From: Joerg Roedel <joro@8bytes.org>
To: Christoph Hellwig <hch@lst.de>
Cc: "Michael S . Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Jens Axboe <axboe@kernel.dk>,
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
Subject: Re: [PATCH 5/5] virtio-blk: Consider virtio_max_dma_size() for maximum segment size
Date: Thu, 24 Jan 2019 09:40:11 +0100 [thread overview]
Message-ID: <20190124084011.GJ32526@8bytes.org> (raw)
In-Reply-To: <20190123213139.GD9032@lst.de>
On Wed, Jan 23, 2019 at 10:31:39PM +0100, Christoph Hellwig wrote:
> On Wed, Jan 23, 2019 at 05:30:49PM +0100, Joerg Roedel wrote:
> > + max_size = virtio_max_dma_size(vdev);
> > +
> > /* Host can optionally specify maximum segment size and number of
> > * segments. */
> > err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
> > struct virtio_blk_config, size_max, &v);
> > if (!err)
> > - blk_queue_max_segment_size(q, v);
> > - else
> > - blk_queue_max_segment_size(q, -1U);
> > + max_size = min(max_size, v);
> > +
> > + blk_queue_max_segment_size(q, max_size);
>
> I wonder if we should just move the dma max segment size check
> into blk_queue_max_segment_size so that all block drivers benefit
> from it. Even if not I think at least the SCSI midlayer should
> be updated to support it.
In that case the limit would also apply to virtio-blk even if it doesn't
use the DMA-API. If that is acceptable we can move the check to
blk_queue_max_segment_size().
Regards,
Joerg
next prev parent reply other threads:[~2019-01-24 8:40 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-23 16:30 [PATCH 0/5 v3] Fix virtio-blk issue with SWIOTLB Joerg Roedel
2019-01-23 16:30 ` [PATCH 1/5] swiotlb: Introduce swiotlb_max_mapping_size() Joerg Roedel
2019-01-23 21:28 ` Christoph Hellwig
2019-01-24 8:24 ` Joerg Roedel
2019-01-24 8:47 ` Christoph Hellwig
2019-01-23 16:30 ` [PATCH 2/5] swiotlb: Add is_swiotlb_active() function Joerg Roedel
2019-01-23 21:27 ` Christoph Hellwig
2019-01-24 8:29 ` Joerg Roedel
2019-01-24 8:41 ` Christoph Hellwig
2019-01-24 15:00 ` Joerg Roedel
2019-01-28 17:19 ` Michael S. Tsirkin
2019-01-23 16:30 ` [PATCH 3/5] dma: Introduce dma_max_mapping_size() Joerg Roedel
2019-01-23 21:29 ` Christoph Hellwig
2019-01-23 16:30 ` [PATCH 4/5] virtio: Introduce virtio_max_dma_size() Joerg Roedel
2019-01-23 16:30 ` [PATCH 5/5] virtio-blk: Consider virtio_max_dma_size() for maximum segment size Joerg Roedel
2019-01-23 21:31 ` Christoph Hellwig
2019-01-23 22:25 ` Michael S. Tsirkin
2019-01-24 8:40 ` Joerg Roedel [this message]
2019-01-24 8:42 ` Christoph Hellwig
2019-01-24 9:51 ` Joerg Roedel
2019-01-28 8:05 ` Christoph Hellwig
2019-01-28 17:14 ` Michael S. Tsirkin
2019-01-29 7:38 ` Christoph Hellwig
2019-01-23 17:09 ` [PATCH 0/5 v3] Fix virtio-blk issue with SWIOTLB Konrad Rzeszutek Wilk
2019-01-23 18:51 ` Michael S. Tsirkin
2019-01-23 21:14 ` Konrad Rzeszutek Wilk
2019-01-28 15:20 ` Michael S. Tsirkin
2019-01-28 15:53 ` Konrad Rzeszutek Wilk
2019-01-29 8:43 [PATCH 0/5 v4] " Joerg Roedel
2019-01-29 8:43 ` [PATCH 5/5] virtio-blk: Consider virtio_max_dma_size() for maximum segment size Joerg Roedel
2019-01-29 17:13 ` Christoph Hellwig
2019-01-30 16:40 [PATCH 0/5 v5] Fix virtio-blk issue with SWIOTLB Joerg Roedel
2019-01-30 16:40 ` [PATCH 5/5] virtio-blk: Consider virtio_max_dma_size() for maximum segment size Joerg Roedel
2019-01-31 16:33 [PATCH 0/5 v6] Fix virtio-blk issue with SWIOTLB Joerg Roedel
2019-01-31 16:34 ` [PATCH 5/5] virtio-blk: Consider virtio_max_dma_size() for maximum segment size Joerg Roedel
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