Black frame content noticed on guest screen for Fedora 36 GOS on M1
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Black frame content noticed on guest screen for Fedora 36 GOS on M1

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Article ID: 315604

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Updated On:

Products

VMware Desktop Hypervisor

Issue/Introduction

This article provides steps to avoid the desktop repaint issue as manifested under the GLAMOR accelerated driver.

Symptoms:
ARM64 Linux guests which use the Xserver with GLAMOR acceleration architecture might exhibit visual artifacts due to some damage region repaint bugs in GLAMOR. The breakage commonly manifests as desktop regions that need repainting, e.g. as a result of window pop-up/refresh/movement, not getting repainted until the mouse cursor moves over these regions. Specifically, only a small square area around the mouse gets repainted, effectively creating a "repaint trail" behind the mouse.

Resolution

VMware's Linux guest display stack for ARM64 currently does not include a Xorg video driver, so GLAMOR is used as the default 2D-graphics accelerated driver for Xorg in many Linux distros such as Fedora and Ubuntu. We advise the general disablement of GLAMOR in VMs running such distros under Fusion/M1.

A straightforward way to achieve that is to switch to a Wayland-based desktop, where GLAMOR does not participate. The simplest way to switch to Wayland in a GNOME environment is via editing the GDM (GNOME display manager) configuration file.
In Ubuntu that file resides at /etc/gdm3/custom.conf
In Fedora/RedHat/Archlinux that file resides at /etc/gdm/custom.conf.
  • In the config file, please find the line that states #WaylandEnable=false (or WaylandEnable=false) 
  • Change that to
WaylandEnable=true
  • On the next desktop restart or system boot Wayland will be used as the new display server.
  • Alternatively, you can force the restart of GDM via the service management interface. In Ubuntu that can be done on the command line as:
$ service gdm3 restart

Note: Users normally need superuser credentials to edit files under /etc, or to restart services.

If Xserver is required, you can specifically disable GLAMOR in favor of modesetting Xorg driver. On Ubuntu, that is achieved via creating a (or editing a pre-existing) Xorg config file residing at /usr/share/X11/xorg.conf.d/glamor.conf, to the following content:
    Section "Device"
    Identifier "modesetting"
    Driver "modesetting"
    Option "AccelMethod" "shadowfb"
    EndSection

Note: This approach does not allow SVGA3D acceleration. To get SVGA3D acceleration you need a Wayland-based display server.