xref: /qemu/include/hw/virtio/vhost-user.h (revision 954a6c4f7862b45617ff3b65609f0f290dcd5077)
1  /*
2   * Copyright (c) 2017-2018 Intel Corporation
3   *
4   * This work is licensed under the terms of the GNU GPL, version 2.
5   * See the COPYING file in the top-level directory.
6   */
7  
8  #ifndef HW_VIRTIO_VHOST_USER_H
9  #define HW_VIRTIO_VHOST_USER_H
10  
11  #include "chardev/char-fe.h"
12  #include "hw/virtio/virtio.h"
13  
14  /**
15   * VhostUserHostNotifier - notifier information for one queue
16   * @rcu: rcu_head for cleanup
17   * @mr: memory region of notifier
18   * @addr: current mapped address
19   * @unmap_addr: address to be un-mapped
20   * @idx: virtioqueue index
21   *
22   * The VhostUserHostNotifier entries are re-used. When an old mapping
23   * is to be released it is moved to @unmap_addr and @addr is replaced.
24   * Once the RCU process has completed the unmap @unmap_addr is
25   * cleared.
26   */
27  typedef struct VhostUserHostNotifier {
28      struct rcu_head rcu;
29      MemoryRegion mr;
30      void *addr;
31      void *unmap_addr;
32      int idx;
33  } VhostUserHostNotifier;
34  
35  /**
36   * VhostUserState - shared state for all vhost-user devices
37   * @chr: the character backend for the socket
38   * @notifiers: GPtrArray of @VhostUserHostnotifier
39   * @memory_slots:
40   */
41  typedef struct VhostUserState {
42      CharBackend *chr;
43      GPtrArray *notifiers;
44      int memory_slots;
45      bool supports_config;
46  } VhostUserState;
47  
48  /**
49   * vhost_user_init() - initialise shared vhost_user state
50   * @user: allocated area for storing shared state
51   * @chr: the chardev for the vhost socket
52   * @errp: error handle
53   *
54   * User can either directly g_new() space for the state or embed
55   * VhostUserState in their larger device structure and just point to
56   * it.
57   *
58   * Return: true on success, false on error while setting errp.
59   */
60  bool vhost_user_init(VhostUserState *user, CharBackend *chr, Error **errp);
61  
62  /**
63   * vhost_user_cleanup() - cleanup state
64   * @user: ptr to use state
65   *
66   * Cleans up shared state and notifiers, callee is responsible for
67   * freeing the @VhostUserState memory itself.
68   */
69  void vhost_user_cleanup(VhostUserState *user);
70  
71  /**
72   * vhost_user_async_close() - cleanup vhost-user post connection drop
73   * @d: DeviceState for the associated device (passed to callback)
74   * @chardev: the CharBackend associated with the connection
75   * @vhost: the common vhost device
76   * @cb: the user callback function to complete the clean-up
77   *
78   * This function is used to handle the shutdown of a vhost-user
79   * connection to a backend. We handle this centrally to make sure we
80   * do all the steps and handle potential races due to VM shutdowns.
81   * Once the connection is disabled we call a backhalf to ensure
82   */
83  typedef void (*vu_async_close_fn)(DeviceState *cb);
84  
85  void vhost_user_async_close(DeviceState *d,
86                              CharBackend *chardev, struct vhost_dev *vhost,
87                              vu_async_close_fn cb);
88  
89  #endif
90