reproduce (this is a W=1 build):
        git checkout 2014c95afecee3e76ca4a56956a936e23283f05b
        b4 shazam https://lore.kernel.org/r/2-v2-a3b72fd4b99a+1b6-iommu_virtio_domains_jgg@nvidia.com
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/