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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C46D2C83F17 for ; Tue, 29 Aug 2023 09:24:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234681AbjH2JYa (ORCPT ); Tue, 29 Aug 2023 05:24:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234772AbjH2JYV (ORCPT ); Tue, 29 Aug 2023 05:24:21 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91A7CCC3 for ; Tue, 29 Aug 2023 02:24:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1693301049; x=1724837049; h=date:from:to:cc:subject:message-id:reply-to:references: mime-version:in-reply-to; bh=k8wmz6gLOLehQl5Tc2Eejiul0oThtEUob0a0/5GkVOs=; b=beISe5TN7d0vZtB3p7zTI6/b/CAE2CKF3uQmmzEpdgGZmV0x1nmvTmzc qtndFhgcpSLTiGwGqlHzED+EHN4gANfb1cSXe0EbNKsEm483bSM2psmth 1QuJoJZvc3aYaupEdB7InoB8icO47JNwvxWRq92yt0dAot5NVzf8Qghwx 2W02c2tzZdq0WiUSN1wLxvYA11ebVhtiL3QqLOs48WM0ZmQUl+/kiQh86 faNGoj9EjFC7E0X7lFk+wPSzPV6aWBp6t+Ut/UCJj/BsKeiIUn2TgFAva cOWFbfKKiTjwG/rsMOkklF7GEksqj5b0MH8oYJgUMP5+0/GOGMJmS6gAs g==; X-IronPort-AV: E=McAfee;i="6600,9927,10816"; a="441672239" X-IronPort-AV: E=Sophos;i="6.02,210,1688454000"; d="scan'208";a="441672239" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Aug 2023 02:24:09 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10816"; a="741743418" X-IronPort-AV: E=Sophos;i="6.02,210,1688454000"; d="scan'208";a="741743418" Received: from chaop.bj.intel.com (HELO localhost) ([10.240.193.80]) by fmsmga007.fm.intel.com with ESMTP; 29 Aug 2023 02:24:04 -0700 Date: Tue, 29 Aug 2023 17:12:33 +0800 From: Chao Peng To: Sean Christopherson Cc: kvm@vger.kernel.org, Fuad Tabba , Yu Zhang , Vishal Annapurve , Ackerley Tng , Maciej Szmigiero , Vlastimil Babka , Quentin Perret , Michael Roth , Wang , Liam Merwick , Isaku Yamahata , "Kirill A . Shutemov" , Paolo Bonzini , Jorg Rodel , Vitaly Kuznetsov Subject: Re: [RFC PATCH v11 00/29] KVM: guest_memfd() and per-page attributes Message-ID: <20230829091233.GA72470@chaop.bj.intel.com> Reply-To: Chao Peng References: <20230718234512.1690985-1-seanjc@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Aug 25, 2023 at 10:47:12AM -0700, Sean Christopherson wrote: > > > Filemap vs. xarray > ------------------ > This is the main item that needs attention. I don't want to merge guest_memfd() > without doing this comparison, as not using filemap means we don't need AS_UNMOVABLE. > Arguably we could merge a filemap implementation without AS_UNMOVABLE and just eat > the suboptimal behavior, but not waiting a little while longer to do everything we > can to get this right the first time seems ridiculous after we've been working on > this for literally years. > > Paolo was going to work on an axarray implementation, but AFAIK he hasn't done > anything yet. We (Google) don't have anyone available to work on an xarray > implementation for several weeks (at best), so if anyone has the bandwidth and > desire to take stab at an xarray implementation, please speak up. I can do some experiments in the following weeks on the xarray direction. I'm not quite confident I understood all what Paolo originally wanted to do, so questions may have. Chao