Yesterday, my beloved Thinkpad x230 started to randomly crash, sometimes even with bootloops, and the lasts things available in the logs, when it to get past disk encryption, where the following lines:
Jun 25 22:25:43 grimhilde kernel: [ 551.300388] DMAR: DRHD: handling fault status reg 2
Jun 25 22:25:43 grimhilde kernel: [ 551.300402] DMAR: [INTR-REMAP] Request device [03:00.0] fault index 18 [fault reason 38] Blocked an interrupt request due to source-id verification failure
DMAR stands for DMA-remapping (you can check the related code
here),
and INTR for interruption: something must likely be wrong in their neighbourhood.
A completely wild guess would be that the crash is related to
Intel Vt
since:
- Virtualisation deals with DMA a lot;
- Intel Vt is explicitly mentioned in the code next to the error message;
- my machine is sometimes correctly booting;
- it's one of the laziest low-hanging switch to toggle to see if it is the culprit.
I turned Intel Vt off in the BIOS, and didn't experience bootloops or crashes since but since my CMOS battery is likely dying, it might also be a completely random coincidence.