From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A6737C7618B for ; Thu, 25 Jul 2019 13:04:22 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7A2C421951 for ; Thu, 25 Jul 2019 13:04:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A2C421951 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 2B411DC3; Thu, 25 Jul 2019 13:04:22 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 2722F9EE; Thu, 25 Jul 2019 13:04:21 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id AEBD77F8; Thu, 25 Jul 2019 13:04:20 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 557F068B02; Thu, 25 Jul 2019 15:04:16 +0200 (CEST) Date: Thu, 25 Jul 2019 15:04:16 +0200 From: Christoph Hellwig To: Auger Eric Subject: Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call Message-ID: <20190725130416.GA4992@lst.de> References: <20190722145509.1284-1-eric.auger@redhat.com> <20190722145509.1284-3-eric.auger@redhat.com> <20190723153851.GE720@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Cc: mst@redhat.com, jasowang@redhat.com, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, iommu@lists.linux-foundation.org, eric.auger.pro@gmail.com, Robin Murphy , Christoph Hellwig X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Thu, Jul 25, 2019 at 01:53:49PM +0200, Auger Eric wrote: > I am confused: if vring_use_dma_api() returns false if the dma_mask is > unset (ie. vring_use_dma_api() returns false), the virtio-blk-pci device > will not be able to get translated addresses and won't work properly. > > The patch above allows the dma api to be used and only influences the > max_segment_size and it works properly. > > So is it normal the dma_mask is unset in my case? Its not normal. I assume you use virtio-nmio? Due to the mess with the dma_mask being a pointer a lot of subsystems forgot to set a dma mask up, and oddly enough seem to mostly get away with it. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu