From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7125AC001B2 for ; Mon, 19 Dec 2022 20:03:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232410AbiLSUDO (ORCPT ); Mon, 19 Dec 2022 15:03:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232207AbiLSUDN (ORCPT ); Mon, 19 Dec 2022 15:03:13 -0500 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0CDC713F68 for ; Mon, 19 Dec 2022 12:03:12 -0800 (PST) Received: by mail-pl1-x649.google.com with SMTP id u6-20020a170903124600b00188cd4769bcso7564089plh.0 for ; Mon, 19 Dec 2022 12:03:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=B93Ere0lh6/8aqm4JgiAxJ/jdGiP7qSbPB4CT/66Oaw=; b=Lfpguxg1frG0D7dBTC/sOSV3iTGWzZIjjDjX6GxO7UKgIrGgBPdsfwUdoEBGDy0FSu iykv3g6pFQCM42WgaFvwRxGSbrXnW8tAhGOYI9u/xolNJBGDmtrhUrkDgeOgWEEr0oIj +NS4+pDhy0gtzlJavgnMxdRGv6VdNKIbP+sv2zg7ZgzIWKK9Mx4iOfEWpWzZ1gZZyVap D9HHaHZWdJhqWrXxf1nAWWr9ly3kbh2qgEB/ojs7xGwvbryXkLKBfIbAFJMxi0GSVFRY kBdKreYqeMUfeMxKntBFLivjwMGky6b5Gzjp+1zwomL1hg7/TmfjHOQcTUhYzKI6wYim XSLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=B93Ere0lh6/8aqm4JgiAxJ/jdGiP7qSbPB4CT/66Oaw=; b=dWL/YPqTieVSVm2nEt+Y4owyymSgVdqujI1hIyuQjZVz+AFH8uvzOnZs6M0cIWMeIO SQsGwosavkzp9U16JvZ6arQ0YZJfTrxeXWAFzBYJjJ/Gsdcogvees8DG3gpAa9nTQDUd Rf/evc0lKxadNMTFKAnRAhj4n33J1ye17ZXlsEaaa2XThB6ypRvsGyWbYdLBdORhjYP7 pbRlUngAMaDi/QAezytZFg9U+JFoDNetp0jRPYPGdLq3CK87HGklNDT4+iDQZ/PduxbL vktSZpwGNb53Jy+LRjwumOgvPf8Yc+oCli86lf6pL7VhnII2cGBB00qhDT56S2z3MSI1 pugA== X-Gm-Message-State: AFqh2krcSIL28A78dj3gFXEeNUfzoFbD/SaphwLcHYMg74C3Os3sEmA/ jFbXCB3V0XJWQrZ2igoHOu/vYVs= X-Google-Smtp-Source: AMrXdXsx6noD2wWH0DbWT6pPsOKfsqEWhJ1gVTk9BKTO1WPgvZTY40rYjG+JjMQVgVQdmbqLwC1d8MY= X-Received: from sdf.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5935]) (user=sdf job=sendgmr) by 2002:a17:90b:4ccf:b0:219:b015:58cd with SMTP id nd15-20020a17090b4ccf00b00219b01558cdmr2486553pjb.40.1671480191438; Mon, 19 Dec 2022 12:03:11 -0800 (PST) Date: Mon, 19 Dec 2022 12:03:09 -0800 In-Reply-To: <43c340d440d8a87396198b301c5ffbf5ab56f304.1671462950.git.lorenzo@kernel.org> Mime-Version: 1.0 References: <43c340d440d8a87396198b301c5ffbf5ab56f304.1671462950.git.lorenzo@kernel.org> Message-ID: Subject: Re: [RFC bpf-next 2/8] net: introduce XDP features flag From: sdf@google.com To: Lorenzo Bianconi Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, davem@davemloft.net, kuba@kernel.org, hawk@kernel.org, pabeni@redhat.com, edumazet@google.com, toke@redhat.com, memxor@gmail.com, alardam@gmail.com, saeedm@nvidia.com, anthony.l.nguyen@intel.com, gospo@broadcom.com, vladimir.oltean@nxp.com, nbd@nbd.name, john@phrozen.org, leon@kernel.org, simon.horman@corigine.com, aelior@marvell.com, christophe.jaillet@wanadoo.fr, ecree.xilinx@gmail.com, grygorii.strashko@ti.com, mst@redhat.com, bjorn@kernel.org, magnus.karlsson@intel.com, maciej.fijalkowski@intel.com, intel-wired-lan@lists.osuosl.org, lorenzo.bianconi@redhat.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 12/19, Lorenzo Bianconi wrote: > From: Marek Majtyka > Implement support for checking what kind of XDP features a netdev > supports. Previously, there was no way to do this other than to try to > create an AF_XDP socket on the interface or load an XDP program and see > if it worked. This commit changes this by adding a new variable which > describes all xdp supported functions on pretty detailed level: > - aborted > - drop > - pass > - tx > - redirect > - sock_zerocopy > - hw_offload > - redirect_target > - tx_lock > - frag_rx > - frag_target > Zerocopy mode requires that redirect XDP operation is implemented in a > driver and the driver supports also zero copy mode. Full mode requires > that all XDP operation are implemented in the driver. Basic mode is just > full mode without redirect operation. Frag target requires > redirect_target one is supported by the driver. Can you share more about _why_ is it needed? If we can already obtain most of these signals via probing, why export the flags? > Initially, these new flags are disabled for all drivers by default. > Co-developed-by: Kumar Kartikeya Dwivedi > Signed-off-by: Kumar Kartikeya Dwivedi > Co-developed-by: Lorenzo Bianconi > Signed-off-by: Lorenzo Bianconi > Signed-off-by: Marek Majtyka > --- > .../networking/netdev-xdp-features.rst | 60 +++++++++++++++++ > include/linux/netdevice.h | 2 + > include/linux/xdp_features.h | 64 +++++++++++++++++++ > include/uapi/linux/if_link.h | 7 ++ > include/uapi/linux/xdp_features.h | 34 ++++++++++ > net/core/rtnetlink.c | 34 ++++++++++ > tools/include/uapi/linux/if_link.h | 7 ++ > tools/include/uapi/linux/xdp_features.h | 34 ++++++++++ > 8 files changed, 242 insertions(+) > create mode 100644 Documentation/networking/netdev-xdp-features.rst > create mode 100644 include/linux/xdp_features.h > create mode 100644 include/uapi/linux/xdp_features.h > create mode 100644 tools/include/uapi/linux/xdp_features.h > diff --git a/Documentation/networking/netdev-xdp-features.rst > b/Documentation/networking/netdev-xdp-features.rst > new file mode 100644 > index 000000000000..1dc803fe72dd > --- /dev/null > +++ b/Documentation/networking/netdev-xdp-features.rst > @@ -0,0 +1,60 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +===================== > +Netdev XDP features > +===================== > + > + * XDP FEATURES FLAGS > + > +Following netdev xdp features flags can be retrieved over route netlink > +interface (compact form) - the same way as netdev feature flags. > +These features flags are read only and cannot be change at runtime. > + > +* XDP_ABORTED > + > +This feature informs if netdev supports xdp aborted action. > + > +* XDP_DROP > + > +This feature informs if netdev supports xdp drop action. > + > +* XDP_PASS > + > +This feature informs if netdev supports xdp pass action. > + > +* XDP_TX > + > +This feature informs if netdev supports xdp tx action. > + > +* XDP_REDIRECT > + > +This feature informs if netdev supports xdp redirect action. > +It assumes the all beforehand mentioned flags are enabled. > + > +* XDP_SOCK_ZEROCOPY > + > +This feature informs if netdev driver supports xdp zero copy. > +It assumes the all beforehand mentioned flags are enabled. > + > +* XDP_HW_OFFLOAD > + > +This feature informs if netdev driver supports xdp hw oflloading. > + > +* XDP_TX_LOCK > + > +This feature informs if netdev ndo_xdp_xmit function requires locking. > + > +* XDP_REDIRECT_TARGET > + > +This feature informs if netdev implements ndo_xdp_xmit callback. > + > +* XDP_FRAG_RX > + > +This feature informs if netdev implements non-linear xdp buff support in > +the driver napi callback. > + > +* XDP_FRAG_TARGET > + > +This feature informs if netdev implements non-linear xdp buff support in > +ndo_xdp_xmit callback. XDP_FRAG_TARGET requires XDP_REDIRECT_TARGET is > properly > +supported. > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > index aad12a179e54..ae5a8564383b 100644 > --- a/include/linux/netdevice.h > +++ b/include/linux/netdevice.h > @@ -43,6 +43,7 @@ > #include > #include > +#include > #include > #include > #include > @@ -2362,6 +2363,7 @@ struct net_device { > struct rtnl_hw_stats64 *offload_xstats_l3; > struct devlink_port *devlink_port; > + xdp_features_t xdp_features; > }; > #define to_net_dev(d) container_of(d, struct net_device, dev) > diff --git a/include/linux/xdp_features.h b/include/linux/xdp_features.h > new file mode 100644 > index 000000000000..4e72a86ef329 > --- /dev/null > +++ b/include/linux/xdp_features.h > @@ -0,0 +1,64 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +/* > + * Network device xdp features. > + */ > +#ifndef _LINUX_XDP_FEATURES_H > +#define _LINUX_XDP_FEATURES_H > + > +#include > +#include > +#include > +#include > + > +typedef u32 xdp_features_t; > + > +#define __XDP_F_BIT(bit) ((xdp_features_t)1 << (bit)) > +#define __XDP_F(name) __XDP_F_BIT(XDP_F_##name##_BIT) > + > +#define XDP_F_ABORTED __XDP_F(ABORTED) > +#define XDP_F_DROP __XDP_F(DROP) > +#define XDP_F_PASS __XDP_F(PASS) > +#define XDP_F_TX __XDP_F(TX) > +#define XDP_F_REDIRECT __XDP_F(REDIRECT) > +#define XDP_F_REDIRECT_TARGET __XDP_F(REDIRECT_TARGET) > +#define XDP_F_SOCK_ZEROCOPY __XDP_F(SOCK_ZEROCOPY) > +#define XDP_F_HW_OFFLOAD __XDP_F(HW_OFFLOAD) > +#define XDP_F_TX_LOCK __XDP_F(TX_LOCK) > +#define XDP_F_FRAG_RX __XDP_F(FRAG_RX) > +#define XDP_F_FRAG_TARGET __XDP_F(FRAG_TARGET) > + > +#define XDP_F_BASIC (XDP_F_ABORTED | XDP_F_DROP | \ > + XDP_F_PASS | XDP_F_TX) > + > +#define XDP_F_FULL (XDP_F_BASIC | XDP_F_REDIRECT) > + > +#define XDP_F_FULL_ZC (XDP_F_FULL | XDP_F_SOCK_ZEROCOPY) > + > +#define XDP_FEATURES_ABORTED_STR "xdp-aborted" > +#define XDP_FEATURES_DROP_STR "xdp-drop" > +#define XDP_FEATURES_PASS_STR "xdp-pass" > +#define XDP_FEATURES_TX_STR "xdp-tx" > +#define XDP_FEATURES_REDIRECT_STR "xdp-redirect" > +#define XDP_FEATURES_REDIRECT_TARGET_STR "xdp-redirect-target" > +#define XDP_FEATURES_SOCK_ZEROCOPY_STR "xdp-sock-zerocopy" > +#define XDP_FEATURES_HW_OFFLOAD_STR "xdp-hw-offload" > +#define XDP_FEATURES_TX_LOCK_STR "xdp-tx-lock" > +#define XDP_FEATURES_FRAG_RX_STR "xdp-frag-rx" > +#define XDP_FEATURES_FRAG_TARGET_STR "xdp-frag-target" > + > +#define DECLARE_XDP_FEATURES_TABLE(name, length) \ > + const char name[][length] = { \ > + [XDP_F_ABORTED_BIT] = XDP_FEATURES_ABORTED_STR, \ > + [XDP_F_DROP_BIT] = XDP_FEATURES_DROP_STR, \ > + [XDP_F_PASS_BIT] = XDP_FEATURES_PASS_STR, \ > + [XDP_F_TX_BIT] = XDP_FEATURES_TX_STR, \ > + [XDP_F_REDIRECT_BIT] = XDP_FEATURES_REDIRECT_STR, \ > + [XDP_F_REDIRECT_TARGET_BIT] = XDP_FEATURES_REDIRECT_TARGET_STR, \ > + [XDP_F_SOCK_ZEROCOPY_BIT] = XDP_FEATURES_SOCK_ZEROCOPY_STR, \ > + [XDP_F_HW_OFFLOAD_BIT] = XDP_FEATURES_HW_OFFLOAD_STR, \ > + [XDP_F_TX_LOCK_BIT] = XDP_FEATURES_TX_LOCK_STR, \ > + [XDP_F_FRAG_RX_BIT] = XDP_FEATURES_FRAG_RX_STR, \ > + [XDP_F_FRAG_TARGET_BIT] = XDP_FEATURES_FRAG_TARGET_STR, \ > + } > + > +#endif /* _LINUX_XDP_FEATURES_H */ > diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h > index 1021a7e47a86..971c658ceaea 100644 > --- a/include/uapi/linux/if_link.h > +++ b/include/uapi/linux/if_link.h > @@ -374,6 +374,8 @@ enum { > IFLA_DEVLINK_PORT, > + IFLA_XDP_FEATURES, > + > __IFLA_MAX > }; > @@ -1318,6 +1320,11 @@ enum { > #define IFLA_XDP_MAX (__IFLA_XDP_MAX - 1) > +enum { > + IFLA_XDP_FEATURES_WORD_UNSPEC = 0, > + IFLA_XDP_FEATURES_BITS_WORD, > +}; > + > enum { > IFLA_EVENT_NONE, > IFLA_EVENT_REBOOT, /* internal reset / reboot */ > diff --git a/include/uapi/linux/xdp_features.h > b/include/uapi/linux/xdp_features.h > new file mode 100644 > index 000000000000..48eb42069bcd > --- /dev/null > +++ b/include/uapi/linux/xdp_features.h > @@ -0,0 +1,34 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > +/* > + * Copyright (c) 2020 Intel > + */ > + > +#ifndef __UAPI_LINUX_XDP_FEATURES__ > +#define __UAPI_LINUX_XDP_FEATURES__ > + > +enum { > + XDP_F_ABORTED_BIT, > + XDP_F_DROP_BIT, > + XDP_F_PASS_BIT, > + XDP_F_TX_BIT, > + XDP_F_REDIRECT_BIT, > + XDP_F_REDIRECT_TARGET_BIT, > + XDP_F_SOCK_ZEROCOPY_BIT, > + XDP_F_HW_OFFLOAD_BIT, > + XDP_F_TX_LOCK_BIT, > + XDP_F_FRAG_RX_BIT, > + XDP_F_FRAG_TARGET_BIT, > + /* > + * Add your fresh new property above and remember to update > + * documentation. > + */ > + XDP_FEATURES_COUNT, > +}; > + > +#define XDP_FEATURES_WORDS ((XDP_FEATURES_COUNT + 32 - 1) / 32) > +#define XDP_FEATURES_WORD(blocks, index) ((blocks)[(index) / 32U]) > +#define XDP_FEATURES_FIELD_FLAG(index) (1U << (index) % 32U) > +#define XDP_FEATURES_BIT_IS_SET(blocks, index) \ > + (XDP_FEATURES_WORD(blocks, index) & XDP_FEATURES_FIELD_FLAG(index)) > + > +#endif /* __UAPI_LINUX_XDP_FEATURES__ */ > diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c > index 64289bc98887..1c299746b614 100644 > --- a/net/core/rtnetlink.c > +++ b/net/core/rtnetlink.c > @@ -1016,6 +1016,14 @@ static size_t rtnl_xdp_size(void) > return xdp_size; > } > +static size_t rtnl_xdp_features_size(void) > +{ > + size_t xdp_size = nla_total_size(0) + /* nest IFLA_XDP_FEATURES */ > + XDP_FEATURES_WORDS * nla_total_size(4); > + > + return xdp_size; > +} > + > static size_t rtnl_prop_list_size(const struct net_device *dev) > { > struct netdev_name_node *name_node; > @@ -1103,6 +1111,7 @@ static noinline size_t if_nlmsg_size(const struct > net_device *dev, > + rtnl_prop_list_size(dev) > + nla_total_size(MAX_ADDR_LEN) /* IFLA_PERM_ADDRESS */ > + rtnl_devlink_port_size(dev) > + + rtnl_xdp_features_size() /* IFLA_XDP_FEATURES */ > + 0; > } > @@ -1546,6 +1555,27 @@ static int rtnl_xdp_fill(struct sk_buff *skb, > struct net_device *dev) > return err; > } > +static int rtnl_xdp_features_fill(struct sk_buff *skb, struct net_device > *dev) > +{ > + struct nlattr *attr; > + > + attr = nla_nest_start_noflag(skb, IFLA_XDP_FEATURES); > + if (!attr) > + return -EMSGSIZE; > + > + BUILD_BUG_ON(XDP_FEATURES_WORDS != 1); > + if (nla_put_u32(skb, IFLA_XDP_FEATURES_BITS_WORD, dev->xdp_features)) > + goto err_cancel; > + > + nla_nest_end(skb, attr); > + > + return 0; > + > +err_cancel: > + nla_nest_cancel(skb, attr); > + return -EMSGSIZE; > +} > + > static u32 rtnl_get_event(unsigned long event) > { > u32 rtnl_event_type = IFLA_EVENT_NONE; > @@ -1904,6 +1934,9 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, > if (rtnl_fill_devlink_port(skb, dev)) > goto nla_put_failure; > + if (rtnl_xdp_features_fill(skb, dev)) > + goto nla_put_failure; > + > nlmsg_end(skb, nlh); > return 0; > @@ -1968,6 +2001,7 @@ static const struct nla_policy > ifla_policy[IFLA_MAX+1] = { > [IFLA_TSO_MAX_SIZE] = { .type = NLA_REJECT }, > [IFLA_TSO_MAX_SEGS] = { .type = NLA_REJECT }, > [IFLA_ALLMULTI] = { .type = NLA_REJECT }, > + [IFLA_XDP_FEATURES] = { .type = NLA_NESTED }, > }; > static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = { > diff --git a/tools/include/uapi/linux/if_link.h > b/tools/include/uapi/linux/if_link.h > index 82fe18f26db5..994228e9909a 100644 > --- a/tools/include/uapi/linux/if_link.h > +++ b/tools/include/uapi/linux/if_link.h > @@ -354,6 +354,8 @@ enum { > IFLA_DEVLINK_PORT, > + IFLA_XDP_FEATURES, > + > __IFLA_MAX > }; > @@ -1222,6 +1224,11 @@ enum { > #define IFLA_XDP_MAX (__IFLA_XDP_MAX - 1) > +enum { > + IFLA_XDP_FEATURES_WORD_UNSPEC = 0, > + IFLA_XDP_FEATURES_BITS_WORD, > +}; > + > enum { > IFLA_EVENT_NONE, > IFLA_EVENT_REBOOT, /* internal reset / reboot */ > diff --git a/tools/include/uapi/linux/xdp_features.h > b/tools/include/uapi/linux/xdp_features.h > new file mode 100644 > index 000000000000..48eb42069bcd > --- /dev/null > +++ b/tools/include/uapi/linux/xdp_features.h > @@ -0,0 +1,34 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > +/* > + * Copyright (c) 2020 Intel > + */ > + > +#ifndef __UAPI_LINUX_XDP_FEATURES__ > +#define __UAPI_LINUX_XDP_FEATURES__ > + > +enum { > + XDP_F_ABORTED_BIT, > + XDP_F_DROP_BIT, > + XDP_F_PASS_BIT, > + XDP_F_TX_BIT, > + XDP_F_REDIRECT_BIT, > + XDP_F_REDIRECT_TARGET_BIT, > + XDP_F_SOCK_ZEROCOPY_BIT, > + XDP_F_HW_OFFLOAD_BIT, > + XDP_F_TX_LOCK_BIT, > + XDP_F_FRAG_RX_BIT, > + XDP_F_FRAG_TARGET_BIT, > + /* > + * Add your fresh new property above and remember to update > + * documentation. > + */ > + XDP_FEATURES_COUNT, > +}; > + > +#define XDP_FEATURES_WORDS ((XDP_FEATURES_COUNT + 32 - 1) / 32) > +#define XDP_FEATURES_WORD(blocks, index) ((blocks)[(index) / 32U]) > +#define XDP_FEATURES_FIELD_FLAG(index) (1U << (index) % 32U) > +#define XDP_FEATURES_BIT_IS_SET(blocks, index) \ > + (XDP_FEATURES_WORD(blocks, index) & XDP_FEATURES_FIELD_FLAG(index)) > + > +#endif /* __UAPI_LINUX_XDP_FEATURES__ */ > -- > 2.38.1