s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem
authorPierre Morel <pmorel@linux.ibm.com>
Tue, 12 Feb 2019 15:53:45 +0000 (16:53 +0100)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Fri, 22 Feb 2019 08:20:01 +0000 (09:20 +0100)
Libudev relies on having a subsystem link for non-root devices. To
avoid libudev (and potentially other userspace tools) choking on the
matrix device let us introduce a matrix bus and with it the matrix
bus subsytem. Also make the matrix device reside within the matrix
bus.

Doing this we remove the forced link from the matrix device to the
vfio_ap driver and the device_type we do not need anymore.

Since the associated matrix driver is not the vfio_ap driver any more,
we have to change the search for the devices on the vfio_ap driver in
the function vfio_ap_verify_queue_reserved.
Fixes: 1fde573413b5 ("s390: vfio-ap: base implementation of VFIO AP device driver")
Cc: stable@vger.kernel.org
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
drivers/s390/crypto/vfio_ap_drv.c
drivers/s390/crypto/vfio_ap_ops.c
drivers/s390/crypto/vfio_ap_private.h

index 31c6c847eacaefae24fa97ece349d47d515a2bf8..e9824c35c34f789de7404e52dc0a48e04080fd9c 100644 (file)
@@ -15,7 +15,6 @@
 #include "vfio_ap_private.h"
 
 #define VFIO_AP_ROOT_NAME "vfio_ap"
-#define VFIO_AP_DEV_TYPE_NAME "ap_matrix"
 #define VFIO_AP_DEV_NAME "matrix"
 
 MODULE_AUTHOR("IBM Corporation");
@@ -24,10 +23,6 @@ MODULE_LICENSE("GPL v2");
 
 static struct ap_driver vfio_ap_drv;
 
-static struct device_type vfio_ap_dev_type = {
-       .name = VFIO_AP_DEV_TYPE_NAME,
-};
-
 struct ap_matrix_dev *matrix_dev;
 
 /* Only type 10 adapters (CEX4 and later) are supported
@@ -62,6 +57,22 @@ static void vfio_ap_matrix_dev_release(struct device *dev)
        kfree(matrix_dev);
 }
 
+static int matrix_bus_match(struct device *dev, struct device_driver *drv)
+{
+       return 1;
+}
+
+static struct bus_type matrix_bus = {
+       .name = "matrix",
+       .match = &matrix_bus_match,
+};
+
+static struct device_driver matrix_driver = {
+       .name = "vfio_ap",
+       .bus = &matrix_bus,
+       .suppress_bind_attrs = true,
+};
+
 static int vfio_ap_matrix_dev_create(void)
 {
        int ret;
@@ -71,6 +82,10 @@ static int vfio_ap_matrix_dev_create(void)
        if (IS_ERR(root_device))
                return PTR_ERR(root_device);
 
+       ret = bus_register(&matrix_bus);
+       if (ret)
+               goto bus_register_err;
+
        matrix_dev = kzalloc(sizeof(*matrix_dev), GFP_KERNEL);
        if (!matrix_dev) {
                ret = -ENOMEM;
@@ -87,30 +102,41 @@ static int vfio_ap_matrix_dev_create(void)
        mutex_init(&matrix_dev->lock);
        INIT_LIST_HEAD(&matrix_dev->mdev_list);
 
-       matrix_dev->device.type = &vfio_ap_dev_type;
        dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME);
        matrix_dev->device.parent = root_device;
+       matrix_dev->device.bus = &matrix_bus;
        matrix_dev->device.release = vfio_ap_matrix_dev_release;
-       matrix_dev->device.driver = &vfio_ap_drv.driver;
+       matrix_dev->vfio_ap_drv = &vfio_ap_drv;
 
        ret = device_register(&matrix_dev->device);
        if (ret)
                goto matrix_reg_err;
 
+       ret = driver_register(&matrix_driver);
+       if (ret)
+               goto matrix_drv_err;
+
        return 0;
 
+matrix_drv_err:
+       device_unregister(&matrix_dev->device);
 matrix_reg_err:
        put_device(&matrix_dev->device);
 matrix_alloc_err:
+       bus_unregister(&matrix_bus);
+bus_register_err:
        root_device_unregister(root_device);
-
        return ret;
 }
 
 static void vfio_ap_matrix_dev_destroy(void)
 {
+       struct device *root_device = matrix_dev->device.parent;
+
+       driver_unregister(&matrix_driver);
        device_unregister(&matrix_dev->device);
-       root_device_unregister(matrix_dev->device.parent);
+       bus_unregister(&matrix_bus);
+       root_device_unregister(root_device);
 }
 
 static int __init vfio_ap_init(void)
index 272ef427dcc036a511b961ed615356d44e2f3d06..900b9cf20ca5e9a74b2adc452820cca696ad9928 100644 (file)
@@ -198,8 +198,8 @@ static int vfio_ap_verify_queue_reserved(unsigned long *apid,
        qres.apqi = apqi;
        qres.reserved = false;
 
-       ret = driver_for_each_device(matrix_dev->device.driver, NULL, &qres,
-                                    vfio_ap_has_queue);
+       ret = driver_for_each_device(&matrix_dev->vfio_ap_drv->driver, NULL,
+                                    &qres, vfio_ap_has_queue);
        if (ret)
                return ret;
 
index 5675492233c735984b341c221f1e2eb24747c1ae..76b7f98e47e992c54a312ed1fc023ad7db402fe2 100644 (file)
@@ -40,6 +40,7 @@ struct ap_matrix_dev {
        struct ap_config_info info;
        struct list_head mdev_list;
        struct mutex lock;
+       struct ap_driver  *vfio_ap_drv;
 };
 
 extern struct ap_matrix_dev *matrix_dev;