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

6 files changed, 24 insertions, 11 deletions

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;
 }