From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753656AbbALU6s (ORCPT ); Mon, 12 Jan 2015 15:58:48 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:35119 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750981AbbALU6r (ORCPT ); Mon, 12 Jan 2015 15:58:47 -0500 Date: Mon, 12 Jan 2015 12:58:46 -0800 From: Andrew Morton To: David Vrabel Cc: , Subject: Re: [PATCHv2 0/2] mm: infrastructure for correctly handling foreign pages on Xen Message-Id: <20150112125846.4a5a6418c5c130c1b7669086@linux-foundation.org> In-Reply-To: <1421077993-7909-1-git-send-email-david.vrabel@citrix.com> References: <1421077993-7909-1-git-send-email-david.vrabel@citrix.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 12 Jan 2015 15:53:11 +0000 David Vrabel wrote: > These two patches are the common parts of a larger Xen series[1] > fixing several long-standing bugs the handling of foreign[2] pages in > Xen guests. > > The first patch is required to fix get_user_pages[_fast]() with > userspace space mappings of such foreign pages. Basically, pte_page() > doesn't work so an alternate mechanism is needed to get the page from > a VMA and address. By requiring mappings needing this method are > 'special' this should not have an impact on the common use cases. > > The second patch isn't essential but helps with readability of the > resulting user of the page flag. > > For further background reading see: > > http://xenbits.xen.org/people/dvrabel/grant-improvements-C.pdf > Looks OK to me. I can merge them if you like, but it's probably more convenient for you to include them in the Xen tree. It would be nice if PG_foreign (and PG_everythingelse) was properly documented at the definition site.