Arch Linux

archqemu

Member

Registered: 2018-10-26

Posts: 5

[SOLVED] Blacklisting i915 module doesn't work

Hi there,

I'm new to arch, but not new to linux. I am able to blacklist the i915 module on several other distro's, but it won't let me in arch.
I want to disable the i915 subsystem/driver/module because it interferes with my IGD pci passthrough.

What I have tried already:

1. Adding video=vesafb:off to my kernel command line -> no success

[    0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-linux root=UUID=ac374591-4039-4ecb-909a-1a4188f90f58 rw kvm.ignore_msrs=1 intel_iommu=on video=vesafb:off
[    0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-linux root=UUID=ac374591-4039-4ecb-909a-1a4188f90f58 rw kvm.ignore_msrs=1 intel_iommu=on video=vesafb:off
[    0.500570] vesafb: mode is 1920x1080x32, linelength=7680, pages=0
[    0.500571] vesafb: scrolling: redraw
[    0.500573] vesafb: Truecolor: size=8:8:8:8, shift=24:16:8:0
[    0.500584] vesafb: framebuffer at 0x90000000, mapped to 0x(____ptrval____), using 8128k, total 8128k

2. Added modprobe files and rebuild mkinitcpio -p Linux -> no success

[root@archcor modprobe.d]# cat /etc/modprobe.d/modprobe.conf 
blacklist snd_hda_intel
blacklist snd_hda_codec_hdmi
blacklist i915
options vfio-pci ids=8086:5916
install i915 /usr/bin/false
install intel_agp /usr/bin/false

[root@archcor modprobe.d]# cat /etc/mkinitcpio.conf | grep -i files
# FILES
# This setting is similar to BINARIES above, however, files are added
# as-is and are not parsed in any way.  This is useful for config files.
FILES=(/etc/modprobe.d/modprobe.conf)

Arch keeps loading the i915 and offcourse my monitor screen.

Any help is appreciated! Thanks

Last edited by archqemu (2018-11-01 20:57:25)

schard

Forum Moderator

From: Hannover

Registered: 2016-05-06

Posts: 1,992

Website

Re: [SOLVED] Blacklisting i915 module doesn't work

Please provide the output of

grep ^MODULES /etc/mkinitcpio.conf

I.e. is i915 nmaybe built into your initramfs?
Also have a look at blacklisting by kernel command line.

OT:

[root@archcor modprobe.d]# cat /etc/mkinitcpio.conf | grep -i files
# FILES
# This setting is similar to BINARIES above, however, files are added
# as-is and are not parsed in any way.  This is useful for config files.
FILES=(/etc/modprobe.d/modprobe.conf)

Useless use of cat!

---

macro_rules! yolo { { $($tokens:tt)* } => { unsafe { $($tokens)* } }; }

archqemu

Member

Registered: 2018-10-26

Posts: 5

Re: [SOLVED] Blacklisting i915 module doesn't work

Haha thanks for pointing me on the useless use of cat.

The result of:

[root@archcor boot]# grep ^MODULES /etc/mkinitcpio.conf
MODULES=()

I did not built it into the initramfs. I checked with

 zcat initramfs-linux.bak | cpio --extract --verbose --list 

and it didn't show up in the list.

Blacklisting the module via kernel command line-> no success

[root@archcor ~]# dmesg | grep i915
[    0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-linux root=UUID=ac374591-4039-4ecb-909a-1a4188f90f58 rw kvm.ignore_msrs=1 intel_iommu=on module_blacklist=i915 video=vesafb:off
[    0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-linux root=UUID=ac374591-4039-4ecb-909a-1a4188f90f58 rw kvm.ignore_msrs=1 intel_iommu=on module_blacklist=i915 video=vesafb:off

Last edited by archqemu (2018-10-26 14:09:50)

seth

Member

Registered: 2012-09-03

Posts: 51,648

Re: [SOLVED] Blacklisting i915 module doesn't work

lsinitcpio /boot/initramfs-linux.img | grep i915 # what is initramfs-linux.bak ?
lsmod | grep i915 # are you positive the module is actually loaded?

Are you sure you're not loading the initramfs-linux-fallback.img?
Does "module_blacklist=i915" work as kernel parameter?

---

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archqemu

Member

Registered: 2018-10-26

Posts: 5

Re: [SOLVED] Blacklisting i915 module doesn't work

Pretty sure i'm not loading the fallback.img. To be sure I removed it and ran grub-mkconfig again.

No setting it as kernel parameter also doesn't make any difference.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,768

Re: [SOLVED] Blacklisting i915 module doesn't work

As already mentioned are you sure that it is actually loaded? I don't think you would get that little of a return from a grepped dmesg if that was the case. It is much more likely that you are running into the general vfio/virtio issues currently about, that was a change in 4.18.16 kernel config for Arch that changes the way you'd have to set up the passthrough: see this thread and the linked bug i.e. set up the vfio-pci ids on the kernel command line instead.

Edit: Added clarification wrt to changes

Last edited by V1del (2018-10-30 10:16:26)

archqemu

Member

Registered: 2018-10-26

Posts: 5

Re: [SOLVED] Blacklisting i915 module doesn't work

Thanks for the linked thread, I didn't read that already.

I understand you are saying this is a change since 4.18.16. So how is it possible my config works on a ubuntu server with the same kernel? At the moment I upgraded to 4.19 on that server. Same hardware.

root@ubu:/d# cat /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="kvm.ignore_msrs=1 intel_iommu=on video=efifb:off,vesafb:

root@ubu:/tmp# cat /etc/modules
# /etc/modules: kernel modules to load at boot time.
#
# This file contains the names of kernel modules that should be loaded
# at boot time, one per line. Lines beginning with "#" are ignored.

vfio
vfio_iommu_type1
vfio_pci
vfio_virqfd

root@ubu:/etc/modprobe.d# cat vfio.conf 
options vfio-pci ids=8086:5916

root@ubu:/etc/modprobe.d# cat blacklist.conf
blacklist snd_hda_intel
blacklist snd_hda_codec_hdmi
blacklist i915

When adding the vfio-pci ids adding to kernel command line, it does not load the i915 driver, but the vfio-pci instead. So that is good. But when I passthrough the IGD, it doesn't passthrough to the VM. Instead it reactivates the i915 module again on the host. What gives a blurred frame screen. I have to reboot the system then.

I had this same issue on ubuntu server and I  had to blacklist everything related to the IGD to stop the host claiming back the IGD. Apparently this is broken in the Arch kernel?

loqs

Member

Registered: 2014-03-06

Posts: 17,428

Re: [SOLVED] Blacklisting i915 module doesn't work

I understand you are saying this is a change since 4.18.16.

No it was a change in the kernel .config used for the 4.18.16.arch1-1 linux package.
Please post kernel messages from a boot with the issue.

archqemu

Member

Registered: 2018-10-26

Posts: 5

Re: [SOLVED] Blacklisting i915 module doesn't work

I got it working. Thank you guys for pointing out the flaw in kernel 4.18.16.
Right now I'm running 4.19.0-arch1-1-ARCH and it is working directly as I configured intially. Thanks again.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,768

Re: [SOLVED] Blacklisting i915 module doesn't work

Glad to hear, please mark as [SOLVED] by editing the title in your first post: https://wiki.archlinux.org/index.php/Co … ow_to_post