0 Using Wayland on Linux in Hyper-V: How to Disable hyperv_fb on Ubuntu and Rocky Linux.md

Using Wayland on Linux in Hyper-V: How to Disable hyperv_fb on Ubuntu and Rocky Linux

When running a Linux virtual machine on Microsoft Hyper-V, you may want to use the Wayland display server for better performance and smoother graphics compared to X11. However, Wayland cannot function correctly if the Hyper-V framebuffer driver (hyperv_fb) is loaded, because it interferes with the kernel’s native framebuffer setup. To enable Wayland, you need to disable (blacklist) the hyperv_fb module. Below are two methods to do this for Ubuntu and Rocky Linux.

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1. Disabling hyperv_fb via GRUB Kernel Arguments

This method edits the GRUB configuration to prevent hyperv_fb from loading at boot time.

Steps (Ubuntu & Rocky Linux):

1. Edit the GRUB configuration file:

   sudo nano /etc/default/grub

2. Find the line that starts with:

   GRUB_CMDLINE_LINUX_DEFAULT=
   

   or

   GRUB_CMDLINE_LINUX=
   

3. Add the following parameter inside the quotes:

   modprobe.blacklist=hyperv_fb
   

   Example:

   GRUB_CMDLINE_LINUX_DEFAULT="verbose modprobe.blacklist=hyperv_fb"
   

4. Update the GRUB configuration:

   • On Ubuntu:

     sudo update-grub

   • On Rocky Linux:

     sudo grub2-mkconfig -o /boot/grub2/grub.cfg --update-bls-cmdline

     (If using UEFI: /boot/efi/EFI/rocky/grub.cfg)

5. Reboot the system:

   sudo reboot

After rebooting, the hyperv_fb module should no longer be loaded, allowing Wayland to start properly.

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2. Disabling hyperv_fb via Modprobe Blacklist

This method explicitly blacklists the module at the kernel level and updates the initramfs image.

Steps (Ubuntu & Rocky Linux):

1. Create a blacklist configuration file:

   sudo nano /etc/modprobe.d/blacklist-hyperv_fb.conf

2. Add the following line:

   blacklist hyperv_fb
   

3. Update the initramfs (initial RAM filesystem):

   • On Ubuntu:

     sudo update-initramfs -u

   • On Rocky Linux:

     sudo dracut -f

4. Reboot the system:

   sudo reboot

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Verifying the Change

After reboot, check whether the module is still loaded:

lsmod | grep hyperv_fb

If no output appears, it means hyperv_fb has been successfully disabled.

You can then enable or switch to Wayland (for example, by choosing the Wayland session at the login screen in GNOME).

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Summary

Method	Configuration File	Command to Apply	Works On
GRUB Kernel Argument	/etc/default/grub	update-grub or grub2-mkconfig	Ubuntu & Rocky Linux
Modprobe Blacklist	/etc/modprobe.d/blacklist-hyperv_fb.conf	update-initramfs or dracut -f	Ubuntu & Rocky Linux

Either method will successfully disable hyperv_fb, allowing your Linux VM on Hyper-V to run Wayland-based desktop sessions smoothly.