> From: Antonio Caggiano <quic_acagg...@quicinc.com>
>
> The first time gd_egl_scanout_texture() is called, there's a possibility
> that the GTK drawing area might not be realized yet, in which case its
> associated GdkWindow is NULL. This means gd_egl_init() was also skipped
> and the EGLContext and EGLSurface stored in the VirtualGfxConsole are
> not valid yet.
>
> Continuing with the scanout in this conditions would result in hitting
> an assert in libepoxy: "Couldn't find current GLX or EGL context".
>
> A possible workaround is to just ignore the scanout request, giving the
> the GTK drawing area some time to finish its realization. At that point,
> the gd_egl_init() will succeed and the EGLContext and EGLSurface stored
> in the VirtualGfxConsole will be valid.
>
> Signed-off-by: Antonio Caggiano <quic_acagg...@quicinc.com>
> Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> Message-Id: <20231016123215.2699269-1-quic_acagg...@quicinc.com>
> ---
> ui/gtk-egl.c | 17 ++++++++++++-----
> 1 file changed, 12 insertions(+), 5 deletions(-)
Hi Antonio,
this patch breaks the QEMU guest display on my system. QEMU was started
with ./qemu-system-x86_64 -machine q35 -device
virtio-vga-gl,xres=1280,yres=768 -display gtk,zoom-to-fit=off,gl=on. I
can see the OVMF boot screen and then GRUB. After Linux was started,
plymouth normally shows the OVMF boot logo and a rotating spinner. With
your patch the guest screen is black and shows 'Display output is not
active.'. It seems the guest works without issues. I can use ssh to log
in and I can't find any obvious errors in the guest log files. The host
uses a GNOME desktop under X11.
If I revert this patch everything works as expected.
With best regards,
Volker
Cc: Michael Tokarev
This will affect Stable-7.2.7 and Stable-8.1.3.
> diff --git a/ui/gtk-egl.c b/ui/gtk-egl.c
> index a1060fd80f..3e8d1c1d02 100644
> --- a/ui/gtk-egl.c
> +++ b/ui/gtk-egl.c
> @@ -243,12 +243,19 @@ void gd_egl_scanout_texture(DisplayChangeListener *dcl,
> vc->gfx.h = h;
> vc->gfx.y0_top = backing_y_0_top;
>
> - eglMakeCurrent(qemu_egl_display, vc->gfx.esurface,
> - vc->gfx.esurface, vc->gfx.ectx);
> + if (!vc->gfx.esurface) {
> + gd_egl_init(vc);
> + if (!vc->gfx.esurface) {
> + return;
> + }
> +
> + eglMakeCurrent(qemu_egl_display, vc->gfx.esurface,
> + vc->gfx.esurface, vc->gfx.ectx);
>
> - gtk_egl_set_scanout_mode(vc, true);
> - egl_fb_setup_for_tex(&vc->gfx.guest_fb, backing_width, backing_height,
> - backing_id, false);
> + gtk_egl_set_scanout_mode(vc, true);
> + egl_fb_setup_for_tex(&vc->gfx.guest_fb, backing_width,
> backing_height,
> + backing_id, false);
> + }
> }
>
> void gd_egl_scanout_dmabuf(DisplayChangeListener *dcl,
