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virtio/s390: handle failures of READ_VQ_CONF ccw

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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: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Pierre Morel 2015-09-10 16:35:08 +02:00 committed by Michael S. Tsirkin
parent fd2e8d4300
commit ad2aa04218
1 changed files with 9 additions and 1 deletions
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10
drivers/s390/virtio/virtio_ccw.c
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@ -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) {