Public bug reported: [Environment] Tested platform and environments : * Ubuntu Jammy 22.04 LTS : 8.0.0-1ubuntu7.10 and 10.0.0-2ubuntu8.5~cloud0 (Caracal UCA) with HWE kernel (6.8) * Ubuntu Noble 24.04 LTS : 10.0.0-2ubuntu8.6 * Ubuntu Oricular 24.10 : 10.6.0-1ubuntu3.2
Hardware : * HPE DL360 with Intel Xeon Gold 6542Y [Issue] CPU is being recognised as Broadwell, thus missing either Skylake, Cascadelake, Icelake, SapphireRapids features. [Impact] It impacts deployments for any customers using Openstack with Nova and using any recent Intel CPU like Icelake, Sapphire Rapids, Emerald Rapids, Granite Rapids and will prevent the user from using any instruction from anything more recent than Broadwell CPUs. [Root cause] For Skylake, Cascadelake, Icelake CPU maps in /usr/share/libvirt/cpu_map/: The cpu cannot be recognised because of the missing feature "mpx". Upstream has actually a fix for this : https://gitlab.com/libvirt/libvirt/-/commit/fa5459517848f333743c771e90eb01faeced3dae Theorically, it should impact IceLake CPUs as well on Jammy 22.04, Noble 24.04 LTS, meaning we have no current Ubuntu LTS to recognise Icelake, Sapphire Rapids and Emerald Rapids correctly. CPU recognition as Icelake-Server-noTSX from both Icelake and SapphireRapids will work only with libvirt's version from Oricular 24.10. [Potential improvements] Perform a SRU to backport the fix from upstream with the removed "mpx" feature to current LTS to allow proper support for recent Intel CPUs --> it would at least fix the support for Icelake and allow newer CPUs like Sapphire Rapids to no end up using a CPU feature set as old as Broadwell --> this is confirmed to work with Ubuntu 24.10 but is not a LTS release and viaable for production/customers environments. ** Affects: libvirt (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2106812 Title: Recent Intel CPUs cannot use Skylake to Icelake feature sets on Jammy 22.04 LTS and Noble 24.04 LTS To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/2106812/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
