hw/remote/remote-obj.c

   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);