include/qemu/vhost-user-server.h

   1 /*
   2  * Sharing QEMU devices via vhost-user protocol
   3  *
   4  * Copyright (c) Coiby Xu <coiby.xu@gmail.com>.
   5  * Copyright (c) 2020 Red Hat, Inc.
   6  *
   7  * This work is licensed under the terms of the GNU GPL, version 2 or
   8  * later.  See the COPYING file in the top-level directory.
   9  */
  10
  11 #ifndef VHOST_USER_SERVER_H
  12 #define VHOST_USER_SERVER_H
  13
  14 #include "subprojects/libvhost-user/libvhost-user.h" /* only for the type definitions */
  15 #include "io/channel-socket.h"
  16 #include "io/channel-file.h"
  17 #include "io/net-listener.h"
  18 #include "qapi/error.h"
  19 #include "standard-headers/linux/virtio_blk.h"
  20
  21 /* A kick fd that we monitor on behalf of libvhost-user */
  22 typedef struct VuFdWatch {
  23     VuDev *vu_dev;
  24     int fd; /*kick fd*/
  25     void *pvt;
  26     vu_watch_cb cb;
  27     QTAILQ_ENTRY(VuFdWatch) next;
  28 } VuFdWatch;
  29
  30 /**
  31  * VuServer:
  32  * A vhost-user server instance with user-defined VuDevIface callbacks.
  33  * Vhost-user device backends can be implemented using VuServer. VuDevIface
  34  * callbacks and virtqueue kicks run in the given AioContext.
  35  */
  36 typedef struct {
  37     QIONetListener *listener;
  38     QEMUBH *restart_listener_bh;
  39     AioContext *ctx;
  40     int max_queues;
  41     const VuDevIface *vu_iface;
  42
  43     unsigned int in_flight; /* atomic */
  44
  45     /* Protected by ctx lock */
  46     bool in_qio_channel_yield;
  47     bool wait_idle;
  48     bool quiescing;
  49     VuDev vu_dev;
  50     QIOChannel *ioc; /* The I/O channel with the client */
  51     QIOChannelSocket *sioc; /* The underlying data channel with the client */
  52     QTAILQ_HEAD(, VuFdWatch) vu_fd_watches;
  53
  54     Coroutine *co_trip; /* coroutine for processing VhostUserMsg */
  55 } VuServer;
  56
  57 bool vhost_user_server_start(VuServer *server,
  58                              SocketAddress *unix_socket,
  59                              AioContext *ctx,
  60                              uint16_t max_queues,
  61                              const VuDevIface *vu_iface,
  62                              Error **errp);
  63
  64 void vhost_user_server_stop(VuServer *server);
  65
  66 void vhost_user_server_inc_in_flight(VuServer *server);
  67 void vhost_user_server_dec_in_flight(VuServer *server);
  68 bool vhost_user_server_has_in_flight(VuServer *server);
  69
  70 void vhost_user_server_attach_aio_context(VuServer *server, AioContext *ctx);
  71 void vhost_user_server_detach_aio_context(VuServer *server);
  72
  73 #endif /* VHOST_USER_SERVER_H */