From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 5/5] virtio-blk: Consider virtio_max_dma_size() for maximum segment size Date: Mon, 28 Jan 2019 09:05:26 +0100 Message-ID: <20190128080526.GA3874@lst.de> References: <20190123163049.24863-1-joro@8bytes.org> <20190123163049.24863-6-joro@8bytes.org> <20190123213139.GD9032@lst.de> <20190124084011.GJ32526@8bytes.org> <20190124084221.GB19441@lst.de> <20190124095150.GL32526@8bytes.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190124095150.GL32526@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org To: Joerg Roedel Cc: Christoph Hellwig , "Michael S . Tsirkin" , Jason Wang , Konrad Rzeszutek Wilk , 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 Thu, Jan 24, 2019 at 10:51:51AM +0100, Joerg Roedel wrote: > On Thu, Jan 24, 2019 at 09:42:21AM +0100, Christoph Hellwig wrote: > > Yes. But more importantly it would fix the limit for all other block > > drivers that set large segment sizes when running over swiotlb. > > True, so it would be something like the diff below? I havn't worked on > the block layer, so I don't know if that needs additional checks for > ->dev or anything. Looks sensible. Maybe for now we'll just do the virtio-blk case that triggered it, and we'll do something like this patch for the next merge window. We'll also need to apply the same magic to the DMA boundary.