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 C6151C83F37 for ; Thu, 31 Aug 2023 18:29:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345044AbjHaS32 (ORCPT ); Thu, 31 Aug 2023 14:29:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230019AbjHaS31 (ORCPT ); Thu, 31 Aug 2023 14:29:27 -0400 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C020EE43 for ; Thu, 31 Aug 2023 11:29:24 -0700 (PDT) Received: by mail-pl1-x649.google.com with SMTP id d9443c01a7336-1bf707f526bso12759065ad.1 for ; Thu, 31 Aug 2023 11:29:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1693506564; x=1694111364; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=BAQ/pFsVHD1Aoomibgpxf2ZqL3aYZZ65V96hB69Tw9c=; b=fDxwxv2JRt9tSD2mwNu82F5veh8qKIzH4kHxxD85d62MrAMfuY0NGzRcJdp34SuaYW AFVJb7Hh/tHW8uzyes3YJyhOrC6JoiJc4jfvhMs050Eg4c79zIuVsbzY1LPk/mGn8xE4 fggDMeALBIyCfly1WqwUm4vPj5ZFWm7faLOvsoiLtts05kcbSjMOOUmT6tOrDuI/jcCJ RZVfaNiqtEEeP38++akgIW7aWX9alVIeA0XcccNASlczwRwRfIA+4xrkL9yqMLOovtt3 HtgB5cuyrmANwPBqCLzB5cpfwjdifPHGOtgMFRVA3EZTDgnb12m/Bh9MTQfvMAkjdYzi okHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1693506564; x=1694111364; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=BAQ/pFsVHD1Aoomibgpxf2ZqL3aYZZ65V96hB69Tw9c=; b=AokSuplfq12WKgK0wG1rLm3ywOTCgp0SBws1DgEwGmnDAK3/4FhTVFNkCyQgre+ZKU s69wuzKcDUnWJgqy8jt22YQnh09qqfVdVfT7k6eEEcnNy4SFZDxgAbvlO/mBNjxEPIkW tqO+g7l/sGOZemh7zW2bm1hSPW29y4QbX45O3WDHk3GoRi7YaVNJM4gp9qHJi5WdgrlP +t8N5L2mt1zoDR9ZE25OQwBXFGX0xroHbtGpIfjwnXrP1uO70yD0OtdW3qvpjQJslUqL 5QiLOtdU/9z00i2SM0VccnsKk7GB4puOEMXjvwliOULAciJVnrE7wHar6Cd1TQI25FCf S3tw== X-Gm-Message-State: AOJu0YyoQJ+jMv2GYhFHYQHB9z93cGD9kqJEv+anXQ6iWT07TYiHg4vH f1JxsmEmuSuHQVrSppaPkwHb3QTsI9w= X-Google-Smtp-Source: AGHT+IFL1xqBeQ6sRUjnp1DduAFvrSYTtqUwn+ivj8j9EbmZT0+UmpZ+UIr8YgioG1n3CHlx12vtk7JlsdI= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:902:e74f:b0:1bf:cc5:7b53 with SMTP id p15-20020a170902e74f00b001bf0cc57b53mr154232plf.1.1693506564284; Thu, 31 Aug 2023 11:29:24 -0700 (PDT) Date: Thu, 31 Aug 2023 11:29:22 -0700 In-Reply-To: <20230829091233.GA72470@chaop.bj.intel.com> Mime-Version: 1.0 References: <20230718234512.1690985-1-seanjc@google.com> <20230829091233.GA72470@chaop.bj.intel.com> Message-ID: Subject: Re: [RFC PATCH v11 00/29] KVM: guest_memfd() and per-page attributes From: Sean Christopherson To: Chao Peng 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 Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Aug 29, 2023, Chao Peng wrote: > 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. FYI, I jumped the gun, sounds like Paolo got far enough along to form a strong opinion[*]. Thanks for volunteering though, much appreciated! [*] https://lore.kernel.org/all/CABgObfay4FKV=foWLZzAWaC2kVHRnF1ib+6NC058QVZVFhGeyA@mail.gmail.com