vdpa: Sync calls set/get config/status with cf_mutex

Add wrappers to get/set status and protect these operations with
cf_mutex to serialize these operations with respect to get/set config
operations.
Signed-off-by: NEli Cohen <elic@nvidia.com>
Link: https://lore.kernel.org/r/20220105114646.577224-4-elic@nvidia.comSigned-off-by: NMichael S. Tsirkin <mst@redhat.com>

drivers/vdpa/vdpa.c

@@ -21,6 +21,25 @@ static LIST_HEAD(mdev_head);
 static DEFINE_MUTEX(vdpa_dev_mutex);
 static DEFINE_IDA(vdpa_index_ida);
 
+u8 vdpa_get_status(struct vdpa_device *vdev)
+{
+	u8 status;
+
+	mutex_lock(&vdev->cf_mutex);
+	status = vdev->config->get_status(vdev);
+	mutex_unlock(&vdev->cf_mutex);
+	return status;
+}
+EXPORT_SYMBOL(vdpa_get_status);
+
+void vdpa_set_status(struct vdpa_device *vdev, u8 status)
+{
+	mutex_lock(&vdev->cf_mutex);
+	vdev->config->set_status(vdev, status);
+	mutex_unlock(&vdev->cf_mutex);
+}
+EXPORT_SYMBOL(vdpa_set_status);
+
 static struct genl_family vdpa_nl_family;
 
 static int vdpa_dev_probe(struct device *d)

drivers/vhost/vdpa.c

@@ -142,10 +142,9 @@ static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp)
 static long vhost_vdpa_get_status(struct vhost_vdpa *v, u8 __user *statusp)
 {
 	struct vdpa_device *vdpa = v->vdpa;
-	const struct vdpa_config_ops *ops = vdpa->config;
 	u8 status;
 
-	status = ops->get_status(vdpa);
+	status = vdpa_get_status(vdpa);
 
 	if (copy_to_user(statusp, &status, sizeof(status)))
 		return -EFAULT;
@@ -164,7 +163,7 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 	if (copy_from_user(&status, statusp, sizeof(status)))
 		return -EFAULT;
 
-	status_old = ops->get_status(vdpa);
+	status_old = vdpa_get_status(vdpa);
 
 	/*
 	 * Userspace shouldn't remove status bits unless reset the
@@ -182,7 +181,7 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 		if (ret)
 			return ret;
 	} else
-		ops->set_status(vdpa, status);
+		vdpa_set_status(vdpa, status);
 
 	if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK))
 		for (i = 0; i < nvqs; i++)

drivers/virtio/virtio_vdpa.c

@@ -91,9 +91,8 @@ static u8 virtio_vdpa_get_status(struct virtio_device *vdev)
 static void virtio_vdpa_set_status(struct virtio_device *vdev, u8 status)
 {
 	struct vdpa_device *vdpa = vd_get_vdpa(vdev);
-	const struct vdpa_config_ops *ops = vdpa->config;
 
-	return ops->set_status(vdpa, status);
+	return vdpa_set_status(vdpa, status);
 }
 
 static void virtio_vdpa_reset(struct virtio_device *vdev)

include/linux/vdpa.h

@@ -408,6 +408,9 @@ void vdpa_get_config(struct vdpa_device *vdev, unsigned int offset,
 		     void *buf, unsigned int len);
 void vdpa_set_config(struct vdpa_device *dev, unsigned int offset,
 		     const void *buf, unsigned int length);
+u8 vdpa_get_status(struct vdpa_device *vdev);
+void vdpa_set_status(struct vdpa_device *vdev, u8 status);
+
 /**
  * struct vdpa_mgmtdev_ops - vdpa device ops
  * @dev_add: Add a vdpa device using alloc and register