Public bug reported:

SRU Justification

[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.

** Affects: linux-gcp (Ubuntu)
     Importance: Undecided
         Status: New

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux-gcp in Ubuntu.
https://bugs.launchpad.net/bugs/2085904

Title:
  Enable IOMMU Passthrough by default

Status in linux-gcp package in Ubuntu:
  New

Bug description:
  SRU Justification

  [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.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-gcp/+bug/2085904/+subscriptions


-- 
Mailing list: https://launchpad.net/~kernel-packages
Post to     : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help   : https://help.launchpad.net/ListHelp

Reply via email to