Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933076AbbESN6G (ORCPT ); Tue, 19 May 2015 09:58:06 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:26932 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932317AbbESN6E (ORCPT ); Tue, 19 May 2015 09:58:04 -0400 X-IronPort-AV: E=Sophos;i="5.13,458,1427760000"; d="scan'208";a="266492125" Message-ID: <555B4167.7050506@citrix.com> Date: Tue, 19 May 2015 14:57:59 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.4.0 MIME-Version: 1.0 To: Julien Grall , CC: , , , , , David Vrabel , Boris Ostrovsky , Subject: Re: [Xen-devel] [RFC 12/23] xen: Extend page_to_mfn to take an offset in the page References: <1431622863-28575-1-git-send-email-julien.grall@citrix.com> <1431622863-28575-13-git-send-email-julien.grall@citrix.com> In-Reply-To: <1431622863-28575-13-git-send-email-julien.grall@citrix.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 744 Lines: 20 On 14/05/15 18:00, Julien Grall wrote: > With 64KB page granularity support in Linux, a page will be split accross > multiple MFN (Xen is using 4KB page granularity). Thoses MFNs may not be > contiguous. > > With the offset in the page, the helper will be able to know which MFN > the driver needs to retrieve. I think a gnttab_grant_foreign_access_ref()-like helper that takes a page would be better. You will probably want this helper able to return/fill a set of refs for 64 KiB pages. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/