From: Joerg Roedel Date: Thu, 7 Feb 2019 12:59:17 +0100 Subject: virtio-blk: Consider virtio_max_dma_size() for maximum segment size Git-commit: fd1068e1860e44aaaa337b516df4518d1ce98da1 Patch-mainline: v5.1-rc1 References: bsc#1120008 Segments can't be larger than the maximum DMA mapping size supported on the platform. Take that into account when setting the maximum segment size for a block device. Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Christoph Hellwig Signed-off-by: Joerg Roedel Signed-off-by: Michael S. Tsirkin --- drivers/block/virtio_blk.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -621,7 +621,7 @@ static int virtblk_probe(struct virtio_d struct request_queue *q; int err, index; - u32 v, blk_size, sg_elems, opt_io_size; + u32 v, blk_size, max_size, sg_elems, opt_io_size; u16 min_io_size; u8 physical_block_exp, alignment_offset; @@ -735,14 +735,16 @@ static int virtblk_probe(struct virtio_d /* No real sector limit. */ blk_queue_max_hw_sectors(q, -1U); + 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); /* Host can optionally specify the block size of the device */ err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,