From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751929AbbKHLty (ORCPT ); Sun, 8 Nov 2015 06:49:54 -0500 Received: from mx2.suse.de ([195.135.220.15]:51368 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751765AbbKHLtv (ORCPT ); Sun, 8 Nov 2015 06:49:51 -0500 Date: Sun, 8 Nov 2015 12:49:46 +0100 From: Joerg Roedel To: "Michael S. Tsirkin" Cc: David Woodhouse , Andy Lutomirski , Christian Borntraeger , Andy Lutomirski , "linux-kernel@vger.kernel.org" , Cornelia Huck , Sebastian Ott , Paolo Bonzini , Christoph Hellwig , Benjamin Herrenschmidt , KVM , Martin Schwidefsky , linux-s390 , Linux Virtualization Subject: Re: [PATCH v3 0/3] virtio DMA API core stuff Message-ID: <20151108114946.GG2255@suse.de> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151108120627-mutt-send-email-mst@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Nov 08, 2015 at 12:37:47PM +0200, Michael S. Tsirkin wrote: > I have no problem with that. For example, can we teach > the DMA API on intel x86 to use PT for virtio by default? > That would allow merging Andy's patches with > full compatibility with old guests and hosts. Well, the only incompatibility comes from an experimental qemu feature, more explicitly from a bug in that features implementation. So why should we work around that in the kernel? I think it is not too hard to fix qemu to generate a correct DMAR table which excludes the virtio devices from iommu translation. Joerg From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH v3 0/3] virtio DMA API core stuff Date: Sun, 8 Nov 2015 12:49:46 +0100 Message-ID: <20151108114946.GG2255@suse.de> 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> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20151108120627-mutt-send-email-mst@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Archive: List-Post: To: "Michael S. Tsirkin" Cc: linux-s390 , KVM , Benjamin Herrenschmidt , Sebastian Ott , "linux-kernel@vger.kernel.org" , Andy Lutomirski , Christian Borntraeger , Andy Lutomirski , Paolo Bonzini , Linux Virtualization , David Woodhouse , Christoph Hellwig , Martin Schwidefsky List-ID: On Sun, Nov 08, 2015 at 12:37:47PM +0200, Michael S. Tsirkin wrote: > I have no problem with that. For example, can we teach > the DMA API on intel x86 to use PT for virtio by default? > That would allow merging Andy's patches with > full compatibility with old guests and hosts. Well, the only incompatibility comes from an experimental qemu feature, more explicitly from a bug in that features implementation. So why should we work around that in the kernel? I think it is not too hard to fix qemu to generate a correct DMAR table which excludes the virtio devices from iommu translation. Joerg