Subject: Re: [PATCH v6 bpf-next 0/9] introduce support for XDP programs in CPUMAP

From: Lorenzo Bianconi <[email-masked]>
Date: Tue, 14 Jul 2020 15:34:56 +0200

> Similar to what David Ahern proposed in [1] for DEVMAPs, introduce the
> capability to attach and run a XDP program to CPUMAP entries.
> The idea behind this feature is to add the possibility to define on which CPU
> run the eBPF program if the underlying hw does not support RSS.
> I respin patch 1/6 from a previous series sent by David [2].
> The functionality has been tested on Marvell Espressobin, i40e and mlx5.
> Detailed tests results can be found here:
> https://github.com/xdp-project/xdp-project/blob/master/areas/cpumap/cpumap04-map-xdp-prog.org
> 

Hi Alexei and Daniel,

I will post a v7 since v6 does not apply anymore to bpf-next.

Regards,
Lorenzo

> Changes since v5:
> - move bpf_prog_put() in put_cpu_map_entry()
> - remove READ_ONCE(rcpu->prog) in cpu_map_bpf_prog_run_xdp
> - rely on bpf_prog_get_type() instead of bpf_prog_get_type_dev() in
>   __cpu_map_load_bpf_program()
> 
> Changes since v4:
> - move xdp_clear_return_frame_no_direct inside rcu section
> - update David Ahern's email address
> 
> Changes since v3:
> - fix typo in commit message
> - fix access to ctx->ingress_ifindex in cpumap bpf selftest
> 
> Changes since v2:
> - improved comments
> - fix return value in xdp_convert_buff_to_frame
> - added patch 1/9: "cpumap: use non-locked version __ptr_ring_consume_batched"
> - do not run kmem_cache_alloc_bulk if all frames have been consumed by the XDP
>   program attached to the CPUMAP entry
> - removed bpf_trace_printk in kselftest
> 
> Changes since v1:
> - added performance test results
> - added kselftest support
> - fixed memory accounting with page_pool
> - extended xdp_redirect_cpu_user.c to load an external program to perform
>   redirect
> - reported ifindex to attached eBPF program
> - moved bpf_cpumap_val definition to include/uapi/linux/bpf.h
> 
> [1] https://patchwork.ozlabs.org/project/netdev/cover/[email-masked]/
> [2] https://patchwork.ozlabs.org/project/netdev/patch/[email-masked]/
> 
> David Ahern (1):
>   net: refactor xdp_convert_buff_to_frame
> 
> Jesper Dangaard Brouer (1):
>   cpumap: use non-locked version __ptr_ring_consume_batched
> 
> Lorenzo Bianconi (7):
>   samples/bpf: xdp_redirect_cpu_user: do not update bpf maps in option
>     loop
>   cpumap: formalize map value as a named struct
>   bpf: cpumap: add the possibility to attach an eBPF program to cpumap
>   bpf: cpumap: implement XDP_REDIRECT for eBPF programs attached to map
>     entries
>   libbpf: add SEC name for xdp programs attached to CPUMAP
>   samples/bpf: xdp_redirect_cpu: load a eBPF program on cpumap
>   selftest: add tests for XDP programs in CPUMAP entries
> 
>  include/linux/bpf.h                           |   6 +
>  include/net/xdp.h                             |  41 ++--
>  include/trace/events/xdp.h                    |  16 +-
>  include/uapi/linux/bpf.h                      |  14 ++
>  kernel/bpf/cpumap.c                           | 159 ++++++++++---
>  net/core/dev.c                                |   9 +
>  samples/bpf/xdp_redirect_cpu_kern.c           |  25 ++-
>  samples/bpf/xdp_redirect_cpu_user.c           | 209 ++++++++++++++++--
>  tools/include/uapi/linux/bpf.h                |  14 ++
>  tools/lib/bpf/libbpf.c                        |   2 +
>  .../bpf/prog_tests/xdp_cpumap_attach.c        |  70 ++++++
>  .../bpf/progs/test_xdp_with_cpumap_helpers.c  |  36 +++
>  12 files changed, 529 insertions(+), 72 deletions(-)
>  create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
>  create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_helpers.c
> 
> -- 
> 2.26.2
>