Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752327AbbKVREq (ORCPT ); Sun, 22 Nov 2015 12:04:46 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56690 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752003AbbKVREp (ORCPT ); Sun, 22 Nov 2015 12:04:45 -0500 Subject: Re: [PATCH v3 0/3] virtio DMA API core stuff To: David Woodhouse , Joerg Roedel , "Michael S. Tsirkin" References: <1446039327.3405.216.camel@infradead.org> <20151028155105-mutt-send-email-mst@redhat.com> <1446041609.3405.228.camel@infradead.org> <20151028161424-mutt-send-email-mst@redhat.com> <1446042754.3405.237.camel@infradead.org> <20151028175136-mutt-send-email-mst@redhat.com> <20151029104301-mutt-send-email-mst@redhat.com> <1446135536.3405.279.camel@infradead.org> <20151108120627-mutt-send-email-mst@redhat.com> <20151108114946.GG2255@suse.de> <5651BDC0.2040206@gmail.com> <1448207661.89124.50.camel@infradead.org> Cc: linux-s390 , KVM , Benjamin Herrenschmidt , Sebastian Ott , "linux-kernel@vger.kernel.org" , Andy Lutomirski , Christian Borntraeger , Andy Lutomirski , Paolo Bonzini , Linux Virtualization , Christoph Hellwig , Martin Schwidefsky From: Marcel Apfelbaum Message-ID: <5651F5A0.5060400@redhat.com> Date: Sun, 22 Nov 2015 19:04:32 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <1448207661.89124.50.camel@infradead.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1308 Lines: 38 On 11/22/2015 05:54 PM, David Woodhouse wrote: > On Sun, 2015-11-22 at 15:06 +0200, Marcel Apfelbaum wrote: >> >> >> I tried to generate a DMAR table that excludes some devices from >> IOMMU translation, however it does not help. >> >> The reason is, as far as I understand, that Linux kernel does >> not allow any device being outside an IOMMU scope if the >> iommu kernel option is activated. >> >> Does anybody know if it is "by design" or is simply an uncommon >> configuration? >> (some devices in an IOMMU scope, while others outside *any* IOMMU >> scope) > > That's a kernel bug in the way it handles per-device DMA operations. Or > more to the point, in the way it doesn't — the non-translated devices > end up being pointed to the intel_dma_ops despite the fact they > shouldn't be. I'm working on that... > Hi David, Thank you for the fast response. Sadly I am not familiar with the DMA/IOMMU code to contribute with a sane idea, but I'll gladly test it. If you lack the time and have an idea to share, I can give it a try though. Thanks, Marcel -- 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/