[PATCH 1/3] ui/gtk: skip drawing guest scanout when associated VC is invisible

[dongwon.kim@intel.com]

From: Dongwon Kim <dongwon.kim@intel.com>

A new flag "visible" is added to show visibility status of the gfx console.
The flag is set to 'true' when the VC is visible but set to 'false' when
it is hidden or closed. When the VC is invisible, drawing guest frames
should be skipped as it will never be completed and it would potentially
lock up the guest display especially when blob scanout is used.

Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>

Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
---
 include/ui/gtk.h |  1 +
 ui/gtk-egl.c     |  8 ++++++++
 ui/gtk-gl-area.c |  8 ++++++++
 ui/gtk.c         | 10 +++++++++-
 4 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/include/ui/gtk.h b/include/ui/gtk.h
index aa3d637029..2de38e5724 100644
--- a/include/ui/gtk.h
+++ b/include/ui/gtk.h
@@ -57,6 +57,7 @@ typedef struct VirtualGfxConsole {
     bool y0_top;
     bool scanout_mode;
     bool has_dmabuf;
+    bool visible;
 #endif
 } VirtualGfxConsole;
 
diff --git a/ui/gtk-egl.c b/ui/gtk-egl.c
index 3af5ac5bcf..993c283191 100644
--- a/ui/gtk-egl.c
+++ b/ui/gtk-egl.c
@@ -265,6 +265,10 @@ void gd_egl_scanout_dmabuf(DisplayChangeListener *dcl,
 #ifdef CONFIG_GBM
     VirtualConsole *vc = container_of(dcl, VirtualConsole, gfx.dcl);
 
+    if (!vc->gfx.visible) {
+        return;
+    }
+
     eglMakeCurrent(qemu_egl_display, vc->gfx.esurface,
                    vc->gfx.esurface, vc->gfx.ectx);
 
@@ -363,6 +367,10 @@ void gd_egl_flush(DisplayChangeListener *dcl,
     VirtualConsole *vc = container_of(dcl, VirtualConsole, gfx.dcl);
     GtkWidget *area = vc->gfx.drawing_area;
 
+    if (!vc->gfx.visible) {
+        return;
+    }
+
     if (vc->gfx.guest_fb.dmabuf && !vc->gfx.guest_fb.dmabuf->draw_submitted) {
         graphic_hw_gl_block(vc->gfx.dcl.con, true);
         vc->gfx.guest_fb.dmabuf->draw_submitted = true;
diff --git a/ui/gtk-gl-area.c b/ui/gtk-gl-area.c
index 52dcac161e..04e07bd7ee 100644
--- a/ui/gtk-gl-area.c
+++ b/ui/gtk-gl-area.c
@@ -285,6 +285,10 @@ void gd_gl_area_scanout_flush(DisplayChangeListener *dcl,
 {
     VirtualConsole *vc = container_of(dcl, VirtualConsole, gfx.dcl);
 
+    if (!vc->gfx.visible) {
+        return;
+    }
+
     if (vc->gfx.guest_fb.dmabuf && !vc->gfx.guest_fb.dmabuf->draw_submitted) {
         graphic_hw_gl_block(vc->gfx.dcl.con, true);
         vc->gfx.guest_fb.dmabuf->draw_submitted = true;
@@ -299,6 +303,10 @@ void gd_gl_area_scanout_dmabuf(DisplayChangeListener *dcl,
 #ifdef CONFIG_GBM
     VirtualConsole *vc = container_of(dcl, VirtualConsole, gfx.dcl);
 
+    if (!vc->gfx.visible) {
+        return;
+    }
+
     gtk_gl_area_make_current(GTK_GL_AREA(vc->gfx.drawing_area));
     egl_dmabuf_import_texture(dmabuf);
     if (!dmabuf->texture) {
diff --git a/ui/gtk.c b/ui/gtk.c
index 810d7fc796..02eb667d8a 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -1312,15 +1312,20 @@ static void gd_menu_quit(GtkMenuItem *item, void *opaque)
 static void gd_menu_switch_vc(GtkMenuItem *item, void *opaque)
 {
     GtkDisplayState *s = opaque;
-    VirtualConsole *vc = gd_vc_find_by_menu(s);
+    VirtualConsole *vc;
     GtkNotebook *nb = GTK_NOTEBOOK(s->notebook);
     gint page;
 
+    vc = gd_vc_find_current(s);
+    vc->gfx.visible = false;
+
+    vc = gd_vc_find_by_menu(s);
     gtk_release_modifiers(s);
     if (vc) {
         page = gtk_notebook_page_num(nb, vc->tab_item);
         gtk_notebook_set_current_page(nb, page);
         gtk_widget_grab_focus(vc->focus);
+        vc->gfx.visible = true;
     }
 }
 
@@ -1350,6 +1355,7 @@ static gboolean gd_tab_window_close(GtkWidget *widget, GdkEvent *event,
     VirtualConsole *vc = opaque;
     GtkDisplayState *s = vc->s;
 
+    vc->gfx.visible = false;
     gtk_widget_set_sensitive(vc->menu_item, true);
     gd_widget_reparent(vc->window, s->notebook, vc->tab_item);
     gtk_notebook_set_tab_label_text(GTK_NOTEBOOK(s->notebook),
@@ -1423,6 +1429,7 @@ static void gd_menu_untabify(GtkMenuItem *item, void *opaque)
         gd_update_geometry_hints(vc);
         gd_update_caption(s);
     }
+    vc->gfx.visible = true;
 }
 
 static void gd_menu_show_menubar(GtkMenuItem *item, void *opaque)
@@ -2471,6 +2478,7 @@ static void gtk_display_init(DisplayState *ds, DisplayOptions *opts)
 #ifdef CONFIG_GTK_CLIPBOARD
     gd_clipboard_init(s);
 #endif /* CONFIG_GTK_CLIPBOARD */
+    vc->gfx.visible = true;
 }
 
 static void early_gtk_display_init(DisplayOptions *opts)
-- 
2.34.1