From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id C72616B02EB for ; Wed, 20 Sep 2017 20:04:38 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id x78so7121267pff.7 for ; Wed, 20 Sep 2017 17:04:38 -0700 (PDT) Received: from mga09.intel.com (mga09.intel.com. [134.134.136.24]) by mx.google.com with ESMTPS id w12si97909pgo.419.2017.09.20.17.04.37 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Sep 2017 17:04:37 -0700 (PDT) Subject: Re: [PATCH v6 03/11] mm, x86: Add support for eXclusive Page Frame Ownership (XPFO) References: <20170907173609.22696-1-tycho@docker.com> <20170907173609.22696-4-tycho@docker.com> <302be94d-7e44-001d-286c-2b0cd6098f7b@huawei.com> <20170911145020.fat456njvyagcomu@docker> <57e95ad2-81d8-bf83-3e78-1313daa1bb80@canonical.com> <431e2567-7600-3186-1489-93b855c395bd@huawei.com> <20170912143636.avc3ponnervs43kj@docker> <20170912181303.aqjj5ri3mhscw63t@docker> <91923595-7f02-3be0-9c59-9c1fd20c82a8@intel.com> <20170921000210.drjiywtp4n75yovk@docker> From: Dave Hansen Message-ID: <21bcc50a-f333-fb43-adef-ed501fc6b127@intel.com> Date: Wed, 20 Sep 2017 17:04:35 -0700 MIME-Version: 1.0 In-Reply-To: <20170921000210.drjiywtp4n75yovk@docker> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tycho Andersen Cc: Yisheng Xie , Juerg Haefliger , linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com, Marco Benatto , x86@kernel.org On 09/20/2017 05:02 PM, Tycho Andersen wrote: > ...and makes it easier to pair tlb flushes with changing the > protections. I guess we still need the for loop, because we need to > set/unset the xpfo bits as necessary, but I'll switch it to a single > set_kpte(). This also implies that the xpfo bits should all be the > same on every page in the mapping, which I think is true. FWIW, it's a bit bonkers to keep all this duplicate xpfo metadata for compound pages. You could probably get away with only keeping it for the head page. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org