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Commit ad2aa042 authored by Pierre Morel's avatar Pierre Morel Committed by Michael S. Tsirkin
Browse files

virtio/s390: handle failures of READ_VQ_CONF ccw 



In virtio_ccw_read_vq_conf() the return value of ccw_io_helper()
was not checked.
If the configuration could not be read properly, we'd wrongly assume a
queue size of 0.

Let's propagate any I/O error to virtio_ccw_setup_vq() so it may
properly fail.

Signed-off-by: default avatarPierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent fd2e8d43

drivers/s390/virtio/virtio_ccw.c

+9 −1
Original line number Diff line number Diff line
@@ -400,12 +400,16 @@ static bool virtio_ccw_kvm_notify(struct virtqueue *vq) 
static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,

				   struct ccw1 *ccw, int index)

{

	int ret;



	vcdev->config_block->index = index;

	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;

	ccw->flags = 0;

	ccw->count = sizeof(struct vq_config_block);

	ccw->cda = (__u32)(unsigned long)(vcdev->config_block);

	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);

	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);

	if (ret)

		return ret;

	return vcdev->config_block->num;

}
@@ -503,6 +507,10 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev, 
		goto out_err;

	}

	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);

	if (info->num < 0) {

		err = info->num;

		goto out_err;

	}

	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));

	info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);

	if (info->queue == NULL) {