
> MSR[EE] in irq handlers unless perf is in use").

Hi Miguel,

Thanks for the report.

Nick has posted one fix for the commit you identified:

  http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20220124143930.3923442-1-npiggin@gmail.com/


It looks like your kernel-ppc64le-release.config does not have the
hardlockup detector enabled, so I suspect you're hitting the bug
described in that patch.

That fix will hit linux-next in the next day or so and should be in rc2.

cheers