ui/pixman: generalize shared_image_destroy

Learn to free memfd-allocated shared memory.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-ID: <20241008125028.1177932-10-marcandre.lureau@redhat.com>

hw/display/virtio-gpu.c

@@ -298,7 +298,7 @@ static void virtio_gpu_resource_create_2d(VirtIOGPU *g,
             bits, c2d.height ? res->hostmem / c2d.height : 0);
 #ifdef WIN32
         if (res->image) {
-            pixman_image_set_destroy_function(res->image, qemu_pixman_win32_image_destroy, res->handle);
+            pixman_image_set_destroy_function(res->image, qemu_pixman_shared_image_destroy, res->handle);
         }
 #endif
     }
@@ -1317,7 +1317,7 @@ static int virtio_gpu_load(QEMUFile *f, void *opaque, size_t size,
             return -EINVAL;
         }
 #ifdef WIN32
-        pixman_image_set_destroy_function(res->image, qemu_pixman_win32_image_destroy, res->handle);
+        pixman_image_set_destroy_function(res->image, qemu_pixman_shared_image_destroy, res->handle);
 #endif
 
         res->addrs = g_new(uint64_t, res->iov_cnt);

include/ui/qemu-pixman.h

@@ -97,7 +97,7 @@ void qemu_pixman_glyph_render(pixman_image_t *glyph,
 
 void qemu_pixman_image_unref(pixman_image_t *image);
 
-void qemu_pixman_win32_image_destroy(pixman_image_t *image, void *data);
+void qemu_pixman_shared_image_destroy(pixman_image_t *image, void *data);
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(pixman_image_t, qemu_pixman_image_unref)
 

ui/console.c

@@ -487,7 +487,7 @@ DisplaySurface *qemu_create_displaysurface(int width, int height)
 #ifdef WIN32
     qemu_displaysurface_win32_set_handle(surface, handle, 0);
     pixman_image_set_destroy_function(surface->image,
-                                      qemu_pixman_win32_image_destroy, handle);
+                                      qemu_pixman_shared_image_destroy, handle);
 #endif
     return surface;
 }

ui/qemu-pixman.c

@@ -6,6 +6,7 @@
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "ui/console.h"
+#include "qemu/memfd.h"
 #include "standard-headers/drm/drm_fourcc.h"
 #include "trace.h"
 
@@ -269,16 +270,19 @@ void qemu_pixman_glyph_render(pixman_image_t *glyph,
 }
 #endif /* CONFIG_PIXMAN */
 
-#ifdef WIN32
 void
-qemu_pixman_win32_image_destroy(pixman_image_t *image, void *data)
+qemu_pixman_shared_image_destroy(pixman_image_t *image, void *data)
 {
+    void *ptr = pixman_image_get_data(image);
+
+#ifdef WIN32
     HANDLE handle = data;
 
-    qemu_win32_map_free(
-        pixman_image_get_data(image),
-        handle,
-        &error_warn
-    );
-}
+    qemu_win32_map_free(ptr, handle, &error_warn);
+#else
+    int shmfd = GPOINTER_TO_INT(data);
+    size_t size = pixman_image_get_height(image) * pixman_image_get_stride(image);
+
+    qemu_memfd_free(ptr, size, shmfd);
 #endif
+}