xref: /openbmc/qemu/hw/remote/remote-obj.c (revision 93e0932b)
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     RemoteObject *o = REMOTE_OBJECT(obj);
53     int fd = -1;
54 
55     fd = monitor_fd_param(monitor_cur(), str, errp);
56     if (fd == -1) {
57         error_prepend(errp, "Could not parse remote object fd %s:", str);
58         return;
59     }
60 
61     if (!fd_is_socket(fd)) {
62         error_setg(errp, "File descriptor '%s' is not a socket", str);
63         close(fd);
64         return;
65     }
66 
67     o->fd = fd;
68 }
69 
70 static void remote_object_set_devid(Object *obj, const char *str, Error **errp)
71 {
72     RemoteObject *o = REMOTE_OBJECT(obj);
73 
74     g_free(o->devid);
75 
76     o->devid = g_strdup(str);
77 }
78 
79 static void remote_object_unrealize_listener(DeviceListener *listener,
80                                              DeviceState *dev)
81 {
82     RemoteObject *o = container_of(listener, RemoteObject, listener);
83 
84     if (o->dev == dev) {
85         object_unref(OBJECT(o));
86     }
87 }
88 
89 static void remote_object_machine_done(Notifier *notifier, void *data)
90 {
91     RemoteObject *o = container_of(notifier, RemoteObject, machine_done);
92     DeviceState *dev = NULL;
93     QIOChannel *ioc = NULL;
94     Coroutine *co = NULL;
95     RemoteCommDev *comdev = NULL;
96     Error *err = NULL;
97 
98     dev = qdev_find_recursive(sysbus_get_default(), o->devid);
99     if (!dev || !object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
100         error_report("%s is not a PCI device", o->devid);
101         return;
102     }
103 
104     ioc = qio_channel_new_fd(o->fd, &err);
105     if (!ioc) {
106         error_report_err(err);
107         return;
108     }
109     qio_channel_set_blocking(ioc, false, NULL);
110 
111     o->dev = dev;
112 
113     o->listener.unrealize = remote_object_unrealize_listener;
114     device_listener_register(&o->listener);
115 
116     /* co-routine should free this. */
117     comdev = g_new0(RemoteCommDev, 1);
118     *comdev = (RemoteCommDev) {
119         .ioc = ioc,
120         .dev = PCI_DEVICE(dev),
121     };
122 
123     co = qemu_coroutine_create(mpqemu_remote_msg_loop_co, comdev);
124     qemu_coroutine_enter(co);
125 }
126 
127 static void remote_object_init(Object *obj)
128 {
129     RemoteObjectClass *k = REMOTE_OBJECT_GET_CLASS(obj);
130     RemoteObject *o = REMOTE_OBJECT(obj);
131 
132     if (k->nr_devs >= k->max_devs) {
133         error_report("Reached maximum number of devices: %u", k->max_devs);
134         return;
135     }
136 
137     o->ioc = NULL;
138     o->fd = -1;
139     o->devid = NULL;
140 
141     k->nr_devs++;
142 
143     o->machine_done.notify = remote_object_machine_done;
144     qemu_add_machine_init_done_notifier(&o->machine_done);
145 }
146 
147 static void remote_object_finalize(Object *obj)
148 {
149     RemoteObjectClass *k = REMOTE_OBJECT_GET_CLASS(obj);
150     RemoteObject *o = REMOTE_OBJECT(obj);
151 
152     device_listener_unregister(&o->listener);
153 
154     if (o->ioc) {
155         qio_channel_shutdown(o->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
156         qio_channel_close(o->ioc, NULL);
157     }
158 
159     object_unref(OBJECT(o->ioc));
160 
161     k->nr_devs--;
162     g_free(o->devid);
163 }
164 
165 static void remote_object_class_init(ObjectClass *klass, void *data)
166 {
167     RemoteObjectClass *k = REMOTE_OBJECT_CLASS(klass);
168 
169     /*
170      * Limit number of supported devices to 1. This is done to avoid devices
171      * from one VM accessing the RAM of another VM. This is done until we
172      * start using separate address spaces for individual devices.
173      */
174     k->max_devs = 1;
175     k->nr_devs = 0;
176 
177     object_class_property_add_str(klass, "fd", NULL, remote_object_set_fd);
178     object_class_property_add_str(klass, "devid", NULL,
179                                   remote_object_set_devid);
180 }
181 
182 static const TypeInfo remote_object_info = {
183     .name = TYPE_REMOTE_OBJECT,
184     .parent = TYPE_OBJECT,
185     .instance_size = sizeof(RemoteObject),
186     .instance_init = remote_object_init,
187     .instance_finalize = remote_object_finalize,
188     .class_size = sizeof(RemoteObjectClass),
189     .class_init = remote_object_class_init,
190     .interfaces = (InterfaceInfo[]) {
191         { TYPE_USER_CREATABLE },
192         { }
193     }
194 };
195 
196 static void register_types(void)
197 {
198     type_register_static(&remote_object_info);
199 }
200 
201 type_init(register_types);
202