[Qemu-devel] [PATCH] vga: fix byteswapping.

[Gerd Hoffmann]

In case host and guest endianness differ the vga code first creates
a shared surface (using qemu_create_displaysurface_from), then goes
patch the surface format to indicate that the bytes must be swapped.

The switch to pixman broke that hack as the format patching isn't
propagated into the pixman image, so ui code using the pixman image
directly (such as vnc) uses the wrong format.

Fix that by adding a byteswap parameter to
qemu_create_displaysurface_from, so we'll use the correct format
when creating the surface (and the pixman image) and don't have
to patch the format afterwards.

Cc: address@hidden
Cc: address@hidden
Cc: address@hidden
Signed-off-by: Gerd Hoffmann <address@hidden>
---
 hw/qxl-render.c      |    3 ++-
 hw/vga.c             |   18 ++++++++----------
 hw/vmware_vga.c      |    2 +-
 include/ui/console.h |    3 ++-
 ui/console.c         |    9 +++++++--
 5 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/hw/qxl-render.c b/hw/qxl-render.c
index 88e63f8..455fb91 100644
--- a/hw/qxl-render.c
+++ b/hw/qxl-render.c
@@ -118,7 +118,8 @@ static void qxl_render_update_area_unlocked(PCIQXLDevice 
*qxl)
                  qxl->guest_primary.surface.height,
                  qxl->guest_primary.bits_pp,
                  qxl->guest_primary.abs_stride,
-                 qxl->guest_primary.data);
+                 qxl->guest_primary.data,
+                 false);
         } else {
             qemu_resize_displaysurface(vga->ds,
                     qxl->guest_primary.surface.width,
diff --git a/hw/vga.c b/hw/vga.c
index e2ba7f2..1caf23d 100644
--- a/hw/vga.c
+++ b/hw/vga.c
@@ -1643,6 +1643,11 @@ static void vga_draw_graphic(VGACommonState *s, int 
full_update)
     uint8_t *d;
     uint32_t v, addr1, addr;
     vga_draw_line_func *vga_draw_line;
+#if defined(HOST_WORDS_BIGENDIAN) == defined(TARGET_WORDS_BIGENDIAN)
+    static const bool byteswap = false;
+#else
+    static const bool byteswap = true;
+#endif
 
     full_update |= update_basic_params(s);
 
@@ -1685,18 +1690,11 @@ static void vga_draw_graphic(VGACommonState *s, int 
full_update)
         disp_width != s->last_width ||
         height != s->last_height ||
         s->last_depth != depth) {
-#if defined(HOST_WORDS_BIGENDIAN) == defined(TARGET_WORDS_BIGENDIAN)
-        if (depth == 16 || depth == 32) {
-#else
-        if (depth == 32) {
-#endif
+        if (depth == 32 || (depth == 16 && !byteswap)) {
             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));
-#if defined(HOST_WORDS_BIGENDIAN) != defined(TARGET_WORDS_BIGENDIAN)
-            s->ds->surface->pf = qemu_different_endianness_pixelformat(depth);
-#endif
+                    s->vram_ptr + (s->start_addr * 4), byteswap);
             dpy_gfx_resize(s->ds);
         } else {
             qemu_console_resize(s->ds, disp_width, height);
@@ -1715,7 +1713,7 @@ static void vga_draw_graphic(VGACommonState *s, int 
full_update)
         s->ds->surface = qemu_create_displaysurface_from(disp_width,
                 height, depth,
                 s->line_offset,
-                s->vram_ptr + (s->start_addr * 4));
+                s->vram_ptr + (s->start_addr * 4), byteswap);
         dpy_gfx_setdata(s->ds);
     }
 
diff --git a/hw/vmware_vga.c b/hw/vmware_vga.c
index cd15ee4..8fc201b 100644
--- a/hw/vmware_vga.c
+++ b/hw/vmware_vga.c
@@ -1074,7 +1074,7 @@ static void vmsvga_screen_dump(void *opaque, const char 
*filename, bool cswitch,
                                  ds_get_height(s->vga.ds),
                                  32,
                                  ds_get_linesize(s->vga.ds),
-                                 s->vga.vram_ptr);
+                                 s->vga.vram_ptr, false);
         ppm_save(filename, ds, errp);
         g_free(ds);
     }
diff --git a/include/ui/console.h b/include/ui/console.h
index fc23baa..18012f1 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -184,7 +184,8 @@ struct DisplayState {
 void register_displaystate(DisplayState *ds);
 DisplayState *get_displaystate(void);
 DisplaySurface* qemu_create_displaysurface_from(int width, int height, int bpp,
-                                                int linesize, uint8_t *data);
+                                                int linesize, uint8_t *data,
+                                                bool byteswap);
 PixelFormat qemu_different_endianness_pixelformat(int bpp);
 PixelFormat qemu_default_pixelformat(int bpp);
 
diff --git a/ui/console.c b/ui/console.c
index 0a68836..25e06a5 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -1339,11 +1339,16 @@ DisplaySurface *qemu_resize_displaysurface(DisplayState 
*ds,
 }
 
 DisplaySurface *qemu_create_displaysurface_from(int width, int height, int bpp,
-                                                int linesize, uint8_t *data)
+                                                int linesize, uint8_t *data,
+                                                bool byteswap)
 {
     DisplaySurface *surface = g_new0(DisplaySurface, 1);
 
-    surface->pf = qemu_default_pixelformat(bpp);
+    if (byteswap) {
+        surface->pf = qemu_different_endianness_pixelformat(bpp);
+    } else {
+        surface->pf = qemu_default_pixelformat(bpp);
+    }
 
     surface->format = qemu_pixman_get_format(&surface->pf);
     assert(surface->format != 0);
-- 
1.7.9.7