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 5CC2BD33998 for ; Mon, 28 Oct 2024 16:13:28 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t5SMe-0007Aj-VP; Mon, 28 Oct 2024 12:13:08 -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 1t5SMc-0007AL-Vf for qemu-devel@nongnu.org; Mon, 28 Oct 2024 12:13:07 -0400 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t5SMb-0006RZ-8h for qemu-devel@nongnu.org; Mon, 28 Oct 2024 12:13:06 -0400 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 33E935C5D58; Mon, 28 Oct 2024 16:12:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC1B6C4CEC3; Mon, 28 Oct 2024 16:12:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730131979; bh=xuzSVIC+24hcvUH3Uu6IJyxDoI8NF9z/u0YhE9kqbOY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=C0q+lkSKR1cXdmfA70QriKxNHoGAVcH+ZKCc+Zox4ygDHb48qTdn8VuHT2A4+o5V2 zoili6j4ZeZdYddsbvCBmzv4/WQgpSj7kTlw06ahaK4hCP3zTRP9o3R85+DvpU2GYF JOfOD4cd4nqkmkIlo1feNr7WS5I7Lq9w9Ag0huIfm0H86flbsmELoeR1CWqpKwnAA6 NYQH1pJbxeuWuW0ou07d6MW7v+ovxkDt0VgRA/OeSEyVzpisDjPRrKkn0IRURMLEiE huG9vkW7i5jsybC0co+F32KJLuGZov4R0mWfhQFuXfe18nE4zlmADox5tRHMwhBpHw r+wobvKfES9+g== Date: Mon, 28 Oct 2024 09:12:56 -0700 From: Jakub Kicinski To: David Woodhouse Cc: Richard Cochran , Peter Hilber , linux-kernel@vger.kernel.org, virtualization@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-rtc@vger.kernel.org, "Ridoux, Julien" , virtio-dev@lists.linux.dev, "Luu, Ryan" , "Chashper, David" , "Mohamed Abuelfotoh, Hazem" , Paolo Abeni , "Christopher S . Hall" , Jason Wang , John Stultz , "Michael S . Tsirkin" , netdev@vger.kernel.org, Stephen Boyd , Thomas Gleixner , Xuan Zhuo , Marc Zyngier , Mark Rutland , Daniel Lezcano , Alessandro Zummo , Alexandre Belloni , qemu-devel , Simon Horman Subject: Re: [PATCH net-next v7] ptp: Add support for the AMZNC10C 'vmclock' device Message-ID: <20241028091256.1b0752b4@kernel.org> In-Reply-To: References: <78969a39b51ec00e85551b752767be65f6794b46.camel@infradead.org> <20241009173253.5eb545db@kernel.org> <20241014131238.405c1e58@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2604:1380:4641:c500::1; envelope-from=kuba@kernel.org; helo=dfw.source.kernel.org X-Spam_score_int: -47 X-Spam_score: -4.8 X-Spam_bar: ---- X-Spam_report: (-4.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.373, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, 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: 2.1.29 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 Sat, 19 Oct 2024 18:49:24 +0100 David Woodhouse wrote: > > Yes please and thank you! We gotta straighten it out before > > the merge window. > > Hm, as I (finally) come to do that, I realise that many of the others > defined in drivers/ptp/Kconfig are also 'default y'. Which is only > really 'default PTP_1588_CLOCK' in practice since they all depend on > that. AFAICT nothing defaulted to enabled since 2017, so I'd chalk it up to us getting better at catching mistakes over time. > Most importantly, PTP_1588_CLOCK_KVM is 'default y'. And that one is > fundamentally broken (at least in the presence of live migration if > guests care about their clock suddenly being wrong) which is why it's > being superseded by the new VMCLOCK thing. We absolutely don't want to > leave the _KVM one enabled by default and not its _VMCLOCK replacement. You can default to .._CLOCK_KVM, and provide the explanation in the commit message and Kconfig help. Or if you feel strongly even make CLOCK_KVM depend on the new one? > Please advise... I suspect the best answer is to leave it as it is? I'd really rather not. Linus has complained to us about Kconfig symbols appearing / getting enabled by default multiple times in the past. Sorry for the delay, vacation time.