I am having the same issue. Tested on Xubuntu 20.10 (qemu 5.0) and ArchLinux (qemu 5.2).
Furthermore, SDL is broken too: In principle I get some output with SDL but its broken and not very usable. After some time (after starting the Desktop Env. - as far as I can tell), the screen also turns black as with GTK. When redirecting IO to stdio I get the following error message: ## opengl error ## gl_version 45 - core profile enabled vrend_renderer_fill_caps: Entering with stale GL error: 1280 GLSL feature level 430 ## startup command ## qemu-system-x86_64 \ -serial stdio \ -m 8G \ -enable-kvm \ -vga virtio \ -display gtk,gl=on \ -machine q35 \ -cpu host \ -bios /usr/share/OVMF/x64/OVMF_CODE.fd \ -boot order=d \ -drive file=test.img,format=raw \ -cdrom /media/os/xubuntu-20.10-desktop-amd64.iso ## hardware of host ## ryzen 3700x on b450 chipset geforce 1060 with latest nvidia drivers -- 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
