xref: /openbmc/qemu/hw/remote/remote-obj.c (revision 081340d1ddfe27e80f653d707c278edf06a9a803)
1  /*
2   * Copyright © 2020, 2021 Oracle and/or its affiliates.
3   *
4   * This work is licensed under the terms of the GNU GPL-v2, version 2 or later.
5   *
6   * See the COPYING file in the top-level directory.
7   *
8   */
9  
10  #include "qemu/osdep.h"
11  
12  #include "qemu/error-report.h"
13  #include "qemu/notify.h"
14  #include "qom/object_interfaces.h"
15  #include "io/channel.h"
16  #include "hw/qdev-core.h"
17  #include "hw/remote/machine.h"
18  #include "io/channel-util.h"
19  #include "qapi/error.h"
20  #include "sysemu/sysemu.h"
21  #include "hw/pci/pci.h"
22  #include "qemu/sockets.h"
23  #include "monitor/monitor.h"
24  
25  #define TYPE_REMOTE_OBJECT "x-remote-object"
26  OBJECT_DECLARE_TYPE(RemoteObject, RemoteObjectClass, REMOTE_OBJECT)
27  
28  struct RemoteObjectClass {
29      ObjectClass parent_class;
30  
31      unsigned int nr_devs;
32      unsigned int max_devs;
33  };
34  
35  struct RemoteObject {
36      /* private */
37      Object parent;
38  
39      Notifier machine_done;
40  
41      int32_t fd;
42      char *devid;
43  
44      QIOChannel *ioc;
45  
46      DeviceState *dev;
47      DeviceListener listener;
48  };
49  
50  static void remote_object_set_fd(Object *obj, const char *str, Error **errp)
51  {
52      ERRP_GUARD();
53      RemoteObject *o = REMOTE_OBJECT(obj);
54      int fd = -1;
55  
56      fd = monitor_fd_param(monitor_cur(), str, errp);
57      if (fd == -1) {
58          error_prepend(errp, "Could not parse remote object fd %s:", str);
59          return;
60      }
61  
62      if (!fd_is_socket(fd)) {
63          error_setg(errp, "File descriptor '%s' is not a socket", str);
64          close(fd);
65          return;
66      }
67  
68      o->fd = fd;
69  }
70  
71  static void remote_object_set_devid(Object *obj, const char *str, Error **errp)
72  {
73      RemoteObject *o = REMOTE_OBJECT(obj);
74  
75      g_free(o->devid);
76  
77      o->devid = g_strdup(str);
78  }
79  
80  static void remote_object_unrealize_listener(DeviceListener *listener,
81                                               DeviceState *dev)
82  {
83      RemoteObject *o = container_of(listener, RemoteObject, listener);
84  
85      if (o->dev == dev) {
86          object_unref(OBJECT(o));
87      }
88  }
89  
90  static void remote_object_machine_done(Notifier *notifier, void *data)
91  {
92      RemoteObject *o = container_of(notifier, RemoteObject, machine_done);
93      DeviceState *dev = NULL;
94      QIOChannel *ioc = NULL;
95      Coroutine *co = NULL;
96      RemoteCommDev *comdev = NULL;
97      Error *err = NULL;
98  
99      dev = qdev_find_recursive(sysbus_get_default(), o->devid);
100      if (!dev || !object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
101          error_report("%s is not a PCI device", o->devid);
102          return;
103      }
104  
105      ioc = qio_channel_new_fd(o->fd, &err);
106      if (!ioc) {
107          error_report_err(err);
108          return;
109      }
110      qio_channel_set_blocking(ioc, false, NULL);
111  
112      o->dev = dev;
113  
114      o->listener.unrealize = remote_object_unrealize_listener;
115      device_listener_register(&o->listener);
116  
117      /* co-routine should free this. */
118      comdev = g_new0(RemoteCommDev, 1);
119      *comdev = (RemoteCommDev) {
120          .ioc = ioc,
121          .dev = PCI_DEVICE(dev),
122      };
123  
124      co = qemu_coroutine_create(mpqemu_remote_msg_loop_co, comdev);
125      qemu_coroutine_enter(co);
126  }
127  
128  static void remote_object_init(Object *obj)
129  {
130      RemoteObjectClass *k = REMOTE_OBJECT_GET_CLASS(obj);
131      RemoteObject *o = REMOTE_OBJECT(obj);
132  
133      if (k->nr_devs >= k->max_devs) {
134          error_report("Reached maximum number of devices: %u", k->max_devs);
135          return;
136      }
137  
138      o->ioc = NULL;
139      o->fd = -1;
140      o->devid = NULL;
141  
142      k->nr_devs++;
143  
144      o->machine_done.notify = remote_object_machine_done;
145      qemu_add_machine_init_done_notifier(&o->machine_done);
146  }
147  
148  static void remote_object_finalize(Object *obj)
149  {
150      RemoteObjectClass *k = REMOTE_OBJECT_GET_CLASS(obj);
151      RemoteObject *o = REMOTE_OBJECT(obj);
152  
153      device_listener_unregister(&o->listener);
154  
155      if (o->ioc) {
156          qio_channel_shutdown(o->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
157          qio_channel_close(o->ioc, NULL);
158      }
159  
160      object_unref(OBJECT(o->ioc));
161  
162      k->nr_devs--;
163      g_free(o->devid);
164  }
165  
166  static void remote_object_class_init(ObjectClass *klass, void *data)
167  {
168      RemoteObjectClass *k = REMOTE_OBJECT_CLASS(klass);
169  
170      /*
171       * Limit number of supported devices to 1. This is done to avoid devices
172       * from one VM accessing the RAM of another VM. This is done until we
173       * start using separate address spaces for individual devices.
174       */
175      k->max_devs = 1;
176      k->nr_devs = 0;
177  
178      object_class_property_add_str(klass, "fd", NULL, remote_object_set_fd);
179      object_class_property_add_str(klass, "devid", NULL,
180                                    remote_object_set_devid);
181  }
182  
183  static const TypeInfo remote_object_info = {
184      .name = TYPE_REMOTE_OBJECT,
185      .parent = TYPE_OBJECT,
186      .instance_size = sizeof(RemoteObject),
187      .instance_init = remote_object_init,
188      .instance_finalize = remote_object_finalize,
189      .class_size = sizeof(RemoteObjectClass),
190      .class_init = remote_object_class_init,
191      .interfaces = (InterfaceInfo[]) {
192          { TYPE_USER_CREATABLE },
193          { }
194      }
195  };
196  
197  static void register_types(void)
198  {
199      type_register_static(&remote_object_info);
200  }
201  
202  type_init(register_types);
203