The vhost_scsi example code is set to build, even if the requisite header file virtio_scsi.h isn't available. This happens on some Ubuntu systems when some versions of the libc-dev package aren't available. Check whether the virtio_scsi.h file exists, and if not, set the build flag to false. Signed-off-by: Aaron Conole <aconole@redhat.com> Acked-by: Bruce Richardson <bruce.richardson@intel.com>