Re: [PATCH v3 2/3] ui/console: Pass placeholder surface to displays

2021-02-25 Thread Gerd Hoffmann
> +static void dpy_gfx_switch(DisplayChangeListener *dcl, DisplaySurface 
> *surface)

int width, int height;

> +static DisplaySurface *placeholder;
> +static const char placeholder_msg[] = "Display output is not active.";
> +DisplaySurface *broadcast;
> +
> +if (!dcl->ops->dpy_gfx_switch) {
> +return;
> +}
> +
> +if (surface) {
> +broadcast = surface;
> +} else {
> +if (!placeholder) {
> +placeholder = qemu_create_placeholder_surface(640, 480, 
> placeholder_msg);
> +}

Just create a new one unconditionally.

> @@ -1685,9 +1704,7 @@ void dpy_gfx_replace_surface(QemuConsole *con,
>  if (con != (dcl->con ? dcl->con : active_console)) {
>  continue;
>  }
> -if (dcl->ops->dpy_gfx_switch) {
> -dcl->ops->dpy_gfx_switch(dcl, surface);
> -}
> +dpy_gfx_switch(dcl, surface);

You can look at the old_surface here and pass the size to
dpy_gfx_switch(), so the placeholder is created with the same size.

take care,
  Gerd




[PATCH v3 2/3] ui/console: Pass placeholder surface to displays

2021-02-24 Thread Akihiko Odaki
ui/console used to accept NULL as graphic console surface, but its
semantics was inconsistent among displays:
- cocoa and gtk-egl perform NULL dereference.
- egl-headless, spice and spice-egl do nothing.
- gtk releases underlying resources.
- sdl2-2d and sdl2-gl destroys the window.
- vnc shows a message, "Display output is not active."

Fortunately, only virtio-gpu and virtio-gpu-3d assign NULL so
we can study them to figure out the desired behavior. They assign
NULL *except* for the primary display when the device is realized,
reset, or its scanout is disabled. This effectively destroys
windows for the (uninitialized) secondary displays.

To implement the consistent behavior of display device
realization/reset, this change embeds it to the operation
switching the surface. When NULL was given as a new surface when
switching, ui/console will instead passes a placeholder down
to each display listeners.

sdl destroys the window for a secondary console if its surface is a
placeholder. The other displays simply shows the placeholder.

Signed-off-by: Akihiko Odaki 
---
 ui/console.c   | 45 +++--
 ui/gtk.c   |  4 
 ui/sdl2-2d.c   |  7 ++-
 ui/sdl2-gl.c   |  4 ++--
 ui/spice-display.c |  6 +++---
 ui/vnc.c   | 10 --
 6 files changed, 38 insertions(+), 38 deletions(-)

diff --git a/ui/console.c b/ui/console.c
index 0caa39a6ed3..75e54651b5b 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -1088,6 +1088,29 @@ static void console_putchar(QemuConsole *s, int ch)
 }
 }
 
+static void dpy_gfx_switch(DisplayChangeListener *dcl, DisplaySurface *surface)
+{
+static DisplaySurface *placeholder;
+static const char placeholder_msg[] = "Display output is not active.";
+DisplaySurface *broadcast;
+
+if (!dcl->ops->dpy_gfx_switch) {
+return;
+}
+
+if (surface) {
+broadcast = surface;
+} else {
+if (!placeholder) {
+placeholder = qemu_create_placeholder_surface(640, 480, 
placeholder_msg);
+}
+
+broadcast = placeholder;
+}
+
+dcl->ops->dpy_gfx_switch(dcl, broadcast);
+}
+
 void console_select(unsigned int index)
 {
 DisplayChangeListener *dcl;
@@ -1104,9 +1127,7 @@ void console_select(unsigned int index)
 if (dcl->con != NULL) {
 continue;
 }
-if (dcl->ops->dpy_gfx_switch) {
-dcl->ops->dpy_gfx_switch(dcl, s->surface);
-}
+dpy_gfx_switch(dcl, s->surface);
 }
 if (s->surface) {
 dpy_gfx_update(s, 0, 0, surface_width(s->surface),
@@ -1545,15 +1566,13 @@ void 
register_displaychangelistener(DisplayChangeListener *dcl)
 } else {
 con = active_console;
 }
-if (dcl->ops->dpy_gfx_switch) {
-if (con) {
-dcl->ops->dpy_gfx_switch(dcl, con->surface);
-} else {
-if (!dummy) {
-dummy = qemu_create_placeholder_surface(640, 480, nodev);
-}
-dcl->ops->dpy_gfx_switch(dcl, dummy);
+if (con) {
+dpy_gfx_switch(dcl, con->surface);
+} else {
+if (!dummy) {
+dummy = qemu_create_placeholder_surface(640, 480, nodev);
 }
+dpy_gfx_switch(dcl, dummy);
 }
 text_console_update_cursor(NULL);
 }
@@ -1685,9 +1704,7 @@ void dpy_gfx_replace_surface(QemuConsole *con,
 if (con != (dcl->con ? dcl->con : active_console)) {
 continue;
 }
-if (dcl->ops->dpy_gfx_switch) {
-dcl->ops->dpy_gfx_switch(dcl, surface);
-}
+dpy_gfx_switch(dcl, surface);
 }
 qemu_free_displaysurface(old_surface);
 }
diff --git a/ui/gtk.c b/ui/gtk.c
index 79dc2401203..a4a5f981e2a 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -567,10 +567,6 @@ static void gd_switch(DisplayChangeListener *dcl,
 }
 vc->gfx.ds = surface;
 
-if (!surface) {
-return;
-}
-
 if (surface->format == PIXMAN_x8r8g8b8) {
 /*
  * PIXMAN_x8r8g8b8 == CAIRO_FORMAT_RGB24
diff --git a/ui/sdl2-2d.c b/ui/sdl2-2d.c
index a2ea85127d5..bfebbdeaea8 100644
--- a/ui/sdl2-2d.c
+++ b/ui/sdl2-2d.c
@@ -32,14 +32,11 @@ void sdl2_2d_update(DisplayChangeListener *dcl,
 int x, int y, int w, int h)
 {
 struct sdl2_console *scon = container_of(dcl, struct sdl2_console, dcl);
-DisplaySurface *surf = qemu_console_surface(dcl->con);
+DisplaySurface *surf = scon->surface;
 SDL_Rect rect;
 size_t surface_data_offset;
 assert(!scon->opengl);
 
-if (!surf) {
-return;
-}
 if (!scon->texture) {
 return;
 }
@@ -75,7 +72,7 @@ void sdl2_2d_switch(DisplayChangeListener *dcl,
 scon->texture = NULL;
 }
 
-if (!new_surface) {
+if (is_placeholder(new_surface) && qemu_console_get_index(dcl->con)) {
 sdl2_window_destroy(scon);
 return;
 }
diff --git a/ui/sdl2