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 X-Spam-Level: X-Spam-Status: No, score=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BAC00C433E0 for ; Tue, 2 Feb 2021 10:09:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 49BAC64E2A for ; Tue, 2 Feb 2021 10:09:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230316AbhBBKIm (ORCPT ); Tue, 2 Feb 2021 05:08:42 -0500 Received: from mail.katalix.com ([3.9.82.81]:51368 "EHLO mail.katalix.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229902AbhBBKHi (ORCPT ); Tue, 2 Feb 2021 05:07:38 -0500 Received: from localhost (82-69-49-219.dsl.in-addr.zen.co.uk [82.69.49.219]) (Authenticated sender: tom) by mail.katalix.com (Postfix) with ESMTPSA id 427E28356A; Tue, 2 Feb 2021 10:06:53 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=katalix.com; s=mail; t=1612260413; bh=fdGoHkKPCQlotsBfzMQ3rtDIBy+57MQxCyqlj0ITKpo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Disposition:In-Reply-To:From; z=Date:=20Tue,=202=20Feb=202021=2010:06:53=20+0000|From:=20Tom=20Pa rkin=20|To:=20Boris=20Pismenny=20|Cc:=20dsahern@gmail.com,=20kuba@kernel.org,=20davem@dave mloft.net,=0D=0A=09saeedm@nvidia.com,=20hch@lst.de,=20sagi@grimber g.me,=20axboe@fb.com,=0D=0A=09kbusch@kernel.org,=20viro@zeniv.linu x.org.uk,=20edumazet@google.com,=0D=0A=09smalin@marvell.com,=20bor is.pismenny@gmail.com,=0D=0A=09linux-nvme@lists.infradead.org,=20n etdev@vger.kernel.org,=0D=0A=09benishay@nvidia.com,=20ogerlitz@nvi dia.com,=20yorayz@nvidia.com,=0D=0A=09Ben=20Ben-Ishay=20,=0D=0A=09Or=20Gerlitz=20,=0D= 0A=09Yoray=20Zack=20|Subject:=20Re:=20[PATCH= 20v3=20net-next=20=2002/21]=20net:=20Introduce=20direct=20data=20p lacement=0D=0A=20tcp=20offload|Message-ID:=20<20210202100652.GA448 7@katalix.com>|References:=20<20210201100509.27351-1-borisp@mellan ox.com>=0D=0A=20<20210201100509.27351-3-borisp@mellanox.com>|MIME- Version:=201.0|Content-Disposition:=20inline|In-Reply-To:=20<20210 201100509.27351-3-borisp@mellanox.com>; b=AALZNYQl0kcCNw+Z7dMeGRyZaaV5gp9IfgzTc19Y1Zh+XKqGtyXIWzYgfzH1m6y0D EK0783qo8L2IoMudfA3LZzNGZakFvaGgi3y/tRyjjGqAaQ/U9TX66+VCz//P6Fy7an eFPKXuPzTqFg0dICjACztJ0m6M098pXsVRHpkZinU4tzDUZpFV9BvhwRK1vnq0wNPm sIofzzEJ/SJ1REqxZeeGs0vSut8nQlSYVWyPLnpdPSjF8bfvI+fTWrqs5GCf1q4U81 rURcKQ+ADRpKAS50J2Ge0XZq4pK81p7ViWZqLMEwkg5duthuyDOz7F9BoeGuMOmHjP gG6Z+bUUlTQBQ== Date: Tue, 2 Feb 2021 10:06:53 +0000 From: Tom Parkin To: Boris Pismenny Cc: dsahern@gmail.com, kuba@kernel.org, davem@davemloft.net, saeedm@nvidia.com, hch@lst.de, sagi@grimberg.me, axboe@fb.com, kbusch@kernel.org, viro@zeniv.linux.org.uk, edumazet@google.com, smalin@marvell.com, boris.pismenny@gmail.com, linux-nvme@lists.infradead.org, netdev@vger.kernel.org, benishay@nvidia.com, ogerlitz@nvidia.com, yorayz@nvidia.com, Ben Ben-Ishay , Or Gerlitz , Yoray Zack Subject: Re: [PATCH v3 net-next 02/21] net: Introduce direct data placement tcp offload Message-ID: <20210202100652.GA4487@katalix.com> References: <20210201100509.27351-1-borisp@mellanox.com> <20210201100509.27351-3-borisp@mellanox.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="vkogqOf2sHV7VnPd" Content-Disposition: inline In-Reply-To: <20210201100509.27351-3-borisp@mellanox.com> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org --vkogqOf2sHV7VnPd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Feb 01, 2021 at 12:04:50 +0200, Boris Pismenny wrote: > This commit introduces direct data placement offload for TCP. > This capability is accompanied by new net_device operations that > configure hardware contexts. There is a context per socket, and a context= per DDP > opreation. Additionally, a resynchronization routine is used to assist > hardware handle TCP OOO, and continue the offload. > Furthermore, we let the offloading driver advertise what is the max hw > sectors/segments. >=20 > Using this interface, the NIC hardware will scatter TCP payload directly > to the BIO pages according to the command_id. > To maintain the correctness of the network stack, the driver is expected > to construct SKBs that point to the BIO pages. >=20 > The SKB passed to the network stack from the driver > represents data as it is on the wire, while it is pointing > directly to data in destination buffers. > As a result, data from page frags should not be copied out to > the linear part. To avoid needless copies, such as when using > skb_condense, we mark the skb->ddp_crc bit. This bit will be > used to indicate both ddp and crc offload (next patch in series). >=20 > A follow-up patch will use this interface for DDP in NVMe-TCP. >=20 > Signed-off-by: Boris Pismenny > Signed-off-by: Ben Ben-Ishay > Signed-off-by: Or Gerlitz > Signed-off-by: Yoray Zack > --- > include/linux/netdev_features.h | 2 + > include/linux/netdevice.h | 5 ++ > include/linux/skbuff.h | 4 + > include/net/inet_connection_sock.h | 4 + > include/net/tcp_ddp.h | 136 +++++++++++++++++++++++++++++ > net/Kconfig | 9 ++ > net/core/skbuff.c | 8 +- > net/ethtool/common.c | 1 + > net/ipv4/tcp_input.c | 8 ++ > net/ipv4/tcp_ipv4.c | 3 + > net/ipv4/tcp_offload.c | 3 + > 11 files changed, 182 insertions(+), 1 deletion(-) > create mode 100644 include/net/tcp_ddp.h >=20 > diff --git a/include/linux/netdev_features.h b/include/linux/netdev_featu= res.h > index c06d6aaba9df..7977371d2dd1 100644 > --- a/include/linux/netdev_features.h > +++ b/include/linux/netdev_features.h > @@ -85,6 +85,7 @@ enum { > =20 > NETIF_F_HW_MACSEC_BIT, /* Offload MACsec operations */ > NETIF_F_GRO_UDP_FWD_BIT, /* Allow UDP GRO for forwarding */ > + NETIF_F_HW_TCP_DDP_BIT, /* TCP direct data placement offload */ > =20 > /* > * Add your fresh new feature above and remember to update > @@ -159,6 +160,7 @@ enum { > #define NETIF_F_GSO_FRAGLIST __NETIF_F(GSO_FRAGLIST) > #define NETIF_F_HW_MACSEC __NETIF_F(HW_MACSEC) > #define NETIF_F_GRO_UDP_FWD __NETIF_F(GRO_UDP_FWD) > +#define NETIF_F_HW_TCP_DDP __NETIF_F(HW_TCP_DDP) > =20 > /* Finds the next feature with the highest number of the range of start = till 0. > */ > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > index e9e7ada07ea1..bd28520e30f2 100644 > --- a/include/linux/netdevice.h > +++ b/include/linux/netdevice.h > @@ -941,6 +941,7 @@ struct dev_ifalias { > =20 > struct devlink; > struct tlsdev_ops; > +struct tcp_ddp_dev_ops; > =20 > struct netdev_name_node { > struct hlist_node hlist; > @@ -1942,6 +1943,10 @@ struct net_device { > const struct tlsdev_ops *tlsdev_ops; > #endif > =20 > +#ifdef CONFIG_TCP_DDP > + const struct tcp_ddp_dev_ops *tcp_ddp_ops; > +#endif > + > const struct header_ops *header_ops; > =20 > unsigned char operstate; > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index 9313b5aaf45b..6d00d62628c8 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -684,6 +684,7 @@ typedef unsigned char *sk_buff_data_t; > * CHECKSUM_UNNECESSARY (max 3) > * @dst_pending_confirm: need to confirm neighbour > * @decrypted: Decrypted SKB > + * @ddp_crc: DDP or CRC offloaded > * @napi_id: id of the NAPI struct this skb came from > * @sender_cpu: (aka @napi_id) source CPU in XPS > * @secmark: security marking > @@ -860,6 +861,9 @@ struct sk_buff { > #ifdef CONFIG_TLS_DEVICE > __u8 decrypted:1; > #endif > +#ifdef CONFIG_TCP_DDP > + __u8 ddp_crc:1; > +#endif > =20 > #ifdef CONFIG_NET_SCHED > __u16 tc_index; /* traffic control index */ > diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connec= tion_sock.h > index c11f80f328f1..f9eb28f14d43 100644 > --- a/include/net/inet_connection_sock.h > +++ b/include/net/inet_connection_sock.h > @@ -66,6 +66,8 @@ struct inet_connection_sock_af_ops { > * @icsk_ulp_ops Pluggable ULP control hook > * @icsk_ulp_data ULP private data > * @icsk_clean_acked Clean acked data hook > + * @icsk_ulp_ddp_ops Pluggable ULP direct data placement control hook > + * @icsk_ulp_ddp_data ULP direct data placement private data > * @icsk_listen_portaddr_node hash to the portaddr listener hashtable > * @icsk_ca_state: Congestion control state > * @icsk_retransmits: Number of unrecovered [RTO] timeouts > @@ -96,6 +98,8 @@ struct inet_connection_sock { > const struct tcp_ulp_ops *icsk_ulp_ops; > void __rcu *icsk_ulp_data; > void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); > + const struct tcp_ddp_ulp_ops *icsk_ulp_ddp_ops; > + void __rcu *icsk_ulp_ddp_data; > struct hlist_node icsk_listen_portaddr_node; > unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); > __u8 icsk_ca_state:5, > diff --git a/include/net/tcp_ddp.h b/include/net/tcp_ddp.h > new file mode 100644 > index 000000000000..31e5b1a16d0f > --- /dev/null > +++ b/include/net/tcp_ddp.h > @@ -0,0 +1,136 @@ > +/* SPDX-License-Identifier: GPL-2.0 > + * > + * tcp_ddp.h > + * Author: Boris Pismenny > + * Copyright (C) 2021 Mellanox Technologies. > + */ > +#ifndef _TCP_DDP_H > +#define _TCP_DDP_H > + > +#include > +#include > +#include > + > +/* limits returned by the offload driver, zero means don't care */ > +struct tcp_ddp_limits { > + int max_ddp_sgl_len; > +}; > + > +enum tcp_ddp_type { > + TCP_DDP_NVME =3D 1, > +}; > + > +/** > + * struct tcp_ddp_config - Generic tcp ddp configuration: tcp ddp IO que= ue > + * config implementations must use this as the first member. > + * Add new instances of tcp_ddp_config below (nvme-tcp, etc.). > + */ > +struct tcp_ddp_config { > + enum tcp_ddp_type type; > + unsigned char buf[]; > +}; > + > +/** > + * struct nvme_tcp_ddp_config - nvme tcp ddp configuration for an IO que= ue > + * > + * @pfv: pdu version (e.g., NVME_TCP_PFV_1_0) > + * @cpda: controller pdu data alignmend (dwords, 0's based) > + * @dgst: digest types enabled. > + * The netdev will offload crc if ddp_crc is supported. > + * @queue_size: number of nvme-tcp IO queue elements > + * @queue_id: queue identifier > + * @cpu_io: cpu core running the IO thread for this queue > + */ > +struct nvme_tcp_ddp_config { > + struct tcp_ddp_config cfg; > + > + u16 pfv; > + u8 cpda; > + u8 dgst; > + int queue_size; > + int queue_id; > + int io_cpu; > +}; > + > +/** > + * struct tcp_ddp_io - tcp ddp configuration for an IO request. > + * > + * @command_id: identifier on the wire associated with these buffers > + * @nents: number of entries in the sg_table > + * @sg_table: describing the buffers for this IO request > + * @first_sgl: first SGL in sg_table > + */ > +struct tcp_ddp_io { > + u32 command_id; > + int nents; > + struct sg_table sg_table; > + struct scatterlist first_sgl[SG_CHUNK_SIZE]; > +}; > + > +/* struct tcp_ddp_dev_ops - operations used by an upper layer protocol t= o configure ddp offload > + * > + * @tcp_ddp_limits: limit the number of scatter gather entries per IO. > + * the device driver can use this to limit the resou= rces allocated per queue. > + * @tcp_ddp_sk_add: add offload for the queue represennted by the soc= ket+config pair. > + * this function is used to configure either copy, c= rc or both offloads. > + * @tcp_ddp_sk_del: remove offload from the socket, and release any d= evice related resources. > + * @tcp_ddp_setup: request copy offload for buffers associated with = a command_id in tcp_ddp_io. > + * @tcp_ddp_teardown: release offload resources association between buf= fers and command_id in > + * tcp_ddp_io. > + * @tcp_ddp_resync: respond to the driver's resync_request. Called on= ly if resync is successful. > + */ > +struct tcp_ddp_dev_ops { > + int (*tcp_ddp_limits)(struct net_device *netdev, > + struct tcp_ddp_limits *limits); > + int (*tcp_ddp_sk_add)(struct net_device *netdev, > + struct sock *sk, > + struct tcp_ddp_config *config); > + void (*tcp_ddp_sk_del)(struct net_device *netdev, > + struct sock *sk); > + int (*tcp_ddp_setup)(struct net_device *netdev, > + struct sock *sk, > + struct tcp_ddp_io *io); > + int (*tcp_ddp_teardown)(struct net_device *netdev, > + struct sock *sk, > + struct tcp_ddp_io *io, > + void *ddp_ctx); > + void (*tcp_ddp_resync)(struct net_device *netdev, > + struct sock *sk, u32 seq); > +}; > + > +#define TCP_DDP_RESYNC_REQ BIT(0) > + > +/** > + * struct tcp_ddp_ulp_ops - Interface to register uppper layer Direct Da= ta Placement (DDP) TCP offload > + */ Super trivial (my mail filter just happened to pick up on it), but if you happen to respin: s/uppper/upper/ > +struct tcp_ddp_ulp_ops { > + /* NIC requests ulp to indicate if @seq is the start of a message */ > + bool (*resync_request)(struct sock *sk, u32 seq, u32 flags); > + /* NIC driver informs the ulp that ddp teardown is done - used for asyn= c completions*/ > + void (*ddp_teardown_done)(void *ddp_ctx); > +}; > + > +/** > + * struct tcp_ddp_ctx - Generic tcp ddp context: device driver per queue= contexts must > + * use this as the first member. > + */ > +struct tcp_ddp_ctx { > + enum tcp_ddp_type type; > + unsigned char buf[]; > +}; > + > +static inline struct tcp_ddp_ctx *tcp_ddp_get_ctx(const struct sock *sk) > +{ > + struct inet_connection_sock *icsk =3D inet_csk(sk); > + > + return (__force struct tcp_ddp_ctx *)icsk->icsk_ulp_ddp_data; > +} > + > +static inline void tcp_ddp_set_ctx(struct sock *sk, void *ctx) > +{ > + struct inet_connection_sock *icsk =3D inet_csk(sk); > + > + rcu_assign_pointer(icsk->icsk_ulp_ddp_data, ctx); > +} > + > +#endif //_TCP_DDP_H > diff --git a/net/Kconfig b/net/Kconfig > index f4c32d982af6..3876861cdc90 100644 > --- a/net/Kconfig > +++ b/net/Kconfig > @@ -457,6 +457,15 @@ config ETHTOOL_NETLINK > netlink. It provides better extensibility and some new features, > e.g. notification messages. > =20 > +config TCP_DDP > + bool "TCP direct data placement offload" > + default n > + help > + Direct Data Placement (DDP) offload for TCP enables ULP, such as > + NVMe-TCP/iSCSI, to request the NIC to place TCP payload data > + of a command response directly into kernel pages. > + > + > endif # if NET > =20 > # Used by archs to tell that they support BPF JIT compiler plus which fl= avour. > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index 2af12f7e170c..ef3f2714994d 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -69,6 +69,7 @@ > #include > #include > #include > +#include > =20 > #include > #include > @@ -6185,9 +6186,14 @@ EXPORT_SYMBOL(pskb_extract); > */ > void skb_condense(struct sk_buff *skb) > { > + bool is_ddp =3D false; > + > +#ifdef CONFIG_TCP_DDP > + is_ddp =3D skb->ddp_crc; > +#endif > if (skb->data_len) { > if (skb->data_len > skb->end - skb->tail || > - skb_cloned(skb)) > + skb_cloned(skb) || is_ddp) > return; > =20 > /* Nice, we can free page frag(s) right now */ > diff --git a/net/ethtool/common.c b/net/ethtool/common.c > index 181220101a6e..bbf83cd01106 100644 > --- a/net/ethtool/common.c > +++ b/net/ethtool/common.c > @@ -69,6 +69,7 @@ const char netdev_features_strings[NETDEV_FEATURE_COUNT= ][ETH_GSTRING_LEN] =3D { > [NETIF_F_GRO_FRAGLIST_BIT] =3D "rx-gro-list", > [NETIF_F_HW_MACSEC_BIT] =3D "macsec-hw-offload", > [NETIF_F_GRO_UDP_FWD_BIT] =3D "rx-udp-gro-forwarding", > + [NETIF_F_HW_TCP_DDP_BIT] =3D "tcp-ddp-offload", > }; > =20 > const char > diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c > index a8f8f9815953..0ae1ffca090d 100644 > --- a/net/ipv4/tcp_input.c > +++ b/net/ipv4/tcp_input.c > @@ -5149,6 +5149,9 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *= list, struct rb_root *root, > memcpy(nskb->cb, skb->cb, sizeof(skb->cb)); > #ifdef CONFIG_TLS_DEVICE > nskb->decrypted =3D skb->decrypted; > +#endif > +#ifdef CONFIG_TCP_DDP > + nskb->ddp_crc =3D skb->ddp_crc; > #endif > TCP_SKB_CB(nskb)->seq =3D TCP_SKB_CB(nskb)->end_seq =3D start; > if (list) > @@ -5182,6 +5185,11 @@ tcp_collapse(struct sock *sk, struct sk_buff_head = *list, struct rb_root *root, > #ifdef CONFIG_TLS_DEVICE > if (skb->decrypted !=3D nskb->decrypted) > goto end; > +#endif > +#ifdef CONFIG_TCP_DDP > + > + if (skb->ddp_crc !=3D nskb->ddp_crc) > + goto end; > #endif > } > } > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c > index 777306b5bc22..b114fc870513 100644 > --- a/net/ipv4/tcp_ipv4.c > +++ b/net/ipv4/tcp_ipv4.c > @@ -1810,6 +1810,9 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buf= f *skb) > TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_ECE | TCPHDR_CWR)) || > #ifdef CONFIG_TLS_DEVICE > tail->decrypted !=3D skb->decrypted || > +#endif > +#ifdef CONFIG_TCP_DDP > + tail->ddp_crc !=3D skb->ddp_crc || > #endif > thtail->doff !=3D th->doff || > memcmp(thtail + 1, th + 1, hdrlen - sizeof(*th))) > diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c > index e09147ac9a99..3ce196375d94 100644 > --- a/net/ipv4/tcp_offload.c > +++ b/net/ipv4/tcp_offload.c > @@ -262,6 +262,9 @@ struct sk_buff *tcp_gro_receive(struct list_head *hea= d, struct sk_buff *skb) > #ifdef CONFIG_TLS_DEVICE > flush |=3D p->decrypted ^ skb->decrypted; > #endif > +#ifdef CONFIG_TCP_DDP > + flush |=3D p->ddp_crc ^ skb->ddp_crc; > +#endif > =20 > if (flush || skb_gro_receive(p, skb)) { > mss =3D 1; > --=20 > 2.24.1 >=20 --=20 Tom Parkin Katalix Systems Ltd https://katalix.com Catalysts for your Embedded Linux software development --vkogqOf2sHV7VnPd Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEsUkgyDzMwrj81nq0lIwGZQq6i9AFAmAZJDwACgkQlIwGZQq6 i9CbmwgAu3HeJq+s+Bpa7Gu2lSwXiQSD7352f+NVKhHFdDdb0Hfx7kZwh+AV0nMW XS/tVoto1t5nUZM23wgsM9Zqn+DDncpGBo4tFcZUq53LFCWMH1RMDWtoQ+GFmuey Tz0j7JYO9rYmOb+plZo9OxRNepR6PlhZnqOlh6I3v1TslQp0QE/JswwQLJIiSAyP RfP4LxPz6AO0cuwoHYjwtz43rhQ2RuvLb0HJ5hGSMTwAGsjm5JrpdfVGbAnc31QK 0FM+cR7cjEdw/6AqP5pV3191nxpcyZQssufAPLLMRUhx6jAaPZQTmRG7t1ivVFhA 3TVBRwZxvjYcxaSbb68dSlFdEemSJg== =gTf2 -----END PGP SIGNATURE----- --vkogqOf2sHV7VnPd-- 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 X-Spam-Level: X-Spam-Status: No, score=-15.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F9DBC433DB for ; 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a=rsa-sha256; c=relaxed/relaxed; d=katalix.com; s=mail; t=1612260413; bh=fdGoHkKPCQlotsBfzMQ3rtDIBy+57MQxCyqlj0ITKpo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Disposition:In-Reply-To:From; z=Date:=20Tue,=202=20Feb=202021=2010:06:53=20+0000|From:=20Tom=20Pa rkin=20|To:=20Boris=20Pismenny=20|Cc:=20dsahern@gmail.com,=20kuba@kernel.org,=20davem@dave mloft.net,=0D=0A=09saeedm@nvidia.com,=20hch@lst.de,=20sagi@grimber g.me,=20axboe@fb.com,=0D=0A=09kbusch@kernel.org,=20viro@zeniv.linu x.org.uk,=20edumazet@google.com,=0D=0A=09smalin@marvell.com,=20bor is.pismenny@gmail.com,=0D=0A=09linux-nvme@lists.infradead.org,=20n etdev@vger.kernel.org,=0D=0A=09benishay@nvidia.com,=20ogerlitz@nvi dia.com,=20yorayz@nvidia.com,=0D=0A=09Ben=20Ben-Ishay=20,=0D=0A=09Or=20Gerlitz=20,=0D= 0A=09Yoray=20Zack=20|Subject:=20Re:=20[PATCH= 20v3=20net-next=20=2002/21]=20net:=20Introduce=20direct=20data=20p lacement=0D=0A=20tcp=20offload|Message-ID:=20<20210202100652.GA448 7@katalix.com>|References:=20<20210201100509.27351-1-borisp@mellan ox.com>=0D=0A=20<20210201100509.27351-3-borisp@mellanox.com>|MIME- Version:=201.0|Content-Disposition:=20inline|In-Reply-To:=20<20210 201100509.27351-3-borisp@mellanox.com>; b=AALZNYQl0kcCNw+Z7dMeGRyZaaV5gp9IfgzTc19Y1Zh+XKqGtyXIWzYgfzH1m6y0D EK0783qo8L2IoMudfA3LZzNGZakFvaGgi3y/tRyjjGqAaQ/U9TX66+VCz//P6Fy7an eFPKXuPzTqFg0dICjACztJ0m6M098pXsVRHpkZinU4tzDUZpFV9BvhwRK1vnq0wNPm sIofzzEJ/SJ1REqxZeeGs0vSut8nQlSYVWyPLnpdPSjF8bfvI+fTWrqs5GCf1q4U81 rURcKQ+ADRpKAS50J2Ge0XZq4pK81p7ViWZqLMEwkg5duthuyDOz7F9BoeGuMOmHjP gG6Z+bUUlTQBQ== Date: Tue, 2 Feb 2021 10:06:53 +0000 From: Tom Parkin To: Boris Pismenny Subject: Re: [PATCH v3 net-next 02/21] net: Introduce direct data placement tcp offload Message-ID: <20210202100652.GA4487@katalix.com> References: <20210201100509.27351-1-borisp@mellanox.com> <20210201100509.27351-3-borisp@mellanox.com> MIME-Version: 1.0 In-Reply-To: <20210201100509.27351-3-borisp@mellanox.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210202_050658_000372_6C7ECF0E X-CRM114-Status: GOOD ( 40.77 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: smalin@marvell.com, sagi@grimberg.me, yorayz@nvidia.com, boris.pismenny@gmail.com, Ben Ben-Ishay , Yoray Zack , linux-nvme@lists.infradead.org, davem@davemloft.net, axboe@fb.com, edumazet@google.com, netdev@vger.kernel.org, viro@zeniv.linux.org.uk, dsahern@gmail.com, kbusch@kernel.org, kuba@kernel.org, Or Gerlitz , benishay@nvidia.com, saeedm@nvidia.com, hch@lst.de, ogerlitz@nvidia.com Content-Type: multipart/mixed; boundary="===============0878112613515195056==" Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org --===============0878112613515195056== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="vkogqOf2sHV7VnPd" Content-Disposition: inline --vkogqOf2sHV7VnPd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Feb 01, 2021 at 12:04:50 +0200, Boris Pismenny wrote: > This commit introduces direct data placement offload for TCP. > This capability is accompanied by new net_device operations that > configure hardware contexts. There is a context per socket, and a context= per DDP > opreation. Additionally, a resynchronization routine is used to assist > hardware handle TCP OOO, and continue the offload. > Furthermore, we let the offloading driver advertise what is the max hw > sectors/segments. >=20 > Using this interface, the NIC hardware will scatter TCP payload directly > to the BIO pages according to the command_id. > To maintain the correctness of the network stack, the driver is expected > to construct SKBs that point to the BIO pages. >=20 > The SKB passed to the network stack from the driver > represents data as it is on the wire, while it is pointing > directly to data in destination buffers. > As a result, data from page frags should not be copied out to > the linear part. To avoid needless copies, such as when using > skb_condense, we mark the skb->ddp_crc bit. This bit will be > used to indicate both ddp and crc offload (next patch in series). >=20 > A follow-up patch will use this interface for DDP in NVMe-TCP. >=20 > Signed-off-by: Boris Pismenny > Signed-off-by: Ben Ben-Ishay > Signed-off-by: Or Gerlitz > Signed-off-by: Yoray Zack > --- > include/linux/netdev_features.h | 2 + > include/linux/netdevice.h | 5 ++ > include/linux/skbuff.h | 4 + > include/net/inet_connection_sock.h | 4 + > include/net/tcp_ddp.h | 136 +++++++++++++++++++++++++++++ > net/Kconfig | 9 ++ > net/core/skbuff.c | 8 +- > net/ethtool/common.c | 1 + > net/ipv4/tcp_input.c | 8 ++ > net/ipv4/tcp_ipv4.c | 3 + > net/ipv4/tcp_offload.c | 3 + > 11 files changed, 182 insertions(+), 1 deletion(-) > create mode 100644 include/net/tcp_ddp.h >=20 > diff --git a/include/linux/netdev_features.h b/include/linux/netdev_featu= res.h > index c06d6aaba9df..7977371d2dd1 100644 > --- a/include/linux/netdev_features.h > +++ b/include/linux/netdev_features.h > @@ -85,6 +85,7 @@ enum { > =20 > NETIF_F_HW_MACSEC_BIT, /* Offload MACsec operations */ > NETIF_F_GRO_UDP_FWD_BIT, /* Allow UDP GRO for forwarding */ > + NETIF_F_HW_TCP_DDP_BIT, /* TCP direct data placement offload */ > =20 > /* > * Add your fresh new feature above and remember to update > @@ -159,6 +160,7 @@ enum { > #define NETIF_F_GSO_FRAGLIST __NETIF_F(GSO_FRAGLIST) > #define NETIF_F_HW_MACSEC __NETIF_F(HW_MACSEC) > #define NETIF_F_GRO_UDP_FWD __NETIF_F(GRO_UDP_FWD) > +#define NETIF_F_HW_TCP_DDP __NETIF_F(HW_TCP_DDP) > =20 > /* Finds the next feature with the highest number of the range of start = till 0. > */ > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > index e9e7ada07ea1..bd28520e30f2 100644 > --- a/include/linux/netdevice.h > +++ b/include/linux/netdevice.h > @@ -941,6 +941,7 @@ struct dev_ifalias { > =20 > struct devlink; > struct tlsdev_ops; > +struct tcp_ddp_dev_ops; > =20 > struct netdev_name_node { > struct hlist_node hlist; > @@ -1942,6 +1943,10 @@ struct net_device { > const struct tlsdev_ops *tlsdev_ops; > #endif > =20 > +#ifdef CONFIG_TCP_DDP > + const struct tcp_ddp_dev_ops *tcp_ddp_ops; > +#endif > + > const struct header_ops *header_ops; > =20 > unsigned char operstate; > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index 9313b5aaf45b..6d00d62628c8 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -684,6 +684,7 @@ typedef unsigned char *sk_buff_data_t; > * CHECKSUM_UNNECESSARY (max 3) > * @dst_pending_confirm: need to confirm neighbour > * @decrypted: Decrypted SKB > + * @ddp_crc: DDP or CRC offloaded > * @napi_id: id of the NAPI struct this skb came from > * @sender_cpu: (aka @napi_id) source CPU in XPS > * @secmark: security marking > @@ -860,6 +861,9 @@ struct sk_buff { > #ifdef CONFIG_TLS_DEVICE > __u8 decrypted:1; > #endif > +#ifdef CONFIG_TCP_DDP > + __u8 ddp_crc:1; > +#endif > =20 > #ifdef CONFIG_NET_SCHED > __u16 tc_index; /* traffic control index */ > diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connec= tion_sock.h > index c11f80f328f1..f9eb28f14d43 100644 > --- a/include/net/inet_connection_sock.h > +++ b/include/net/inet_connection_sock.h > @@ -66,6 +66,8 @@ struct inet_connection_sock_af_ops { > * @icsk_ulp_ops Pluggable ULP control hook > * @icsk_ulp_data ULP private data > * @icsk_clean_acked Clean acked data hook > + * @icsk_ulp_ddp_ops Pluggable ULP direct data placement control hook > + * @icsk_ulp_ddp_data ULP direct data placement private data > * @icsk_listen_portaddr_node hash to the portaddr listener hashtable > * @icsk_ca_state: Congestion control state > * @icsk_retransmits: Number of unrecovered [RTO] timeouts > @@ -96,6 +98,8 @@ struct inet_connection_sock { > const struct tcp_ulp_ops *icsk_ulp_ops; > void __rcu *icsk_ulp_data; > void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); > + const struct tcp_ddp_ulp_ops *icsk_ulp_ddp_ops; > + void __rcu *icsk_ulp_ddp_data; > struct hlist_node icsk_listen_portaddr_node; > unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); > __u8 icsk_ca_state:5, > diff --git a/include/net/tcp_ddp.h b/include/net/tcp_ddp.h > new file mode 100644 > index 000000000000..31e5b1a16d0f > --- /dev/null > +++ b/include/net/tcp_ddp.h > @@ -0,0 +1,136 @@ > +/* SPDX-License-Identifier: GPL-2.0 > + * > + * tcp_ddp.h > + * Author: Boris Pismenny > + * Copyright (C) 2021 Mellanox Technologies. > + */ > +#ifndef _TCP_DDP_H > +#define _TCP_DDP_H > + > +#include > +#include > +#include > + > +/* limits returned by the offload driver, zero means don't care */ > +struct tcp_ddp_limits { > + int max_ddp_sgl_len; > +}; > + > +enum tcp_ddp_type { > + TCP_DDP_NVME =3D 1, > +}; > + > +/** > + * struct tcp_ddp_config - Generic tcp ddp configuration: tcp ddp IO que= ue > + * config implementations must use this as the first member. > + * Add new instances of tcp_ddp_config below (nvme-tcp, etc.). > + */ > +struct tcp_ddp_config { > + enum tcp_ddp_type type; > + unsigned char buf[]; > +}; > + > +/** > + * struct nvme_tcp_ddp_config - nvme tcp ddp configuration for an IO que= ue > + * > + * @pfv: pdu version (e.g., NVME_TCP_PFV_1_0) > + * @cpda: controller pdu data alignmend (dwords, 0's based) > + * @dgst: digest types enabled. > + * The netdev will offload crc if ddp_crc is supported. > + * @queue_size: number of nvme-tcp IO queue elements > + * @queue_id: queue identifier > + * @cpu_io: cpu core running the IO thread for this queue > + */ > +struct nvme_tcp_ddp_config { > + struct tcp_ddp_config cfg; > + > + u16 pfv; > + u8 cpda; > + u8 dgst; > + int queue_size; > + int queue_id; > + int io_cpu; > +}; > + > +/** > + * struct tcp_ddp_io - tcp ddp configuration for an IO request. > + * > + * @command_id: identifier on the wire associated with these buffers > + * @nents: number of entries in the sg_table > + * @sg_table: describing the buffers for this IO request > + * @first_sgl: first SGL in sg_table > + */ > +struct tcp_ddp_io { > + u32 command_id; > + int nents; > + struct sg_table sg_table; > + struct scatterlist first_sgl[SG_CHUNK_SIZE]; > +}; > + > +/* struct tcp_ddp_dev_ops - operations used by an upper layer protocol t= o configure ddp offload > + * > + * @tcp_ddp_limits: limit the number of scatter gather entries per IO. > + * the device driver can use this to limit the resou= rces allocated per queue. > + * @tcp_ddp_sk_add: add offload for the queue represennted by the soc= ket+config pair. > + * this function is used to configure either copy, c= rc or both offloads. > + * @tcp_ddp_sk_del: remove offload from the socket, and release any d= evice related resources. > + * @tcp_ddp_setup: request copy offload for buffers associated with = a command_id in tcp_ddp_io. > + * @tcp_ddp_teardown: release offload resources association between buf= fers and command_id in > + * tcp_ddp_io. > + * @tcp_ddp_resync: respond to the driver's resync_request. Called on= ly if resync is successful. > + */ > +struct tcp_ddp_dev_ops { > + int (*tcp_ddp_limits)(struct net_device *netdev, > + struct tcp_ddp_limits *limits); > + int (*tcp_ddp_sk_add)(struct net_device *netdev, > + struct sock *sk, > + struct tcp_ddp_config *config); > + void (*tcp_ddp_sk_del)(struct net_device *netdev, > + struct sock *sk); > + int (*tcp_ddp_setup)(struct net_device *netdev, > + struct sock *sk, > + struct tcp_ddp_io *io); > + int (*tcp_ddp_teardown)(struct net_device *netdev, > + struct sock *sk, > + struct tcp_ddp_io *io, > + void *ddp_ctx); > + void (*tcp_ddp_resync)(struct net_device *netdev, > + struct sock *sk, u32 seq); > +}; > + > +#define TCP_DDP_RESYNC_REQ BIT(0) > + > +/** > + * struct tcp_ddp_ulp_ops - Interface to register uppper layer Direct Da= ta Placement (DDP) TCP offload > + */ Super trivial (my mail filter just happened to pick up on it), but if you happen to respin: s/uppper/upper/ > +struct tcp_ddp_ulp_ops { > + /* NIC requests ulp to indicate if @seq is the start of a message */ > + bool (*resync_request)(struct sock *sk, u32 seq, u32 flags); > + /* NIC driver informs the ulp that ddp teardown is done - used for asyn= c completions*/ > + void (*ddp_teardown_done)(void *ddp_ctx); > +}; > + > +/** > + * struct tcp_ddp_ctx - Generic tcp ddp context: device driver per queue= contexts must > + * use this as the first member. > + */ > +struct tcp_ddp_ctx { > + enum tcp_ddp_type type; > + unsigned char buf[]; > +}; > + > +static inline struct tcp_ddp_ctx *tcp_ddp_get_ctx(const struct sock *sk) > +{ > + struct inet_connection_sock *icsk =3D inet_csk(sk); > + > + return (__force struct tcp_ddp_ctx *)icsk->icsk_ulp_ddp_data; > +} > + > +static inline void tcp_ddp_set_ctx(struct sock *sk, void *ctx) > +{ > + struct inet_connection_sock *icsk =3D inet_csk(sk); > + > + rcu_assign_pointer(icsk->icsk_ulp_ddp_data, ctx); > +} > + > +#endif //_TCP_DDP_H > diff --git a/net/Kconfig b/net/Kconfig > index f4c32d982af6..3876861cdc90 100644 > --- a/net/Kconfig > +++ b/net/Kconfig > @@ -457,6 +457,15 @@ config ETHTOOL_NETLINK > netlink. It provides better extensibility and some new features, > e.g. notification messages. > =20 > +config TCP_DDP > + bool "TCP direct data placement offload" > + default n > + help > + Direct Data Placement (DDP) offload for TCP enables ULP, such as > + NVMe-TCP/iSCSI, to request the NIC to place TCP payload data > + of a command response directly into kernel pages. > + > + > endif # if NET > =20 > # Used by archs to tell that they support BPF JIT compiler plus which fl= avour. > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index 2af12f7e170c..ef3f2714994d 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -69,6 +69,7 @@ > #include > #include > #include > +#include > =20 > #include > #include > @@ -6185,9 +6186,14 @@ EXPORT_SYMBOL(pskb_extract); > */ > void skb_condense(struct sk_buff *skb) > { > + bool is_ddp =3D false; > + > +#ifdef CONFIG_TCP_DDP > + is_ddp =3D skb->ddp_crc; > +#endif > if (skb->data_len) { > if (skb->data_len > skb->end - skb->tail || > - skb_cloned(skb)) > + skb_cloned(skb) || is_ddp) > return; > =20 > /* Nice, we can free page frag(s) right now */ > diff --git a/net/ethtool/common.c b/net/ethtool/common.c > index 181220101a6e..bbf83cd01106 100644 > --- a/net/ethtool/common.c > +++ b/net/ethtool/common.c > @@ -69,6 +69,7 @@ const char netdev_features_strings[NETDEV_FEATURE_COUNT= ][ETH_GSTRING_LEN] =3D { > [NETIF_F_GRO_FRAGLIST_BIT] =3D "rx-gro-list", > [NETIF_F_HW_MACSEC_BIT] =3D "macsec-hw-offload", > [NETIF_F_GRO_UDP_FWD_BIT] =3D "rx-udp-gro-forwarding", > + [NETIF_F_HW_TCP_DDP_BIT] =3D "tcp-ddp-offload", > }; > =20 > const char > diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c > index a8f8f9815953..0ae1ffca090d 100644 > --- a/net/ipv4/tcp_input.c > +++ b/net/ipv4/tcp_input.c > @@ -5149,6 +5149,9 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *= list, struct rb_root *root, > memcpy(nskb->cb, skb->cb, sizeof(skb->cb)); > #ifdef CONFIG_TLS_DEVICE > nskb->decrypted =3D skb->decrypted; > +#endif > +#ifdef CONFIG_TCP_DDP > + nskb->ddp_crc =3D skb->ddp_crc; > #endif > TCP_SKB_CB(nskb)->seq =3D TCP_SKB_CB(nskb)->end_seq =3D start; > if (list) > @@ -5182,6 +5185,11 @@ tcp_collapse(struct sock *sk, struct sk_buff_head = *list, struct rb_root *root, > #ifdef CONFIG_TLS_DEVICE > if (skb->decrypted !=3D nskb->decrypted) > goto end; > +#endif > +#ifdef CONFIG_TCP_DDP > + > + if (skb->ddp_crc !=3D nskb->ddp_crc) > + goto end; > #endif > } > } > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c > index 777306b5bc22..b114fc870513 100644 > --- a/net/ipv4/tcp_ipv4.c > +++ b/net/ipv4/tcp_ipv4.c > @@ -1810,6 +1810,9 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buf= f *skb) > TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_ECE | TCPHDR_CWR)) || > #ifdef CONFIG_TLS_DEVICE > tail->decrypted !=3D skb->decrypted || > +#endif > +#ifdef CONFIG_TCP_DDP > + tail->ddp_crc !=3D skb->ddp_crc || > #endif > thtail->doff !=3D th->doff || > memcmp(thtail + 1, th + 1, hdrlen - sizeof(*th))) > diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c > index e09147ac9a99..3ce196375d94 100644 > --- a/net/ipv4/tcp_offload.c > +++ b/net/ipv4/tcp_offload.c > @@ -262,6 +262,9 @@ struct sk_buff *tcp_gro_receive(struct list_head *hea= d, struct sk_buff *skb) > #ifdef CONFIG_TLS_DEVICE > flush |=3D p->decrypted ^ skb->decrypted; > #endif > +#ifdef CONFIG_TCP_DDP > + flush |=3D p->ddp_crc ^ skb->ddp_crc; > +#endif > =20 > if (flush || skb_gro_receive(p, skb)) { > mss =3D 1; > --=20 > 2.24.1 >=20 --=20 Tom Parkin Katalix Systems Ltd https://katalix.com Catalysts for your Embedded Linux software development --vkogqOf2sHV7VnPd Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEsUkgyDzMwrj81nq0lIwGZQq6i9AFAmAZJDwACgkQlIwGZQq6 i9CbmwgAu3HeJq+s+Bpa7Gu2lSwXiQSD7352f+NVKhHFdDdb0Hfx7kZwh+AV0nMW XS/tVoto1t5nUZM23wgsM9Zqn+DDncpGBo4tFcZUq53LFCWMH1RMDWtoQ+GFmuey Tz0j7JYO9rYmOb+plZo9OxRNepR6PlhZnqOlh6I3v1TslQp0QE/JswwQLJIiSAyP RfP4LxPz6AO0cuwoHYjwtz43rhQ2RuvLb0HJ5hGSMTwAGsjm5JrpdfVGbAnc31QK 0FM+cR7cjEdw/6AqP5pV3191nxpcyZQssufAPLLMRUhx6jAaPZQTmRG7t1ivVFhA 3TVBRwZxvjYcxaSbb68dSlFdEemSJg== =gTf2 -----END PGP SIGNATURE----- --vkogqOf2sHV7VnPd-- --===============0878112613515195056== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme --===============0878112613515195056==--