From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 4/5] virtio: Introduce virtio_max_dma_size() Date: Tue, 29 Jan 2019 18:13:34 +0100 Message-ID: <20190129171334.GD15195@lst.de> References: <20190129084342.26030-1-joro@8bytes.org> <20190129084342.26030-5-joro@8bytes.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190129084342.26030-5-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org To: Joerg Roedel Cc: "Michael S . Tsirkin" , Jason Wang , Konrad Rzeszutek Wilk , Christoph Hellwig , Jens Axboe , virtualization@lists.linux-foundation.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, jfehlig@suse.com, jon.grimm@amd.com, brijesh.singh@amd.com, jroedel@suse.de List-Id: iommu@lists.linux-foundation.org On Tue, Jan 29, 2019 at 09:43:41AM +0100, Joerg Roedel wrote: > From: Joerg Roedel > > This function returns the maximum segment size for a single > dma transaction of a virtio device. The possible limit comes > from the SWIOTLB implementation in the Linux kernel, that > has an upper limit of (currently) 256kb of contiguous > memory it can map. Other DMA-API implementations might also > have limits. > > Use the new dma_max_mapping_size() function to determine the > maximum mapping size when DMA-API is in use for virtio. > > Reviewed-by: Konrad Rzeszutek Wilk > Signed-off-by: Joerg Roedel Looks good, Reviewed-by: Christoph Hellwig