/usr/lib/x86_64-linux-gnu/libpfm.so is in libpfm4-dev 4.8.0+git16-g8385268-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libpfm.so.4.8.0
/usr/lib/x86_64-linux-gnu/libpfm.so.4.8.0