virtio_balloon: disable VIOMMU support

virtio balloon bypasses the DMA API entirely so does not support the VIOMMU right now. It's not clear we need that support, for now let's just make sure we don't pretend to support it. Cc: [email protected] Cc: Wei Wang <[email protected]> Fixes: 1a93769 ("virtio: new feature to detect IOMMU device quirk") Signed-off-by: Michael S. Tsirkin <[email protected]> Acked-by: Jason Wang <[email protected]>
josf · Jun 18, 2017 · e41b135 · e41b135
1 parent 32c1431
commit e41b135
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
@@ -663,6 +663,12 @@ static int virtballoon_restore(struct virtio_device *vdev)
 }
 #endif
 
+static int virtballoon_validate(struct virtio_device *vdev)
+{
+	__virtio_clear_bit(vdev, VIRTIO_F_IOMMU_PLATFORM);
+	return 0;
+}
+
 static unsigned int features[] = {
 	VIRTIO_BALLOON_F_MUST_TELL_HOST,
 	VIRTIO_BALLOON_F_STATS_VQ,
@@ -675,6 +681,7 @@ static struct virtio_driver virtio_balloon_driver = {
 	.driver.name =	KBUILD_MODNAME,
 	.driver.owner =	THIS_MODULE,
 	.id_table =	id_table,
+	.validate =	virtballoon_validate,
 	.probe =	virtballoon_probe,
 	.remove =	virtballoon_remove,
 	.config_changed = virtballoon_changed,