Public bug reported: An upstream commit added Intel cpu model/microcode checks to disable TSC_DEADLINE due to cpu errata:
commit bd9240a18edfbfa72e957fc2ba831cf1f13ea073 Author: Peter Zijlstra <[email protected]> Date: Wed May 31 17:52:03 2017 +0200 x86/apic: Add TSC_DEADLINE quirk due to errata That commit is included in the Ubuntu kernels starting at artful v4.13. However, most hypervisors virtualize TSC deadline timer (and therefore it isn't affected by Intel CPU errata inside the guest), and even if any hypervisors directly exposed the hardware TSC deadline timer, the guests cannot update CPU microcode and therefore it's the hypervisor's job to disable/hide/virtualize the TSC deadline timer from the guest. This upstream commit skips the microcode check to disable the TSC deadline timer if it detects it's running under a hypervisor: commit cc6afe2240298049585e86b1ade85efc8a7f225d Author: Paolo Bonzini <[email protected]> Date: Tue Oct 10 12:12:57 2017 +0200 x86/apic: Silence "FW_BUG TSC_DEADLINE disabled due to Errata" on hypervisors ** Affects: linux (Ubuntu) Importance: Medium Assignee: Dan Streetman (ddstreet) Status: In Progress ** Affects: linux (Ubuntu Artful) Importance: Medium Assignee: Dan Streetman (ddstreet) Status: In Progress ** Affects: linux (Ubuntu Bb-series) Importance: Medium Assignee: Dan Streetman (ddstreet) Status: In Progress ** Changed in: linux (Ubuntu) Status: New => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1724912 Title: TSC_DEADLINE incorrectly disabled inside virtual guests To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1724912/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
