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dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:57436 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kh56b-0005mh-1Q for qemu-devel@archiver.kernel.org; Mon, 23 Nov 2020 01:13:41 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:46298) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kh51x-00014Z-UR for qemu-devel@nongnu.org; Mon, 23 Nov 2020 01:08:53 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:56931) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kh51v-0006Vo-WB for qemu-devel@nongnu.org; Mon, 23 Nov 2020 01:08:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606111731; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+3pX7kpyUgAc7fnu8t/5AoCmRbFf8PWEg3DJqKNYXIM=; b=Sv5QbtXoYpvK0VXWScvTdGfDRwz1cZG6fyC19bPgbnRfccajlClndKnO1RFWLpqR1a1KKS BZ7RaZxGVPGAS8LRhv8tSeS21YqgeO3iTr7nstNj79OmonBvQswp4eAAyPZITeUBiD/v0R Ej1LnD1rvWwrm0OvVeB6JVM717PeMUs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-489-QH_gPb13OHGDU02oKG00Mw-1; Mon, 23 Nov 2020 01:08:46 -0500 X-MC-Unique: QH_gPb13OHGDU02oKG00Mw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C9CBA1084C80; Mon, 23 Nov 2020 06:08:44 +0000 (UTC) Received: from [10.72.13.199] (ovpn-13-199.pek2.redhat.com [10.72.13.199]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8936060BF3; Mon, 23 Nov 2020 06:08:38 +0000 (UTC) Subject: Re: [RFC PATCH v2 0/5] eBPF RSS support for virtio-net To: Andrew Melnychenko , mst@redhat.com References: <20201119111305.485202-1-andrew@daynix.com> From: Jason Wang Message-ID: Date: Mon, 23 Nov 2020 14:08:37 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201119111305.485202-1-andrew@daynix.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jasowang@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Received-SPF: pass client-ip=216.205.24.124; envelope-from=jasowang@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: yan@daynix.com, yuri.benditovich@daynix.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2020/11/19 下午7:13, Andrew Melnychenko wrote: > This set of patches introduces the usage of eBPF for packet steering > and RSS hash calculation: > * RSS(Receive Side Scaling) is used to distribute network packets to > guest virtqueues by calculating packet hash > * Additionally adding support for the usage of RSS with vhost > > The eBPF works on kernels 5.8+ > On earlier kerneld it fails to load and the RSS feature is reported > only without vhost and implemented in 'in-qemu' software. > > Implementation notes: > Linux TAP TUNSETSTEERINGEBPF ioctl was used to set the eBPF program. > Added libbpf dependency and eBPF support. > The eBPF program is part of the qemu and presented as an array > of BPF ELF file data. > The compilation of eBPF is not part of QEMU build and can be done > using provided Makefile.ebpf(need to adjust 'linuxhdrs'). > Added changes to virtio-net and vhost, primary eBPF RSS is used. > 'in-qemu' RSS used in the case of hash population and as a fallback option. > For vhost, the hash population feature is not reported to the guest. > > Please also see the documentation in PATCH 5/5. > > I am sending those patches as RFC to initiate the discussions and get > feedback on the following points: > * Fallback when eBPF is not supported by the kernel > * Live migration to the kernel that doesn't have eBPF support > * Integration with current QEMU build > * Additional usage for eBPF for packet filtering > > Known issues: > * hash population not supported by eBPF RSS: 'in-qemu' RSS used > as a fallback, also, hash population feature is not reported to guests > with vhost. > * big-endian BPF support: for now, eBPF isn't supported on > big-endian systems. Can be added in future if required. > * huge .h file with eBPF binary. The size of .h file containing > eBPF binary is currently ~5K lines, because the binary is built with debug information. > The binary without debug/BTF info can't be loaded by libbpf. > We're looking for possibilities to reduce the size of the .h files. A question here, is this because the binary file contains DWARF data? If yes, is it a building or loading dependency? If it's latter, maybe we can try to strip them out, anyhow it can't be recognized by kernel. Thanks > > Changes since v1: > * using libbpf instead of direct 'bpf' system call. > * added libbpf dependency to the configure/meson scripts. > * changed python script for eBPF .h file generation. > * changed eBPF program - reading L3 proto from ethernet frame. > * added TUNSETSTEERINGEBPF define for TUN. > * changed the maintainer's info. > * added license headers. > * refactored code. > > Andrew (5): > net: Added SetSteeringEBPF method for NetClientState. > ebpf: Added eBPF RSS program. > ebpf: Added eBPF RSS loader. > virtio-net: Added eBPF RSS to virtio-net. > docs: Added eBPF RSS documentation. > > MAINTAINERS | 7 + > configure | 33 + > docs/ebpf_rss.rst | 133 + > ebpf/EbpfElf_to_C.py | 36 + > ebpf/Makefile.ebpf | 33 + > ebpf/ebpf_rss-stub.c | 40 + > ebpf/ebpf_rss.c | 186 ++ > ebpf/ebpf_rss.h | 44 + > ebpf/meson.build | 1 + > ebpf/rss.bpf.c | 505 +++ > ebpf/tun_rss_steering.h | 5439 ++++++++++++++++++++++++++++++++ > hw/net/vhost_net.c | 2 + > hw/net/virtio-net.c | 120 +- > include/hw/virtio/virtio-net.h | 4 + > include/net/net.h | 2 + > meson.build | 11 + > net/tap-bsd.c | 5 + > net/tap-linux.c | 13 + > net/tap-linux.h | 1 + > net/tap-solaris.c | 5 + > net/tap-stub.c | 5 + > net/tap.c | 9 + > net/tap_int.h | 1 + > net/vhost-vdpa.c | 2 + > 24 files changed, 6633 insertions(+), 4 deletions(-) > create mode 100644 docs/ebpf_rss.rst > create mode 100644 ebpf/EbpfElf_to_C.py > create mode 100755 ebpf/Makefile.ebpf > create mode 100644 ebpf/ebpf_rss-stub.c > create mode 100644 ebpf/ebpf_rss.c > create mode 100644 ebpf/ebpf_rss.h > create mode 100644 ebpf/meson.build > create mode 100644 ebpf/rss.bpf.c > create mode 100644 ebpf/tun_rss_steering.h >