From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753354Ab1IWLQR (ORCPT ); Fri, 23 Sep 2011 07:16:17 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:28483 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752118Ab1IWLQQ (ORCPT ); Fri, 23 Sep 2011 07:16:16 -0400 X-IronPort-AV: E=Sophos;i="4.68,429,1312171200"; d="scan'208";a="164425892" Message-ID: <4E7C6B18.7030100@citrix.com> Date: Fri, 23 Sep 2011 12:18:48 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.16) Gecko/20110818 Icedove/3.0.11 MIME-Version: 1.0 To: Jeremy Fitzhardinge CC: Stefano Stabellini , "linux-kernel@vger.kernel.org" , Andrew Morton , "xen-devel@lists.xensource.com" , Konrad Rzeszutek Wilk Subject: Re: [Xen-devel] Re: [PATCH 0/6] xen: don't call vmalloc_sync_all() when mapping foreign pages References: <1316090411-22608-1-git-send-email-david.vrabel@citrix.com> <4E727017.4030001@goop.org> <4E7A3394.3090806@goop.org> <4E7BA677.9090907@goop.org> In-Reply-To: <4E7BA677.9090907@goop.org> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/09/11 22:19, Jeremy Fitzhardinge wrote: > > But I'd be happier pretending that vmalloc_sync_* just doesn't exist, > and deal with it at the hypercall level - in the short term, by just > making sure that the callers touch all those pages before passing them > into the hypercall. I don't think you can access the pages at the addresses allocated with alloc_vm_area() because the pages don't exist yet and there's a check of pte_present() in vmalloc_fault() and I think an Oops will be reported. David