Commit "ca58b45f ui/virtio-gpu: add and use qemu_create_displaysurface_pixman"
breaks scanouts which use a region of the underlying resource only.

So, we need another way to handle the underlying issue.  Lets create a
new pixman image, grab a reference on the pixman providing the
underlying storage, hook up a destroy callback which releases the
reference.  That way regions work again and releasing the backing
storage should still be impossible thanks to the extra reference we are
holding.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 1464597655-26341-1-git-send-email-kraxel@redhat.com