Comment 5 for bug 1871354

On init amon other things libpmem will do:

161 /*
162 * os_auto_flush -- check if platform supports auto flush for all regions
163 *
164 * Traverse "/sys/bus/nd/devices" path to find all the nvdimm regions,
165 * then for each region checks if "persistence_domain" file exists and
166 * contains "cpu_cache" string.
167 * If for any region "persistence_domain" entry does not exists, or its
168 * context is not as expected, assume eADR is not available on this platform.
169 */

That will open "." and PWD for a libvirt executed qemu will be nothing => "/"
Followed by "/sys/bus/nd/devices"

But from the code I see that it expects there to be symlinks.
We will need the patterns those will follow to add rules for those as well.

TODO:
1. silence access to "/"
2. allow enumeration (read only) of
  /sys/bus/nd/devices r,
  /sys/bus/nd/devices/* r,
3. find where the symlinks usually point to and add these

Can we find a way to only add these when pmem is actually used?
In that case we want to silence #2 as well, but allow it if used