From patchwork Tue Oct 10 20:04:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ahmed Zaki X-Patchwork-Id: 13415976 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A9E2C29CF2 for ; Tue, 10 Oct 2023 20:05:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="ACnmzq4C" Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D12BC19AE; Tue, 10 Oct 2023 13:05:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1696968315; x=1728504315; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=2pfiZ1iiQtm2Zf4jLMIwrRDukxJh6A084sAa/FTq25E=; b=ACnmzq4C9znTgRUTX3TlmLOIb2YQ4/Grr9Xm758GgmKqYGvOSq+P7C5j PgFJ0v9/qPwQH9c9LSTxUIzaWCmfaIVa/oCsTdz09yvTzXlEuXak9sjcY 8jKLRjBQsGbi9iwE05gnaK0xHhLB2y1roIeB1g2cpAbR6CiYheI6MnKA2 qBbQdUXHzbUsci/MZJktq8WgvdMsfm3d3hhfCUug4qzc5tRYTRJoajRFY QvRJAWW7pHaeABfEXSVxhSftkyuiYAuy+EqudrJLW3rdhz8riUcjxGrox 5ygqSDsj9PE36nI/k/BzMLnpwvRSHeeNV+mKwf8tAUeVfX5oDxq7IHnW6 w==; X-IronPort-AV: E=McAfee;i="6600,9927,10859"; a="374840013" X-IronPort-AV: E=Sophos;i="6.03,213,1694761200"; d="scan'208";a="374840013" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Oct 2023 13:04:59 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10859"; a="1000819900" X-IronPort-AV: E=Sophos;i="6.03,213,1694761200"; d="scan'208";a="1000819900" Received: from rhaeussl-mobl.ger.corp.intel.com (HELO azaki-desk1.intel.com) ([10.252.42.107]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Oct 2023 13:04:54 -0700 From: Ahmed Zaki To: netdev@vger.kernel.org Cc: intel-wired-lan@lists.osuosl.org, corbet@lwn.net, jesse.brandeburg@intel.com, anthony.l.nguyen@intel.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, vladimir.oltean@nxp.com, andrew@lunn.ch, horms@kernel.org, mkubecek@suse.cz, willemdebruijn.kernel@gmail.com, linux-doc@vger.kernel.org, Ahmed Zaki , Wojciech Drewek Subject: [PATCH net-next v3 1/6] net: ethtool: allow symmetric-xor RSS hash for any flow type Date: Tue, 10 Oct 2023 14:04:32 -0600 Message-Id: <20231010200437.9794-2-ahmed.zaki@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231010200437.9794-1-ahmed.zaki@intel.com> References: <20231010200437.9794-1-ahmed.zaki@intel.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL, SPF_HELO_NONE,SPF_NONE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org Symmetric RSS hash functions are beneficial in applications that monitor both Tx and Rx packets of the same flow (IDS, software firewalls, ..etc). Getting all traffic of the same flow on the same RX queue results in higher CPU cache efficiency. A NIC that supports "symmetric-xor" can achieve this RSS hash symmetry by XORing the source and destination fields and pass the values to the RSS hash algorithm. Only fields that has counterparts in the other direction can be accepted; IP src/dst and L4 src/dst ports. The user may request RSS hash symmetry for a specific flow type, via: # ethtool -N|-U eth0 rx-flow-hash s|d|f|n symmetric-xor or turn symmetry off (asymmetric) by: # ethtool -N|-U eth0 rx-flow-hash s|d|f|n Reviewed-by: Wojciech Drewek Signed-off-by: Ahmed Zaki --- Documentation/networking/scaling.rst | 6 ++++++ include/uapi/linux/ethtool.h | 17 +++++++++-------- net/ethtool/ioctl.c | 11 +++++++++++ 3 files changed, 26 insertions(+), 8 deletions(-) diff --git a/Documentation/networking/scaling.rst b/Documentation/networking/scaling.rst index 92c9fb46d6a2..64f3d7566407 100644 --- a/Documentation/networking/scaling.rst +++ b/Documentation/networking/scaling.rst @@ -44,6 +44,12 @@ by masking out the low order seven bits of the computed hash for the packet (usually a Toeplitz hash), taking this number as a key into the indirection table and reading the corresponding value. +Some NICs support symmetric RSS hashing where, if the IP (source address, +destination address) and TCP/UDP (source port, destination port) tuples +are swapped, the computed hash is the same. This is beneficial in some +applications that monitor TCP/IP flows (IDS, firewalls, ...etc) and need +both directions of the flow to land on the same Rx queue (and CPU). + Some advanced NICs allow steering packets to queues based on programmable filters. For example, webserver bound TCP port 80 packets can be directed to their own receive queue. Such “n-tuple” filters can diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h index f7fba0dc87e5..b9ee667ad7e5 100644 --- a/include/uapi/linux/ethtool.h +++ b/include/uapi/linux/ethtool.h @@ -2018,14 +2018,15 @@ static inline int ethtool_validate_duplex(__u8 duplex) #define FLOW_RSS 0x20000000 /* L3-L4 network traffic flow hash options */ -#define RXH_L2DA (1 << 1) -#define RXH_VLAN (1 << 2) -#define RXH_L3_PROTO (1 << 3) -#define RXH_IP_SRC (1 << 4) -#define RXH_IP_DST (1 << 5) -#define RXH_L4_B_0_1 (1 << 6) /* src port in case of TCP/UDP/SCTP */ -#define RXH_L4_B_2_3 (1 << 7) /* dst port in case of TCP/UDP/SCTP */ -#define RXH_DISCARD (1 << 31) +#define RXH_L2DA (1 << 1) +#define RXH_VLAN (1 << 2) +#define RXH_L3_PROTO (1 << 3) +#define RXH_IP_SRC (1 << 4) +#define RXH_IP_DST (1 << 5) +#define RXH_L4_B_0_1 (1 << 6) /* src port in case of TCP/UDP/SCTP */ +#define RXH_L4_B_2_3 (1 << 7) /* dst port in case of TCP/UDP/SCTP */ +#define RXH_SYMMETRIC_XOR (1 << 30) +#define RXH_DISCARD (1 << 31) #define RX_CLS_FLOW_DISC 0xffffffffffffffffULL #define RX_CLS_FLOW_WAKE 0xfffffffffffffffeULL diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index 0b0ce4f81c01..b1bd0d4b48e8 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -980,6 +980,17 @@ static noinline_for_stack int ethtool_set_rxnfc(struct net_device *dev, if (rc) return rc; + /* If a symmetric hash is requested, then: + * 1 - no other fields besides IP src/dst and/or L4 src/dst + * 2 - If src is set, dst must also be set + */ + if ((info.data & RXH_SYMMETRIC_XOR) && + ((info.data & ~(RXH_SYMMETRIC_XOR | RXH_IP_SRC | RXH_IP_DST | + RXH_L4_B_0_1 | RXH_L4_B_2_3)) || + (!!(info.data & RXH_IP_SRC) ^ !!(info.data & RXH_IP_DST)) || + (!!(info.data & RXH_L4_B_0_1) ^ !!(info.data & RXH_L4_B_2_3)))) + return -EINVAL; + rc = dev->ethtool_ops->set_rxnfc(dev, &info); if (rc) return rc;