/usr/src/linux-headers-4.10.0-26/drivers/vfio/ is in linux-headers-4.10.0-26 4.10.0-26.30~16.04.1.
This file is owned by root:root, with mode 0o755.
..
/usr/src/linux-headers-4.10.0-26/drivers/vfio/Kconfig
/usr/src/linux-headers-4.10.0-26/drivers/vfio/Makefile
/usr/src/linux-headers-4.10.0-26/drivers/vfio/mdev/
/usr/src/linux-headers-4.10.0-26/drivers/vfio/mdev/Kconfig
/usr/src/linux-headers-4.10.0-26/drivers/vfio/mdev/Makefile
/usr/src/linux-headers-4.10.0-26/drivers/vfio/pci/
/usr/src/linux-headers-4.10.0-26/drivers/vfio/pci/Kconfig
/usr/src/linux-headers-4.10.0-26/drivers/vfio/pci/Makefile
/usr/src/linux-headers-4.10.0-26/drivers/vfio/platform/
/usr/src/linux-headers-4.10.0-26/drivers/vfio/platform/Kconfig
/usr/src/linux-headers-4.10.0-26/drivers/vfio/platform/Makefile
/usr/src/linux-headers-4.10.0-26/drivers/vfio/platform/reset/
/usr/src/linux-headers-4.10.0-26/drivers/vfio/platform/reset/Kconfig
/usr/src/linux-headers-4.10.0-26/drivers/vfio/platform/reset/Makefile