Debian upgrade and xf86EnableIO: failed to enable I/O ports (Operation not permitted)

Same symptom as ["xf86EnableIO: failed to enable I/O ports 0000-03ff (Operation not permitted)"](https://askubuntu.com/questions/1481183/xf86enableio-failed-to-enable-i-o-ports-0000-03ff-operation-not-permitted) , which solution was: > Looks like a lot of people are having similar issues today. In my case, on Ubuntu 22.04.3 I fixed the issue by installing ubuntu-desktop: > > sudo apt install ubuntu-desktop because the [root cause was](https://bugs.launchpad.net/ubuntu/+source/apt/+bug/2030262) : > I noticed xorg and the whole desktop (lubuntu first, kubuntu later at another laptop) had been removed However, that's not the case for my Debian 12 bookworm, which I have just upgraded kernel from linux-image-6.1.0-9-amd64 to linux-image-6.1.0-13-amd64, and right afterwards, my startx is failing. I posted the full log at: https://pastebin.com/tAfEBazQ The most important line seems to be xf86EnableIO: failed to enable I/O ports 0000-03ff (Operation not permitted) I tried the answer from https://unix.stackexchange.com/questions/159124/xf86enableioports-failed-to-set-iopl-for-i-o-operation-not-permitted , and can confirm that the sudo chmod u+s /usr/bin/xinit is not working for my case. I believe it is purely kernel related as - I can boot from my old linux-image-6.1.0-9-amd64 and able to startx - and with linux-image-6.1.0-13-amd64 and even with elevated xinit my startx is still failing - My xserver-xorg is the same after kernel upgrade, and is already the latest version. Judging from that fact that merely swapping the kernel when booting makes the vital differences, the kernel upgrade seems to be the root cause. But I'm wondering how to fix it. PS. More info: I use startx as myself as always, and

$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 12 (bookworm)
Release:        12
Codename:       bookworm

$ apt-cache policy xserver-xorg
xserver-xorg:
  Installed: 1:7.7+23
  Candidate: 1:7.7+23
  Version table:
 *** 1:7.7+23 500
        500 http://deb.debian.org/debian  bookworm/main amd64 Packages
         80 http://deb.debian.org/debian  trixie/main amd64 Packages
        100 /var/lib/dpkg/status

$ plocate vesa.conf | wc
      0       0       0

$ plocate xorg.conf.d | grep /etc/
/etc/X11/xorg.conf.d

$ ls /etc/X11/xorg.conf.d | wc
      0       0       0

$ stat /usr/bin/xinit
  File: /usr/bin/xinit
  Size: 19064           Blocks: 40         IO Block: 4096   regular file
Device: 8,11    Inode: 524333      Links: 1
Access: (4755/-rwsr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)