[PATCH v3 0/9] net/memif: lifecycle fixes and unit test

[Sriram Yagnaraman]

This series fixes a set of error-path and lifecycle bugs in the memif
PMD and adds a unit test for the driver.

The first eight patches are fixes:

 - guard eth_memif_tx() against an empty burst (nb_pkts == 0);
 - close file descriptor 0 instead of leaking it;
 - do not close the EAL-owned memseg fd in zero-copy mode;
 - free the MAC address allocated during probe on failure;
 - unwind a partially-created device on create failure;
 - refuse connections on a stopped server so it does not come up on a
   stopped port;
 - disconnect on close so a stopped server's control channel is not
   leaked, and make memif_disconnect() safe on a never-started device;
 - fix eth_memif_tx_zc() returning 65535 on an invalid interrupt fd.

The last patch adds a memif PMD unit test (app/test, memif_pmd_autotest):
a server/client vdev pair over a loopback socket covering dev_info, link
state, stats, single-segment loopback (slow and fast path), multi-segment
loopback across a ring wrap, stop/start reconnect, empty Tx burst, close
without stop, and a stopped server refusing a peer.

Verified: memif_pmd_autotest passes 11/11; each commit builds with
-Dwerror=true; check-git-log and checkpatch are clean.

Thanks to Stephen Hemminger and the ai-code-review bot for the reviews
that shaped this series.

v3:
 - Rebase on main, picking up rte_intr_fd_close() from
   d9191f684c ("interrupts: add helpers to close FD"): patch 2 keeps
   only the owned-fd ">= 0" fixes not superseded by that helper, and
   patch 7 keeps the NULL-queue guards above the rte_intr_fd_close()
   calls.
 - New patch 6: refuse connections on a stopped server. The started-
   then-stopped case is the actual trigger for the control-channel
   leak; dev_stop now sets ETH_MEMIF_FLAG_DISABLED. (v2 patch 6/7
   described this as never-started, which was wrong.)
 - Patch 7 (disconnect on close): reword to the real trigger and keep
   the close-time disconnect as a backstop.
 - Patch 3 (memseg fd): also stop closing the EAL-owned fd in
   memif_connect(), not only memif_free_regions().
 - Test: new test_memif_stopped_server_rejects_peer covering patch 6
   (fails without it); reword close-without-stop to what it actually
   covers (the NULL-queue skip); verify the full fast-path payload.

v2:
 - P1: correct Fixes tag (Tx fast path, not original driver); move the
   empty-burst check after the ring == NULL block.
 - P2: split the memseg-fd change into its own patch rather than
   widening the check to ">= 0".
 - P4 (MAC leak): document the secondary -1 -> -ENOMEM change.
 - P5 (unwind): add Fixes: multi-process support.
 - New patch: fix eth_memif_tx_zc() bogus Tx count on invalid fd.
 - Test: add to MAINTAINERS; return TEST_FAILED (not SKIPPED) on probe
   failure; add a default-bsize pair to cover the Tx fast path; set
   ring size via rsize and fix the stale comments.

Sriram Yagnaraman (9):
  net/memif: guard against empty Tx burst
  net/memif: close file descriptor zero
  net/memif: do not close EAL-owned memseg file descriptor
  net/memif: fix MAC address leak on probe failure
  net/memif: unwind partial device on create failure
  net/memif: refuse connection on stopped device
  net/memif: disconnect on device close
  net/memif: fix bogus Tx count on invalid interrupt FD
  test/memif: add memif PMD unit test

 MAINTAINERS                       |   1 +
 app/test/meson.build              |   1 +
 app/test/test_pmd_memif.c         | 751 ++++++++++++++++++++++++++++++
 drivers/net/memif/memif_socket.c  |  10 +-
 drivers/net/memif/rte_eth_memif.c |  76 ++-
 5 files changed, 812 insertions(+), 27 deletions(-)
 create mode 100644 app/test/test_pmd_memif.c

-- 
2.43.7