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     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);