On Sun, Jan 9, 2022 at 7:05 AM Lorenzo Bianconi <lorenzo@xxxxxxxxxx> wrote:
>
> Introduce support for the following SEC entries for XDP multi-buff
> property:
> - SEC("xdp_mb/")
> - SEC("xdp_devmap_mb/")
> - SEC("xdp_cpumap_mb/")
Libbpf seemed to went with .<suffix> rule (e.g., fentry.s for
sleepable, seems like we'll have kprobe.multi or something along
those lines as well), so let's stay consistent and call this "xdp_mb",
"xdp_devmap.mb", "xdp_cpumap.mb" (btw, is "mb" really all that
recognizable? would ".multibuf" be too verbose?). Also, why the "/"
part? Also it shouldn't be "sloppy" either. Neither expected attach
type should be optional. Also not sure SEC_ATTACHABLE is needed. So
at most it should be SEC_XDP_MB, probably.
>
> Acked-by: Toke Hoiland-Jorgensen <toke@xxxxxxxxxx>
> Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>
> Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
> ---
> tools/lib/bpf/libbpf.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 7f10dd501a52..c93f6afef96c 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -235,6 +235,8 @@ enum sec_def_flags {
> SEC_SLEEPABLE = 8,
> /* allow non-strict prefix matching */
> SEC_SLOPPY_PFX = 16,
> + /* BPF program support XDP multi-buff */
> + SEC_XDP_MB = 32,
> };
>
> struct bpf_sec_def {
> @@ -6562,6 +6564,9 @@ static int libbpf_preload_prog(struct bpf_program *prog,
> if (def & SEC_SLEEPABLE)
> opts->prog_flags |= BPF_F_SLEEPABLE;
>
> + if (prog->type == BPF_PROG_TYPE_XDP && (def & SEC_XDP_MB))
> + opts->prog_flags |= BPF_F_XDP_MB;
I'd say you don't even need SEC_XDP_MB flag at all, you can just check
that prog->sec_name is one of "xdp.mb", "xdp_devmap.mb" or
"xdp_cpumap.mb" and add the flag. SEC_XDP_MB doesn't seem generic
enough to warrant a flag.
> +
> if ((prog->type == BPF_PROG_TYPE_TRACING ||
> prog->type == BPF_PROG_TYPE_LSM ||
> prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) {
> @@ -8600,8 +8605,11 @@ static const struct bpf_sec_def section_defs[] = {
> SEC_DEF("lsm.s/", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_lsm),
> SEC_DEF("iter/", TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF, attach_iter),
> SEC_DEF("syscall", SYSCALL, 0, SEC_SLEEPABLE),
> + SEC_DEF("xdp_devmap_mb/", XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE | SEC_XDP_MB),
> SEC_DEF("xdp_devmap/", XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE),
> + SEC_DEF("xdp_cpumap_mb/", XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE | SEC_XDP_MB),
> SEC_DEF("xdp_cpumap/", XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE),
> + SEC_DEF("xdp_mb/", XDP, BPF_XDP, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX | SEC_XDP_MB),
> SEC_DEF("xdp", XDP, BPF_XDP, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
> SEC_DEF("perf_event", PERF_EVENT, 0, SEC_NONE | SEC_SLOPPY_PFX),
> SEC_DEF("lwt_in", LWT_IN, 0, SEC_NONE | SEC_SLOPPY_PFX),
> --
> 2.33.1
>
