qemu

vhost-user.c (5008B)

---

 /*
  * QEMU vhost-user backend
  *
  * Copyright (C) 2018 Red Hat Inc
  *
  * Authors:
  *  Marc-André Lureau <marcandre.lureau@redhat.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  */
 
 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/error-report.h"
 #include "qom/object_interfaces.h"
 #include "sysemu/vhost-user-backend.h"
 #include "sysemu/kvm.h"
 #include "io/channel-command.h"
 #include "hw/virtio/virtio-bus.h"
 
 static bool
 ioeventfd_enabled(void)
 {
     return kvm_enabled() && kvm_eventfds_enabled();
 }
 
 int
 vhost_user_backend_dev_init(VhostUserBackend *b, VirtIODevice *vdev,
                             unsigned nvqs, Error **errp)
 {
     int ret;
 
     assert(!b->vdev && vdev);
 
     if (!ioeventfd_enabled()) {
         error_setg(errp, "vhost initialization failed: requires kvm");
         return -1;
     }
 
     if (!vhost_user_init(&b->vhost_user, &b->chr, errp)) {
         return -1;
     }
 
     b->vdev = vdev;
     b->dev.nvqs = nvqs;
     b->dev.vqs = g_new0(struct vhost_virtqueue, nvqs);
 
     ret = vhost_dev_init(&b->dev, &b->vhost_user, VHOST_BACKEND_TYPE_USER, 0,
                          errp);
     if (ret < 0) {
         return -1;
     }
 
     return 0;
 }
 
 void
 vhost_user_backend_start(VhostUserBackend *b)
 {
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     int ret, i ;
 
     if (b->started) {
         return;
     }
 
     if (!k->set_guest_notifiers) {
         error_report("binding does not support guest notifiers");
         return;
     }
 
     ret = vhost_dev_enable_notifiers(&b->dev, b->vdev);
     if (ret < 0) {
         return;
     }
 
     ret = k->set_guest_notifiers(qbus->parent, b->dev.nvqs, true);
     if (ret < 0) {
         error_report("Error binding guest notifier");
         goto err_host_notifiers;
     }
 
     b->dev.acked_features = b->vdev->guest_features;
     ret = vhost_dev_start(&b->dev, b->vdev, true);
     if (ret < 0) {
         error_report("Error start vhost dev");
         goto err_guest_notifiers;
     }
 
     /* guest_notifier_mask/pending not used yet, so just unmask
      * everything here.  virtio-pci will do the right thing by
      * enabling/disabling irqfd.
      */
     for (i = 0; i < b->dev.nvqs; i++) {
         vhost_virtqueue_mask(&b->dev, b->vdev,
                              b->dev.vq_index + i, false);
     }
 
     b->started = true;
     return;
 
 err_guest_notifiers:
     k->set_guest_notifiers(qbus->parent, b->dev.nvqs, false);
 err_host_notifiers:
     vhost_dev_disable_notifiers(&b->dev, b->vdev);
 }
 
 void
 vhost_user_backend_stop(VhostUserBackend *b)
 {
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     int ret = 0;
 
     if (!b->started) {
         return;
     }
 
     vhost_dev_stop(&b->dev, b->vdev, true);
 
     if (k->set_guest_notifiers) {
         ret = k->set_guest_notifiers(qbus->parent,
                                      b->dev.nvqs, false);
         if (ret < 0) {
             error_report("vhost guest notifier cleanup failed: %d", ret);
         }
     }
     assert(ret >= 0);
 
     vhost_dev_disable_notifiers(&b->dev, b->vdev);
     b->started = false;
 }
 
 static void set_chardev(Object *obj, const char *value, Error **errp)
 {
     VhostUserBackend *b = VHOST_USER_BACKEND(obj);
     Chardev *chr;
 
     if (b->completed) {
         error_setg(errp, "Property 'chardev' can no longer be set");
         return;
     }
 
     g_free(b->chr_name);
     b->chr_name = g_strdup(value);
 
     chr = qemu_chr_find(b->chr_name);
     if (chr == NULL) {
         error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
                   "Chardev '%s' not found", b->chr_name);
         return;
     }
 
     if (!qemu_chr_fe_init(&b->chr, chr, errp)) {
         return;
     }
 
     b->completed = true;
     /* could call vhost_dev_init() so early message can be exchanged */
 }
 
 static char *get_chardev(Object *obj, Error **errp)
 {
     VhostUserBackend *b = VHOST_USER_BACKEND(obj);
     Chardev *chr = qemu_chr_fe_get_driver(&b->chr);
 
     if (chr && chr->label) {
         return g_strdup(chr->label);
     }
 
     return NULL;
 }
 
 static void vhost_user_backend_class_init(ObjectClass *oc, void *data)
 {
     object_class_property_add_str(oc, "chardev", get_chardev, set_chardev);
 }
 
 static void vhost_user_backend_finalize(Object *obj)
 {
     VhostUserBackend *b = VHOST_USER_BACKEND(obj);
 
     g_free(b->dev.vqs);
     g_free(b->chr_name);
 
     vhost_user_cleanup(&b->vhost_user);
     qemu_chr_fe_deinit(&b->chr, true);
 }
 
 static const TypeInfo vhost_user_backend_info = {
     .name = TYPE_VHOST_USER_BACKEND,
     .parent = TYPE_OBJECT,
     .instance_size = sizeof(VhostUserBackend),
     .class_init = vhost_user_backend_class_init,
     .instance_finalize = vhost_user_backend_finalize,
 };
 
 static void register_types(void)
 {
     type_register_static(&vhost_user_backend_info);
 }
 
 type_init(register_types);