From patchwork Sun Sep 15 01:17:39 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Akihiko Odaki X-Patchwork-Id: 13804584 Received: from mail-pl1-f174.google.com (mail-pl1-f174.google.com [209.85.214.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1C4E6184E for ; Sun, 15 Sep 2024 01:18:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.174 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726363090; cv=none; b=W8BzpGq/2epr6rkxHIPy8P3SAFEqOTsy0wjmMk0ctBbqYojyzbB9jaGbXxGasOKKOdsANTIDhtEN/eNwlw4fYRuSiEeg+zbT1atdePqD8xkWuW5J3ZB66LmWzXp2iOKK3Y4QrL/H6j5ilbEneOIkEoMuvyot3xGmMec1hqa+o/Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726363090; c=relaxed/simple; bh=DjLACX6Izp1tDR7jnoxIGZpV6PDSLXserAQrHsvK6tI=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To; b=u4CHayVpYNDWt+MAJFTzo1+3/ZTW+F1E/BD2qL/f3glYPzV7nwJEfIBgPLk3otG04F0QppUXOm2DS1smDeNU4vPMy3RXnjRe82yNEZ5YLGihVGIku6iuk1tVAfUWuIK50u30xFrBosWa9NhuwiG0QBQnRVHylGTicPJxnwD1Eiw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=daynix.com; spf=none smtp.mailfrom=daynix.com; dkim=pass (2048-bit key) header.d=daynix-com.20230601.gappssmtp.com header.i=@daynix-com.20230601.gappssmtp.com header.b=MB8JxnIv; arc=none smtp.client-ip=209.85.214.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=daynix.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=daynix.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=daynix-com.20230601.gappssmtp.com header.i=@daynix-com.20230601.gappssmtp.com header.b="MB8JxnIv" Received: by mail-pl1-f174.google.com with SMTP id d9443c01a7336-2059204f448so30431725ad.0 for ; Sat, 14 Sep 2024 18:18:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=daynix-com.20230601.gappssmtp.com; s=20230601; t=1726363088; x=1726967888; darn=vger.kernel.org; h=to:content-transfer-encoding:mime-version:message-id:date:subject :from:from:to:cc:subject:date:message-id:reply-to; bh=4RlYLWTGEUWVMmH5uAZ3KmcTjt8vGdeFUKq4t4XgGZI=; b=MB8JxnIvPG1zgxFx0z664yagV4HCyoXFZRMK72RU/Fza2Wib+ymw0auV7RhRVhRr1f tIOYexepibcAayZ+jvfc6LAFXykIPErkafcFMLzHlEXJxlN7iimWhnMz9bH1coe9YUpT cFiqCUizHuU3Wkb1++WVAiaany4W2nxfVv6F+A4zOBdFja2umX0fOXxTQvEo8styrigP XLrgK3UhzV8koz3Gi3C7LH3rvJ+cP+nGM27jgfTNcv30aA1SHWatTx+WkGI30zMVQGD1 fkYVrC1te5mnSXVfIHlO+uYJjwYHNWN7jm9w8JXQsCJ7n1t7pH1hu+oRzzjFSa8OQL7e 7t7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726363088; x=1726967888; h=to:content-transfer-encoding:mime-version:message-id:date:subject :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=4RlYLWTGEUWVMmH5uAZ3KmcTjt8vGdeFUKq4t4XgGZI=; b=d7oPYPNEpHBRDHg8mSNfHWwTm1Nr5j6Ci90H4ufCLoK898bErcZKgHB1ND5I/tV4I9 J85FylU9ifkTwy2zyrMHr7VnUqahLkWqbFFNHs8L3pekQZYSuH3bg6CqxnF3cOddceJg kwliX1DQ9aIoDn0ojSDw9OCYR1SCnntRYmhCnpasjrUflyTbbP22IfDnDuupvyZQYuaL F/iLEEG/fomVsTwHxxho4OQYewEfSe3F2mB02Ti/6EJRGBppDllzGMkrZ2aCFOZQ9LXZ dfk0b1pMTx4b2KHHo6JVC1rNBgT7K66zzEs7gFR7gi4txRMDmmwzoiIkA8troZIfALFZ WSEQ== X-Forwarded-Encrypted: i=1; AJvYcCUdVmbE7yQnATxYC7w27t8yWqEAr2uV0OxYR6RACoSLRm8HIyVq+DcLi+sp/e0MbCD6drea+RbtCxXoru3h3g8=@vger.kernel.org X-Gm-Message-State: AOJu0YwPL4gqIAX01DEGNvO/4Z/TJIhXadueUTwWBCo8ksFTCYpwVBGg 0W+iwxsliB3vxJ2BHRLscpHv+cFNfz2hB2vpYC295v2S6PUfZMPkAfoIBRjg20U= X-Google-Smtp-Source: AGHT+IEiuSb5mz6nz0x+3ls5vJS2I1fqTIfJlWtcvvYAYRCP14NP9cyLAAgnz5CXLZHRFQsX1yZDwg== X-Received: by 2002:a17:902:e842:b0:205:5f35:80a0 with SMTP id d9443c01a7336-2076e460c8bmr183980385ad.57.1726363088286; Sat, 14 Sep 2024 18:18:08 -0700 (PDT) Received: from localhost ([210.160.217.68]) by smtp.gmail.com with UTF8SMTPSA id d9443c01a7336-207946d181fsm14749405ad.133.2024.09.14.18.18.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 14 Sep 2024 18:18:07 -0700 (PDT) From: Akihiko Odaki Subject: [PATCH RFC v3 0/9] tun: Introduce virtio-net hashing feature Date: Sun, 15 Sep 2024 10:17:39 +0900 Message-Id: <20240915-rss-v3-0-c630015db082@daynix.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-B4-Tracking: v=1; b=H4sIALM15mYC/32MuwrCMBSGX6VkNiEnOU2qkyD4AK7iEJrUHoqNJ FJaSt/d0MnJ7b9+K8shUcjsVK0shYkyxbEYfahY27vxGTj54pmSCiVKzVPOPFhtfXMMnbOWleU 7hY7mnXJnt+uFPUrYU/7EtOzkCfaqQDRI2chagQQBiKgUB+4G6mmIIvqizt4tI82ija+dM6mfL 9SAYBCFMtKg+fvdtu0LzTrgp98AAAA= To: Jonathan Corbet , Willem de Bruijn , Jason Wang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "Michael S. Tsirkin" , Xuan Zhuo , Shuah Khan , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kselftest@vger.kernel.org, Yuri Benditovich , Andrew Melnychenko , Akihiko Odaki X-Mailer: b4 0.14-dev-fd6e3 virtio-net have two usage of hashes: one is RSS and another is hash reporting. Conventionally the hash calculation was done by the VMM. However, computing the hash after the queue was chosen defeats the purpose of RSS. Another approach is to use eBPF steering program. This approach has another downside: it cannot report the calculated hash due to the restrictive nature of eBPF. Introduce the code to compute hashes to the kernel in order to overcome thse challenges. An alternative solution is to extend the eBPF steering program so that it will be able to report to the userspace, but it is based on context rewrites, which is in feature freeze. We can adopt kfuncs, but they will not be UAPIs. We opt to ioctl to align with other relevant UAPIs (KVM and vhost_net). QEMU patched to use this new feature is available at: https://github.com/daynix/qemu/tree/akihikodaki/rss2 The QEMU patches will soon be submitted to the upstream as RFC too. This work will be presented at LPC 2024: https://lpc.events/event/18/contributions/1963/ V1 -> V2: Changed to introduce a new BPF program type. Signed-off-by: Akihiko Odaki --- Changes in v3: - Reverted back to add ioctl. - Split patch "tun: Introduce virtio-net hashing feature" into "tun: Introduce virtio-net hash reporting feature" and "tun: Introduce virtio-net RSS". - Changed to reuse hash values computed for automq instead of performing RSS hashing when hash reporting is requested but RSS is not. - Extracted relevant data from struct tun_struct to keep it minimal. - Added kernel-doc. - Changed to allow calling TUNGETVNETHASHCAP before TUNSETIFF. - Initialized num_buffers with 1. - Added a test case for unclassified packets. - Fixed error handling in tests. - Changed tests to verify that the queue index will not overflow. - Rebased. - Link to v2: https://lore.kernel.org/r/20231015141644.260646-1-akihiko.odaki@daynix.com --- Akihiko Odaki (9): skbuff: Introduce SKB_EXT_TUN_VNET_HASH virtio_net: Add functions for hashing net: flow_dissector: Export flow_keys_dissector_symmetric tap: Pad virtio header with zero tun: Pad virtio header with zero tun: Introduce virtio-net hash reporting feature tun: Introduce virtio-net RSS selftest: tun: Add tests for virtio-net hashing vhost/net: Support VIRTIO_NET_F_HASH_REPORT Documentation/networking/tuntap.rst | 7 + drivers/net/Kconfig | 1 + drivers/net/tap.c | 2 +- drivers/net/tun.c | 255 ++++++++++++-- drivers/vhost/net.c | 16 +- include/linux/skbuff.h | 10 + include/linux/virtio_net.h | 198 +++++++++++ include/net/flow_dissector.h | 1 + include/uapi/linux/if_tun.h | 71 ++++ net/core/flow_dissector.c | 3 +- net/core/skbuff.c | 3 + tools/testing/selftests/net/Makefile | 2 +- tools/testing/selftests/net/tun.c | 666 ++++++++++++++++++++++++++++++++++- 13 files changed, 1195 insertions(+), 40 deletions(-) --- base-commit: 46a0057a5853cbdb58211c19e89ba7777dc6fd50 change-id: 20240403-rss-e737d89efa77 Best regards,