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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4722CEB64DA for ; Fri, 14 Jul 2023 07:42:34 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qKDR4-0004g4-Gw; Fri, 14 Jul 2023 03:41:54 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qKDR2-0004fc-G5 for qemu-devel@nongnu.org; Fri, 14 Jul 2023 03:41:52 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qKDQu-0004Lw-ME for qemu-devel@nongnu.org; Fri, 14 Jul 2023 03:41:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1689320502; 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: in-reply-to:in-reply-to:references:references; bh=aspo+uzVHIUUZbW0harIoUN2APT6Ijx5wloKb8l+ebk=; b=bXOgADphhwYCkIg7Pi6IdExrCHN+SkbwbJI5VjngeI3cT7SLGZPhmA/DrnhX1Ua8nOLuY0 JkZmVyDYrOs0aYiktoPComDm4v2CCbdAQCVSWjPyENyR/pdySYFjXgajBqteEgXiIC65lm nTCIk+o/fJ4Fuyp4MSr6tT3Ik1OIu6Y= Received: from mimecast-mx02.redhat.com (66.187.233.73 [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-224-IiChLGhHM9GlHkW60t4b8A-1; Fri, 14 Jul 2023 03:41:38 -0400 X-MC-Unique: IiChLGhHM9GlHkW60t4b8A-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 730723806703; Fri, 14 Jul 2023 07:41:38 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.37]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3560CC57964; Fri, 14 Jul 2023 07:41:38 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 2116721E6A1F; Fri, 14 Jul 2023 09:41:37 +0200 (CEST) From: Markus Armbruster To: Andrew Melnychenko Cc: jasowang@redhat.com, mst@redhat.com, eblake@redhat.com, qemu-devel@nongnu.org, berrange@redhat.com, yuri.benditovich@daynix.com, yan@daynix.com Subject: Re: [PATCH v4 5/6] qmp: Added new command to retrieve eBPF blob. References: <20230714022358.2438995-1-andrew@daynix.com> <20230714022358.2438995-6-andrew@daynix.com> Date: Fri, 14 Jul 2023 09:41:37 +0200 In-Reply-To: <20230714022358.2438995-6-andrew@daynix.com> (Andrew Melnychenko's message of "Fri, 14 Jul 2023 05:23:57 +0300") Message-ID: <87sf9rey8e.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, DKIM_INVALID=0.1, DKIM_SIGNED=0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Andrew Melnychenko writes: > Added command "request-ebpf". This command returns > eBPF program encoded base64. The program taken from the > skeleton and essentially is an ELF object that can be > loaded in the future with libbpf. > > The reason to use the command to provide the eBPF object > instead of a separate artifact was to avoid issues related > to finding the eBPF itself. As the eBPF maps/program should > correspond to QEMU, the eBPF cant be used from different can't > QEMU build. Blank line between paragaphs. > The first solution was a helper that comes with QEMU > and loads appropriate eBPF objects. And the issue is > to find a proper helper if the system has several > different QEMUs installed and/or built from the source, > which helpers may not be compatible. Blank line between paragaphs. > Another issue is QEMU updating while there is a running > QEMU instance. With an updated helper, it may not be > possible to hotplug virtio-net device to the already > running QEMU. Overall, requesting the eBPF object from > QEMU itself solves possible failures with very little effort. I respectfully disagree with "very little". But it's your commit message, not mine. "Acceptable effort"? > Links: > [PATCH 3/5] qmp: Added the helper stamp check. > https://lore.kernel.org/all/20230219162100.174318-4-andrew@daynix.com/ > > Signed-off-by: Andrew Melnychenko > --- > qapi/ebpf.json | 58 +++++++++++++++++++++++++++++++++++++++++++ > qapi/meson.build | 1 + > qapi/qapi-schema.json | 1 + > 3 files changed, 60 insertions(+) > create mode 100644 qapi/ebpf.json > > diff --git a/qapi/ebpf.json b/qapi/ebpf.json > new file mode 100644 > index 0000000000..3237da69a7 > --- /dev/null > +++ b/qapi/ebpf.json > @@ -0,0 +1,58 @@ > +# -*- Mode: Python -*- > +# vim: filetype=python > +# > +# This work is licensed under the terms of the GNU GPL, version 2 or later. > +# See the COPYING file in the top-level directory. > + > +## > +# = eBPF Objects > +## > + > +{ 'include': 'common.json' } > + > +## > +# @EbpfObject: > +# > +# Structure that holds eBPF ELF object encoded in base64. > +# > +# Since: 8.3 > +# > +## > +{ 'struct': 'EbpfObject', > + 'data': {'object': 'str'}, > + 'if': 'CONFIG_EBPF' } > + > +## > +# @EbpfProgramID: > +# > +# The eBPF programs that can be gotten with request-ebpf. > +# > +# @rss: Receive side scaling, technology that allows steering traffic > +# between queues by calculation hash. Users may set up indirection table > +# and hash/packet types configurations. Used with virtio-net. > +# > +# Since: 8.3 > +## > +{ 'enum': 'EbpfProgramID', > + 'if': 'CONFIG_EBPF', > + 'data': [ { 'name': 'rss' } ] } > + > +## > +# @request-ebpf: > +# > +# Returns eBPF object that can be loaded with libbpf. > +# Management applications (g.e. libvirt) may load it and pass file > +# descriptors to QEMU. Which allows running QEMU without BPF capabilities. > +# It's crucial that eBPF program/map is compatible with QEMU, so it's > +# provided through QMP. > +# > +# Returns: RSS eBPF object encoded in base64. > +# > +# Since: 8.3 > +# > +## > +{ 'command': 'request-ebpf', > + 'data': { 'id': 'EbpfProgramID' }, > + 'returns': 'EbpfObject', > + 'if': 'CONFIG_EBPF' } > + Trim the trailing blank line. Terminology: you use "eBPF program" and "eBPF object". What's the difference? If there's none, use only one term, please. To me, "program" feels more clear. > diff --git a/qapi/meson.build b/qapi/meson.build > index 60a668b343..90047dae1c 100644 > --- a/qapi/meson.build > +++ b/qapi/meson.build > @@ -33,6 +33,7 @@ qapi_all_modules = [ > 'crypto', > 'cxl', > 'dump', > + 'ebpf', > 'error', > 'introspect', > 'job', > diff --git a/qapi/qapi-schema.json b/qapi/qapi-schema.json > index 6594afba31..2c82a49bae 100644 > --- a/qapi/qapi-schema.json > +++ b/qapi/qapi-schema.json > @@ -53,6 +53,7 @@ > { 'include': 'char.json' } > { 'include': 'dump.json' } > { 'include': 'net.json' } > +{ 'include': 'ebpf.json' } > { 'include': 'rdma.json' } > { 'include': 'rocker.json' } > { 'include': 'tpm.json' }