On Mon, Mar 06, 2023 at 05:32:34PM +0300, Dmitry Osipenko wrote: > VirtIO-GPU got a new config option for disabling KMS. There were two > problems left unnoticed during review when the new option was added: > > 1. The IS_ENABLED(CONFIG_DRM_VIRTIO_GPU_KMS) check in the code was > inverted, hence KMS was disabled when it should be enabled and vice versa. > > 2. The disabled KMS crashed kernel with a NULL dereference in > drm_kms_helper_hotplug_event(), which shall not be invoked with a > disabled KMS. > > Fix the inverted config option check in the code and skip handling the > VIRTIO_GPU_EVENT_DISPLAY sent by host when KMS is disabled in guest to fix > the crash. > > Fixes: 72122c69d717 ("drm/virtio: Add option to disable KMS support") > Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx> > --- > > Changelog: > > v2: - Moved the "has_edid" under the "num_scanouts" condition, like was > suggested by Gerd Hoffmann. Acked-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>