Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753565AbaJTVhm (ORCPT ); Mon, 20 Oct 2014 17:37:42 -0400 Received: from mail-la0-f44.google.com ([209.85.215.44]:45840 "EHLO mail-la0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751704AbaJTVhj (ORCPT ); Mon, 20 Oct 2014 17:37:39 -0400 MIME-Version: 1.0 In-Reply-To: <1413205748-6300-3-git-send-email-a.motakis@virtualopensystems.com> References: <1413205748-6300-1-git-send-email-a.motakis@virtualopensystems.com> <1413205748-6300-3-git-send-email-a.motakis@virtualopensystems.com> From: Andy Lutomirski Date: Mon, 20 Oct 2014 14:37:17 -0700 Message-ID: Subject: Re: [PATCH 2/5] vfio: introduce the VFIO_DMA_MAP_FLAG_NOEXEC flag To: Antonios Motakis Cc: kvmarm@lists.cs.columbia.edu, iommu@lists.linux-foundation.org, Alex Williamson , Will Deacon , tech@virtualopensystems.com, christoffer.dall@linaro.org, eric.auger@linaro.org, kim.phillips@freescale.com, marc.zyngier@arm.com, "open list:VFIO DRIVER" , "open list:ABI/API" , open list Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 13, 2014 at 6:09 AM, Antonios Motakis wrote: > We introduce the VFIO_DMA_MAP_FLAG_NOEXEC flag to the VFIO dma map call, > and expose its availability via the capability VFIO_DMA_NOEXEC_IOMMU. > This way the user can control whether the XN flag will be set on the > requested mappings. The IOMMU_NOEXEC flag needs to be available for all > the IOMMUs of the container used. Since you sent this to the linux-api list, I'll bite: what's the XN flag? I know what PROT_EXEC does when you mmap something, and I presume that vfio is mmappable, but I don't actually have any clue what this patch does. I assume that this does not have anything to do with a non-CPU DMA master executing code in main memory, because that makes rather little sense. (Or maybe it really does, in which case: weird.) --Andy -- 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/