On Wed, Jan 12, 2022 at 10:18 AM Lorenzo Bianconi <lorenzo@xxxxxxxxxx> wrote:
>
> > 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.
>
> ack, I fine with it. Something like:
>
> 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.multibuf", XDP, BPF_XDP_DEVMAP, 0),
> SEC_DEF("xdp_devmap/", XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE),
> + SEC_DEF("xdp_cpumap.multibuf", XDP, BPF_XDP_CPUMAP, 0),
> SEC_DEF("xdp_cpumap/", XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE),
> + SEC_DEF("xdp.multibuf", XDP, BPF_XDP, 0),
yep, but please use SEC_NONE instead of zero
> 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),
>
> >
> > >
> > > 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.
>
> ack, something like:
>
> + if (prog->type == BPF_PROG_TYPE_XDP &&
> + (!strcmp(prog->sec_name, "xdp_devmap.multibuf") ||
> + !strcmp(prog->sec_name, "xdp_cpumap.multibuf") ||
> + !strcmp(prog->sec_name, "xdp.multibuf")))
> + opts->prog_flags |= BPF_F_XDP_MB;
yep, can also simplify it a bit with strstr(prog->sec_name,
".multibuf") instead of three strcmp
>
> Regards,
> Lorenzo
>
> >
> > > +
> > > 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
> > >
