#995773 intel_iommu hangs some old HPE Server

Package:
src:linux
Source:
linux
Submitter:
Artem Anikeev
Date:
2021-10-23 16:27:05 UTC
Severity:
important
#995773#5
Date:
2021-10-05 13:00:53 UTC
From:
To:
Dear Maintainer,

I upgraded a kernel from 4.19.0-17 to 5.10.0-8 during a system
upgrade from buster to bullseye release.

The new kernel panics soon after the boot with an NMI error message.

IML and iLO are empty.

I can reproduce the bug on HP ProLiant DL380G6 and DL360G7.
#995773#10
Date:
2021-10-06 06:11:05 UTC
From:
To:
I've seen this too and documented my findings here:
https://www.claudiokuenzler.com/blog/1125/debian-11-bullseye-boot-freeze-kernel-panic-hp-proliant-dl380

(reason is the hpwdt module)

This bug is most likely a duplicate of
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=898336 where the same
NMI's are reported with Kernel 4.16 but with Kernel 5.10 the boot
issues/crashes seem to be even worse.

Maintainers, please consider disabling (blacklisting) the hpwdt module by
default (same as Ubuntu). If anyone REALLY needs it, it can be manually
enabled.
#995773#15
Date:
2021-10-23 15:59:13 UTC
From:
To:

My HPE ProLiant BL460c Gen9 has the same problem.
And with some debug, I find the problem is due to
   CONFIG_INTEL_IOMMU_DEFAULT_ON=y

So, as a workaround, we can use intel_iommu=off kernel option.