From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: [PATCH 3/3] virtio-blk: Consider virtio_max_dma_size() for maximum segment size Date: Thu, 10 Jan 2019 14:44:33 +0100 Message-ID: <20190110134433.15672-4-joro@8bytes.org> References: <20190110134433.15672-1-joro@8bytes.org> Return-path: In-Reply-To: <20190110134433.15672-1-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org To: "Michael S . Tsirkin" , Jason Wang , Konrad Rzeszutek Wilk Cc: 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, hch@lst.de, Joerg Roedel List-Id: iommu@lists.linux-foundation.org From: Joerg Roedel Segments can't be larger than the maximum DMA allocation size supported by virtio on the platform. Take that into account when setting the maximum segment size for a block device. Signed-off-by: Joerg Roedel --- drivers/block/virtio_blk.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index b16a887bbd02..6062faa8d213 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -723,7 +723,7 @@ static int virtblk_probe(struct virtio_device *vdev) struct request_queue *q; int err, index; - u32 v, blk_size, sg_elems, opt_io_size; + u32 v, blk_size, seg_size, sg_elems, opt_io_size; u16 min_io_size; u8 physical_block_exp, alignment_offset; @@ -826,14 +826,16 @@ static int virtblk_probe(struct virtio_device *vdev) /* No real sector limit. */ blk_queue_max_hw_sectors(q, -1U); + seg_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); + seg_size = min(v, seg_size); + + blk_queue_max_segment_size(q, seg_size); /* Host can optionally specify the block size of the device */ err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, -- 2.17.1