Revert "virtio-gpu: fix crashes upon warm reboot with vga mode"

This reverts commit 93f874fe.

Now with virtio-vga being resetted properly the
crash workaround is not needed any more.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20180821111313.27792-3-kraxel@redhat.com

hw/display/virtio-gpu.c

@@ -421,11 +421,6 @@ static void virtio_gpu_disable_scanout(VirtIOGPU *g, int scanout_id)
                                          scanout->height ?: 480,
                                          "Guest disabled display.");
     }
-
-    if (g->disable_scanout) {
-        g->disable_scanout(g, scanout_id);
-    }
-
     dpy_gfx_replace_surface(scanout->con, ds);
     scanout->resource_id = 0;
     scanout->ds = NULL;

hw/display/virtio-vga.c

@@ -75,16 +75,6 @@ static void virtio_vga_gl_block(void *opaque, bool block)
     }
 }
 
-static void virtio_vga_disable_scanout(VirtIOGPU *g, int scanout_id)
-{
-    VirtIOVGA *vvga = container_of(g, VirtIOVGA, vdev);
-
-    if (scanout_id == 0) {
-        /* reset surface if needed */
-        vvga->vga.graphic_mode = -1;
-    }
-}
-
 static const GraphicHwOps virtio_vga_ops = {
     .invalidate = virtio_vga_invalidate_display,
     .gfx_update = virtio_vga_update_display,
@@ -166,7 +156,6 @@ static void virtio_vga_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
                                  vvga->vga_mrs, true);
 
     vga->con = g->scanout[0].con;
-    g->disable_scanout = virtio_vga_disable_scanout;
     graphic_console_set_hwops(vga->con, &virtio_vga_ops, vvga);
 
     for (i = 0; i < g->conf.max_outputs; i++) {

include/hw/virtio/virtio-gpu.h

@@ -125,7 +125,6 @@ typedef struct VirtIOGPU {
         uint32_t bytes_3d;
     } stats;
 
-    void (*disable_scanout)(struct VirtIOGPU *g, int scanout_id);
     Error *migration_blocker;
 } VirtIOGPU;