/usr/lib/x86_64-linux-gnu/libxengnttab-4.9.so.1 is in libxen-4.9 4.9.2-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libxengnttab-4.9.so.1.1
/usr/lib/x86_64-linux-gnu/libxengnttab-4.9.so.1.1