* [PATCH bpf-next] bpf: Allow to use kfunc XDP hints and frags together @ 2023-09-14 8:37 Larysa Zaremba 2023-09-14 16:29 ` Stanislav Fomichev 2023-09-14 16:38 ` Maciej Fijalkowski 0 siblings, 2 replies; 7+ messages in thread From: Larysa Zaremba @ 2023-09-14 8:37 UTC (permalink / raw) To: bpf Cc: Larysa Zaremba, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song, John Fastabend, KP Singh, Stanislav Fomichev, Hao Luo, Jiri Olsa, linux-kernel There is no fundamental reason, why multi-buffer XDP and XDP kfunc RX hints cannot coexist in a single program. Allow those features to be used together by modifying the flags conditions. Suggested-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/CAKH8qBuzgtJj=OKMdsxEkyML36VsAuZpcrsXcyqjdKXSJCBq=Q@mail.gmail.com/ Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> --- kernel/bpf/offload.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c index ee35f33a96d1..43aded96c79b 100644 --- a/kernel/bpf/offload.c +++ b/kernel/bpf/offload.c @@ -232,7 +232,11 @@ int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr) attr->prog_type != BPF_PROG_TYPE_XDP) return -EINVAL; - if (attr->prog_flags & ~BPF_F_XDP_DEV_BOUND_ONLY) + if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS)) + return -EINVAL; + + if (attr->prog_flags & BPF_F_XDP_HAS_FRAGS && + !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)) return -EINVAL; if (attr->prog_type == BPF_PROG_TYPE_SCHED_CLS && -- 2.41.0 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH bpf-next] bpf: Allow to use kfunc XDP hints and frags together 2023-09-14 8:37 [PATCH bpf-next] bpf: Allow to use kfunc XDP hints and frags together Larysa Zaremba @ 2023-09-14 16:29 ` Stanislav Fomichev 2023-09-14 16:49 ` Larysa Zaremba 2023-09-14 16:38 ` Maciej Fijalkowski 1 sibling, 1 reply; 7+ messages in thread From: Stanislav Fomichev @ 2023-09-14 16:29 UTC (permalink / raw) To: Larysa Zaremba Cc: bpf, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song, John Fastabend, KP Singh, Hao Luo, Jiri Olsa, linux-kernel On 09/14, Larysa Zaremba wrote: > There is no fundamental reason, why multi-buffer XDP and XDP kfunc RX hints > cannot coexist in a single program. > > Allow those features to be used together by modifying the flags conditions. > > Suggested-by: Stanislav Fomichev <sdf@google.com> > Link: https://lore.kernel.org/bpf/CAKH8qBuzgtJj=OKMdsxEkyML36VsAuZpcrsXcyqjdKXSJCBq=Q@mail.gmail.com/ > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> > --- > kernel/bpf/offload.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c > index ee35f33a96d1..43aded96c79b 100644 > --- a/kernel/bpf/offload.c > +++ b/kernel/bpf/offload.c > @@ -232,7 +232,11 @@ int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr) > attr->prog_type != BPF_PROG_TYPE_XDP) > return -EINVAL; > > - if (attr->prog_flags & ~BPF_F_XDP_DEV_BOUND_ONLY) > + if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS)) > + return -EINVAL; > + [..] > + if (attr->prog_flags & BPF_F_XDP_HAS_FRAGS && > + !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)) > return -EINVAL; Any reason we have 'attr->prog_flags & BPF_F_XDP_HAS_FRAGS' part here? Seems like doing '!(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)' should be enough, right? We only want to bail out here when BPF_F_XDP_DEV_BOUND_ONLY is not set and we don't really care whether BPF_F_XDP_HAS_FRAGS is set or not at this point. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH bpf-next] bpf: Allow to use kfunc XDP hints and frags together 2023-09-14 16:29 ` Stanislav Fomichev @ 2023-09-14 16:49 ` Larysa Zaremba 2023-09-14 17:05 ` Stanislav Fomichev 0 siblings, 1 reply; 7+ messages in thread From: Larysa Zaremba @ 2023-09-14 16:49 UTC (permalink / raw) To: Stanislav Fomichev Cc: bpf, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song, John Fastabend, KP Singh, Hao Luo, Jiri Olsa, linux-kernel On Thu, Sep 14, 2023 at 09:29:57AM -0700, Stanislav Fomichev wrote: > On 09/14, Larysa Zaremba wrote: > > There is no fundamental reason, why multi-buffer XDP and XDP kfunc RX hints > > cannot coexist in a single program. > > > > Allow those features to be used together by modifying the flags conditions. > > > > Suggested-by: Stanislav Fomichev <sdf@google.com> > > Link: https://lore.kernel.org/bpf/CAKH8qBuzgtJj=OKMdsxEkyML36VsAuZpcrsXcyqjdKXSJCBq=Q@mail.gmail.com/ > > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> > > --- > > kernel/bpf/offload.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c > > index ee35f33a96d1..43aded96c79b 100644 > > --- a/kernel/bpf/offload.c > > +++ b/kernel/bpf/offload.c > > @@ -232,7 +232,11 @@ int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr) > > attr->prog_type != BPF_PROG_TYPE_XDP) > > return -EINVAL; > > > > - if (attr->prog_flags & ~BPF_F_XDP_DEV_BOUND_ONLY) > > + if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS)) > > + return -EINVAL; > > + > > [..] > > > + if (attr->prog_flags & BPF_F_XDP_HAS_FRAGS && > > + !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)) > > return -EINVAL; > > Any reason we have 'attr->prog_flags & BPF_F_XDP_HAS_FRAGS' part here? > Seems like doing '!(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)' should > be enough, right? We only want to bail out here when BPF_F_XDP_DEV_BOUND_ONLY > is not set and we don't really care whether BPF_F_XDP_HAS_FRAGS is set > or not at this point. If !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY) at this point, program could be requesting offload. Now I have thought about those conditions once more and they could be reduced to this: if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY) && attr->prog_flags != (BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS)) return -EINVAL; What do you think? ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH bpf-next] bpf: Allow to use kfunc XDP hints and frags together 2023-09-14 16:49 ` Larysa Zaremba @ 2023-09-14 17:05 ` Stanislav Fomichev 2023-09-14 17:04 ` Larysa Zaremba 0 siblings, 1 reply; 7+ messages in thread From: Stanislav Fomichev @ 2023-09-14 17:05 UTC (permalink / raw) To: Larysa Zaremba Cc: bpf, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song, John Fastabend, KP Singh, Hao Luo, Jiri Olsa, linux-kernel On Thu, Sep 14, 2023 at 9:55 AM Larysa Zaremba <larysa.zaremba@intel.com> wrote: > > On Thu, Sep 14, 2023 at 09:29:57AM -0700, Stanislav Fomichev wrote: > > On 09/14, Larysa Zaremba wrote: > > > There is no fundamental reason, why multi-buffer XDP and XDP kfunc RX hints > > > cannot coexist in a single program. > > > > > > Allow those features to be used together by modifying the flags conditions. > > > > > > Suggested-by: Stanislav Fomichev <sdf@google.com> > > > Link: https://lore.kernel.org/bpf/CAKH8qBuzgtJj=OKMdsxEkyML36VsAuZpcrsXcyqjdKXSJCBq=Q@mail.gmail.com/ > > > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> > > > --- > > > kernel/bpf/offload.c | 6 +++++- > > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > > > diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c > > > index ee35f33a96d1..43aded96c79b 100644 > > > --- a/kernel/bpf/offload.c > > > +++ b/kernel/bpf/offload.c > > > @@ -232,7 +232,11 @@ int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr) > > > attr->prog_type != BPF_PROG_TYPE_XDP) > > > return -EINVAL; > > > > > > - if (attr->prog_flags & ~BPF_F_XDP_DEV_BOUND_ONLY) > > > + if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS)) > > > + return -EINVAL; > > > + > > > > [..] > > > > > + if (attr->prog_flags & BPF_F_XDP_HAS_FRAGS && > > > + !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)) > > > return -EINVAL; > > > > Any reason we have 'attr->prog_flags & BPF_F_XDP_HAS_FRAGS' part here? > > Seems like doing '!(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)' should > > be enough, right? We only want to bail out here when BPF_F_XDP_DEV_BOUND_ONLY > > is not set and we don't really care whether BPF_F_XDP_HAS_FRAGS is set > > or not at this point. > > If !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY) at this point, program could > be requesting offload. > > Now I have thought about those conditions once more and they could be reduced to > this: > > if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY) && > attr->prog_flags != (BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS)) > return -EINVAL; > > What do you think? Ah, so this check is here to protect against the mbuf+offloaded combination? (looking at that other thread with Maciej) Let's keep your current way with two separate checks, but let's add your "/* Frags are allowed only if program is dev-bound-only, but not if it is requesting bpf offload. */" as a comment to the second check? ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH bpf-next] bpf: Allow to use kfunc XDP hints and frags together 2023-09-14 17:05 ` Stanislav Fomichev @ 2023-09-14 17:04 ` Larysa Zaremba 0 siblings, 0 replies; 7+ messages in thread From: Larysa Zaremba @ 2023-09-14 17:04 UTC (permalink / raw) To: Stanislav Fomichev Cc: bpf, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song, John Fastabend, KP Singh, Hao Luo, Jiri Olsa, linux-kernel On Thu, Sep 14, 2023 at 10:05:47AM -0700, Stanislav Fomichev wrote: > On Thu, Sep 14, 2023 at 9:55 AM Larysa Zaremba <larysa.zaremba@intel.com> wrote: > > > > On Thu, Sep 14, 2023 at 09:29:57AM -0700, Stanislav Fomichev wrote: > > > On 09/14, Larysa Zaremba wrote: > > > > There is no fundamental reason, why multi-buffer XDP and XDP kfunc RX hints > > > > cannot coexist in a single program. > > > > > > > > Allow those features to be used together by modifying the flags conditions. > > > > > > > > Suggested-by: Stanislav Fomichev <sdf@google.com> > > > > Link: https://lore.kernel.org/bpf/CAKH8qBuzgtJj=OKMdsxEkyML36VsAuZpcrsXcyqjdKXSJCBq=Q@mail.gmail.com/ > > > > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> > > > > --- > > > > kernel/bpf/offload.c | 6 +++++- > > > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c > > > > index ee35f33a96d1..43aded96c79b 100644 > > > > --- a/kernel/bpf/offload.c > > > > +++ b/kernel/bpf/offload.c > > > > @@ -232,7 +232,11 @@ int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr) > > > > attr->prog_type != BPF_PROG_TYPE_XDP) > > > > return -EINVAL; > > > > > > > > - if (attr->prog_flags & ~BPF_F_XDP_DEV_BOUND_ONLY) > > > > + if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS)) > > > > + return -EINVAL; > > > > + > > > > > > [..] > > > > > > > + if (attr->prog_flags & BPF_F_XDP_HAS_FRAGS && > > > > + !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)) > > > > return -EINVAL; > > > > > > Any reason we have 'attr->prog_flags & BPF_F_XDP_HAS_FRAGS' part here? > > > Seems like doing '!(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)' should > > > be enough, right? We only want to bail out here when BPF_F_XDP_DEV_BOUND_ONLY > > > is not set and we don't really care whether BPF_F_XDP_HAS_FRAGS is set > > > or not at this point. > > > > If !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY) at this point, program could > > be requesting offload. > > > > Now I have thought about those conditions once more and they could be reduced to > > this: > > > > if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY) && > > attr->prog_flags != (BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS)) > > return -EINVAL; > > > > What do you think? > > Ah, so this check is here to protect against the mbuf+offloaded > combination? (looking at that other thread with Maciej) > Let's keep your current way with two separate checks, but let's add > your "/* Frags are allowed only if program is dev-bound-only, but not > if it is requesting > bpf offload. */" as a comment to the second check? Ok, sound good to me. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH bpf-next] bpf: Allow to use kfunc XDP hints and frags together 2023-09-14 8:37 [PATCH bpf-next] bpf: Allow to use kfunc XDP hints and frags together Larysa Zaremba 2023-09-14 16:29 ` Stanislav Fomichev @ 2023-09-14 16:38 ` Maciej Fijalkowski 2023-09-14 16:53 ` Larysa Zaremba 1 sibling, 1 reply; 7+ messages in thread From: Maciej Fijalkowski @ 2023-09-14 16:38 UTC (permalink / raw) To: Larysa Zaremba Cc: bpf, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song, John Fastabend, KP Singh, Stanislav Fomichev, Hao Luo, Jiri Olsa, linux-kernel On Thu, Sep 14, 2023 at 10:37:11AM +0200, Larysa Zaremba wrote: > There is no fundamental reason, why multi-buffer XDP and XDP kfunc RX hints > cannot coexist in a single program. > > Allow those features to be used together by modifying the flags conditions. > > Suggested-by: Stanislav Fomichev <sdf@google.com> > Link: https://lore.kernel.org/bpf/CAKH8qBuzgtJj=OKMdsxEkyML36VsAuZpcrsXcyqjdKXSJCBq=Q@mail.gmail.com/ > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Though it would be worth spelling out something in the commit msg about additional check you're adding (frags flag can't go without dev bound) > --- > kernel/bpf/offload.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c > index ee35f33a96d1..43aded96c79b 100644 > --- a/kernel/bpf/offload.c > +++ b/kernel/bpf/offload.c > @@ -232,7 +232,11 @@ int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr) > attr->prog_type != BPF_PROG_TYPE_XDP) > return -EINVAL; > > - if (attr->prog_flags & ~BPF_F_XDP_DEV_BOUND_ONLY) > + if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS)) > + return -EINVAL; > + > + if (attr->prog_flags & BPF_F_XDP_HAS_FRAGS && > + !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)) > return -EINVAL; > > if (attr->prog_type == BPF_PROG_TYPE_SCHED_CLS && > -- > 2.41.0 > > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH bpf-next] bpf: Allow to use kfunc XDP hints and frags together 2023-09-14 16:38 ` Maciej Fijalkowski @ 2023-09-14 16:53 ` Larysa Zaremba 0 siblings, 0 replies; 7+ messages in thread From: Larysa Zaremba @ 2023-09-14 16:53 UTC (permalink / raw) To: Maciej Fijalkowski Cc: bpf, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Martin KaFai Lau, Song Liu, Yonghong Song, John Fastabend, KP Singh, Stanislav Fomichev, Hao Luo, Jiri Olsa, linux-kernel On Thu, Sep 14, 2023 at 06:38:15PM +0200, Maciej Fijalkowski wrote: > On Thu, Sep 14, 2023 at 10:37:11AM +0200, Larysa Zaremba wrote: > > There is no fundamental reason, why multi-buffer XDP and XDP kfunc RX hints > > cannot coexist in a single program. > > > > Allow those features to be used together by modifying the flags conditions. > > > > Suggested-by: Stanislav Fomichev <sdf@google.com> > > Link: https://lore.kernel.org/bpf/CAKH8qBuzgtJj=OKMdsxEkyML36VsAuZpcrsXcyqjdKXSJCBq=Q@mail.gmail.com/ > > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com> > > Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> > > Though it would be worth spelling out something in the commit msg about > additional check you're adding (frags flag can't go without dev bound) > Ok, I'll add to the commit message the below: Frags are allowed only if program is dev-bound-only, but not if it is requesting bpf offload. > > --- > > kernel/bpf/offload.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c > > index ee35f33a96d1..43aded96c79b 100644 > > --- a/kernel/bpf/offload.c > > +++ b/kernel/bpf/offload.c > > @@ -232,7 +232,11 @@ int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr) > > attr->prog_type != BPF_PROG_TYPE_XDP) > > return -EINVAL; > > > > - if (attr->prog_flags & ~BPF_F_XDP_DEV_BOUND_ONLY) > > + if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS)) > > + return -EINVAL; > > + > > + if (attr->prog_flags & BPF_F_XDP_HAS_FRAGS && > > + !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)) > > return -EINVAL; > > > > if (attr->prog_type == BPF_PROG_TYPE_SCHED_CLS && > > -- > > 2.41.0 > > > > ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2023-09-14 17:10 UTC | newest] Thread overview: 7+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2023-09-14 8:37 [PATCH bpf-next] bpf: Allow to use kfunc XDP hints and frags together Larysa Zaremba 2023-09-14 16:29 ` Stanislav Fomichev 2023-09-14 16:49 ` Larysa Zaremba 2023-09-14 17:05 ` Stanislav Fomichev 2023-09-14 17:04 ` Larysa Zaremba 2023-09-14 16:38 ` Maciej Fijalkowski 2023-09-14 16:53 ` Larysa Zaremba
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