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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 356B9C3F6B0 for ; Thu, 11 Aug 2022 13:44:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A2A7B8E0001; Thu, 11 Aug 2022 09:44:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9DAD46B0074; Thu, 11 Aug 2022 09:44:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8397A8E0001; Thu, 11 Aug 2022 09:44:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 7459E6B0073 for ; Thu, 11 Aug 2022 09:44:13 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 56B1014161A for ; Thu, 11 Aug 2022 13:44:13 +0000 (UTC) X-FDA: 79787430786.15.6319AFE Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by imf07.hostedemail.com (Postfix) with ESMTP id 7CC5C40185 for ; Thu, 11 Aug 2022 13:44:11 +0000 (UTC) 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="291345757" X-IronPort-AV: E=Sophos;i="5.93,230,1654585200"; d="scan'208";a="291345757" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga103.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> Reply-To: Chao Peng 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: ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660225451; a=rsa-sha256; cv=none; b=yLCDdJ/TLfbKEJ6i79MhKmmDAzlpYfO5W7+dyFjZDmBfxCjBEz4Yoy5ghP+1wHACe3t7gM ix6HbPbxe/+dkmrWIofZAt3SyNQX6Wa/d0t0BnOOWrp0p21Vqo9HBGIDIUyL5g2sneDcVu KzMbg+6v6U+pk8CUcOYM4jDaEH5oWT4= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=WVLdsVDk; spf=none (imf07.hostedemail.com: domain of chao.p.peng@linux.intel.com has no SPF policy when checking 192.55.52.115) smtp.mailfrom=chao.p.peng@linux.intel.com; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660225451; h=from:from:sender:reply-to: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=a5FivZwqPIG3OSE6uKmUKq5fs/EQk+LJuYHspiIyjT8=; b=HY7J/ZwZ9y5pb+pXWh2oYzOtqBfS8y/jK9KLGR66M2o3hkTAB8UBXIsZWgc2KLPOnLFxm3 eTD2M826MKJJOdOgU/Is5oGg/mR450FURRswlBuzsg/8UwUD0mjYEujcDU+U1LH/nPyKrr jiZa7RPCfK4BhJRhj2o+DTqbL/i/+Z8= X-Stat-Signature: 53xtm4rh55abjxcgtq58hqn7e3wa1xfu X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 7CC5C40185 Authentication-Results: imf07.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=WVLdsVDk; spf=none (imf07.hostedemail.com: domain of chao.p.peng@linux.intel.com has no SPF policy when checking 192.55.52.115) smtp.mailfrom=chao.p.peng@linux.intel.com; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none) X-Rspam-User: X-HE-Tag: 1660225451-368953 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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