From a6fb61dbf265fe902587f3c7365ff8694c63a0bf Mon Sep 17 00:00:00 2001
From: Christian Helmuth <christian.helmuth@genode-labs.com>
Date: Tue, 17 Aug 2021 15:26:18 +0200
Subject: [PATCH] vbox6: support dynamic framebuffer resolution

Issue #4031
---
 repos/ports/src/virtualbox6/include/fb.h | 14 +++++----
 repos/ports/src/virtualbox6/main.cc      | 38 +++++++++++++++++++++++-
 2 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/repos/ports/src/virtualbox6/include/fb.h b/repos/ports/src/virtualbox6/include/fb.h
index caec3f8f6f..7847697225 100644
--- a/repos/ports/src/virtualbox6/include/fb.h
+++ b/repos/ports/src/virtualbox6/include/fb.h
@@ -148,10 +148,13 @@ class Genodefb :
 			/* save the new bitmap reference */
 			_display->QuerySourceBitmap(screen, _display_bitmap.asOutParam());
 
-			bool ok = (w <= (ULONG)_fb_mode.area.w()) &&
-			          (h <= (ULONG)_fb_mode.area.h());
+			bool const ok = (w <= (ULONG)_fb_mode.area.w()) &&
+			                (h <= (ULONG)_fb_mode.area.h());
 
-			if (ok) {
+			bool const changed = (w != (ULONG)_virtual_fb_mode.area.w()) ||
+			                     (h != (ULONG)_virtual_fb_mode.area.h());
+
+			if (ok && changed) {
 				Genode::log("fb resize : [", screen, "] ",
 				            _virtual_fb_mode.area, " -> ",
 				            w, "x", h,
@@ -160,13 +163,13 @@ class Genodefb :
 				if ((w < (ULONG)_fb_mode.area.w()) ||
 				    (h < (ULONG)_fb_mode.area.h())) {
 					/* clear the old content around the new, smaller area. */
-				    _clear_screen();
+					_clear_screen();
 				}
 
 				_virtual_fb_mode = Fb_Genode::Mode { .area = { w, h } };
 
 				result = S_OK;
-			} else {
+			} else if (changed) {
 				Genode::log("fb resize : [", screen, "] ",
 				            _virtual_fb_mode.area, " -> ",
 				            w, "x", h, " ignored"
@@ -205,7 +208,6 @@ class Genodefb :
 			Lock();
 
 			if (_display_bitmap.isNull()) {
-				_clear_screen();
 				Unlock();
 				return S_OK;
 			}
diff --git a/repos/ports/src/virtualbox6/main.cc b/repos/ports/src/virtualbox6/main.cc
index e71dde1b82..deac9aff51 100644
--- a/repos/ports/src/virtualbox6/main.cc
+++ b/repos/ports/src/virtualbox6/main.cc
@@ -265,6 +265,10 @@ struct Main : Event_handler
 
 	void _handle_input();
 
+	Signal_handler<Main> _fb_mode_handler { _env.ep(), *this, &Main::_handle_fb_mode };
+
+	void _handle_fb_mode();
+
 	Input_adapter _input_adapter { _iconsole };
 
 	bool const _genode_gui_attached = ( _attach_genode_gui(), true );
@@ -275,9 +279,12 @@ struct Main : Event_handler
 
 		for (unsigned i = 0; i < num_monitors.value; i++) {
 
-			Gui::Connection &gui = *new Registered<Gui::Connection>(_gui_connections, _env);
+			String<3> label { i };
+
+			Gui::Connection &gui = *new Registered<Gui::Connection>(_gui_connections, _env, label.string());
 
 			gui.input()->sigh(_input_handler);
+			gui.mode_sigh(_fb_mode_handler);
 
 			Genodefb *fb = new Genodefb(_env, gui, _idisplay);
 
@@ -371,6 +378,35 @@ void Main::_handle_input()
 }
 
 
+void Main::_handle_fb_mode()
+{
+	Libc::with_libc([&] {
+		_gui_connections.for_each([&] (Gui::Connection &gui) {
+			IFramebuffer *pFramebuffer = NULL;
+			HRESULT rc = _idisplay->QueryFramebuffer(0, &pFramebuffer);
+			Assert(SUCCEEDED(rc) && pFramebuffer);
+
+			Genodefb *fb = dynamic_cast<Genodefb *>(pFramebuffer);
+
+			fb->update_mode(gui.mode());
+
+			if ((fb->w() <= 1) && (fb->h() <= 1)) {
+				/* interpret a size of 0x0 as indication to quit VirtualBox */
+				if (_iconsole->PowerButton() != S_OK)
+					Genode::error("ACPI shutdown failed");
+				return;
+			}
+
+			_idisplay->SetVideoModeHint(0 /*=display*/,
+			                            true /*=enabled*/, false /*=changeOrigin*/,
+			                            0 /*=originX*/, 0 /*=originY*/,
+			                            fb->w(), fb->h(),
+			                            32, true);
+		});
+	});
+}
+
+
 void Main::handle_vbox_event(VBoxEventType_T ev_type, IEvent &ev)
 {
 	switch (ev_type) {