[Bug 1786139] Re: [GLK/CLX] Enhanced IBRS

** Changed in: linux (Ubuntu Cosmic)
Status: In Progress => Fix Committed

** Changed in: linux (Ubuntu Cosmic)
Importance: Undecided => Medium

** Changed in: linux (Ubuntu Bionic)
Importance: Undecided => Medium

** Changed in: linux (Ubuntu Xenial)
Importance: Undecided => Medium

** Changed in: linux (Ubuntu Bionic)
Status: In Progress => Fix Committed

** Changed in: linux (Ubuntu Xenial)
Status: In Progress => Fix Committed

--
You received this bug notification because you are subscribed to linux
in Ubuntu.
Matching subscriptions: Bgg, Bmail, Nb
https://bugs.launchpad.net/bugs/1786139

Title:
[GLK/CLX] Enhanced IBRS

Status in intel:
Triaged
Status in linux package in Ubuntu:
In Progress
Status in linux source package in Trusty:
Won't Fix
Status in linux source package in Xenial:
Fix Committed
Status in linux source package in Bionic:
Fix Committed
Status in linux source package in Cosmic:
Fix Committed
Status in linux source package in Disco:
In Progress

Bug description:
Description:

[Impact]

Future Intel CPU's like Cascade Lake and GLK+ support Enhanced IBRS.
Enhanced IBRS is a H/W mitigation technique for Spectre V2 bug. So,
it's important for us to make sure that all the OSV's are using this
feature.

The patch that enables kernel support for this feature has been taken
by Thomas and it's in TIP tree. So, please back port it to all the
OSV's. Please find the patch here:
https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=x86/pti&id=706d51681d636a0c4a5ef53395ec3b803e45ed4d

[Test Case]

For processors that don't support Enhanced IBRS, the test is to ensure
that /sys/devices/system/cpu/vulnerabilities/spectre_v2 doesn't change
state after applying the patches. This will typically be the string
when running on Intel processors that don't support Enhanced IBRS:

  "Mitigation: Full generic retpoline, IBPB, IBRS_FW"

New Intel processors that do support Enhanced IBRS will display
"Enhanced IBRS" in place of "Full generic retpoline"

[Regression Potential]

Pretty low. The patches are fairly simple and they should only affect
new processors. The main concern is around the possibility of
regressing IBRS support on processors that don't support Enhanced IBRS

Target Kernel:TBD
Target Release: 19.04

To manage notifications about this bug go to:
https://bugs.launchpad.net/intel/+bug/1786139/+subscriptions