net: Introduce generic failover module
The failover module provides a generic interface for paravirtual drivers
to register a netdev and a set of ops with a failover instance. The ops
are used as event handlers that get called to handle netdev register/
unregister/link change/name change events on slave pci ethernet devices
with the same mac address as the failover netdev.
This enables paravirtual drivers to use a VF as an accelerated low latency
datapath. It also allows migration of VMs with direct attached VFs by
failing over to the paravirtual datapath when the VF is unplugged.
Signed-off-by: Sridhar Samudrala <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
diff --git a/include/net/failover.h b/include/net/failover.h
new file mode 100644
index 0000000..bb15438
--- /dev/null
+++ b/include/net/failover.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018, Intel Corporation. */
+
+#ifndef _FAILOVER_H
+#define _FAILOVER_H
+
+#include <linux/netdevice.h>
+
+struct failover_ops {
+ int (*slave_pre_register)(struct net_device *slave_dev,
+ struct net_device *failover_dev);
+ int (*slave_register)(struct net_device *slave_dev,
+ struct net_device *failover_dev);
+ int (*slave_pre_unregister)(struct net_device *slave_dev,
+ struct net_device *failover_dev);
+ int (*slave_unregister)(struct net_device *slave_dev,
+ struct net_device *failover_dev);
+ int (*slave_link_change)(struct net_device *slave_dev,
+ struct net_device *failover_dev);
+ int (*slave_name_change)(struct net_device *slave_dev,
+ struct net_device *failover_dev);
+ rx_handler_result_t (*slave_handle_frame)(struct sk_buff **pskb);
+};
+
+struct failover {
+ struct list_head list;
+ struct net_device __rcu *failover_dev;
+ struct failover_ops __rcu *ops;
+};
+
+struct failover *failover_register(struct net_device *dev,
+ struct failover_ops *ops);
+void failover_unregister(struct failover *failover);
+int failover_slave_unregister(struct net_device *slave_dev);
+
+#endif /* _FAILOVER_H */
