vhost: introduce API to start a specific driver

[dpdk.git] / lib / librte_vhost / rte_virtio_net.h

diff --git a/lib/librte_vhost/rte_virtio_net.h b/lib/librte_vhost/rte_virtio_net.h
index 78828cd..fd9cbb0 100644 (file)
--- a/lib/librte_vhost/rte_virtio_net.h
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -93,7 +93,15 @@ struct vhost_device_ops {
 
        int (*vring_state_changed)(int vid, uint16_t queue_id, int enable);     /**< triggered when a vring is enabled or disabled */
 
-       void *reserved[5]; /**< Reserved for future extension */
+       /**
+        * Features could be changed after the feature negotiation.
+        * For example, VHOST_F_LOG_ALL will be set/cleared at the
+        * start/end of live migration, respectively. This callback
+        * is used to inform the application on such change.
+        */
+       int (*features_changed)(int vid, uint64_t features);
+
+       void *reserved[4]; /**< Reserved for future extension */
 };
 
 /**
@@ -124,6 +132,49 @@ rte_vhost_gpa_to_vva(struct rte_vhost_memory *mem, uint64_t gpa)
        return 0;
 }
 
+#define RTE_VHOST_NEED_LOG(features)   ((features) & (1ULL << VHOST_F_LOG_ALL))
+
+/**
+ * Log the memory write start with given address.
+ *
+ * This function only need be invoked when the live migration starts.
+ * Therefore, we won't need call it at all in the most of time. For
+ * making the performance impact be minimum, it's suggested to do a
+ * check before calling it:
+ *
+ *        if (unlikely(RTE_VHOST_NEED_LOG(features)))
+ *                rte_vhost_log_write(vid, addr, len);
+ *
+ * @param vid
+ *  vhost device ID
+ * @param addr
+ *  the starting address for write
+ * @param len
+ *  the length to write
+ */
+void rte_vhost_log_write(int vid, uint64_t addr, uint64_t len);
+
+/**
+ * Log the used ring update start at given offset.
+ *
+ * Same as rte_vhost_log_write, it's suggested to do a check before
+ * calling it:
+ *
+ *        if (unlikely(RTE_VHOST_NEED_LOG(features)))
+ *                rte_vhost_log_used_vring(vid, vring_idx, offset, len);
+ *
+ * @param vid
+ *  vhost device ID
+ * @param vring_idx
+ *  the vring index
+ * @param offset
+ *  the offset inside the used ring
+ * @param len
+ *  the length to write
+ */
+void rte_vhost_log_used_vring(int vid, uint16_t vring_idx,
+                             uint64_t offset, uint64_t len);
+
 int rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable);
 
 /**
@@ -205,8 +256,19 @@ int rte_vhost_get_negotiated_features(int vid, uint64_t *features);
 /* Register callbacks. */
 int rte_vhost_driver_callback_register(const char *path,
        struct vhost_device_ops const * const ops);
-/* Start vhost driver session blocking loop. */
-int rte_vhost_driver_session_start(void);
+
+/**
+ *
+ * Start the vhost-user driver.
+ *
+ * This function triggers the vhost-user negotiation.
+ *
+ * @param path
+ *  The vhost-user socket file path
+ * @return
+ *  0 on success, -1 on failure
+ */
+int rte_vhost_driver_start(const char *path);
 
 /**
  * Get the MTU value of the device if set in QEMU.