I've verified the [Test Case] for older processors that do not support Enhanced IBRS. I've asked Intel if they'd be able to verify the this fix on the latest processors that support Enhanced IBRS but I don't feel like that should be a blocker.
** Tags removed: verification-needed-bionic verification-needed-cosmic verification-needed-xenial ** Tags added: verification-done-bionic verification-done-cosmic verification-done-xenial ** Changed in: linux (Ubuntu Disco) Status: In Progress => Fix Committed ** Changed in: linux (Ubuntu Disco) Importance: Undecided => Medium -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1786139 Title: [GLK/CLX] Enhanced IBRS Status in intel: Triaged Status in linux package in Ubuntu: Fix Committed 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: Fix Committed 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 -- 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