virtio-blk: Consider virtio_max_dma_size() for maximum segment size (fd1068e1) · Commits · 戴 / test

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. Cc: stable@vger.kernel.org Reviewed-by:

Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by:

Christoph Hellwig <hch@lst.de> Signed-off-by:

Joerg Roedel <jroedel@suse.de> Signed-off-by:

Michael S. Tsirkin <mst@redhat.com>

drivers/block/virtio_blk.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -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, max_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);

		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,

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