Arch Linux

mbirkis

Member

Registered: 2013-12-12

Posts: 18

Kernel 4.2.1 problem with IOMMU

Hi!
After upgrading to the 4.2.1 kernel it seems to be causing trouble with IOMMU. My kernel messages is spammed by the following:

sep. 29 09:39:22 archkvm kernel: AMD-Vi: Event logged [INVALID_DEVICE_REQUEST device=00:14.0 address=0x000000fdf9103300 flags=0x0600]

I boot the kernel using command line parameters:

amd_iommu=on iommu=pt

This problem causes libvirt guests to stop working. Anyone have any insights to the issue?

tuttiarch

Member

Registered: 2015-01-31

Posts: 13

Re: Kernel 4.2.1 problem with IOMMU

I have a similar (Intel instead of AMD) issue but no such error messages : My KVM won't boot since upgrading to Linux 4.2.1 -- it's stuck in a boot loop. In fact, there are no error messages in the log at all.

Returning to Linux 4.2-4 until this is sorted out.

EDIT: 4.2 is broken for me, too. I actually upgraded from linux-4.1.6-1-x86_64 to linux-4.2.1-1-x86_64, so I'll revert to 4.1.6.

Last edited by tuttiarch (2015-09-30 23:20:47)

rbellamy

Member

Registered: 2012-11-30

Posts: 17

Re: Kernel 4.2.1 problem with IOMMU

I'm seeing the exact same error with same side effect. This is likely an upstream bug in the Kernel, so I submitted a bug report: https://bugzilla.kernel.org/show_bug.cgi?id=105311

miles969

Member

Registered: 2013-02-03

Posts: 23

Re: Kernel 4.2.1 problem with IOMMU

getting the same error here, thanks for reporting the bug.

i guess i couldve saved myself some unnessecary work (i opened up my machine, because i suspected a faulty usb connector on the mainboard, as the errors showed up directly after the kernel registered my 2 front usb3 ports)…

rbellamy

Member

Registered: 2012-11-30

Posts: 17

Re: Kernel 4.2.1 problem with IOMMU

I was told that this is best reported on the IOMMU mailing list, so in addition to the bug report: http://lists.linuxfoundation.org/piperm … 14523.html

Overload

Member

Registered: 2014-09-18

Posts: 3

Re: Kernel 4.2.1 problem with IOMMU

I have a laptop and a desktop, both with first gen i7 that can't boot any VM with 4.2.2 when using KVM. I upgraded from 4.1.6 so i'm not sure about 4.2.1.

A simple iso boot fine without -enable-kvm but is stuck on boot if i use -enable-kvm. With KVM i get a black screen and nothing at all in the host logs or in the guest serial console.

Rolling back the kernel fixed the issue.

miles969

Member

Registered: 2013-02-03

Posts: 23

Re: Kernel 4.2.1 problem with IOMMU

FWIW, setting

iommu=soft

got rid of the journal spam in my case (found here)

full disclosure: i don't care about virtualisation (i only ever messed around with it to check out gnome boxes) and i've disabled kvm and kvm_amd (even blacklisted the modules in a file /etc/modprobe.d/blacklist_kvm.conf), even disabled virtualisation in BIOS while debugging this issue (none of which worked)…

good luck with fixing this, guys!

regards,
M.

mbirkis

Member

Registered: 2013-12-12

Posts: 18

Re: Kernel 4.2.1 problem with IOMMU

Great job on filing bug reports and using the mailing list, reading the thread: http://lists.linuxfoundation.org/piperm … 14727.html it looks like there is a patch that sorts this issue.

Anyone know if that patch is coming into the arch kernel soon, or have som advice on how i can look for it myself?

rbellamy

Member

Registered: 2012-11-30

Posts: 17

Re: Kernel 4.2.1 problem with IOMMU

Patch set: http://lists.linuxfoundation.org/piperm … 14743.html
Pull request: http://lists.linuxfoundation.org/piperm … 14789.html

Looks like it should be in the 4.3 Kernel with a backport to 3.10, 3.14, 4.1 and 4.2 stable trees.