Hi,
On 10/06/2017 00:00, Alex Williamson wrote:
> Generally we don't know about vfio bus drivers until a device is
> added to the vfio-core with vfio_add_group_dev(), this optional
> registration with vfio_register_bus_driver() allows vfio-core to
> track known drivers. Our current use for this information is to
> know whether a driver is vfio compatible during a bind operation.
> For devices on buses with driver_override support, we can use this
> linkage to block non-vfio drivers from binding to devices where
> the iommu group state would trigger a BUG to avoid host/user
> integrity issues.
>
> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>
Thanks
Eric
> ---
> drivers/vfio/vfio.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/vfio.h | 3 +++
> 2 files changed, 58 insertions(+)
>
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index e6117de60f87..a25ee4930200 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -43,6 +43,8 @@
> struct class *class;
> struct list_head iommu_drivers_list;
> struct mutex iommu_drivers_lock;
> + struct list_head bus_drivers_list;
> + struct mutex bus_drivers_lock;
> struct list_head group_list;
> struct idr group_idr;
> struct mutex group_lock;
> @@ -51,6 +53,11 @@
> wait_queue_head_t release_q;
> } vfio;
>
> +struct vfio_bus_driver {
> + struct device_driver *drv;
> + struct list_head vfio_next;
> +};
> +
> struct vfio_iommu_driver {
> const struct vfio_iommu_driver_ops *ops;
> struct list_head vfio_next;
> @@ -2243,6 +2250,52 @@ int vfio_unregister_notifier(struct device *dev, enum vfio_notify_type type,
> }
> EXPORT_SYMBOL(vfio_unregister_notifier);
>
> +int vfio_register_bus_driver(struct device_driver *drv)
> +{
> + struct vfio_bus_driver *driver, *tmp;
> +
> + driver = kzalloc(sizeof(*driver), GFP_KERNEL);
> + if (!driver)
> + return -ENOMEM;
> +
> + driver->drv = drv;
> +
> + mutex_lock(&vfio.bus_drivers_lock);
> +
> + /* Check for duplicates */
> + list_for_each_entry(tmp, &vfio.bus_drivers_list, vfio_next) {
> + if (tmp->drv == drv) {
> + mutex_unlock(&vfio.bus_drivers_lock);
> + kfree(driver);
> + return -EINVAL;
> + }
> + }
> +
> + list_add(&driver->vfio_next, &vfio.bus_drivers_list);
> +
> + mutex_unlock(&vfio.bus_drivers_lock);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(vfio_register_bus_driver);
> +
> +void vfio_unregister_bus_driver(struct device_driver *drv)
> +{
> + struct vfio_bus_driver *driver;
> +
> + mutex_lock(&vfio.bus_drivers_lock);
> + list_for_each_entry(driver, &vfio.bus_drivers_list, vfio_next) {
> + if (driver->drv == drv) {
> + list_del(&driver->vfio_next);
> + mutex_unlock(&vfio.bus_drivers_lock);
> + kfree(driver);
> + return;
> + }
> + }
> + mutex_unlock(&vfio.bus_drivers_lock);
> +}
> +EXPORT_SYMBOL_GPL(vfio_unregister_bus_driver);
> +
> /**
> * Module/class support
> */
> @@ -2266,8 +2319,10 @@ static int __init vfio_init(void)
> idr_init(&vfio.group_idr);
> mutex_init(&vfio.group_lock);
> mutex_init(&vfio.iommu_drivers_lock);
> + mutex_init(&vfio.bus_drivers_lock);
> INIT_LIST_HEAD(&vfio.group_list);
> INIT_LIST_HEAD(&vfio.iommu_drivers_list);
> + INIT_LIST_HEAD(&vfio.bus_drivers_list);
> init_waitqueue_head(&vfio.release_q);
>
> ret = misc_register(&vfio_dev);
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index 9b34d0af5d27..dab0f8105e4a 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -92,6 +92,9 @@ struct vfio_iommu_driver_ops {
> extern void vfio_unregister_iommu_driver(
> const struct vfio_iommu_driver_ops *ops);
>
> +extern int vfio_register_bus_driver(struct device_driver *drv);
> +extern void vfio_unregister_bus_driver(struct device_driver *drv);
> +
> /*
> * External user API
> */
>
