DisplayAllocator interface (Stefano Stabellini)

Hi all,
this patch adds a DisplayAllocator interface that allows display
frontends (sdl in particular) to provide a preallocated display buffer
for the graphical backend to use.

Whenever a graphical backend cannot use
qemu_create_displaysurface_from because its own internal pixel format
cannot be exported directly (text mode or graphical mode with color
depth 8 or 24), it creates another display buffer in memory using
qemu_create_displaysurface and does the conversion.
This new buffer needs to be blitted into the sdl surface buffer every time
we need to update portions of the screen.
We can avoid this using the DisplayAllocator interace: sdl provides its
own implementation of qemu_create_displaysurface, giving back the sdl
surface buffer directly (as we used to do before the DisplayState
changes).
Since the buffer returned by sdl could be in bgr format we need to put
back in the handlers of that case.

This approach is good if the two following conditions are true:

1) the sdl surface is a software surface that resides in main memory;

2) the host display color depth is either 16 or 32 bpp.

If first condition is false we can have bad performances using sdl
and vnc together.
If the second condition is false performances are certainly not going to
improve but they shouldn't get worse either.

The first condition is always true, at least on linux/X11 systems; but I
believe is true also on other platforms.
The second condition is true in the vast majority of the cases.

This patch should also have the good side effect of solving the sdl
2D slowness malc was reporting on MacOS, because SDL_BlitSurface is not
going to be called anymore when the guest is in text mode or 24bpp.
However the root problem is still present so I suspect we may
still see some slowness on MacOS when the guest is in 32 or 16 bpp.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6839 c046a42c-6fe2-441c-8c8c-71466251a162

12 files changed, 207 insertions, 43 deletions

diff --git a/console.c b/console.c
index 9aeac8c969..e37397d2a0 100644
--- a/console.c
+++ b/console.c
@@ -1068,8 +1068,7 @@ void console_select(unsigned int index)
         DisplayState *ds = s->ds;
         active_console = s;
         if (ds_get_bits_per_pixel(s->ds)) {
-            ds->surface = qemu_resize_displaysurface(ds->surface, s->g_width,
-                    s->g_height, 32, 4 * s->g_width);
+            ds->surface = qemu_resize_displaysurface(ds, s->g_width, s->g_height);
         } else {
             s->ds->surface->width = s->width;
             s->ds->surface->height = s->height;
@@ -1277,11 +1276,12 @@ DisplayState *graphic_console_init(vga_hw_update_ptr update,
     DisplayState *ds;
 
     ds = (DisplayState *) qemu_mallocz(sizeof(DisplayState));
-    ds->surface = qemu_create_displaysurface(640, 480, 32, 640 * 4);
+    ds->allocator = &default_allocator; 
+    ds->surface = qemu_create_displaysurface(ds, 640, 480);
 
     s = new_console(ds, GRAPHIC_CONSOLE);
     if (s == NULL) {
-        qemu_free_displaysurface(ds->surface);
+        qemu_free_displaysurface(ds);
         qemu_free(ds);
         return NULL;
     }
@@ -1429,7 +1429,7 @@ void qemu_console_resize(DisplayState *ds, int width, int height)
     s->g_width = width;
     s->g_height = height;
     if (is_graphic_console()) {
-        ds->surface = qemu_resize_displaysurface(ds->surface, width, height, 32, 4 * width);
+        ds->surface = qemu_resize_displaysurface(ds, width, height);
         dpy_resize(ds);
     }
 }
@@ -1552,14 +1552,14 @@ PixelFormat qemu_default_pixelformat(int bpp)
     return pf;
 }
 
-DisplaySurface* qemu_create_displaysurface(int width, int height, int bpp, int linesize)
+DisplaySurface* defaultallocator_create_displaysurface(int width, int height)
 {
     DisplaySurface *surface = (DisplaySurface*) qemu_mallocz(sizeof(DisplaySurface));
 
     surface->width = width;
     surface->height = height;
-    surface->linesize = linesize;
-    surface->pf = qemu_default_pixelformat(bpp);
+    surface->linesize = width * 4;
+    surface->pf = qemu_default_pixelformat(32);
 #ifdef WORDS_BIGENDIAN
     surface->flags = QEMU_ALLOCATED_FLAG | QEMU_BIG_ENDIAN_FLAG;
 #else
@@ -1570,13 +1570,13 @@ DisplaySurface* qemu_create_displaysurface(int width, int height, int bpp, int l
     return surface;
 }
 
-DisplaySurface* qemu_resize_displaysurface(DisplaySurface *surface,
-                                          int width, int height, int bpp, int linesize)
+DisplaySurface* defaultallocator_resize_displaysurface(DisplaySurface *surface,
+                                          int width, int height)
 {
     surface->width = width;
     surface->height = height;
-    surface->linesize = linesize;
-    surface->pf = qemu_default_pixelformat(bpp);
+    surface->linesize = width * 4;
+    surface->pf = qemu_default_pixelformat(32);
     if (surface->flags & QEMU_ALLOCATED_FLAG)
         surface->data = (uint8_t*) qemu_realloc(surface->data, surface->linesize * surface->height);
     else
@@ -1607,7 +1607,7 @@ DisplaySurface* qemu_create_displaysurface_from(int width, int height, int bpp,
     return surface;
 }
 
-void qemu_free_displaysurface(DisplaySurface *surface)
+void defaultallocator_free_displaysurface(DisplaySurface *surface)
 {
     if (surface == NULL)
         return;
diff --git a/console.h b/console.h
index 6b72fa5e5a..93e3109d72 100644
--- a/console.h
+++ b/console.h
@@ -113,11 +113,18 @@ struct DisplayChangeListener {
     struct DisplayChangeListener *next;
 };
 
+struct DisplayAllocator {
+    DisplaySurface* (*create_displaysurface)(int width, int height);
+    DisplaySurface* (*resize_displaysurface)(DisplaySurface *surface, int width, int height);
+    void (*free_displaysurface)(DisplaySurface *surface);
+};
+
 struct DisplayState {
     struct DisplaySurface *surface;
     void *opaque;
     struct QEMUTimer *gui_timer;
 
+    struct DisplayAllocator* allocator;
     struct DisplayChangeListener* listeners;
 
     void (*mouse_set)(int x, int y, int on);
@@ -129,15 +136,40 @@ struct DisplayState {
 
 void register_displaystate(DisplayState *ds);
 DisplayState *get_displaystate(void);
-DisplaySurface* qemu_create_displaysurface(int width, int height, int bpp, int linesize);
-DisplaySurface* qemu_resize_displaysurface(DisplaySurface *surface,
-                                           int width, int height, int bpp, int linesize);
 DisplaySurface* qemu_create_displaysurface_from(int width, int height, int bpp,
                                                 int linesize, uint8_t *data);
-void qemu_free_displaysurface(DisplaySurface *surface);
 PixelFormat qemu_different_endianness_pixelformat(int bpp);
 PixelFormat qemu_default_pixelformat(int bpp);
 
+extern struct DisplayAllocator default_allocator;
+DisplayAllocator *register_displayallocator(DisplayState *ds, DisplayAllocator *da);
+DisplaySurface* defaultallocator_create_displaysurface(int width, int height);
+DisplaySurface* defaultallocator_resize_displaysurface(DisplaySurface *surface, int width, int height);
+void defaultallocator_free_displaysurface(DisplaySurface *surface);
+
+static inline DisplaySurface* qemu_create_displaysurface(DisplayState *ds, int width, int height)
+{
+    return ds->allocator->create_displaysurface(width, height);    
+}
+
+static inline DisplaySurface* qemu_resize_displaysurface(DisplayState *ds, int width, int height)
+{
+    return ds->allocator->resize_displaysurface(ds->surface, width, height);
+}
+
+static inline void qemu_free_displaysurface(DisplayState *ds)
+{
+    ds->allocator->free_displaysurface(ds->surface);
+}
+
+static inline int is_surface_bgr(DisplaySurface *surface)
+{
+    if (surface->pf.bits_per_pixel == 32 && surface->pf.rshift == 0)
+        return 1;
+    else
+        return 0;
+}
+
 static inline int is_buffer_shared(DisplaySurface *surface)
 {
     return (!(surface->flags & QEMU_ALLOCATED_FLAG));
diff --git a/curses.c b/curses.c
index 03f00d693a..8aae818f24 100644
--- a/curses.c
+++ b/curses.c
@@ -364,7 +364,7 @@ void curses_display_init(DisplayState *ds, int full_screen)
     dcl->dpy_refresh = curses_refresh;
     dcl->dpy_text_cursor = curses_cursor_position;
     register_displaychangelistener(ds, dcl);
-    qemu_free_displaysurface(ds->surface);
+    qemu_free_displaysurface(ds);
     ds->surface = qemu_create_displaysurface_from(640, 400, 0, 0, (uint8_t*) screen);
 
     invalidate = 1;
diff --git a/hw/musicpal.c b/hw/musicpal.c
index 03f40d3ea3..abd3afa9eb 100644
--- a/hw/musicpal.c
+++ b/hw/musicpal.c
@@ -831,7 +831,7 @@ static void lcd_refresh(void *opaque)
         break;
     LCD_REFRESH(8, rgb_to_pixel8)
     LCD_REFRESH(16, rgb_to_pixel16)
-    LCD_REFRESH(32, rgb_to_pixel32)
+    LCD_REFRESH(32, (is_surface_bgr(s->ds) ? rgb_to_pixel32bgr : rgb_to_pixel32))
     default:
         cpu_abort(cpu_single_env, "unsupported colour depth %i\n",
                   ds_get_bits_per_pixel(s->ds));
diff --git a/hw/nseries.c b/hw/nseries.c
index 32aaead27d..0c7da77f87 100644
--- a/hw/nseries.c
+++ b/hw/nseries.c
@@ -1362,7 +1362,7 @@ static void n8x0_init(ram_addr_t ram_size, const char *boot_device,
        will set the size once configured, so this just sets an initial
        size until the guest activates the display.  */
     ds = get_displaystate();
-    ds->surface = qemu_resize_displaysurface(ds->surface, 800, 480, 32, 4 * 800);
+    ds->surface = qemu_resize_displaysurface(ds, 800, 480);
     dpy_resize(ds);
 }
 
diff --git a/hw/palm.c b/hw/palm.c
index 93d12365b3..10fcd021b2 100644
--- a/hw/palm.c
+++ b/hw/palm.c
@@ -278,7 +278,7 @@ static void palmte_init(ram_addr_t ram_size, int vga_ram_size,
     /* FIXME: We shouldn't really be doing this here.  The LCD controller
        will set the size once configured, so this just sets an initial
        size until the guest activates the display.  */
-    ds->surface = qemu_resize_displaysurface(ds->surface, 320, 320, 32, 4 * 320);
+    ds->surface = qemu_resize_displaysurface(ds, 320, 320);
     dpy_resize(ds);
 }
 
diff --git a/hw/sm501.c b/hw/sm501.c
index ca9528b60e..f94fa0e167 100644
--- a/hw/sm501.c
+++ b/hw/sm501.c
@@ -948,7 +948,10 @@ static inline int get_depth_index(DisplayState *s)
     case 16:
         return 2;
     case 32:
-        return 3;
+	if (is_surface_bgr(s->surface))
+	    return 4;
+	else
+	    return 3;
     }
 }
 
diff --git a/hw/tcx.c b/hw/tcx.c
index 20c0dbbeec..485481589c 100644
--- a/hw/tcx.c
+++ b/hw/tcx.c
@@ -66,7 +66,10 @@ static void update_palette_entries(TCXState *s, int start, int end)
             s->palette[i] = rgb_to_pixel16(s->r[i], s->g[i], s->b[i]);
             break;
         case 32:
-            s->palette[i] = rgb_to_pixel32(s->r[i], s->g[i], s->b[i]);
+            if (is_surface_bgr(s->ds->surface))
+                s->palette[i] = rgb_to_pixel32bgr(s->r[i], s->g[i], s->b[i]);
+            else
+                s->palette[i] = rgb_to_pixel32(s->r[i], s->g[i], s->b[i]);
             break;
         }
     }
@@ -124,11 +127,12 @@ static inline void tcx24_draw_line32(TCXState *s1, uint8_t *d,
                                      const uint32_t *cplane,
                                      const uint32_t *s24)
 {
-    int x, r, g, b;
+    int x, bgr, r, g, b;
     uint8_t val, *p8;
     uint32_t *p = (uint32_t *)d;
     uint32_t dval;
 
+    bgr = is_surface_bgr(s1->ds->surface);
     for(x = 0; x < width; x++, s++, s24++) {
         if ((be32_to_cpu(*cplane++) & 0xff000000) == 0x03000000) {
             // 24-bit direct, BGR order
@@ -137,7 +141,10 @@ static inline void tcx24_draw_line32(TCXState *s1, uint8_t *d,
             b = *p8++;
             g = *p8++;
             r = *p8++;
-            dval = rgb_to_pixel32(r, g, b);
+            if (bgr)
+                dval = rgb_to_pixel32bgr(r, g, b);
+            else
+                dval = rgb_to_pixel32(r, g, b);
         } else {
             val = *s;
             dval = s1->palette[val];
diff --git a/hw/vga.c b/hw/vga.c
index f20c6cc861..8604eb57c1 100644
--- a/hw/vga.c
+++ b/hw/vga.c
@@ -1161,7 +1161,10 @@ static inline int get_depth_index(DisplayState *s)
     case 16:
         return 2;
     case 32:
-        return 3;
+        if (is_surface_bgr(s->surface))
+            return 4;
+        else
+            return 3;
     }
 }
 
@@ -1627,7 +1630,7 @@ static void vga_draw_graphic(VGAState *s, int full_update)
         if (depth == 32) {
 #endif
             if (is_graphic_console()) {
-                qemu_free_displaysurface(s->ds->surface);
+                qemu_free_displaysurface(s->ds);
                 s->ds->surface = qemu_create_displaysurface_from(disp_width, height, depth,
                                                                s->line_offset,
                                                                s->vram_ptr + (s->start_addr * 4));
@@ -2619,7 +2622,7 @@ static void vga_screen_dump_common(VGAState *s, const char *filename,
     dcl.dpy_resize = vga_save_dpy_resize;
     dcl.dpy_refresh = vga_save_dpy_refresh;
     register_displaychangelistener(ds, &dcl);
-    ds->surface = qemu_create_displaysurface(w, h, 32, 4 * w);
+    ds->surface = qemu_create_displaysurface(ds, w, h);
 
     s->ds = ds;
     s->graphic_mode = -1;
@@ -2627,7 +2630,7 @@ static void vga_screen_dump_common(VGAState *s, const char *filename,
 
     ppm_save(filename, ds->surface);
 
-    qemu_free_displaysurface(ds->surface);
+    qemu_free_displaysurface(ds);
     s->ds = saved_ds;
 }
 
diff --git a/qemu-common.h b/qemu-common.h
index 6848b337fa..28f47918dc 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -162,6 +162,7 @@ typedef struct BlockDriverState BlockDriverState;
 typedef struct DisplayState DisplayState;
 typedef struct DisplayChangeListener DisplayChangeListener;
 typedef struct DisplaySurface DisplaySurface;
+typedef struct DisplayAllocator DisplayAllocator;
 typedef struct PixelFormat PixelFormat;
 typedef struct TextConsole TextConsole;
 typedef TextConsole QEMUConsole;
diff --git a/sdl.c b/sdl.c
index a748426abc..843a6fc89a 100644
--- a/sdl.c
+++ b/sdl.c
@@ -53,17 +53,20 @@ static int absolute_enabled = 0;
 static int guest_cursor = 0;
 static int guest_x, guest_y;
 static SDL_Cursor *guest_sprite = 0;
+static uint8_t allocator;
+static uint8_t hostbpp;
 
 static void sdl_update(DisplayState *ds, int x, int y, int w, int h)
 {
-    SDL_Rect rec;
-    rec.x = x;
-    rec.y = y;
-    rec.w = w;
-    rec.h = h;
     //    printf("updating x=%d y=%d w=%d h=%d\n", x, y, w, h);
-
-    SDL_BlitSurface(guest_screen, &rec, real_screen, &rec);
+    if (guest_screen) {
+        SDL_Rect rec;
+        rec.x = x;
+        rec.y = y;
+        rec.w = w;
+        rec.h = h;
+        SDL_BlitSurface(guest_screen, &rec, real_screen, &rec);
+    }
     SDL_UpdateRect(real_screen, x, y, w, h);
 }
 
@@ -83,7 +86,7 @@ static void sdl_setdata(DisplayState *ds)
                                             ds->surface->pf.bmask, ds->surface->pf.amask);
 }
 
-static void sdl_resize(DisplayState *ds)
+static void do_sdl_resize(int width, int height, int bpp)
 {
     int flags;
 
@@ -95,15 +98,101 @@ static void sdl_resize(DisplayState *ds)
     if (gui_noframe)
         flags |= SDL_NOFRAME;
 
-    width = ds_get_width(ds);
-    height = ds_get_height(ds);
-    real_screen = SDL_SetVideoMode(width, height, 0, flags);
+    real_screen = SDL_SetVideoMode(width, height, bpp, flags);
     if (!real_screen) {
         fprintf(stderr, "Could not open SDL display\n");
         exit(1);
     }
+}
+
+static void sdl_resize(DisplayState *ds)
+{
+    if  (!allocator) {
+        do_sdl_resize(ds_get_width(ds), ds_get_height(ds), 0);
+        sdl_setdata(ds);
+    } else {
+        if (guest_screen != NULL) {
+            SDL_FreeSurface(guest_screen);
+            guest_screen = NULL;
+        }
+    }
+}
+
+static PixelFormat sdl_to_qemu_pixelformat(SDL_PixelFormat *sdl_pf)
+{
+    PixelFormat qemu_pf;
+
+    memset(&qemu_pf, 0x00, sizeof(PixelFormat));
+
+    qemu_pf.bits_per_pixel = sdl_pf->BitsPerPixel;
+    qemu_pf.bytes_per_pixel = sdl_pf->BytesPerPixel;
+    qemu_pf.depth = (qemu_pf.bits_per_pixel) == 32 ? 24 : (qemu_pf.bits_per_pixel);
+
+    qemu_pf.rmask = sdl_pf->Rmask;
+    qemu_pf.gmask = sdl_pf->Gmask;
+    qemu_pf.bmask = sdl_pf->Bmask;
+    qemu_pf.amask = sdl_pf->Amask;
+
+    qemu_pf.rshift = sdl_pf->Rshift;
+    qemu_pf.gshift = sdl_pf->Gshift;
+    qemu_pf.bshift = sdl_pf->Bshift;
+    qemu_pf.ashift = sdl_pf->Ashift;
+
+    qemu_pf.rbits = 8 - sdl_pf->Rloss;
+    qemu_pf.gbits = 8 - sdl_pf->Gloss;
+    qemu_pf.bbits = 8 - sdl_pf->Bloss;
+    qemu_pf.abits = 8 - sdl_pf->Aloss;
+
+    qemu_pf.rmax = ((1 << qemu_pf.rbits) - 1);
+    qemu_pf.gmax = ((1 << qemu_pf.gbits) - 1);
+    qemu_pf.bmax = ((1 << qemu_pf.bbits) - 1);
+    qemu_pf.amax = ((1 << qemu_pf.abits) - 1);
+
+    return qemu_pf;
+}
+
+static DisplaySurface* sdl_create_displaysurface(int width, int height)
+{
+    DisplaySurface *surface = (DisplaySurface*) qemu_mallocz(sizeof(DisplaySurface));
+    if (surface == NULL) {
+        fprintf(stderr, "sdl_create_displaysurface: malloc failed\n");
+        exit(1);
+    }
+
+    surface->width = width;
+    surface->height = height;
 
-    sdl_setdata(ds);
+    if (hostbpp == 16)
+        do_sdl_resize(width, height, 16);
+    else
+        do_sdl_resize(width, height, 32);
+
+    surface->pf = sdl_to_qemu_pixelformat(real_screen->format);
+    surface->linesize = real_screen->pitch;
+    surface->data = real_screen->pixels;
+
+#ifdef WORDS_BIGENDIAN
+    surface->flags = QEMU_ALLOCATED_FLAG | QEMU_BIG_ENDIAN_FLAG;
+#else
+    surface->flags = QEMU_ALLOCATED_FLAG;
+#endif
+    allocator = 1;
+
+    return surface;
+}
+
+static void sdl_free_displaysurface(DisplaySurface *surface)
+{
+    allocator = 0;
+    if (surface == NULL)
+        return;
+    qemu_free(surface);
+}
+
+static DisplaySurface* sdl_resize_displaysurface(DisplaySurface *surface, int width, int height)
+{
+    sdl_free_displaysurface(surface);
+    return sdl_create_displaysurface(width, height);
 }
 
 /* generic keyboard conversion */
@@ -391,7 +480,7 @@ static void sdl_send_mouse_event(int dx, int dy, int dz, int x, int y, int state
 static void toggle_full_screen(DisplayState *ds)
 {
     gui_fullscreen = !gui_fullscreen;
-    sdl_resize(ds);
+    do_sdl_resize(real_screen->w, real_screen->h, real_screen->format->BitsPerPixel);
     if (gui_fullscreen) {
         gui_saved_grab = gui_grab;
         sdl_grab_start();
@@ -669,6 +758,8 @@ void sdl_display_init(DisplayState *ds, int full_screen, int no_frame)
 {
     int flags;
     uint8_t data = 0;
+    DisplayAllocator *da;
+    const SDL_VideoInfo *vi;
 
 #if defined(__APPLE__)
     /* always use generic keymaps */
@@ -689,6 +780,8 @@ void sdl_display_init(DisplayState *ds, int full_screen, int no_frame)
         fprintf(stderr, "Could not initialize SDL - exiting\n");
         exit(1);
     }
+    vi = SDL_GetVideoInfo();
+    hostbpp = vi->vfmt->BitsPerPixel;
 
     dcl = qemu_mallocz(sizeof(DisplayChangeListener));
     dcl->dpy_update = sdl_update;
@@ -700,6 +793,18 @@ void sdl_display_init(DisplayState *ds, int full_screen, int no_frame)
     ds->cursor_define = sdl_mouse_define;
     register_displaychangelistener(ds, dcl);
 
+    da = qemu_mallocz(sizeof(DisplayAllocator));
+    da->create_displaysurface = sdl_create_displaysurface;
+    da->resize_displaysurface = sdl_resize_displaysurface;
+    da->free_displaysurface = sdl_free_displaysurface;
+    if (register_displayallocator(ds, da) == da) {
+        DisplaySurface *surf;
+        surf = sdl_create_displaysurface(ds_get_width(ds), ds_get_height(ds));
+        defaultallocator_free_displaysurface(ds->surface);
+        ds->surface = surf;
+        dpy_resize(ds);
+    }
+
     sdl_update_caption();
     SDL_EnableKeyRepeat(250, 50);
     gui_grab = 0;
diff --git a/vl.c b/vl.c
index c49a6d1d4b..2adfebfd59 100644
--- a/vl.c
+++ b/vl.c
@@ -2874,6 +2874,12 @@ void pcmcia_info(Monitor *mon)
 /***********************************************************/
 /* register display */
 
+struct DisplayAllocator default_allocator = {
+    defaultallocator_create_displaysurface,
+    defaultallocator_resize_displaysurface,
+    defaultallocator_free_displaysurface
+};
+
 void register_displaystate(DisplayState *ds)
 {
     DisplayState **s;
@@ -2889,12 +2895,19 @@ DisplayState *get_displaystate(void)
     return display_state;
 }
 
+DisplayAllocator *register_displayallocator(DisplayState *ds, DisplayAllocator *da)
+{
+    if(ds->allocator ==  &default_allocator) ds->allocator = da;
+    return ds->allocator;
+}
+
 /* dumb display */
 
 static void dumb_display_init(void)
 {
     DisplayState *ds = qemu_mallocz(sizeof(DisplayState));
-    ds->surface = qemu_create_displaysurface(640, 480, 32, 640 * 4);
+    ds->allocator = &default_allocator;
+    ds->surface = qemu_create_displaysurface(ds, 640, 480);
     register_displaystate(ds);
 }