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=-9.9 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL autolearn=no 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 7139AC43603 for ; Thu, 12 Dec 2019 19:16:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 404CC2073B for ; Thu, 12 Dec 2019 19:16:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="KAaolzVG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730610AbfLLTQh (ORCPT ); Thu, 12 Dec 2019 14:16:37 -0500 Received: from mail-pl1-f193.google.com ([209.85.214.193]:34173 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730486AbfLLTQh (ORCPT ); Thu, 12 Dec 2019 14:16:37 -0500 Received: by mail-pl1-f193.google.com with SMTP id x17so1057565pln.1 for ; Thu, 12 Dec 2019 11:16:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=MNaR/QuknJAHIB0pQcQsq4R3Kk/5rQ+DPsOAQIxnnSw=; b=KAaolzVGGhfdtct3LZlhCTEopQdtdhFue5scfWobqwTsj8pWuL8PPQeLqKwSEwDDPT RH6zj3ONxLD+ZNNz2rnjB8aOkq+zyRGMUKrwm47RHKOKhZLJjBMEFm+Oprp2T+rETJsj u3YQMbP2yvBsoYxCqcj4VtuRXuZgqZI06zy9VGC0ph50IaQHvHUlW6pvuzBQqamMWb/6 MxKKPVfqkUfpOJKet7l4NXuP1wWltJKpviBeyXO6YQd5nklpHbB09zTViE0KGCvRYD1e mgR27tzL277oAJHraSihXtCCjBO3L65OKHZ0vDGDPX7aHDav/w/EBjeVOcSGNbXhWfOg tltA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=MNaR/QuknJAHIB0pQcQsq4R3Kk/5rQ+DPsOAQIxnnSw=; b=f6LXzXafM9WJUybX6BUoM5M2w3hL+Yv530W+6o7LPSdapBPY3kcc0cDRdgYSE8VUz9 CK4rN2PO//TR5uWWv7tDdfXEa/7DG0FXpuXkY4LBvbpJny1QW4uHFEQ7uv63JF2glPbA lEY7udIrRDf+CzQeceSh7jASqSOp9+/f3D3Lawb4isO3GZldFEBh4NWIf102hSDRJcG/ 914NPbqruuqZbwwdsnwaRFHX+8M/LWKC9554oZ5Q6WT64IHrJywNkc9IxsWVZCNBCNX5 TDqtiNzr1dGRPSdFzkmHMKElbT9/OFK5dcAdvv0NyguxoGb1bkDpZchrHi73WhzEl//6 GdJg== X-Gm-Message-State: APjAAAXxquM7vfXqLc9/PJ6xfq+xPxyLSJj+xQYj31MriConO7DzIVvx l9gWEdrMALda/5vqSYQbup81tg== X-Google-Smtp-Source: APXvYqx/9O2gkZlxhLDydhoZN8PUSRgnOhN7UqLc/bxYHtv2gdkUDry2PRLvM5QCHRSKPYXaQiMGYg== X-Received: by 2002:a17:90b:85:: with SMTP id bb5mr11377895pjb.22.1576178195916; Thu, 12 Dec 2019 11:16:35 -0800 (PST) Received: from gnomeregan.cam.corp.google.com ([2620:15c:6:14:ad22:1cbb:d8fa:7d55]) by smtp.googlemail.com with ESMTPSA id e1sm8314913pfl.98.2019.12.12.11.16.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 12 Dec 2019 11:16:35 -0800 (PST) Subject: Re: [PATCH v4 2/2] kvm: Use huge pages for DAX-backed files To: Dan Williams Cc: Sean Christopherson , Paolo Bonzini , David Hildenbrand , Dave Jiang , Alexander Duyck , linux-nvdimm , X86 ML , KVM list , Linux Kernel Mailing List , "Zeng, Jason" References: <20191211213207.215936-1-brho@google.com> <20191211213207.215936-3-brho@google.com> <20191212173413.GC3163@linux.intel.com> From: Barret Rhoden Message-ID: Date: Thu, 12 Dec 2019 14:16:33 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/12/19 12:37 PM, Dan Williams wrote: > Yeah, since device-dax is the only path to support longterm page > pinning for vfio device assignment, testing with device-dax + 1GB > pages would be a useful sanity check. What are the issues with fs-dax and page pinning? Is that limitation something that is permanent and unfixable (by me or anyone)? I'd like to put a lot more in a DAX/pmem region than just a guest's memory, and having a mountable filesystem would be extremely convenient. Thanks, Barret