[dpdk-dev] [PATCH 00/10] Make DPDK tailqs fully local

[Anatoly Burakov <anatoly.burakov@intel.com>]

This issue was reported by OVS-DPDK project, and the fix should go to
upstream DPDK. This is not memnic-related - this is to do with
DPDK's rte_ivshmem library.

Every DPDK data structure has a corresponding TAILQ reserved for it in
the runtime config file. Those TAILQs are fully local to the process,
however most data structures contain pointers to next entry in the
TAILQ.

Since the data structures such as rings are shared in their entirety,
those TAILQ pointers are shared as well. Meaning that, after a
successful rte_ring creation, the tailq_next pointer of the last
ring in the TAILQ will be updated with a pointer to a ring which may
not be present in the address space of another process (i.e. a ring
that may be host-local or guest-local, and not shared over IVSHMEM).
Any successive ring create/lookup on the other side of IVSHMEM will
result in trying to dereference an invalid pointer.

This patchset fixes this problem by creating a default tailq entry
that may be used by any data structure that chooses to use TAILQs.
This default TAILQ entry will consist of a tailq_next/tailq_prev
pointers, and an opaque pointer to arbitrary data. All TAILQ
pointers from data structures themselves will be removed and
replaced by those generic TAILQ entries, thus fixing the problem
of potentially exposing local address space to shared structures.

Technically, only rte_ring structure require modification, because
IVSHMEM is only using memzones (which aren't in TAILQs) and rings,
but for consistency's sake other TAILQ-based data structures were
adapted as well.

As part of this patchset, rte_malloc is also fixed to properly support
multiprocess malloc and free. Previously, if the memory was malloc'd
and freed in different processes, this could lead to segmentation
faults due to different heap pointers in malloc elements themselves.
This is fixed by making shared config to be mapped at the same
addresses in both primary and secondary processes, so that the heap
pointers in malloc elements are always valid, whatever process is
doing malloc or free.

The mapping address for the shared config is also now set with the
base-virtaddr flag, mapping the config file just before the start
address for the hugepages.

v2 changes:
* fixed race conditions in *_free operations
* fixed multiprocess support for malloc heaps
* added similar changes for acl
* rebased on top of e88b42f818bc1a6d4ce6cb70371b66e37fa34f7d

v3 changes:
* fixed race reported by Konstantin Ananyev (introduced in v2)

v4 changes:
* rte_mem_config mapping address is now also set by --base-virtaddr

Anatoly Burakov (10):
  eal: map shared config into exact same address as primary process
  eal: use --base-virtaddr for mapping rte_config as well
  rte_tailq: change rte_dummy to rte_tailq_entry, add data pointer
  rte_ring: make ring tailq fully local
  rte_hash: make rte_hash tailq fully local
  rte_fbk_hash: make rte_fbk_hash tailq fully local
  rte_mempool: make mempool tailq fully local
  rte_lpm: make lpm tailq fully local
  rte_lpm6: make lpm6 tailq fully local
  rte_acl: make acl tailq fully local

 app/test/test_tailq.c                             | 33 +++++-----
 lib/librte_acl/acl.h                              |  1 -
 lib/librte_acl/rte_acl.c                          | 74 ++++++++++++++++++-----
 lib/librte_eal/common/eal_common_tailqs.c         |  2 +-
 lib/librte_eal/common/include/rte_eal_memconfig.h |  5 ++
 lib/librte_eal/common/include/rte_tailq.h         |  9 +--
 lib/librte_eal/linuxapp/eal/eal.c                 | 54 +++++++++++++++--
 lib/librte_eal/linuxapp/eal/eal_ivshmem.c         | 17 +++++-
 lib/librte_hash/rte_fbk_hash.c                    | 73 +++++++++++++++++-----
 lib/librte_hash/rte_fbk_hash.h                    |  3 -
 lib/librte_hash/rte_hash.c                        | 61 ++++++++++++++++---
 lib/librte_hash/rte_hash.h                        |  2 -
 lib/librte_lpm/rte_lpm.c                          | 65 ++++++++++++++++----
 lib/librte_lpm/rte_lpm.h                          |  2 -
 lib/librte_lpm/rte_lpm6.c                         | 62 +++++++++++++++----
 lib/librte_mempool/Makefile                       |  3 +-
 lib/librte_mempool/rte_mempool.c                  | 37 +++++++++---
 lib/librte_mempool/rte_mempool.h                  |  2 -
 lib/librte_ring/Makefile                          |  4 +-
 lib/librte_ring/rte_ring.c                        | 33 +++++++---
 lib/librte_ring/rte_ring.h                        |  2 -
 21 files changed, 424 insertions(+), 120 deletions(-)

-- 
1.8.1.4