@@ -173,7 +173,9 @@ static int __init vfio_ap_init(void)
memset(&vfio_ap_drv, 0, sizeof(vfio_ap_drv));
vfio_ap_drv.probe = vfio_ap_queue_dev_probe;
vfio_ap_drv.remove = vfio_ap_queue_dev_remove;
+ vfio_ap_drv.in_use = vfio_ap_mdev_resource_in_use;
vfio_ap_drv.ids = ap_queue_ids;
+ vfio_ap_drv.driver.suppress_bind_attrs = true;
ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
if (ret) {
@@ -1431,3 +1431,14 @@ void vfio_ap_mdev_remove_queue(struct ap_queue *queue)
vfio_ap_irq_disable(q);
kfree(q);
}
+
+bool vfio_ap_mdev_resource_in_use(unsigned long *apm, unsigned long *aqm)
+{
+ bool in_use;
+
+ mutex_lock(&matrix_dev->lock);
+ in_use = vfio_ap_mdev_verify_no_sharing(NULL, apm, aqm) ? true : false;
+ mutex_unlock(&matrix_dev->lock);
+
+ return in_use;
+}
@@ -104,4 +104,6 @@ struct vfio_ap_queue {
int vfio_ap_mdev_probe_queue(struct ap_queue *queue);
void vfio_ap_mdev_remove_queue(struct ap_queue *queue);
+bool vfio_ap_mdev_resource_in_use(unsigned long *apm, unsigned long *aqm);
+
#endif /* _VFIO_AP_PRIVATE_H_ */
Let's implement the callback to indicate when an APQN is in use by the vfio_ap device driver. The callback is invoked whenever a change to the apmask or aqmask may result in one or APQNs being removed from the driver. The vfio_ap device driver will indicate a resource is in use if any of the removed APQNs are assigned to any of the matrix mdev devices. To ensure that the AP bus apmask/aqmask interfaces are used to control which AP queues get manually bound to or unbound from the vfio_ap device driver, the bind/unbind sysfs interfaces will be disabled for the vfio_ap device driver. The reasons for this are: * To prevent unbinding an AP queue device from the vfio_ap device driver representing a queue that is assigned to an mdev device. * To enforce the policy that the the AP resources must first be unassigned from the mdev device - which will hot unplug them from a guest using the mdev device - before changing ownership of APQNs from the vfio_ap driver to a zcrypt driver. This ensures that private crypto data intended for the guest will never be accessible from the host. * It takes advantage of the AP architecture to prevent dynamic changes to the LPAR configuration using the SE or SCLP commands from compromising the guest crypto devices. For example: * Even if an adapter is configured off, if and when it is configured back on, the queue devices associated with the adapter will be bound back to the vfio_ap driver and the queues will automatically be available to a guest using the mdev to which the APQN of the queue device is assigned. * If adapters or domains are dynamically unassigned from the LPAR in which the linux guest is running, effective masking will prevent access to the AP resources by a guest using them. Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> --- drivers/s390/crypto/vfio_ap_drv.c | 2 ++ drivers/s390/crypto/vfio_ap_ops.c | 11 +++++++++++ drivers/s390/crypto/vfio_ap_private.h | 2 ++ 3 files changed, 15 insertions(+)