[PATCH net-next v2 00/12] xdp: page_pool fixes and in-flight accounting

[Jesper Dangaard Brouer <brouer@redhat.com>]

This patchset fix page_pool API and users, such that drivers can use it for
DMA-mapping. A number of places exist, where the DMA-mapping would not get
released/unmapped, all these are fixed. This occurs e.g. when an xdp_frame
gets converted to an SKB. As network stack doesn't have any callback for XDP
memory models.

The patchset also address a shutdown race-condition. Today removing a XDP
memory model, based on page_pool, is only delayed one RCU grace period. This
isn't enough as redirected xdp_frames can still be in-flight on different
queues (remote driver TX, cpumap or veth).

We stress that when drivers use page_pool for DMA-mapping, then they MUST
use one packet per page. This might change in the future, but more work lies
ahead, before we can lift this restriction.

This patchset change the page_pool API to be more strict, as in-flight page
accounting is added.

---

Ilias Apalodimas (2):
      net: page_pool: add helper function to retrieve dma addresses
      net: page_pool: add helper function to unmap dma addresses

Jesper Dangaard Brouer (10):
      xdp: fix leak of IDA cyclic id if rhashtable_insert_slow fails
      xdp: page_pool related fix to cpumap
      veth: use xdp_release_frame for XDP_PASS
      page_pool: introduce page_pool_free and use in mlx5
      mlx5: more strict use of page_pool API
      xdp: tracking page_pool resources and safe removal
      xdp: force mem allocator removal and periodic warning
      xdp: add tracepoints for XDP mem
      page_pool: add tracepoints for page_pool with details need by XDP
      page_pool: make sure struct device is stable


 drivers/net/ethernet/mellanox/mlx5/core/en_main.c |   12 +-
 drivers/net/ethernet/mellanox/mlx5/core/en_rx.c   |    3 -
 drivers/net/veth.c                                |    1 
 include/net/page_pool.h                           |   69 +++++++++++-
 include/net/xdp.h                                 |   15 +++
 include/net/xdp_priv.h                            |   23 ++++
 include/trace/events/page_pool.h                  |   87 +++++++++++++++
 include/trace/events/xdp.h                        |  115 ++++++++++++++++++++
 kernel/bpf/cpumap.c                               |    3 +
 net/core/net-traces.c                             |    4 +
 net/core/page_pool.c                              |   95 +++++++++++++++--
 net/core/xdp.c                                    |  120 ++++++++++++++++++---
 12 files changed, 502 insertions(+), 45 deletions(-)
 create mode 100644 include/net/xdp_priv.h
 create mode 100644 include/trace/events/page_pool.h

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