virtio-gpu-gl-pci console tries to make GL context before widget is realized leading to crash

Host environment

Operating system: Arch Linux
OS/kernel version: Linux archlinux 6.3.7-arch1-1 #1 SMP PREEMPT_DYNAMIC Sat, 10 Jun 2023 00:35:35 +0000 x86_64 GNU/Linux
Architecture: x86
QEMU flavor: qemu-system-x86_64
QEMU version: freshly cloned at commit b455ce4c

QEMU command line:

./qemu-system-x86_64 -drive if=pflash,format=raw,readonly=on,file=/usr/share/edk2-ovmf/x64/OVMF_CODE.fd -device virtio-gpu-gl -display gtk,gl=on

Description of problem

When -vga none is added to the command line, there is no crash.

When it is not, two GtkGLArea widgets are created: one for VGA and one for virtio-gpu-gl-pci. Only the first one is realized, but the virgl code tries to create a GL context for the second. In gd_gl_area_create_context, gtk_widget_get_window(vc->gfx.drawing_area) evaluates to NULL a crash follows:

qemu: Gdk: gdk_window_create_gl_context: assertion 'GDK_IS_WINDOW (window)' failed
qemu: Gdk: gdk_gl_context_set_required_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_realize: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_make_current: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_get_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gtk: gtk_gl_area_make_current: assertion 'gtk_widget_get_realized (widget)' failed
qemu: Gdk: gdk_window_create_gl_context: assertion 'GDK_IS_WINDOW (window)' failed
qemu: Gdk: gdk_gl_context_set_required_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_realize: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_make_current: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_get_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gtk: gtk_gl_area_make_current: assertion 'gtk_widget_get_realized (widget)' failed
qemu: Gdk: gdk_window_create_gl_context: assertion 'GDK_IS_WINDOW (window)' failed
qemu: Gdk: gdk_gl_context_set_required_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_realize: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_make_current: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_get_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gtk: gtk_gl_area_make_current: assertion 'gtk_widget_get_realized (widget)' failed
qemu: Gdk: gdk_window_create_gl_context: assertion 'GDK_IS_WINDOW (window)' failed
qemu: Gdk: gdk_gl_context_set_required_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_realize: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_make_current: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_get_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gtk: gtk_gl_area_make_current: assertion 'gtk_widget_get_realized (widget)' failed
qemu: Gdk: gdk_window_create_gl_context: assertion 'GDK_IS_WINDOW (window)' failed
qemu: Gdk: gdk_gl_context_set_required_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_realize: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_make_current: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_get_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gtk: gtk_gl_area_make_current: assertion 'gtk_widget_get_realized (widget)' failed
qemu: Gdk: gdk_window_create_gl_context: assertion 'GDK_IS_WINDOW (window)' failed
qemu: Gdk: gdk_gl_context_set_required_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_realize: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_make_current: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_get_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gtk: gtk_gl_area_make_current: assertion 'gtk_widget_get_realized (widget)' failed
qemu: Gdk: gdk_window_create_gl_context: assertion 'GDK_IS_WINDOW (window)' failed
qemu: Gdk: gdk_gl_context_set_required_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_realize: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_make_current: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_get_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gtk: gtk_gl_area_make_current: assertion 'gtk_widget_get_realized (widget)' failed
qemu: Gdk: gdk_window_create_gl_context: assertion 'GDK_IS_WINDOW (window)' failed
qemu: Gdk: gdk_gl_context_set_required_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_realize: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_make_current: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_get_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gtk: gtk_gl_area_make_current: assertion 'gtk_widget_get_realized (widget)' failed
qemu: Gdk: gdk_window_create_gl_context: assertion 'GDK_IS_WINDOW (window)' failed
qemu: Gdk: gdk_gl_context_set_required_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_realize: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_make_current: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_get_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gtk: gtk_gl_area_make_current: assertion 'gtk_widget_get_realized (widget)' failed
qemu: Gdk: gdk_window_create_gl_context: assertion 'GDK_IS_WINDOW (window)' failed
qemu: Gdk: gdk_gl_context_set_required_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_realize: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_make_current: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_get_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gtk: gtk_gl_area_make_current: assertion 'gtk_widget_get_realized (widget)' failed
qemu: Gdk: gdk_window_create_gl_context: assertion 'GDK_IS_WINDOW (window)' failed
qemu: Gdk: gdk_gl_context_set_required_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_realize: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_make_current: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gdk: gdk_gl_context_get_version: assertion 'GDK_IS_GL_CONTEXT (context)' failed
qemu: Gtk: gtk_gl_area_make_current: assertion 'gtk_widget_get_realized (widget)' failed
qemu: Gdk: gdk_gl_context_make_current: assertion 'GDK_IS_GL_CONTEXT (context)' failed
gl_version 0 - compat profile
WARNING: running without ARB/KHR robustness in place may crash
qemu-system-x86_64: ../libepoxy/src/dispatch_common.c:872: epoxy_get_proc_address: Assertion `0 && "Couldn't find current GLX or EGL context.\n"' failed.

Steps to reproduce

Get OVMF. On Arch Linux, you can install the edk2-ovmf package. On other distros, find a similar package and modify the path in the command accordingly.
Run the command above.

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