Re: [PATCH v5 04/13] s390: vfio-ap: base implementation of VFIO AP device driver

[Pierre Morel]

On 07/05/2018 17:11, Tony Krowiak wrote:
> Introduces a new AP device driver. This device driver
> is built on the VFIO mediated device framework. The framework
> provides sysfs interfaces that facilitate passthrough
> access by guests to devices installed on the linux host.
...snip...
> +static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
> +{

You should take care of the ap devices when they are added or removed
from the matrix.
I suggest you add a remove callback to avoid unbinding a queue while
it is assigned to a guest.

> +	return 0;
> +}
> +
> +static void vfio_ap_matrix_dev_release(struct device *dev)
> +{
> +	struct ap_matrix *ap_matrix = dev_get_drvdata(dev);
> +
> +	kfree(ap_matrix);
> +}
...snip...

--
Pierre Morel
Linux/KVM/QEMU in BÃblingen - Germany