diff options
Diffstat (limited to 'drivers/s390/kvm/virtio_ccw.c')
| -rw-r--r-- | drivers/s390/kvm/virtio_ccw.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c index bda52f18e967..397e6b8b9656 100644 --- a/drivers/s390/kvm/virtio_ccw.c +++ b/drivers/s390/kvm/virtio_ccw.c @@ -64,6 +64,7 @@ struct virtio_ccw_device { bool is_thinint; bool going_away; bool device_lost; + unsigned int config_ready; void *airq_info; }; @@ -758,8 +759,11 @@ static void virtio_ccw_get_config(struct virtio_device *vdev, if (ret) goto out_free; - memcpy(vcdev->config, config_area, sizeof(vcdev->config)); - memcpy(buf, &vcdev->config[offset], len); + memcpy(vcdev->config, config_area, offset + len); + if (buf) + memcpy(buf, &vcdev->config[offset], len); + if (vcdev->config_ready < offset + len) + vcdev->config_ready = offset + len; out_free: kfree(config_area); @@ -782,6 +786,9 @@ static void virtio_ccw_set_config(struct virtio_device *vdev, if (!config_area) goto out_free; + /* Make sure we don't overwrite fields. */ + if (vcdev->config_ready < offset) + virtio_ccw_get_config(vdev, 0, NULL, offset); memcpy(&vcdev->config[offset], buf, len); /* Write the config area to the host. */ memcpy(config_area, vcdev->config, sizeof(vcdev->config)); |