virtio: unify config_changed handling

Replace duplicated code in all transports with a single wrapper in
virtio.c.

The only functional change is in virtio_mmio.c: if a buggy device sends
us an interrupt before driver is set, we previously returned IRQ_NONE,
now we return IRQ_HANDLED.

As this must not happen in practice, this does not look like a big deal.

See also commit 3fff0179e33cd7d0a688dab65700c46ad089e934
	virtio-pci: do not oops on config change if driver not loaded.
for the original motivation behind the driver check.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

2 files changed, 2 insertions, 13 deletions

diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c
index a1349653c6d9..643129070c51 100644
--- a/drivers/s390/kvm/kvm_virtio.c
+++ b/drivers/s390/kvm/kvm_virtio.c
@@ -406,15 +406,8 @@ static void kvm_extint_handler(struct ext_code ext_code,
 
         switch (param) {
         case VIRTIO_PARAM_CONFIG_CHANGED:
-        {
-                struct virtio_driver *drv;
-                drv = container_of(vq->vdev->dev.driver,
-                                   struct virtio_driver, driver);
-                if (drv->config_changed)
-                        drv->config_changed(vq->vdev);
-
+                virtio_config_changed(vq->vdev);
                 break;
-        }
         case VIRTIO_PARAM_DEV_ADD:
                 schedule_work(&hotplug_work);
                 break;
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index d2c0b442bce5..6cbe6ef3c889 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -940,11 +940,7 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev,
                 vring_interrupt(0, vq);
         }
         if (test_bit(0, &vcdev->indicators2)) {
-                drv = container_of(vcdev->vdev.dev.driver,
-                                   struct virtio_driver, driver);
-
-                if (drv && drv->config_changed)
-                        drv->config_changed(&vcdev->vdev);
+                virtio_config_changed(&vcdev->vdev);
                 clear_bit(0, &vcdev->indicators2);
         }
 }