[SRU][j:linux-gcp][PATCH 0/1] Enable IOMMU Passthrough by default

[Ian Whitfield]

[Impact]

C3 bare metal instances run into a problem on 6.8 kernels due to Intel
IOMMU being enabled by default. After performing enough disk-intensive
work on the instance, the system becomes unusable and reports I/O
errors at the command line until rebooted, losing data in the process.
The root issue is being worked on long-term, but in the meantime we
will apply a workaround to the issue for affected customers. This fix
has a negative impact on security, so it is limited to Jammy kernels
for which this issue is a regression. Noble kernels have always had
this problem and therefore will be waiting for the long-term fix.

[Fix]

Change the kernel config to use IOMMU passthrough by default.

[Test Plan]

Perform up to 50 kernel builds on the instance in sequence. Failures on
affected instances are usually detected after only 1 or 2.

[Regression potential]

Regression potential is especially low for Jammy as we are essentially
reverting a breaking change.

Ian Whitfield (1):
  UBUNTU: gcp: Enable IOMMU Passthrough by default

 debian.gcp-6.8/config/annotations | 9 +++++++++
 1 file changed, 9 insertions(+)

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2.43.0