dmabuf: add y0_top, pass it to spice

Some scanouts during boot are top-down without it.

y0_top is set from VHOST_USER_GPU_DMABUF_SCANOUT code path in the last
patch of this series.

In current QEMU code base, only vfio/display uses dmabuf API. But the
VFIO query interface doesn't provide or need that detail so far.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180713130916.4153-5-marcandre.lureau@redhat.com>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

include/ui/console.h

@@ -186,6 +186,7 @@ struct QemuDmaBuf {
     uint32_t  stride;
     uint32_t  fourcc;
     uint32_t  texture;
+    bool      y0_top;
 };
 
 typedef struct DisplayChangeListenerOps {

ui/spice-display.c

@@ -1056,7 +1056,8 @@ static void qemu_spice_gl_update(DisplayChangeListener *dcl,
             /* note: spice server will close the fd, so hand over a dup */
             spice_qxl_gl_scanout(&ssd->qxl, dup(dmabuf->fd),
                                  dmabuf->width, dmabuf->height,
-                                 dmabuf->stride, dmabuf->fourcc, false);
+                                 dmabuf->stride, dmabuf->fourcc,
+                                 dmabuf->y0_top);
         }
         qemu_spice_gl_monitor_config(ssd, 0, 0, dmabuf->width, dmabuf->height);
         ssd->guest_dmabuf_refresh = false;