Re: [PATCH v3 8/8] virtio/s390: make airq summary indicators DMA

[Cornelia Huck <cohuck@redhat.com>]

On Wed, 29 May 2019 14:26:57 +0200
Michael Mueller <mimu@linux.ibm.com> wrote:

> From: Halil Pasic <pasic@linux.ibm.com>
> 
> Hypervisor needs to interact with the summary indicators, so these
> need to be DMA memory as well (at least for protected virtualization
> guests).
> 
> Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
> Signed-off-by: Michael Mueller <mimu@linux.ibm.com>
> ---
>  drivers/s390/virtio/virtio_ccw.c | 26 +++++++++++++++++++-------
>  1 file changed, 19 insertions(+), 7 deletions(-)

(...)

> @@ -1501,6 +1508,11 @@ static int __init virtio_ccw_init(void)
>  {
>  	/* parse no_auto string before we do anything further */
>  	no_auto_parse();
> +
> +	summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS);
> +	if (!summary_indicators)
> +		return -ENOMEM;
> +
>  	return ccw_driver_register(&virtio_ccw_driver);

Don't you need to free summary_indicators again if registering the
driver fails?

>  }
>  device_initcall(virtio_ccw_init);