From b1cf266c82cb1211ee2785f1813a6a3f3e693390 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Wed, 5 Jun 2024 15:14:41 +0200 Subject: [PATCH] stdvga: fix screen blanking MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In case the display surface uses a shared buffer (i.e. uses vga vram directly instead of a shadow) go unshare the buffer before clearing it. This avoids vga memory corruption, which in turn fixes unblanking not working properly with X11. Cc: qemu-stable@nongnu.org Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2067 Signed-off-by: Gerd Hoffmann Reviewed-by: Marc-André Lureau Message-ID: <20240605131444.797896-2-kraxel@redhat.com> Signed-off-by: Philippe Mathieu-Daudé --- hw/display/vga.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/hw/display/vga.c b/hw/display/vga.c index 30facc6c8e..be2b19b839 100644 --- a/hw/display/vga.c +++ b/hw/display/vga.c @@ -1762,6 +1762,13 @@ static void vga_draw_blank(VGACommonState *s, int full_update) if (s->last_scr_width <= 0 || s->last_scr_height <= 0) return; + if (is_buffer_shared(surface)) { + /* unshare buffer, otherwise the blanking corrupts vga vram */ + surface = qemu_create_displaysurface(s->last_scr_width, + s->last_scr_height); + dpy_gfx_replace_surface(s->con, surface); + } + w = s->last_scr_width * surface_bytes_per_pixel(surface); d = surface_data(surface); for(i = 0; i < s->last_scr_height; i++) {