From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0F1302D052; Mon, 28 Oct 2024 16:18:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730132317; cv=none; b=tT4CqQ08IE6C7Rt1iN3tYJEuCSrMSTywccTmK8V/Suco1eGXy8Mo4OifZwytLHCyFQUsDSD8JpmcJCXCDyO4nP3ymn/rqGfdljyWydpitNZmKNcFMl78FdbIW4ZXuEzYXFaBqaweW0RWfEea89sWG3G5LiFsTG2mCn74ldbZS44= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730132317; c=relaxed/simple; bh=C8mX4PXEjoqXMUGgb5Mn9KAI5YZMFTWUiBiXo2pQxEU=; h=Date:From:To:CC:Subject:In-Reply-To:References:Message-ID: MIME-Version:Content-Type; b=IoPgvxpHPldRokZWGeAsOYHSWuX4+7NGnggjaZNIyPmV5cg4nnNUcfpXnCUhiAFtdYxngAe+kruZJsrsjWxbqH69lm4ISdNSuc3yvrR+s4tLXdZXVTnbcMLRv23Is73LKhxgZoOeThF0zR3wm699mlF//+wqTQChtiUYbzZoXB4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=desiato.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=CSixJc9K; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=desiato.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="CSixJc9K" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Transfer-Encoding:Content-Type :MIME-Version:Message-ID:References:In-Reply-To:Subject:CC:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=C8mX4PXEjoqXMUGgb5Mn9KAI5YZMFTWUiBiXo2pQxEU=; b=CSixJc9KbGoYLDfMbDpJHLrYeW aeqSc6UBpwLif9DvpVrg/Kg9xn2TRK3rAuUoDII7dSly1eXME5mL2ZMwuFA+twED1xRHK5Xyj8jE3 PB1J6eq1bxEYglvPRauXsodP5jp+wcoUCpULXLVnsekUjdTUXxyfzI12GHSHVxQDctVyEjUmYlyjC a7BWHea/obZJrLtPXkdC6Daj+AEl52k1zVOzqV8U11nC4JNIrUbzjZkGZrdpp2aSMheR9OJnXRUE2 NMXhOoN5ws6i7ZrvSC3bUOBf+5jdQBKOtrFCVUHooMo0YpdQEy/v/H2uPF/O6t7WAU9GABJvcqCVp XZjdmJaA==; Received: from [78.133.40.109] (helo=[127.0.0.1]) by desiato.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1t5SRi-00000009hqM-19H1; Mon, 28 Oct 2024 16:18:22 +0000 Date: Mon, 28 Oct 2024 17:17:14 +0100 From: David Woodhouse To: Jakub Kicinski 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: =?US-ASCII?Q?Re=3A_=5BPATCH_net-next_v7=5D_ptp=3A_Add_supp?= =?US-ASCII?Q?ort_for_the_AMZNC10C_=27vmclock=27_device?= User-Agent: K-9 Mail for Android In-Reply-To: <20241028091256.1b0752b4@kernel.org> References: <78969a39b51ec00e85551b752767be65f6794b46.camel@infradead.org> <20241009173253.5eb545db@kernel.org> <20241014131238.405c1e58@kernel.org> <20241028091256.1b0752b4@kernel.org> Message-ID: <5077F160-52F0-4E76-B2B9-F0EA9DA76FB4@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-SRS-Rewrite: SMTP reverse-path rewritten from by desiato.infradead.org. See http://www.infradead.org/rpr.html On 28 October 2024 17:12:56 CET, Jakub Kicinski wrote: >On Sat, 19 Oct 2024 18:49:24 +0100 David Woodhouse wrote: >> > Yes please and thank you! We gotta straighten it out before=20 >> > the merge window=2E =20 >>=20 >> Hm, as I (finally) come to do that, I realise that many of the others >> defined in drivers/ptp/Kconfig are also 'default y'=2E Which is only >> really 'default PTP_1588_CLOCK' in practice since they all depend on >> that=2E > >AFAICT nothing defaulted to enabled since 2017, so I'd chalk it up >to us getting better at catching mistakes over time=2E > >> Most importantly, PTP_1588_CLOCK_KVM is 'default y'=2E 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=2E We absolutely don't want t= o >> leave the _KVM one enabled by default and not its _VMCLOCK replacement= =2E > >You can default to =2E=2E_CLOCK_KVM, and provide the explanation in >the commit message and Kconfig help=2E That works for me=2E But now it's my vacation time so it'll be at least Th= ursday before I can do that=2E I'll offer a preemptive Acked-by: David Wood= house to anyone who beats me to it :)