Virtualbox does not start Windows VM anymore, kernel issue?

Because kernel 5.11.4_rt11-1 is now unsupported I installed kernel 5.10.52_rt47-3.
After a reboot the Windows 11 VM in Virtualbox 6.1.24 did not start anymore and Vb showed a message about running as root /sbin/vboxconfig. I could not find a vboxconfig in /sbin…
I then installed ‘linux510-rt-virtualbox-host-modules 6.1.24-3’ with Pamac and rebooted.
The Windows 11 VM does start and hangs at 20% completion (and does not show ‘press F12 etc’ which indicates Windows booting).
With the 5.11.4_rt11-1 -kernel Virtualbox still runs fine and still the Windows 11 VM runs.

Help! What should I do?

Have you tried installing a non rt kernel.I have win 10 running in vbox and haven’t had any issues.Also vbox is updated to 6.1.26 now as well.

No, non-rt kernel I did not try, I am using real time version for musical audio stuff. On the stable channel 6.1.24 is the actual version.

What was the exact error message? Please copy and paste it here with proper formatting.

Thanks. I can not show the exact error message, because the error message does not appear anymore. Unloading / Loading the kernel modules works also with ‘sudo rcvboxdrv’ but does not make a difference.

I have removed kernel 5.10.52-3-rt47 and re-installed. The details show “(3/5) Install DKMS modules
==> Unable to install module vboxhost/6.1.26_OSE for kernel 5.10.52-3-rt47-MANJARO: Missing kernel headers.”

See below. What should I do to resolve this?

The following packages will be installed:
linux510-rt


Starting
resolving dependencies...
looking for conflicting packages...
Packages (1) linux510-rt-5.10.52_rt47-3
Total Installed Size:  79.70 MiB
:: Proceed with installation? [Y/n]
checking keyring...
checking package integrity...
loading package files...
checking for file conflicts...
checking available disk space...
:: Processing package changes...
installing linux510-rt...
Optional dependencies for linux510-rt
    crda: to set the correct wireless channels of your country [installed]
:: Running post-transaction hooks...
(1/5) Arming ConditionNeedsUpdate...
(2/5) Updating module dependencies...
(3/5) Install DKMS modules
==> Unable to install module vboxhost/6.1.26_OSE for kernel 5.10.52-3-rt47-MANJARO: Missing kernel headers.
(4/5) Updating linux initcpios...
==> Building image from preset: /etc/mkinitcpio.d/linux510-rt.preset: 'default'
  -> -k /boot/vmlinuz-5.10-rt-x86_64 -c /etc/mkinitcpio.conf -g /boot/initramfs-5.10-rt-x86_64.img
==> Starting build: 5.10.52-3-rt47-MANJARO
-> Running build hook: [base]
-> Running build hook: [udev]
-> Running build hook: [autodetect]
-> Running build hook: [modconf]
-> Running build hook: [block]
-> Running build hook: [keyboard]
-> Running build hook: [keymap]
-> Running build hook: [filesystems]
==> Generating module dependencies
==> Creating gzip-compressed initcpio image: /boot/initramfs-5.10-rt-x86_64.img
==> Image generation successful
==> Building image from preset: /etc/mkinitcpio.d/linux510-rt.preset: 'fallback'
-> -k /boot/vmlinuz-5.10-rt-x86_64 -c /etc/mkinitcpio.conf -g /boot/initramfs-5.10-rt-x86_64-fallback.img -S autodetect
==> Starting build: 5.10.52-3-rt47-MANJARO
-> Running build hook: [base]
-> Running build hook: [udev]
-> Running build hook: [modconf]
-> Running build hook: [block]
-> Running build hook: [keyboard]
-> Running build hook: [keymap]
-> Running build hook: [filesystems]
==> Generating module dependencies
==> Creating gzip-compressed initcpio image: /boot/initramfs-5.10-rt-x86_64-fallback.img
==> Image generation successful
(5/5) Updating Grub-Bootmenu
Generating grub configuration file ...
Found theme: /usr/share/grub/themes/manjaro/theme.txt
Found linux image: /boot/vmlinuz-5.11-rt-x86_64
Found initrd image: /boot/intel-ucode.img /boot/initramfs-5.11-rt-x86_64.img
Found initrd fallback image: /boot/initramfs-5.11-rt-x86_64-fallback.img
Found linux image: /boot/vmlinuz-5.10-rt-x86_64
Found initrd image: /boot/intel-ucode.img /boot/initramfs-5.10-rt-x86_64.img
Found initrd fallback image: /boot/initramfs-5.10-rt-x86_64-fallback.img
Warning: os-prober will be executed to detect other bootable partitions.

Have you installed linux510-rt-headers?

No, I did not yet. Isn’t that something that normally happens automagically when a kernel is added? I would rather not install all sort of stuff manually to fix errors without understanding the root cause.

Headers aren’t automatically installed as not everyone needs them (I don’t have them installed). Your error message is telling you the cause of the failure:

OK. Should I install those headers and then re-install kernel 5.10.52-3-rt47 to install module vboxhost/6.1.26_OSE or something else?

Install the headers then you should just be able to run sudo mkinitcpio -P to regenerate the initramfs images.

Thanks. After I executed the followings steps VB is running OK:

  1. Install kernel 5.10. xx
  2. reboot / select kernel 5.10.xx in Grub
  3. Install dkms / virtualbox-host-dkms
  4. Install kernel headers 5.10
  5. reboot

After that VB could run my installed VMs.