[RFC PATCH 0/4] VRF support in FIB library

Vladimir Medvedkin
2026-03-22T15:42:24Z

This series adds multi-VRF support to both IPv4 and IPv6 FIB paths by
allowing a single FIB instance to host multiple isolated routing domains.

Currently FIB instance represents one routing instance. For workloads that
need multiple VRFs, the only option is to create multiple FIB objects. In a
burst oriented datapath, packets in the same batch can belong to different VRFs, so
the application either does per-packet lookup in different FIB instances or
regroups packets by VRF before lookup. Both approaches are expensive.

To remove that cost, this series keeps all VRFs inside one FIB instance and
extends lookup input with per-packet VRF IDs.

The design follows the existing fast-path structure for both families. IPv4 and
IPv6 use multi-ary trees with a 2^24 associativity on a first level (tbl24). The
first-level table scales per configured VRF. This increases memory usage, but
keeps performance and lookup complexity on par with non-VRF implementation.

Vladimir Medvedkin (4):
fib: add multi-VRF support
fib: add VRF functional and unit tests
fib6: add multi-VRF support
fib6: add VRF functional and unit tests

app/test-fib/main.c | 257 ++++++++++++++++++++++--
app/test/test_fib.c | 298 +++++++++++++++++++++++++++
app/test/test_fib6.c | 319 ++++++++++++++++++++++++++++-
lib/fib/dir24_8.c | 241 ++++++++++++++++------
lib/fib/dir24_8.h | 255 ++++++++++++++++--------
lib/fib/dir24_8_avx512.c | 420 +++++++++++++++++++++++++++++++--------
lib/fib/dir24_8_avx512.h | 80 +++++++-
lib/fib/rte_fib.c | 158 ++++++++++++---
lib/fib/rte_fib.h | 94 ++++++++-
lib/fib/rte_fib6.c | 166 +++++++++++++---
lib/fib/rte_fib6.h | 88 +++++++-
lib/fib/trie.c | 158 +++++++++++----
lib/fib/trie.h | 51 +++--
lib/fib/trie_avx512.c | 225 +++++++++++++++++++--
lib/fib/trie_avx512.h | 39 +++-
15 files changed, 2453 insertions(+), 396 deletions(-)

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2.43.0