console: save current scanout details

Add a new DisplayScanout structure to save the current scanout details.
This allows to attach later UI backends and set the scanout.

Introduce displaychangelistener_display_console() helper function to
handle the dpy_gfx_switch/gl_scanout() & dpy_gfx_update() calls.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>

include/ui/console.h

@@ -108,6 +108,17 @@ struct QemuConsoleClass {
 #define QEMU_ALLOCATED_FLAG     0x01
 #define QEMU_PLACEHOLDER_FLAG   0x02
 
+typedef struct ScanoutTexture {
+    uint32_t backing_id;
+    bool backing_y_0_top;
+    uint32_t backing_width;
+    uint32_t backing_height;
+    uint32_t x;
+    uint32_t y;
+    uint32_t width;
+    uint32_t height;
+} ScanoutTexture;
+
 typedef struct DisplaySurface {
     pixman_format_code_t format;
     pixman_image_t *image;
@@ -178,6 +189,22 @@ typedef struct QemuDmaBuf {
     bool      draw_submitted;
 } QemuDmaBuf;
 
+enum display_scanout {
+    SCANOUT_NONE,
+    SCANOUT_SURFACE,
+    SCANOUT_TEXTURE,
+    SCANOUT_DMABUF,
+};
+
+typedef struct DisplayScanout {
+    enum display_scanout kind;
+    union {
+        /* DisplaySurface *surface; is kept in QemuConsole */
+        ScanoutTexture texture;
+        QemuDmaBuf *dmabuf;
+    };
+} DisplayScanout;
+
 typedef struct DisplayState DisplayState;
 typedef struct DisplayGLCtx DisplayGLCtx;
 

ui/console.c

@@ -77,6 +77,7 @@ struct QemuConsole {
     console_type_t console_type;
     DisplayState *ds;
     DisplaySurface *surface;
+    DisplayScanout scanout;
     int dcls;
     DisplayGLCtx *gl;
     int gl_block;
@@ -146,6 +147,7 @@ static void dpy_refresh(DisplayState *s);
 static DisplayState *get_alloc_displaystate(void);
 static void text_console_update_cursor_timer(void);
 static void text_console_update_cursor(void *opaque);
+static bool displaychangelistener_has_dmabuf(DisplayChangeListener *dcl);
 
 static void gui_update(void *opaque)
 {
@@ -481,6 +483,8 @@ static void text_console_resize(QemuConsole *s)
     TextCell *cells, *c, *c1;
     int w1, x, y, last_width;
 
+    assert(s->scanout.kind == SCANOUT_SURFACE);
+
     last_width = s->width;
     s->width = surface_width(s->surface) / FONT_WIDTH;
     s->height = surface_height(s->surface) / FONT_HEIGHT;
@@ -1052,6 +1056,48 @@ static void console_putchar(QemuConsole *s, int ch)
     }
 }
 
+static void displaychangelistener_display_console(DisplayChangeListener *dcl,
+                                                  QemuConsole *con)
+{
+    static const char nodev[] =
+        "This VM has no graphic display device.";
+    static DisplaySurface *dummy;
+
+    if (!con) {
+        if (!dcl->ops->dpy_gfx_switch) {
+            return;
+        }
+        if (!dummy) {
+            dummy = qemu_create_placeholder_surface(640, 480, nodev);
+        }
+        dcl->ops->dpy_gfx_switch(dcl, dummy);
+        return;
+    }
+
+    if (con->scanout.kind == SCANOUT_DMABUF &&
+        displaychangelistener_has_dmabuf(dcl)) {
+        dcl->ops->dpy_gl_scanout_dmabuf(dcl, con->scanout.dmabuf);
+    } else if (con->scanout.kind == SCANOUT_TEXTURE &&
+               dcl->ops->dpy_gl_scanout_texture) {
+        dcl->ops->dpy_gl_scanout_texture(dcl,
+                                         con->scanout.texture.backing_id,
+                                         con->scanout.texture.backing_y_0_top,
+                                         con->scanout.texture.backing_width,
+                                         con->scanout.texture.backing_height,
+                                         con->scanout.texture.x,
+                                         con->scanout.texture.y,
+                                         con->scanout.texture.width,
+                                         con->scanout.texture.height);
+    } else if (con->scanout.kind == SCANOUT_SURFACE &&
+               dcl->ops->dpy_gfx_switch) {
+        dcl->ops->dpy_gfx_switch(dcl, con->surface);
+    }
+
+    dcl->ops->dpy_gfx_update(dcl, 0, 0,
+                             qemu_console_get_width(con, 0),
+                             qemu_console_get_height(con, 0));
+}
+
 void console_select(unsigned int index)
 {
     DisplayChangeListener *dcl;
@@ -1068,13 +1114,7 @@ void console_select(unsigned int index)
                 if (dcl->con != NULL) {
                     continue;
                 }
-                if (dcl->ops->dpy_gfx_switch) {
+                displaychangelistener_display_console(dcl, s);
-                    dcl->ops->dpy_gfx_switch(dcl, s->surface);
-                }
-            }
-            if (s->surface) {
-                dpy_gfx_update(s, 0, 0, surface_width(s->surface),
-                               surface_height(s->surface));
             }
         }
         if (ds->have_text) {
@@ -1480,9 +1520,6 @@ static bool dpy_gl_compatible_with(QemuConsole *con, DisplayChangeListener *dcl)
 
 void register_displaychangelistener(DisplayChangeListener *dcl)
 {
-    static const char nodev[] =
-        "This VM has no graphic display device.";
-    static DisplaySurface *dummy;
     QemuConsole *con;
 
     assert(!dcl->ds);
@@ -1507,16 +1544,7 @@ void register_displaychangelistener(DisplayChangeListener *dcl)
     } else {
         con = active_console;
     }
-    if (dcl->ops->dpy_gfx_switch) {
+    displaychangelistener_display_console(dcl, con);
-        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);
-        }
-    }
     text_console_update_cursor(NULL);
 }
 
@@ -1597,13 +1625,9 @@ void dpy_gfx_update(QemuConsole *con, int x, int y, int w, int h)
 {
     DisplayState *s = con->ds;
     DisplayChangeListener *dcl;
-    int width = w;
+    int width = qemu_console_get_width(con, x + w);
-    int height = h;
+    int height = qemu_console_get_height(con, y + h);
 
-    if (con->surface) {
-        width = surface_width(con->surface);
-        height = surface_height(con->surface);
-    }
     x = MAX(x, 0);
     y = MAX(y, 0);
     x = MIN(x, width);
@@ -1626,12 +1650,10 @@ void dpy_gfx_update(QemuConsole *con, int x, int y, int w, int h)
 
 void dpy_gfx_update_full(QemuConsole *con)
 {
-    if (!con->surface) {
+    int w = qemu_console_get_width(con, 0);
-        return;
+    int h = qemu_console_get_height(con, 0);
-    }
+
-    dpy_gfx_update(con, 0, 0,
+    dpy_gfx_update(con, 0, 0, w, h);
-                   surface_width(con->surface),
-                   surface_height(con->surface));
 }
 
 void dpy_gfx_replace_surface(QemuConsole *con,
@@ -1658,6 +1680,7 @@ void dpy_gfx_replace_surface(QemuConsole *con,
 
     assert(old_surface != surface);
 
+    con->scanout.kind = SCANOUT_SURFACE;
     con->surface = surface;
     QLIST_FOREACH(dcl, &s->listeners, next) {
         if (con != (dcl->con ? dcl->con : active_console)) {
@@ -1833,6 +1856,9 @@ void dpy_gl_scanout_disable(QemuConsole *con)
     DisplayState *s = con->ds;
     DisplayChangeListener *dcl;
 
+    if (con->scanout.kind != SCANOUT_SURFACE) {
+        con->scanout.kind = SCANOUT_NONE;
+    }
     QLIST_FOREACH(dcl, &s->listeners, next) {
         dcl->ops->dpy_gl_scanout_disable(dcl);
     }
@@ -1849,6 +1875,11 @@ void dpy_gl_scanout_texture(QemuConsole *con,
     DisplayState *s = con->ds;
     DisplayChangeListener *dcl;
 
+    con->scanout.kind = SCANOUT_TEXTURE;
+    con->scanout.texture = (ScanoutTexture) {
+        backing_id, backing_y_0_top, backing_width, backing_height,
+        x, y, width, height
+    };
     QLIST_FOREACH(dcl, &s->listeners, next) {
         dcl->ops->dpy_gl_scanout_texture(dcl, backing_id,
                                          backing_y_0_top,
@@ -1863,6 +1894,8 @@ void dpy_gl_scanout_dmabuf(QemuConsole *con,
     DisplayState *s = con->ds;
     DisplayChangeListener *dcl;
 
+    con->scanout.kind = SCANOUT_DMABUF;
+    con->scanout.dmabuf = dmabuf;
     QLIST_FOREACH(dcl, &s->listeners, next) {
         dcl->ops->dpy_gl_scanout_dmabuf(dcl, dmabuf);
     }
@@ -1989,10 +2022,8 @@ QemuConsole *graphic_console_init(DeviceState *dev, uint32_t head,
     s = qemu_console_lookup_unused();
     if (s) {
         trace_console_gfx_reuse(s->index);
-        if (s->surface) {
+        width = qemu_console_get_width(s, 0);
-            width = surface_width(s->surface);
+        height = qemu_console_get_height(s, 0);
-            height = surface_height(s->surface);
-        }
     } else {
         trace_console_gfx_new();
         s = new_console(ds, GRAPHIC_CONSOLE, head);
@@ -2021,13 +2052,8 @@ void graphic_console_close(QemuConsole *con)
     static const char unplugged[] =
         "Guest display has been unplugged";
     DisplaySurface *surface;
-    int width = 640;
+    int width = qemu_console_get_width(con, 640);
-    int height = 480;
+    int height = qemu_console_get_height(con, 480);
-
-    if (con->surface) {
-        width = surface_width(con->surface);
-        height = surface_height(con->surface);
-    }
 
     trace_console_gfx_close(con->index);
     object_property_set_link(OBJECT(con), "device", NULL, &error_abort);
@@ -2179,7 +2205,19 @@ int qemu_console_get_width(QemuConsole *con, int fallback)
     if (con == NULL) {
         con = active_console;
     }
-    return con ? surface_width(con->surface) : fallback;
+    if (con == NULL) {
+        return fallback;
+    }
+    switch (con->scanout.kind) {
+    case SCANOUT_DMABUF:
+        return con->scanout.dmabuf->width;
+    case SCANOUT_TEXTURE:
+        return con->scanout.texture.width;
+    case SCANOUT_SURFACE:
+        return surface_width(con->surface);
+    default:
+        return fallback;
+    }
 }
 
 int qemu_console_get_height(QemuConsole *con, int fallback)
@@ -2187,7 +2225,19 @@ int qemu_console_get_height(QemuConsole *con, int fallback)
     if (con == NULL) {
         con = active_console;
     }
-    return con ? surface_height(con->surface) : fallback;
+    if (con == NULL) {
+        return fallback;
+    }
+    switch (con->scanout.kind) {
+    case SCANOUT_DMABUF:
+        return con->scanout.dmabuf->height;
+    case SCANOUT_TEXTURE:
+        return con->scanout.texture.height;
+    case SCANOUT_SURFACE:
+        return surface_height(con->surface);
+    default:
+        return fallback;
+    }
 }
 
 static void vc_chr_accept_input(Chardev *chr)
@@ -2253,12 +2303,13 @@ static void text_console_do_init(Chardev *chr, DisplayState *ds)
     s->total_height = DEFAULT_BACKSCROLL;
     s->x = 0;
     s->y = 0;
-    if (!s->surface) {
+    if (s->scanout.kind != SCANOUT_SURFACE) {
-        if (active_console && active_console->surface) {
+        if (active_console && active_console->scanout.kind == SCANOUT_SURFACE) {
-            g_width = surface_width(active_console->surface);
+            g_width = qemu_console_get_width(active_console, g_width);
-            g_height = surface_height(active_console->surface);
+            g_height = qemu_console_get_height(active_console, g_height);
         }
         s->surface = qemu_create_displaysurface(g_width, g_height);
+        s->scanout.kind = SCANOUT_SURFACE;
     }
 
     s->hw_ops = &text_console_ops;
@@ -2317,6 +2368,7 @@ static void vc_chr_open(Chardev *chr,
         s = new_console(NULL, TEXT_CONSOLE, 0);
     } else {
         s = new_console(NULL, TEXT_CONSOLE_FIXED_SIZE, 0);
+        s->scanout.kind = SCANOUT_SURFACE;
         s->surface = qemu_create_displaysurface(width, height);
     }
 
@@ -2340,13 +2392,13 @@ static void vc_chr_open(Chardev *chr,
 
 void qemu_console_resize(QemuConsole *s, int width, int height)
 {
-    DisplaySurface *surface;
+    DisplaySurface *surface = qemu_console_surface(s);
 
     assert(s->console_type == GRAPHIC_CONSOLE);
 
-    if (s->surface && (s->surface->flags & QEMU_ALLOCATED_FLAG) &&
+    if (surface && (surface->flags & QEMU_ALLOCATED_FLAG) &&
-        pixman_image_get_width(s->surface->image) == width &&
+        pixman_image_get_width(surface->image) == width &&
-        pixman_image_get_height(s->surface->image) == height) {
+        pixman_image_get_height(surface->image) == height) {
         return;
     }
 
@@ -2356,7 +2408,12 @@ void qemu_console_resize(QemuConsole *s, int width, int height)
 
 DisplaySurface *qemu_console_surface(QemuConsole *console)
 {
-    return console->surface;
+    switch (console->scanout.kind) {
+    case SCANOUT_SURFACE:
+        return console->surface;
+    default:
+        return NULL;
+    }
 }
 
 PixelFormat qemu_default_pixelformat(int bpp)