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 858ADC19F2A for ; Thu, 11 Aug 2022 13:45:07 +0000 (UTC) Received: from localhost ([::1]:44246 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oM8Uk-0005w1-Hz for qemu-devel@archiver.kernel.org; Thu, 11 Aug 2022 09:45:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49802) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oM8Tt-00058U-R9 for qemu-devel@nongnu.org; Thu, 11 Aug 2022 09:44:13 -0400 Received: from mga11.intel.com ([192.55.52.93]:31518) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oM8Ts-0008OM-0S for qemu-devel@nongnu.org; Thu, 11 Aug 2022 09:44:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1660225451; x=1691761451; h=date:from:to:cc:subject:message-id:reply-to:references: mime-version:in-reply-to; bh=6G1vjfFDPRBJq3hrus4RUCAj1Ik6SbGGx7LGPLT4CKc=; b=WVLdsVDkaPM+9uF36ZZZhATCv7P6gj8eaqWg4EFJY1mwHYSB+jfFKIev gnbq4lAW41INLQ1NFh28rHlXjLPl9FaMIv4DRyw/EYhnLLgOemlyqxveC sBUY0rdxaC7tUIk//uDRrVNWAcNkP9u5e4DvAQUSzH1zcVfS7ocwhA16G DSDk4RB+jAa87Q4xGshFXpexhPyS79ynNqlkX3bQUk+MO3t0hAVZU8Jp6 y9hMuMt5BEMFKM65q8MxUxSaoARDc1MAmpXy/X2IEK00UZ0IDtrIV0fTO IAwUZfu/o7wpmMJM1mXdhIabWqKA/3QMpj3pMOk+UnWotk7Cx/s45sa3S A==; X-IronPort-AV: E=McAfee;i="6400,9594,10435"; a="288914020" X-IronPort-AV: E=Sophos;i="5.93,230,1654585200"; d="scan'208";a="288914020" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Aug 2022 06:44:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.93,230,1654585200"; d="scan'208";a="665377410" Received: from chaop.bj.intel.com (HELO localhost) ([10.240.193.75]) by fmsmga008.fm.intel.com with ESMTP; 11 Aug 2022 06:43:59 -0700 Date: Thu, 11 Aug 2022 21:39:14 +0800 From: Chao Peng To: Quentin Perret Cc: Sean Christopherson , David Hildenbrand , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-doc@vger.kernel.org, qemu-devel@nongnu.org, linux-kselftest@vger.kernel.org, Paolo Bonzini , Jonathan Corbet , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , Hugh Dickins , Jeff Layton , "J . Bruce Fields" , Andrew Morton , Shuah Khan , Mike Rapoport , Steven Price , "Maciej S . Szmigiero" , Vlastimil Babka , Vishal Annapurve , Yu Zhang , "Kirill A . Shutemov" , luto@kernel.org, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, aarcange@redhat.com, ddutile@redhat.com, dhildenb@redhat.com, Michael Roth , mhocko@suse.com, Muchun Song , Will Deacon , Fuad Tabba Subject: Re: [PATCH v7 03/14] mm: Introduce memfile_notifier Message-ID: <20220811133914.GC916119@chaop.bj.intel.com> References: <20220706082016.2603916-1-chao.p.peng@linux.intel.com> <20220706082016.2603916-4-chao.p.peng@linux.intel.com> <13394075-fca0-6f2b-92a2-f1291fcec9a3@redhat.com> <20220810092232.GC862421@chaop.bj.intel.com> <00f1aa03-bc82-ffce-569b-e2d5c459992c@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Received-SPF: none client-ip=192.55.52.93; envelope-from=chao.p.peng@linux.intel.com; helo=mga11.intel.com X-Spam_score_int: -70 X-Spam_score: -7.1 X-Spam_bar: ------- X-Spam_report: (-7.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_NONE=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: , Reply-To: Chao Peng Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Aug 11, 2022 at 12:27:56PM +0000, Quentin Perret wrote: > +CC Fuad > > On Wednesday 10 Aug 2022 at 14:38:43 (+0000), Sean Christopherson wrote: > > > I understand Sean's suggestion about abstracting, but if the new name > > > makes it harder to grasp and there isn't really an alternative to memfd > > > in sight, I'm not so sure I enjoy the tried abstraction here. > > > > ARM's pKVM implementation is potentially (hopefully) going to switch to this API > > (as a consumer) sooner than later. If they anticipate being able to use memfd, > > then there's unlikely to be a second backing type any time soon. > > > > Quentin, Will? > > Yep, Fuad is currently trying to port the pKVM mm stuff on top of this > series to see how well it fits, so stay tuned. Good to hear that. >I think there is still > some room for discussion around page conversions (private->shared etc), > and we'll need a clearer idea of what the code might look like to have a > constructive discussion, That's fine. Looking forward to your feedbacks. >but so far it does seem like using a memfd (the > new private one or perhaps just memfd_secret, to be discussed) + memfd > notifiers is a promising option. If it still memfd (even memfd_secret), maybe we can use the name memfd_notifier? Chao