Re: xdp_iphash_to_cpu_cmdline: Error loading BTF: Invalid argument(22)

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

On Thu, 24 Jun 2021 17:04:58 -0300
"Ethy H. Brito" <ethy.brito@inexo.com.br> wrote:

> On Tue, 22 Jun 2021 17:22:16 -0300
> "Ethy"  wrote:
> 
> > Hi
> > 
> > Runing "# ./xdp_iphash_to_cpu --dev eth1 --all-cpus --wan" returns 2 loading errors:
> > 
> > ----------------------8<----------------------------------
> > libbpf: Error loading BTF: Invalid argument(22)
> > libbpf: magic: 0xeb9f
> > version: 1
> > flags: 0x0
> > hdr_len: 24
> > type_off: 0
> > type_len: 492
> > str_off: 492
> > str_len: 1724
> > btf_total_size: 2240
> > [1] PTR (anon) type_id=2
> > [2] STRUCT xdp_md size=20 vlen=5
> > 	data type_id=3 bits_offset=0
> > 	data_end type_id=3 bits_offset=32
> > 	data_meta type_id=3 bits_offset=64
> > 	ingress_ifindex type_id=3 bits_offset=96
> > 	rx_queue_index type_id=3 bits_offset=128
> > [3] TYPEDEF __u32 type_id=4
> > [4] INT unsigned int size=4 bits_offset=0 nr_bits=32 encoding=(none)
> > [5] FUNC_PROTO (anon) return=6 args=(1 ctx)
> > [6] INT int size=4 bits_offset=0 nr_bits=32 encoding=SIGNED
> > [7] FUNC xdp_program type_id=5 vlen != 0
> > 
> > libbpf: Error loading ELF section .BTF: -22. Ignored and continue.

NOTICE above: "Ignored and continue".

Thus, this is not a real *error*, instead this is just a (very) verbose
*warning* that your system (kernel version? / compile options?) doesn't
support BTF correctly.  The BTF info is not really needed by
xdp-cpuma-tc, so you can safely ignore this "warning".


> > TC workaround for mapname: map_ifindex_type map_fd:5
> > Added CPU:0 queue_size:192
> > Added CPU:1 queue_size:192
> > Added CPU:2 queue_size:192
> > Added CPU:3 queue_size:192
> > Added CPU:4 queue_size:192
> > Added CPU:5 queue_size:192
> > Added CPU:6 queue_size:192
> > Added CPU:7 queue_size:192
> > Added CPU:8 queue_size:192
> > Added CPU:9 queue_size:192
> > Added CPU:10 queue_size:192
> > Added CPU:11 queue_size:192
> > Added CPU:12 queue_size:192
> > Added CPU:13 queue_size:192
> > Added CPU:14 queue_size:192
> > Added CPU:15 queue_size:192
> > Documentation:
> >  XDP: Lookup IPv4 and redirect to CPU hash
> > 
> > This program loads the XDP eBPF program into the kernel.
> > Use the cmdline tool for add/removing dest IPs to the hash
> > 
> >  - Attached to device:eth1 (ifindex:4) prog_id:73
> > ----------------------------------8<-------------------------------
> > 
> > Since the XDP program was correctly listed by "bpftool net", I continued an added just ONE ip
> > 
> > # ./xdp_iphash_to_cpu_cmdline --add --ip 1.2.3.4 --classid 1:1234 --cpu 1
> > key: 0x4030201
> > WARN: Looks like map_txq_config --base-setup is missing
> > WARN: Fixing, doing map_txq_config --base-setup
> > iphash_modify() IP:1.2.3.4 key:0x4030201 TC-handle:0x11234
> > 
> > listed the map
> > 
> > # ./xdp_iphash_to_cpu_cmdline --list
> > {
> > "1.2.3.4" : { "cpu" : 1, "tc_maj" : "1" , "tc_min" : "1234" }}
> > 
> > 
> > And right after I tried to remove the program from XDP:
> > 
> > # ./xdp_iphash_to_cpu --dev eth1 --remove
> > Removing XDP program on ifindex:4 device:eth1
> > ERR: Clear ifindex type failed 
> > INFO: not cleanup pinned map file:/sys/fs/bpf/tc/globals/map_ip_hash (use 'rm')
> > 
> > All seems to be rigth despite the errors.
> > Are all these errors and warnings serious problems? Should I worry? 
> > 
> > Hints??  
> 
> Hi.
> 
> Doesn't anybody know how to answer these?

This is just a warning you can ignore.
It looks like it works...

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer