[RFC PATCH 2/2] block: virtio-blk: support multi virt queues per virtio-blk device

Rusty Russell
2014-06-16T12:47:05Z

Ming Lei <ming.lei at canonical.com> writes:
> +	if (virtio_has_feature(vdev, VIRTIO_BLK_F_MQ))
> +		err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
> +				   struct virtio_blk_config, num_queues,
> +				   &num_vqs);
> +	else
> +		num_vqs = 1;

This is redundant: virtio_cread_feature() checks the feature.

So, either:
        if (virtio_has_feature(vdev, VIRTIO_BLK_F_MQ))
                virtio_cread(vdev, struct virtio_blk_config, num_queues,
          		     &num_vqs);
        else
                num_vqs = 1;

Or:
	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
			   struct virtio_blk_config, num_queues,
			   &num_vqs);
        if (err)
                num_vqs = 1;

Otherwise, the patch looks pretty straight-forward.

Cheers,
Rusty.