From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755151AbbJ1CZi (ORCPT ); Tue, 27 Oct 2015 22:25:38 -0400 Received: from mx2.suse.de ([195.135.220.15]:52300 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754754AbbJ1CZg (ORCPT ); Tue, 27 Oct 2015 22:25:36 -0400 Date: Wed, 28 Oct 2015 11:25:24 +0900 From: Joerg Roedel To: Andy Lutomirski Cc: linux-kernel@vger.kernel.org, Christian Borntraeger , Cornelia Huck , Sebastian Ott , Paolo Bonzini , Christoph Hellwig , benh@kernel.crashing.org, KVM , dwmw2@infradead.org, Martin Schwidefsky , linux-s390 , Andy Lutomirski Subject: Re: [PATCH 3/3] virtio_pci: Use the DMA API Message-ID: <20151028022524.GE18467@suse.de> References: <20151028021530.GC18467@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151028021530.GC18467@suse.de> 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 Wed, Oct 28, 2015 at 11:15:30AM +0900, Joerg Roedel wrote: > Same here, you need to call the dma_sync* functions when passing data > from/to the virtio-device. Okay, forget about this comment. This patch only converts to dma_coherent allocations, which don't need synchronization. > I think a good test for that is to boot a virtio kvm-guest with > swiotlb=force and see if it still works. But this holds, Its a good way to test if your changes work with bounce-buffering. Together with DMA_API_DEBUG you also see if your specified dma_directions are right. Joerg