The problem is that Xfwm's built-in compositor and virgl don't play nice together.
Work-around: Boot the VM with virgl=off (on the video device) or gl=off (on the display), run xfwm4-tweaks-settings in the VM, select the "Compositor" tab, and uncheck "Enable display compositing". Then shut down the VM and re-enable virgl. picom works with Xfwm and doesn't seem to have the same issues, so if you want a compositor, install/use picom in the VM instead of using Xfwm's built-in compositor: https://wiki.archlinux.org/index.php/Picom -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1898490 Title: gtk with virtio and opengl black screen Status in QEMU: New Bug description: qemu-system-x86_64 -name manjaro -enable-kvm -cpu host -smp cores=4,threads=1 -M q35 -m 8G -cdrom /mnt/Storage/ISO/manjaro- gnome-20.0.3-minimal-200606-linux56.iso -machine type=pc,accel=kvm -vga virtio -display sdl,gl=on Boots properly and has working 3d acceleration with virgl. Running qemu-system-x86_64 -name manjaro -enable-kvm -cpu host -smp cores=4,threads=1 -M q35 -m 8G -cdrom /mnt/Storage/ISO/manjaro- gnome-20.0.3-minimal-200606-linux56.iso -machine type=pc,accel=kvm -vga virtio -display gtk,gl=on however, (difference being gtk instead of sdl), the screen is black, and the vm still starts. System Specs Gentoo Linux 64bit Gentoo-Sources 5.8.13 Kernel Qemu 5.10.0-r1 compiled with USE="aio bzip2 caps curl fdt filecaps gtk jpeg ncurses nls opengl oss pin-upstream-blobs png pulseaudio sdl seccomp slirp spice usb usbredir vhost-net virgl vnc xattr xkb" PYTHON_TARGETS="python3_7" QEMU_SOFTMMU_TARGETS="x86_64" QEMU_USER_TARGETS="x86_64" Ryzen 7 2700x Nvidia 1070ti GPU I can confirm the same issue when using libvirt with opengl. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1898490/+subscriptions
