[PATCH v3 0/3] stdvga: fix screen blanking

[PATCH v3 0/3] stdvga: fix screen blanking

[Gerd Hoffmann]

Gerd Hoffmann (3):
  stdvga: fix screen blanking
  ui+display: rename is_placeholder() -> surface_is_placeholder()
  ui+display: rename is_buffer_shared() -> surface_is_allocated()

 include/ui/surface.h    |  6 +++---
 hw/display/qxl-render.c |  2 +-
 hw/display/vga.c        | 24 +++++++++++++++---------
 hw/display/xenfb.c      |  5 +++--
 ui/console.c            |  3 ++-
 ui/sdl2-2d.c            |  2 +-
 ui/sdl2-gl.c            |  2 +-
 7 files changed, 26 insertions(+), 18 deletions(-)

-- 
2.45.1

[PATCH v3 1/3] stdvga: fix screen blanking

[Gerd Hoffmann]

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 <kraxel@redhat.com>
---
 hw/display/vga.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/display/vga.c b/hw/display/vga.c
index 30facc6c8e33..474b6b14c327 100644
--- a/hw/display/vga.c
+++ b/hw/display/vga.c
@@ -1762,6 +1762,12 @@ 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++) {
-- 
2.45.1

[PATCH v3 2/3] ui+display: rename is_placeholder() -> surface_is_placeholder()

[Gerd Hoffmann]

No functional change.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 include/ui/surface.h | 2 +-
 ui/console.c         | 2 +-
 ui/sdl2-2d.c         | 2 +-
 ui/sdl2-gl.c         | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/ui/surface.h b/include/ui/surface.h
index 4244e0ca4a32..273bb4769a02 100644
--- a/include/ui/surface.h
+++ b/include/ui/surface.h
@@ -50,7 +50,7 @@ static inline int is_buffer_shared(DisplaySurface *surface)
     return !(surface->flags & QEMU_ALLOCATED_FLAG);
 }
 
-static inline int is_placeholder(DisplaySurface *surface)
+static inline int surface_is_placeholder(DisplaySurface *surface)
 {
     return surface->flags & QEMU_PLACEHOLDER_FLAG;
 }
diff --git a/ui/console.c b/ui/console.c
index 1b2cd0c7365d..c2173fc0b1e5 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -1510,7 +1510,7 @@ void qemu_console_resize(QemuConsole *s, int width, int height)
     assert(QEMU_IS_GRAPHIC_CONSOLE(s));
 
     if ((s->scanout.kind != SCANOUT_SURFACE ||
-         (surface && !is_buffer_shared(surface) && !is_placeholder(surface))) &&
+         (surface && !is_buffer_shared(surface) && !surface_is_placeholder(surface))) &&
         qemu_console_get_width(s, -1) == width &&
         qemu_console_get_height(s, -1) == height) {
         return;
diff --git a/ui/sdl2-2d.c b/ui/sdl2-2d.c
index 06468cd493ea..73052383c2e0 100644
--- a/ui/sdl2-2d.c
+++ b/ui/sdl2-2d.c
@@ -72,7 +72,7 @@ void sdl2_2d_switch(DisplayChangeListener *dcl,
         scon->texture = NULL;
     }
 
-    if (is_placeholder(new_surface) && qemu_console_get_index(dcl->con)) {
+    if (surface_is_placeholder(new_surface) && qemu_console_get_index(dcl->con)) {
         sdl2_window_destroy(scon);
         return;
     }
diff --git a/ui/sdl2-gl.c b/ui/sdl2-gl.c
index 28d796607c08..91b7ee2419b7 100644
--- a/ui/sdl2-gl.c
+++ b/ui/sdl2-gl.c
@@ -89,7 +89,7 @@ void sdl2_gl_switch(DisplayChangeListener *dcl,
 
     scon->surface = new_surface;
 
-    if (is_placeholder(new_surface) && qemu_console_get_index(dcl->con)) {
+    if (surface_is_placeholder(new_surface) && qemu_console_get_index(dcl->con)) {
         qemu_gl_fini_shader(scon->gls);
         scon->gls = NULL;
         sdl2_window_destroy(scon);
-- 
2.45.1

[PATCH v3 3/3] ui+display: rename is_buffer_shared() -> surface_is_allocated()

[Gerd Hoffmann]

Boolean return value is reversed, to align with QEMU_ALLOCATED_FLAG, so
all callers must be adapted.  Also rename share_surface variable in
vga_draw_graphic() to reduce confusion.

No functional change.

Suggested-by: Marc-André Lureau <marcandre.lureau@gmail.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 include/ui/surface.h    |  4 ++--
 hw/display/qxl-render.c |  2 +-
 hw/display/vga.c        | 20 ++++++++++----------
 hw/display/xenfb.c      |  5 +++--
 ui/console.c            |  3 ++-
 5 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/include/ui/surface.h b/include/ui/surface.h
index 273bb4769a02..345b19169d2e 100644
--- a/include/ui/surface.h
+++ b/include/ui/surface.h
@@ -45,9 +45,9 @@ void qemu_displaysurface_win32_set_handle(DisplaySurface *surface,
 DisplaySurface *qemu_create_displaysurface(int width, int height);
 void qemu_free_displaysurface(DisplaySurface *surface);
 
-static inline int is_buffer_shared(DisplaySurface *surface)
+static inline int surface_is_allocated(DisplaySurface *surface)
 {
-    return !(surface->flags & QEMU_ALLOCATED_FLAG);
+    return surface->flags & QEMU_ALLOCATED_FLAG;
 }
 
 static inline int surface_is_placeholder(DisplaySurface *surface)
diff --git a/hw/display/qxl-render.c b/hw/display/qxl-render.c
index ec99ec887a6e..8daae72c8d04 100644
--- a/hw/display/qxl-render.c
+++ b/hw/display/qxl-render.c
@@ -31,7 +31,7 @@ static void qxl_blit(PCIQXLDevice *qxl, QXLRect *rect)
     uint8_t *src;
     int len, i;
 
-    if (is_buffer_shared(surface)) {
+    if (!surface_is_allocated(surface)) {
         return;
     }
     trace_qxl_render_blit(qxl->guest_primary.qxl_stride,
diff --git a/hw/display/vga.c b/hw/display/vga.c
index 474b6b14c327..0ed933596584 100644
--- a/hw/display/vga.c
+++ b/hw/display/vga.c
@@ -1487,7 +1487,7 @@ 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 = NULL;
-    bool share_surface, force_shadow = false;
+    bool allocate_surface, force_shadow = false;
     pixman_format_code_t format;
 #if HOST_BIG_ENDIAN
     bool byteswap = !s->big_endian_fb;
@@ -1609,10 +1609,10 @@ static void vga_draw_graphic(VGACommonState *s, int full_update)
      */
     format = qemu_default_pixman_format(depth, !byteswap);
     if (format) {
-        share_surface = dpy_gfx_check_format(s->con, format)
-            && !s->force_shadow && !force_shadow;
+        allocate_surface = !dpy_gfx_check_format(s->con, format)
+            || s->force_shadow || force_shadow;
     } else {
-        share_surface = false;
+        allocate_surface = true;
     }
 
     if (s->params.line_offset != s->last_line_offset ||
@@ -1620,7 +1620,7 @@ static void vga_draw_graphic(VGACommonState *s, int full_update)
         height != s->last_height ||
         s->last_depth != depth ||
         s->last_byteswap != byteswap ||
-        share_surface != is_buffer_shared(surface)) {
+        allocate_surface != surface_is_allocated(surface)) {
         /* display parameters changed -> need new display surface */
         s->last_scr_width = disp_width;
         s->last_scr_height = height;
@@ -1635,14 +1635,14 @@ static void vga_draw_graphic(VGACommonState *s, int full_update)
         full_update = 1;
     }
     if (surface_data(surface) != s->vram_ptr + (s->params.start_addr * 4)
-        && is_buffer_shared(surface)) {
+        && !surface_is_allocated(surface)) {
         /* base address changed (page flip) -> shared display surfaces
          * must be updated with the new base address */
         full_update = 1;
     }
 
     if (full_update) {
-        if (share_surface) {
+        if (!allocate_surface) {
             surface = qemu_create_displaysurface_from(disp_width,
                     height, format, s->params.line_offset,
                     s->vram_ptr + (s->params.start_addr * 4));
@@ -1655,7 +1655,7 @@ static void vga_draw_graphic(VGACommonState *s, int full_update)
 
     vga_draw_line = vga_draw_line_table[v];
 
-    if (!is_buffer_shared(surface) && s->cursor_invalidate) {
+    if (surface_is_allocated(surface) && s->cursor_invalidate) {
         s->cursor_invalidate(s);
     }
 
@@ -1707,7 +1707,7 @@ static void vga_draw_graphic(VGACommonState *s, int full_update)
         if (update) {
             if (y_start < 0)
                 y_start = y;
-            if (!(is_buffer_shared(surface))) {
+            if (surface_is_allocated(surface)) {
                 uint8_t *p;
                 p = vga_draw_line(s, d, addr, width, hpel);
                 if (p) {
@@ -1762,7 +1762,7 @@ 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)) {
+    if (!surface_is_allocated(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);
diff --git a/hw/display/xenfb.c b/hw/display/xenfb.c
index 27536bfce0cb..06f84ed39d64 100644
--- a/hw/display/xenfb.c
+++ b/hw/display/xenfb.c
@@ -637,7 +637,7 @@ static void xenfb_guest_copy(struct XenFB *xenfb, int x, int y, int w, int h)
     int linesize = surface_stride(surface);
     uint8_t *data = surface_data(surface);
 
-    if (!is_buffer_shared(surface)) {
+    if (surface_is_allocated(surface)) {
         switch (xenfb->depth) {
         case 8:
             if (bpp == 16) {
@@ -755,7 +755,8 @@ static void xenfb_update(void *opaque)
         xen_pv_printf(&xenfb->c.xendev, 1,
                       "update: resizing: %dx%d @ %d bpp%s\n",
                       xenfb->width, xenfb->height, xenfb->depth,
-                      is_buffer_shared(surface) ? " (shared)" : "");
+                      surface_is_allocated(surface)
+                      ? " (allocated)" : " (borrowed)");
         xenfb->up_fullscreen = 1;
     }
 
diff --git a/ui/console.c b/ui/console.c
index c2173fc0b1e5..1a7eb7fe8e8c 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -1510,7 +1510,8 @@ void qemu_console_resize(QemuConsole *s, int width, int height)
     assert(QEMU_IS_GRAPHIC_CONSOLE(s));
 
     if ((s->scanout.kind != SCANOUT_SURFACE ||
-         (surface && !is_buffer_shared(surface) && !surface_is_placeholder(surface))) &&
+         (surface && surface_is_allocated(surface) &&
+          !surface_is_placeholder(surface))) &&
         qemu_console_get_width(s, -1) == width &&
         qemu_console_get_height(s, -1) == height) {
         return;
-- 
2.45.1

Re: [PATCH v3 0/3] stdvga: fix screen blanking

[Marc-André Lureau]

On Wed, Jun 5, 2024 at 5:14 PM Gerd Hoffmann <kraxel@redhat.com> wrote:
>
>
>
> Gerd Hoffmann (3):
>   stdvga: fix screen blanking
>   ui+display: rename is_placeholder() -> surface_is_placeholder()
>   ui+display: rename is_buffer_shared() -> surface_is_allocated()
>
>  include/ui/surface.h    |  6 +++---
>  hw/display/qxl-render.c |  2 +-
>  hw/display/vga.c        | 24 +++++++++++++++---------
>  hw/display/xenfb.c      |  5 +++--
>  ui/console.c            |  3 ++-
>  ui/sdl2-2d.c            |  2 +-
>  ui/sdl2-gl.c            |  2 +-
>  7 files changed, 26 insertions(+), 18 deletions(-)
>

for the series:
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Re: [PATCH v3 3/3] ui+display: rename is_buffer_shared() -> surface_is_allocated()

[Paul Durrant]

On 05/06/2024 14:14, Gerd Hoffmann wrote:
> Boolean return value is reversed, to align with QEMU_ALLOCATED_FLAG, so
> all callers must be adapted.  Also rename share_surface variable in
> vga_draw_graphic() to reduce confusion.
> 
> No functional change.
> 
> Suggested-by: Marc-André Lureau <marcandre.lureau@gmail.com>
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>   include/ui/surface.h    |  4 ++--
>   hw/display/qxl-render.c |  2 +-
>   hw/display/vga.c        | 20 ++++++++++----------
>   hw/display/xenfb.c      |  5 +++--
>   ui/console.c            |  3 ++-
>   5 files changed, 18 insertions(+), 16 deletions(-)
> 

Reviewed-by: Paul Durrant <paul@xen.org>

Re: [PATCH v3 2/3] ui+display: rename is_placeholder() -> surface_is_placeholder()

[Philippe Mathieu-Daudé]

On 5/6/24 15:14, Gerd Hoffmann wrote:
> No functional change.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>   include/ui/surface.h | 2 +-
>   ui/console.c         | 2 +-
>   ui/sdl2-2d.c         | 2 +-
>   ui/sdl2-gl.c         | 2 +-
>   4 files changed, 4 insertions(+), 4 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH v3 0/3] stdvga: fix screen blanking

[Philippe Mathieu-Daudé]

On 5/6/24 15:14, Gerd Hoffmann wrote:

> Gerd Hoffmann (3):
>    stdvga: fix screen blanking
>    ui+display: rename is_placeholder() -> surface_is_placeholder()
>    ui+display: rename is_buffer_shared() -> surface_is_allocated()

Since Marc-André reviewed, I'm queuing this series, thanks!