From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yh0-f48.google.com (mail-yh0-f48.google.com [209.85.213.48]) by kanga.kvack.org (Postfix) with ESMTP id 2BB5B6B0070 for ; Mon, 12 Jan 2015 11:11:48 -0500 (EST) Received: by mail-yh0-f48.google.com with SMTP id i57so9977689yha.7 for ; Mon, 12 Jan 2015 08:11:48 -0800 (PST) Received: from SMTP.CITRIX.COM (smtp.citrix.com. [66.165.176.89]) by mx.google.com with ESMTPS id e68si735697yhe.175.2015.01.12.08.11.42 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 12 Jan 2015 08:11:43 -0800 (PST) From: David Vrabel Subject: [PATCHv2 0/2] mm: infrastructure for correctly handling foreign pages on Xen Date: Mon, 12 Jan 2015 15:53:11 +0000 Message-ID: <1421077993-7909-1-git-send-email-david.vrabel@citrix.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , linux-kernel@vger.kernel.org Cc: David Vrabel , linux-mm@kvack.org 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 Changes in v2: - Add a find_page VMA op instead of the pages field so: a) the size of struct vm_area_struct does not increase; and b) the common code need not handling splitting the pages area. David [1] http://lists.xen.org/archives/html/xen-devel/2015-01/msg00979.html [2] Another guest's page temporarily granted to this guest. -- 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