From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-x22f.google.com (mail-oi1-x22f.google.com [IPv6:2607:f8b0:4864:20::22f]) by mail.toke.dk (Postfix) with ESMTPS id 95F449C7694 for ; Mon, 28 Nov 2022 20:22:10 +0100 (CET) Authentication-Results: mail.toke.dk; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20210112 header.b=RNrYRDB7 Received: by mail-oi1-x22f.google.com with SMTP id r76so12684435oie.13 for ; Mon, 28 Nov 2022 11:22:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=lObuvBuVImK8GOxZ/KwRsTUs+Zp60dapoKCv+L/Yh10=; b=RNrYRDB7evRL3IduYhMVUhAVP7ZIfOZ+A//ZZ2mUc0DXCyrb+Nl3tL+LhQwK9Jm2+C ugg/FLjrRswaU3Cp0Zn3aq/bkqiRaV/5e7g7WkbJ1RKDst8pl/YMDOuwk53EGKqCfrUN 3HdCqj3z+/uPaH79PjmavpLyf8FBtH3ebtqwx+oC8R8Iq7JG0TqrDejwwhHxp1yHZxqv Q4mOqeDHmnN8DaFEKNeFvNhPkXc/AM592wZ1cSjEzaeu3cwVlp6yD5devnkofvQLWcan l4/Z8PfAtkr0KlTFyUokqs9RWColRtQjxtfQyIdnHs1Osn64SibITsUXGd81BKypjzyf a4Rg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=lObuvBuVImK8GOxZ/KwRsTUs+Zp60dapoKCv+L/Yh10=; b=tuZ+MGt82K+n++6Ij9h/APs8f5AFp+pjfdp0tA/Nak+hf0ddkBTiTSq17WkZSolG97 gcLBoViMF3ahzv38L/BUoFMaMYHipwu3vMPxtlbEdIyV+FDgPKcjEQHvMJ6NEWQwNFPt 6s8iKYLyjXp47sNT3xEPOlAgiFJ8h6g471g6wTZlV/2V5+4AT1G85HCJisJg0SOF0Ivb lE4AOMg3l8obFn+DLbmcm7ECOyRR/uOW0cygzOXHkjS7SdbAbyAS+xe/rw/WtsyoVciA oiFOYW5ORTvPnwJjzBZseBX7ZLmNXG/6dZd+vcD0HNXJONgdKhcgYG7aHNVr2eFeT3p6 OXMg== X-Gm-Message-State: ANoB5pnrC+PY1Ivh2cRDRqjAA8D2EHRIt6g1CwbWtWIS/Frk6nOJnYVB 0oDY/9DFrZ5XA9tkVPqXQg2mvqymhK4Hh1ZxDdFXFA== X-Google-Smtp-Source: AA0mqf7RAs1w/gvL+XiD5brsD7hgDmY33HsWo2XVDDY2JWNC3KqH6hhEMXHsqiICGjH3SSSQn1ZUrGE9+R1bGFokiUY= X-Received: by 2002:a05:6808:a90:b0:35b:aa33:425a with SMTP id q16-20020a0568080a9000b0035baa33425amr4530689oij.181.1669663329076; Mon, 28 Nov 2022 11:22:09 -0800 (PST) MIME-Version: 1.0 References: <20221121182552.2152891-1-sdf@google.com> <20221121182552.2152891-3-sdf@google.com> <87mt8e2a69.fsf@toke.dk> In-Reply-To: From: Stanislav Fomichev Date: Mon, 28 Nov 2022 11:21:58 -0800 Message-ID: To: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Message-ID-Hash: OZFAZJ6C7KDTE3ZPQ5Z5ZT6LHKIBK3Z2 X-Message-ID-Hash: OZFAZJ6C7KDTE3ZPQ5Z5ZT6LHKIBK3Z2 X-MailFrom: sdf@google.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, haoluo@google.com, jolsa@kernel.org, David Ahern , Jakub Kicinski , Willem de Bruijn , Jesper Dangaard Brouer , Anatoly Burakov , Alexander Lobakin , Magnus Karlsson , Maryam Tahhan , xdp-hints@xdp-project.net, netdev@vger.kernel.org X-Mailman-Version: 3.3.7 Precedence: list Subject: [xdp-hints] Re: [PATCH bpf-next v2 2/8] bpf: XDP metadata RX kfuncs List-Id: XDP hardware hints design discussion Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Mon, Nov 28, 2022 at 10:53 AM Stanislav Fomichev wrote: > > s > > On Fri, Nov 25, 2022 at 9:53 AM Toke H=C3=B8iland-J=C3=B8rgensen wrote: > > > > Stanislav Fomichev writes: > > > > > There is an ndo handler per kfunc, the verifier replaces a call to th= e > > > generic kfunc with a call to the per-device one. > > > > > > For XDP, we define a new kfunc set (xdp_metadata_kfunc_ids) which > > > implements all possible metatada kfuncs. Not all devices have to > > > implement them. If kfunc is not supported by the target device, > > > the default implementation is called instead. > > > > BTW, this "the default implementation is called instead" bit is not > > included in this version... :) > > fixup_xdp_kfunc_call should return 0 when the device doesn't have a > kfunc defined and should fallback to the default kfunc implementation, > right? > Or am I missing something? > > > [...] > > > > > +#ifdef CONFIG_DEBUG_INFO_BTF > > > +BTF_SET8_START(xdp_metadata_kfunc_ids) > > > +#define XDP_METADATA_KFUNC(name, str) BTF_ID_FLAGS(func, str, 0) > > > +XDP_METADATA_KFUNC_xxx > > > +#undef XDP_METADATA_KFUNC > > > +BTF_SET8_END(xdp_metadata_kfunc_ids) > > > + > > > +static const struct btf_kfunc_id_set xdp_metadata_kfunc_set =3D { > > > + .owner =3D THIS_MODULE, > > > + .set =3D &xdp_metadata_kfunc_ids, > > > +}; > > > + > > > +u32 xdp_metadata_kfunc_id(int id) > > > +{ > > > + return xdp_metadata_kfunc_ids.pairs[id].id; > > > +} > > > +EXPORT_SYMBOL_GPL(xdp_metadata_kfunc_id); > > > > So I was getting some really weird values when testing (always getting = a > > timestamp value of '1'), and it turns out to be because this way of > > looking up the ID doesn't work: The set is always sorted by the BTF ID, > > not the order it was defined. Which meant that the mapping code got the > > functions mixed up, and would call a different one instead (so the > > timestamp value I was getting was really the return value of > > rx_hash_enabled()). > > > > I fixed it by building a secondary lookup table as below; feel free to > > incorporate that (or if you can come up with a better way, go ahead!). > > Interesting, will take a closer look. I took this pattern from > BTF_SOCK_TYPE_xxx, which means that 'sorting by btf-id' is something > BTF_SET8_START specific... > But if it's sorted, probably easier to do a bsearch over this table > than to build another one? Ah, I see, there is no place to store an index :-( Maybe the following is easier still? diff --git a/net/core/xdp.c b/net/core/xdp.c index e43f7d4ef4cf..8240805bfdb7 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -743,9 +743,15 @@ static const struct btf_kfunc_id_set xdp_metadata_kfunc_set =3D { .set =3D &xdp_metadata_kfunc_ids, }; +BTF_ID_LIST(xdp_metadata_kfunc_ids_unsorted) +#define XDP_METADATA_KFUNC(name, str) BTF_ID(func, str) +XDP_METADATA_KFUNC_xxx +#undef XDP_METADATA_KFUNC + u32 xdp_metadata_kfunc_id(int id) { - return xdp_metadata_kfunc_ids.pairs[id].id; + /* xdp_metadata_kfunc_ids is sorted and can't be used */ + return xdp_metadata_kfunc_ids_unsorted[id]; } EXPORT_SYMBOL_GPL(xdp_metadata_kfunc_id); > > -Toke > > > > diff --git a/net/core/xdp.c b/net/core/xdp.c > > index e43f7d4ef4cf..dc0a9644dacc 100644 > > --- a/net/core/xdp.c > > +++ b/net/core/xdp.c > > @@ -738,6 +738,15 @@ XDP_METADATA_KFUNC_xxx > > #undef XDP_METADATA_KFUNC > > BTF_SET8_END(xdp_metadata_kfunc_ids) > > > > +static struct xdp_metadata_kfunc_map { > > + const char *fname; > > + u32 btf_id; > > +} xdp_metadata_kfunc_lookup_map[MAX_XDP_METADATA_KFUNC] =3D { > > +#define XDP_METADATA_KFUNC(name, str) { .fname =3D __stringify(str) }, > > +XDP_METADATA_KFUNC_xxx > > +#undef XDP_METADATA_KFUNC > > +}; > > + > > static const struct btf_kfunc_id_set xdp_metadata_kfunc_set =3D { > > .owner =3D THIS_MODULE, > > .set =3D &xdp_metadata_kfunc_ids, > > @@ -745,13 +754,41 @@ static const struct btf_kfunc_id_set xdp_metadata= _kfunc_set =3D { > > > > u32 xdp_metadata_kfunc_id(int id) > > { > > - return xdp_metadata_kfunc_ids.pairs[id].id; > > + return xdp_metadata_kfunc_lookup_map[id].btf_id; > > } > > EXPORT_SYMBOL_GPL(xdp_metadata_kfunc_id); > > > > static int __init xdp_metadata_init(void) > > { > > - return register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &xdp_metada= ta_kfunc_set); > > + const struct btf *btf; > > + int i, j, ret; > > + > > + ret =3D register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &xdp_metad= ata_kfunc_set); > > + if (ret) > > + return ret; > > + > > + btf =3D bpf_get_btf_vmlinux(); > > + > > + for (i =3D 0; i < MAX_XDP_METADATA_KFUNC; i++) { > > + u32 btf_id =3D xdp_metadata_kfunc_ids.pairs[i].id; > > + const struct btf_type *t; > > + const char *name; > > + > > + t =3D btf_type_by_id(btf, btf_id); > > + if (WARN_ON_ONCE(!t || !t->name_off)) > > + continue; > > + > > + name =3D btf_name_by_offset(btf, t->name_off); > > + > > + for (j =3D 0; j < MAX_XDP_METADATA_KFUNC; j++) { > > + if (!strcmp(name, xdp_metadata_kfunc_lookup_map= [j].fname)) { > > + xdp_metadata_kfunc_lookup_map[j].btf_id= =3D btf_id; > > + break; > > + } > > + } > > + } > > + > > + return 0; > > } > > late_initcall(xdp_metadata_init); > > #else /* CONFIG_DEBUG_INFO_BTF */ > >