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 D5A44C4332F for ; Thu, 2 Nov 2023 13:19:14 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qyXax-0007ZG-Gk; Thu, 02 Nov 2023 09:18:47 -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 1qyXav-0007Z1-I8 for qemu-devel@nongnu.org; Thu, 02 Nov 2023 09:18:45 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qyXat-0007Oe-GM for qemu-devel@nongnu.org; Thu, 02 Nov 2023 09:18:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1698931122; 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=TMIj/hF5hAP1fkNBDfEw4wOlEx5Sw35cEC7GEjsufoM=; b=gEWMVJlbydTEOg+KHIysdIRb7Ixs6Qk4ecLS2MYvvRbQzw5CUwYN0nL0VSrgn3r8cKtXyU AixeAmwbtCjhQ9dXju5ZBH0I9tpO8w2H6S2yMaQd+X56dl9CvH+/LZjDlZ8ZldEO7PJMQq s8RneaJQxZH/uWLM1YWZhaj+IrQC2nY= Received: from mail-oa1-f72.google.com (mail-oa1-f72.google.com [209.85.160.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-671-QMLzNWxuOFaT4MpPh_pvgQ-1; Thu, 02 Nov 2023 09:18:41 -0400 X-MC-Unique: QMLzNWxuOFaT4MpPh_pvgQ-1 Received: by mail-oa1-f72.google.com with SMTP id 586e51a60fabf-1eb43ff49b2so1143750fac.2 for ; Thu, 02 Nov 2023 06:18:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698931120; x=1699535920; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=TMIj/hF5hAP1fkNBDfEw4wOlEx5Sw35cEC7GEjsufoM=; b=OjR762yJDs9H9lGLihjgzTU2+3tMyFaWFMcymZjp2tJzKEp9lcQufhNsRY1SOEY4gB /ryC4C5vlkqmCyZdHuuGvbGaM1hjPxvRHYWW6CIjMF3kuNe5pHUq3tTiMboqz+eTSKy3 MYznVyr2pGTvX7YnCxktZfHadUeG1VTvA7kefV2PS6o1ZMe85p+uR4gIKmMmhf9rN8UJ s6MHgpAUYJi14S3Sd9qgUHToKxF25q6/6SekcQ/o0p3J0UF3E8hCEuy5IP005GuedHfV XTTkL4NAhLMwn4hWZzvawzVF08Gc5+4ZfidXEs8KadM2kYm0NPuD+atmQk5Jz2xRm8nE F2VA== X-Gm-Message-State: AOJu0YwIu9B3L1a2yeVwUjQNO7Ec/1sBw5dC4znFoKK3mgygzC4ddQJ9 Q3lE0++nciVK0U0SSouWSI5OZCWzq1sve9JPBcE24s0gORECnwbUoioIW/EaPFZN53RtOngltZX y8ioe95um+QgVeJI= X-Received: by 2002:a05:6870:700e:b0:1e9:9469:a858 with SMTP id u14-20020a056870700e00b001e99469a858mr21269816oae.39.1698931120386; Thu, 02 Nov 2023 06:18:40 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHbFBwotZ6Fw5jebk8JVChBUNwa7tCXz3w5kac73S2tO50qZJLhu5/RG5IcItbgG+ANJwPHCQ== X-Received: by 2002:a05:6870:700e:b0:1e9:9469:a858 with SMTP id u14-20020a056870700e00b001e99469a858mr21269804oae.39.1698931120079; Thu, 02 Nov 2023 06:18:40 -0700 (PDT) Received: from redhat.com ([2a02:14f:174:efc3:a5be:5586:34a6:1108]) by smtp.gmail.com with ESMTPSA id j127-20020a0de085000000b00592236855cesm1191138ywe.61.2023.11.02.06.18.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Nov 2023 06:18:39 -0700 (PDT) Date: Thu, 2 Nov 2023 09:18:35 -0400 From: "Michael S. Tsirkin" To: Yuri Benditovich Cc: Akihiko Odaki , Jason Wang , qemu-devel@nongnu.org, Andrew Melnychenko Subject: Re: [PATCH v6 11/21] virtio-net: Return an error when vhost cannot enable RSS Message-ID: <20231102091717-mutt-send-email-mst@kernel.org> References: <20231101023805-mutt-send-email-mst@kernel.org> <39a02a4c-f8fa-437c-892f-caca84b8d85d@daynix.com> <20231101050838-mutt-send-email-mst@kernel.org> <20231102053202-mutt-send-email-mst@kernel.org> <20231102072540-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Received-SPF: pass client-ip=170.10.129.124; envelope-from=mst@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.393, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-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=ham 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 On Thu, Nov 02, 2023 at 02:00:46PM +0200, Yuri Benditovich wrote: > > > On Thu, Nov 2, 2023 at 1:26 PM Michael S. Tsirkin wrote: > > On Thu, Nov 02, 2023 at 12:20:39PM +0200, Yuri Benditovich wrote: > > > > > > On Thu, Nov 2, 2023 at 11:33 AM Michael S. Tsirkin > wrote: > > > >     On Thu, Nov 02, 2023 at 11:09:27AM +0200, Yuri Benditovich wrote: > >     > Probably we mix two different patches in this discussion. > >     > Focusing on the patch in the e-mail header: > >     > > >     > IMO it is not acceptable to fail QEMU run for one feature that we > can't > >     make > >     > active when we silently drop all other features in such a case. > > > >     If the feature is off by default then it seems more reasonable > >     and silent masking can be seen as a bug. > >     Most virtio features are on by default this is why it's > >     reasonable to mask them. > > > > > > > > If we are talking about RSS: setting it initially off is the development > time > > decision.  > > When it will be completely stable there is no reason to keep it off by > default, > > so this is more a question of time and of a readiness of libvirt.  > > Well when we flip the default we'll need compat machinery for sure ;) > > > Of course, on the flip or default we'll need to keep compatibility to earlier > machine types. > But, because in the perspective it makes sense to make the RSS is on by > default, I do not think we need _now_ to make qemu fail to start if the ebpf > can't be loaded. >   Generally if user asks for something and we can't do it, we must fail. If we can't apply a default we need a better default. qemu has a bug in that it can't generally distinguish between default set automatically and same default given on command line. -- MST