Re: AMD zen microcode updates breaks boot

From: Jens Axboe
Date: Sun Oct 20 2024 - 20:47:40 EST


On 10/20/24 6:18 AM, Borislav Petkov wrote:
> Ok, this diff at the end should fix it completely. I think. The same dance,
> replace, build and boot.

Works, outside of waiting 3 min for the serial console spewage from the
patch! But it boots and it's happy after that. Attached here gzip'ed as
it's 1.3M otherwise.

> I've moved the iteration over the nodes in the late loading path as this is
> where we need it only anyway. If you wanna test that too and you feel brave,
> do this after the machine boots:
>
> # echo 1 > /sys/devices/system/cpu/microcode/reload
>
> It should say
>
> bash: echo: write error: File descriptor in bad state

I get:

root@r7625 ~# echo 1 > /sys/devices/system/cpu/microcode/reload
warning: An error occurred while redirecting file '/sys/devices/system/cpu/microcode/reload'
open: Permission denied

and no output in dmesg.


--
Jens Axboe

Attachment: r7625-dmesg.txt.gz
Description: application/gzip