[rdma-core,0/8] verbs: Query GID table API

Message

Yishai Hadas Sept. 14, 2020, 6:34 a.m. UTC

When an application is not using RDMA CM and if it is using multiple RDMA
devices with one or more RoCE ports, finding the right GID table entry is a
long process.

For example, with two RoCE dual-port devices in a system, when IP failover is
used between two RoCE ports, searching a suitable GID entry for a given source
IP, matching netdevice of given RoCEv1/v2 type requires iterating over all 4
ports * 256 entry GID table.

Even though the best first match GID table for given criteria is used, when the
matching entry is on the 4th port, it requires reading 3 ports * 256 entries *
3 files (GID, netdev, type) = 2304 files.  The GID table needs to be referred
on every QP creation during IP failover on other netdevice of an RDMA device.

We introduce this series of patches, which introduces an API to query the
complete GID tables of an RDMA device, that returns all valid GID table
entries.

This is done through single ioctl, eliminating 2304 read, 2304 open and 2304
close system calls to just a total of 2 calls (one for each device).

While at it, we also introduce an API to query an individual GID entry over
ioctl interface, which provides all GID attributes information.

The APIs are based on the below RFC [1], the matching kernel part was sent to
rdma-next.

PR was sent as well [2].

[1] https://www.spinics.net/lists/linux-rdma/msg91825.html
[2] https://github.com/linux-rdma/rdma-core/pull/828

Avihai Horon (7):
  verbs: Change the name of enum ibv_gid_type
  verbs: Introduce a new query GID entry API
  verbs: Implement ibv_query_gid and ibv_query_gid_type over ioctl
  verbs: Optimize ibv_query_gid and ibv_query_gid_type
  verbs: Introduce a new query GID table API
  pyverbs: Add query_gid_table and query_gid_ex methods
  tests: Add tests for ibv_query_gid_table and ibv_query_gid_ex

Yishai Hadas (1):
  Update kernel headers

 debian/libibverbs1.symbols                |   3 +
 kernel-headers/rdma/ib_user_ioctl_cmds.h  |  16 +++
 kernel-headers/rdma/ib_user_ioctl_verbs.h |  14 ++
 kernel-headers/rdma/ib_user_verbs.h       |  11 ++
 kernel-headers/rdma/rdma_user_rxe.h       |   6 +-
 libibverbs/CMakeLists.txt                 |   2 +-
 libibverbs/cmd_device.c                   | 215 ++++++++++++++++++++++++++++++
 libibverbs/driver.h                       |  29 +++-
 libibverbs/examples/devinfo.c             |  14 +-
 libibverbs/libibverbs.map.in              |   6 +
 libibverbs/man/CMakeLists.txt             |   2 +
 libibverbs/man/ibv_query_gid_ex.3.md      |  93 +++++++++++++
 libibverbs/man/ibv_query_gid_table.3.md   |  73 ++++++++++
 libibverbs/verbs.c                        |  95 ++++++++++---
 libibverbs/verbs.h                        |  45 +++++++
 providers/mlx5/verbs.c                    |   2 +-
 pyverbs/device.pxd                        |   3 +
 pyverbs/device.pyx                        | 108 ++++++++++++++-
 pyverbs/libibverbs.pxd                    |  15 ++-
 pyverbs/libibverbs_enums.pxd              |  11 +-
 tests/base.py                             |   3 +-
 tests/test_device.py                      |  32 +++++
 22 files changed, 761 insertions(+), 37 deletions(-)
 create mode 100644 libibverbs/man/ibv_query_gid_ex.3.md
 create mode 100644 libibverbs/man/ibv_query_gid_table.3.md