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 X-Spam-Level: X-Spam-Status: No, score=-11.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F361C4360F for ; Thu, 4 Apr 2019 20:28:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 396EA2171F for ; Thu, 4 Apr 2019 20:28:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="jDJG+FHe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730969AbfDDU25 (ORCPT ); Thu, 4 Apr 2019 16:28:57 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:37067 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729657AbfDDU24 (ORCPT ); Thu, 4 Apr 2019 16:28:56 -0400 Received: by mail-pf1-f196.google.com with SMTP id 8so1934262pfr.4 for ; Thu, 04 Apr 2019 13:28:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=subject:from:to:cc:references:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=4qUk8W0GAzWA97FnJKu3eUQ+vGfAvxqnmlQdPm3iJDk=; b=jDJG+FHekDqus5RI2HRReA5lJyBIce30V90l3z6R0EapIUZyJVM/pE1M4DjiBuF/nK tRF7L3aHXW76V+03de5yuxJSU6/UY0tpKqdgh+nVTT8/MPtETM4H7Ehfk+K3xwGje/3C up20w6cBeDi8xG4N2EAdHOxsFnRqMxLJspG7hJSiPoLwDGevUnIGq1/OsWOn2iooJjyl EL9H4CsplNsDhLuPN4v7FGdmJJO100k3bnaS8P6E4qN59gb0A7jV1pEVAKf/Gpx/w1TE rjAVdHdOA//eUxwjlp+OuowIZmz+RcRQ0p+taq50XA/eiESMkSua3xIhHaUNPmePiop+ bc7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=4qUk8W0GAzWA97FnJKu3eUQ+vGfAvxqnmlQdPm3iJDk=; b=ZuZsywZbwy7OnV2sDkhuoN9xzLbJBieAcbt1sPdWokUpC39DGYbsQCAb2GWVBeUgRE B8qDhjaNJ45rrD4fiFSKgi8f60u4BapyAL671nKkTjo/MuabQwjfRpFOwnbnLZZmTs9g CVwMFHK0ksG+yVgYQ5JudxuFygn7eK/1pV5TZajjSeunVO+XFg+67QDalkccaMly4FaD a+sTBNLKpJU+b+3O5Th+PvuISFhRYE8OFTEj5+OJ2ECVKzkAYGbQ7hx+pJm6/ath1ppz ybmJuu6Ims76EDH29DOiuzr7tEbOii4fW8ngU1j0+IaUTemSlny3q2Q1ZqdDhZNwYi7d om3A== X-Gm-Message-State: APjAAAUxTn9L2S0ITtamkTxRjjDPvAZXw5n31LkUPHIkCxiODT2iamkP tQwZdSySjNjbm98nTxszmD2Z+1SkIiI= X-Google-Smtp-Source: APXvYqykvrNarnYRrmQ39P2Tb9+d1I8m6DUa+RGJC8yzMyWYP+buLoJAWvAE40aaaXJAY9zYZnL+Ww== X-Received: by 2002:a63:2c3:: with SMTP id 186mr7675400pgc.161.1554409735180; Thu, 04 Apr 2019 13:28:55 -0700 (PDT) Received: from gnomeregan.cam.corp.google.com ([2620:15c:6:14:ad22:1cbb:d8fa:7d55]) by smtp.googlemail.com with ESMTPSA id e21sm28301337pfd.177.2019.04.04.13.28.53 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 Apr 2019 13:28:54 -0700 (PDT) Subject: Re: [PATCH v3 0/3] kvm: Use huge pages for DAX-backed files From: Barret Rhoden To: Paolo Bonzini , Dan Williams , David Hildenbrand , Dave Jiang , Alexander Duyck Cc: linux-nvdimm@lists.01.org, x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, yu.c.zhang@intel.com References: <20190404202345.133553-1-brho@google.com> Message-ID: Date: Thu, 4 Apr 2019 16:28:51 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <20190404202345.133553-1-brho@google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -yi.z.zhang@intel.com (Bad email address / failure) Sorry about that. On 4/4/19 4:23 PM, Barret Rhoden wrote: > This patch series depends on DAX pages not being PageReserved. Once > that is in place, these changes will let KVM use huge pages with > DAX-backed files. > > From previous discussions[1], it sounds like DAX might not need to keep > the PageReserved bit, but that it hadn't been sorted out yet. > > Without the PageReserved change, KVM and DAX still work with these > patches, simply without huge pages - which is the current situation. > > If you want to test the huge-page functionality as if DAX pages weren't > PageReserved for KVM, this hack does the trick: > > ------------------ > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index c44985375e7f..ee539eec1fb8 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -153,6 +153,10 @@ __weak int kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm, > > bool kvm_is_reserved_pfn(kvm_pfn_t pfn) > { > + // XXX hack > + if (is_zone_device_page(pfn_to_page(pfn))) > + return false; > + > if (pfn_valid(pfn)) > return PageReserved(pfn_to_page(pfn)); > > ------------------ > > Perhaps if we are going to leave DAX pages marked PageReserved, then I > can make that hack into a proper commit and have KVM alone treat DAX > pages as if they are not reserved. > > v2 -> v3: > v2: https://lore.kernel.org/lkml/20181114215155.259978-1-brho@google.com/ > - Updated Acks/Reviewed-by > - Rebased onto linux-next > > v1 -> v2: > https://lore.kernel.org/lkml/20181109203921.178363-1-brho@google.com/ > - Updated Acks/Reviewed-by > - Minor touchups > - Added patch to remove redundant PageReserved() check > - Rebased onto linux-next > > RFC/discussion thread: > https://lore.kernel.org/lkml/20181029210716.212159-1-brho@google.com/ > > [1] https://lore.kernel.org/lkml/ee8cc068-903c-d87e-f418-ade46786249e@redhat.com/ > > Barret Rhoden (3): > mm: make dev_pagemap_mapping_shift() externally visible > kvm: Use huge pages for DAX-backed files > kvm: remove redundant PageReserved() check > > arch/x86/kvm/mmu.c | 33 +++++++++++++++++++++++++++++++-- > include/linux/mm.h | 3 +++ > mm/memory-failure.c | 38 +++----------------------------------- > mm/util.c | 34 ++++++++++++++++++++++++++++++++++ > virt/kvm/kvm_main.c | 8 ++------ > 5 files changed, 73 insertions(+), 43 deletions(-) >