x86/kvm: fix LAPIC timer drift when guest uses periodic mode

Bug #1778486 reported by Markus Schade on 2018-06-25
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Status tracked in Cosmic
Bionic
Medium
Joseph Salisbury
Cosmic
Medium
Joseph Salisbury

Bug Description

== SRU Justification ==
This patch fixes a regression introduced by mainline commit
8003c9ae204e in v4.10. Without this new patch, OpenBSD guests encounter
timing issues when running under bionic kernel.

See also:
https://www.spinics.net/lists/kvm/msg161311.html

== Fix ==
d8f2f498d9ed ("x86/kvm: fix LAPIC timer drift when guest uses periodic mode")

== Regression Potential ==
Low. This fixes a current regression.

== Test Case ==
A test kernel was built with this patch and tested by the original bug reporter.
The bug reporter states the test kernel resolved the bug.

OpenBSD guests encounter timing issues when running under bionic kernel.

This issue is actually present since 4.10 and is fixed by:

https://patchwork.kernel.org/patch/10411125/

See also

https://www.spinics.net/lists/kvm/msg161311.html

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1778486

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

Changed in linux (Ubuntu):
status: New → Incomplete
Changed in linux (Ubuntu):
status: Incomplete → Triaged
importance: Undecided → Medium
tags: added: artful bionic
Changed in linux (Ubuntu):
assignee: nobody → Joseph Salisbury (jsalisbury)
status: Triaged → In Progress
Changed in linux (Ubuntu Bionic):
importance: Undecided → Medium
Changed in linux (Ubuntu Artful):
importance: Undecided → Medium
Changed in linux (Ubuntu Bionic):
assignee: nobody → Joseph Salisbury (jsalisbury)
Changed in linux (Ubuntu Artful):
assignee: nobody → Joseph Salisbury (jsalisbury)
Changed in linux (Ubuntu Bionic):
status: New → In Progress
Changed in linux (Ubuntu Artful):
status: New → In Progress
tags: added: cosmic
Joseph Salisbury (jsalisbury) wrote :

I built a test kernel with the patch in the description. The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1778486

Can you test this kernel and see if it resolves this bug?

Note about installing test kernels:
• If the test kernel is prior to 4.15(Bionic) you need to install the linux-image and linux-image-extra .deb packages.
• If the test kernel is 4.15(Bionic) or newer, you need to install the linux-modules, linux-modules-extra and linux-image-unsigned .deb packages.

Thanks in advance!

Markus Schade (lp-markusschade) wrote :

Thanks Joseph.

I tested the kernel with OpenBSD and FreeBSD virtual machines and this patch seems to fix the timing issues.

no longer affects: linux (Ubuntu Artful)
Joseph Salisbury (jsalisbury) wrote :
description: updated
Changed in linux (Ubuntu Bionic):
status: In Progress → Fix Committed
Brad Figg (brad-figg) wrote :

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-bionic' to 'verification-done-bionic'. If the problem still exists, change the tag 'verification-needed-bionic' to 'verification-failed-bionic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

tags: added: verification-needed-bionic
tags: added: verification-done-bionic
removed: verification-needed-bionic
Markus Schade (lp-markusschade) wrote :

If I'm not mistaken, the fix has been released with the latest kernel update that was pushed for the L1TF issue. So this bug should be "fix released"

Vincent Bernat (vbernat) wrote :

The fix is not present in -32. It seems to be scheduled for -33.

Launchpad Janitor (janitor) wrote :
Download full text (35.6 KiB)

This bug was fixed in the package linux - 4.15.0-33.36

---------------
linux (4.15.0-33.36) bionic; urgency=medium

  * linux: 4.15.0-33.36 -proposed tracker (LP: #1787149)

  * RTNL assertion failure on ipvlan (LP: #1776927)
    - ipvlan: drop ipv6 dependency
    - ipvlan: use per device spinlock to protect addrs list updates
    - SAUCE: fix warning from "ipvlan: drop ipv6 dependency"

  * ubuntu_bpf_jit test failed on Bionic s390x systems (LP: #1753941)
    - test_bpf: flag tests that cannot be jited on s390

  * HDMI/DP audio can't work on the laptop of Dell Latitude 5495 (LP: #1782689)
    - drm/nouveau: fix nouveau_dsm_get_client_id()'s return type
    - drm/radeon: fix radeon_atpx_get_client_id()'s return type
    - drm/amdgpu: fix amdgpu_atpx_get_client_id()'s return type
    - platform/x86: apple-gmux: fix gmux_get_client_id()'s return type
    - ALSA: hda: use PCI_BASE_CLASS_DISPLAY to replace PCI_CLASS_DISPLAY_VGA
    - vga_switcheroo: set audio client id according to bound GPU id

  * locking sockets broken due to missing AppArmor socket mediation patches
    (LP: #1780227)
    - UBUNTU SAUCE: apparmor: fix apparmor mediating locking non-fs, unix sockets

  * Update2 for ocxl driver (LP: #1781436)
    - ocxl: Fix page fault handler in case of fault on dying process

  * netns: unable to follow an interface that moves to another netns
    (LP: #1774225)
    - net: core: Expose number of link up/down transitions
    - dev: always advertise the new nsid when the netns iface changes
    - dev: advertise the new ifindex when the netns iface changes

  * [Bionic] Disk IO hangs when using BFQ as io scheduler (LP: #1780066)
    - block, bfq: fix occurrences of request finish method's old name
    - block, bfq: remove batches of confusing ifdefs
    - block, bfq: add requeue-request hook

  * HP ProBook 455 G5 needs mute-led-gpio fixup (LP: #1781763)
    - ALSA: hda: add mute led support for HP ProBook 455 G5

  * [Bionic] bug fixes to improve stability of the ThunderX2 i2c driver
    (LP: #1781476)
    - i2c: xlp9xx: Fix issue seen when updating receive length
    - i2c: xlp9xx: Make sure the transfer size is not more than
      I2C_SMBUS_BLOCK_SIZE

  * x86/kvm: fix LAPIC timer drift when guest uses periodic mode (LP: #1778486)
    - x86/kvm: fix LAPIC timer drift when guest uses periodic mode

  * Please include ax88179_178a and r8152 modules in d-i udeb (LP: #1771823)
    - [Config:] d-i: Add ax88179_178a and r8152 to nic-modules

  * Nvidia fails after switching its mode (LP: #1778658)
    - PCI: Restore config space on runtime resume despite being unbound

  * Kernel error "task zfs:pid blocked for more than 120 seconds" (LP: #1781364)
    - SAUCE: (noup) zfs to 0.7.5-1ubuntu16.3

  * CVE-2018-12232
    - PATCH 1/1] socket: close race condition between sock_close() and
      sockfs_setattr()

  * CVE-2018-10323
    - xfs: set format back to extents if xfs_bmap_extents_to_btree

  * change front mic location for more lenovo m7/8/9xx machines (LP: #1781316)
    - ALSA: hda/realtek - Fix the problem of two front mics on more machines
    - ALSA: hda/realtek - two more lenovo models need fixup of MIC_LOCATION

  * Cephfs + fscache: unab...

Changed in linux (Ubuntu Bionic):
status: Fix Committed → Fix Released
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