Changes

== Initial Support for BPF Maps ==

BPF maps are kernel objects which store data (used by BPF programs) in the form of key-value pairs. Applications access BPF maps using file descriptors. C/R of BPF maps involves serializing their ''meta-data'' and ''data'':

BPF maps are kernel objects which store data (used by BPF programs) in the form of key-value pairs. Applications access BPF maps using file descriptors. C/R of BPF maps involves serializing their ''meta-data'' and ''data'':

: '''Meta-data''' - This includes information such as map type, key size, value size, etc. CRIU obtains this information from the proc filesystem and using the <code>bpf</code> system call with argument <code>BPF_OBJ_GET_INFO_BY_FD</code>.

: '''Meta-data''' - This includes information such as map type, key size, value size, etc. CRIU obtains this information from the proc filesystem and using the <code>bpf</code> system call with argument <code>BPF_OBJ_GET_INFO_BY_FD</code>

: '''Data''' - This is the map's contents, i.e. the actual key-value pairs. CRIU relies on batch operations to read (<code>BPF_MAP_LOOKUP_BATCH</code>) key-value pairs from maps during the checkpoint stage and to write (<code>BPF_MAP_UPDATE_BATCH</code>) them during the restore phase.

CRIU currently supports C/R of the following BPF map types:

CRIU currently supports C/R of the following BPF map types: