diff options
Diffstat (limited to 'hw/display/vga.c')
| -rw-r--r-- | hw/display/vga.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/hw/display/vga.c b/hw/display/vga.c index 72181330b8..a7794f6d1f 100644 --- a/hw/display/vga.c +++ b/hw/display/vga.c @@ -1480,13 +1480,28 @@ static void vga_draw_graphic(VGACommonState *s, int full_update) s->get_resolution(s, &width, &height); disp_width = width; + depth = s->get_bpp(s); region_start = (s->start_addr * 4); region_end = region_start + (ram_addr_t)s->line_offset * height; - region_end += width * s->get_bpp(s) / 8; /* scanline length */ + region_end += width * depth / 8; /* scanline length */ region_end -= s->line_offset; - if (region_end > s->vbe_size) { - /* wraps around (can happen with cirrus vbe modes) */ + if (region_end > s->vbe_size || depth == 0 || depth == 15) { + /* + * We land here on: + * - wraps around (can happen with cirrus vbe modes) + * - depth == 0 (256 color palette video mode) + * - depth == 15 + * + * Take the safe and slow route: + * - create a dirty bitmap snapshot for all vga memory. + * - force shadowing (so all vga memory access goes + * through vga_read_*() helpers). + * + * Given this affects only vga features which are pretty much + * unused by modern guests there should be no performance + * impact. + */ region_start = 0; region_end = s->vbe_size; force_shadow = true; @@ -1520,8 +1535,6 @@ static void vga_draw_graphic(VGACommonState *s, int full_update) } } - depth = s->get_bpp(s); - /* * Check whether we can share the surface with the backend * or whether we need a shadow surface. We share native |