journalctl -b0 -p4
DMAR-IR: This system BIOS has enabled interrupt remapping on a chipset that contains an erratum making that feature unstable.  To maintain system stability interrupt remapping is being disabled.  Please contact your BIOS vendor for an update Switched APIC routing to physical flat.


In general: This feature allows the kernel to replace the remapping tables created by your BIOS.

If it’s a system firmware bug, updates to Arch aren’t going to fix it. You’d need to update your system firmware (BIOS/UEFI) by flashing. I personally don’t recommend that. You should only do this if you really know how to flash your hardware.

The “soft” way is to disable the interrupt remapping in the kernel boot parameters. intremap=off disables the kernel interrupt remapping, which might point to your buggy bios or hardware.

First take a look at your config with cat /proc/cmdline. Copy it to see changes later on. Now back up your /etc/default/grub by copying it to a direction you want. To make the change persistent after a reboot edit /etc/default/grub and append your kernel options to the GRUB_CMDLINE_LINUX_DEFAULT line. In your case it is intremap=off (put it into the ” “). You can delete the quiet if it is in there. Save it and exit.

Now re-generate the grub.cfg file (it is generated with the parameters written in /etc/default/grub) with: sudo grub2-mkconfig -o /boot/grub2/grub.cfg

Reboot your system and the error should be gone. Take a look at your config with cat /proc/cmdline, your changes should be visable.