@@ -158,6 +158,34 @@ static void vfio_ap_matrix_dev_destroy(void)
root_device_unregister(root_device);
}
+static bool vfio_ap_resource_in_use(unsigned long *apm, unsigned long *aqm)
+{
+ bool in_use = false;
+ struct ap_matrix_mdev *matrix_mdev;
+ DECLARE_BITMAP(apm_intrsctn, AP_DEVICES);
+ DECLARE_BITMAP(aqm_intrsctn, AP_DOMAINS);
+
+ mutex_lock(&matrix_dev->lock);
+
+ list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
+ bitmap_and(apm_intrsctn, apm, matrix_mdev->matrix.apm,
+ AP_DEVICES);
+ if (find_first_bit_inv(apm_intrsctn, AP_DEVICES) == AP_DEVICES)
+ continue;
+
+ bitmap_and(aqm_intrsctn, aqm, matrix_mdev->matrix.aqm,
+ AP_DOMAINS);
+ if (find_first_bit_inv(aqm_intrsctn, AP_DEVICES) == AP_DOMAINS)
+ continue;
+
+ in_use = true;
+ }
+
+ mutex_unlock(&matrix_dev->lock);
+
+ return in_use;
+}
+
static int __init vfio_ap_init(void)
{
int ret;
@@ -173,7 +201,9 @@ 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_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) {
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 | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)