** Changed in: linux (Ubuntu Lunar) Assignee: Jeff Lane (bladernr) => Michael Reed (mreed8855)
-- 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/2020022 Title: [SRU][22.04.2 & 23.10] OS cannot boot successfully when enabling VMD in UEFI setup Status in linux package in Ubuntu: Fix Released Status in linux source package in Kinetic: Won't Fix Status in linux source package in Lunar: In Progress Status in linux source package in Mantic: Fix Released Status in linux source package in Noble: Fix Released Bug description: [Impact] When enabling VMD in UEFI setup, OS cannot boot successfully. And, the panic leads to the system reboot. The following log is shown: [ 166.605518] DMAR: VT-d detected Invalidation Queue Error: Reason f [ 166.605522] DMAR: VT-d detected Invalidation Time-out Error: SID ffff [ 166.612445] DMAR: VT-d detected Invalidation Completion Error: SID ffff [ 166.612447] DMAR: QI HEAD: UNKNOWN qw0 = 0x0, qw1 = 0x0 [ 166.612449] DMAR: QI PRIOR: UNKNOWN qw0 = 0x0, qw1 = 0x0 ... Additional info: * The issue happens on both Lenovo SE350 server and Lenovo SR850 v2 server. Debugging info and fix commit info: * `git bisect` indicates the offending commit is 6aab5622296b ("PCI: vmd: Clean up domain before enumeration"). The root cause is that VMD driver tries to clear a PCI configuration space range when resetting a VMD domain (https://github.com/torvalds/linux/blob/master/drivers/pci/controller/vmd.c#L544), which leads to the failure. [Fix] * Another `git bisect` indicates the fix commit is 20f3337d350c ("x86: don't use REP_GOOD or ERMS for small memory clearing). I confirmed that this commit can fix the issue. Would it be possible to include the commit 20f3337d350c in Ubuntu 22.04.2/23.10 kernel? [Test Plan] Reproduce Step 1.Disable Intel VMD in BIOS settings System Settings --> Devices and I/O Ports --> Intel VMD technology --> Enable/Disable Intel VMD : Disabled 2.Install OS 3.Enable Intel VMD in BIOS settings System Settings --> Devices and I/O Ports --> Intel VMD technology --> Enable/Disable Intel VMD : Enabled 4.Rebooting will reproduce this issue [ Where problems could occur ] * Lenovo SE350 server and Lenovo SR850 v2 server * The regression leads to the boot failure (cannot boot info OS successfully). [ Other Info ] https://code.launchpad.net/~bladernr/ubuntu/+source/linux/+git/lunar/+ref/LP2020022 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2020022/+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