1 /* 2 * QEMU vhost-user backend 3 * 4 * Copyright (C) 2018 Red Hat Inc 5 * 6 * Authors: 7 * Marc-André Lureau <marcandre.lureau@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or later. 10 * See the COPYING file in the top-level directory. 11 */ 12 13 14 #include "qemu/osdep.h" 15 #include "qapi/error.h" 16 #include "qemu/error-report.h" 17 #include "qom/object_interfaces.h" 18 #include "sysemu/vhost-user-backend.h" 19 #include "sysemu/kvm.h" 20 #include "io/channel-command.h" 21 #include "hw/virtio/virtio-bus.h" 22 23 static bool 24 ioeventfd_enabled(void) 25 { 26 return kvm_enabled() && kvm_eventfds_enabled(); 27 } 28 29 int 30 vhost_user_backend_dev_init(VhostUserBackend *b, VirtIODevice *vdev, 31 unsigned nvqs, Error **errp) 32 { 33 int ret; 34 35 assert(!b->vdev && vdev); 36 37 if (!ioeventfd_enabled()) { 38 error_setg(errp, "vhost initialization failed: requires kvm"); 39 return -1; 40 } 41 42 if (!vhost_user_init(&b->vhost_user, &b->chr, errp)) { 43 return -1; 44 } 45 46 b->vdev = vdev; 47 b->dev.nvqs = nvqs; 48 b->dev.vqs = g_new0(struct vhost_virtqueue, nvqs); 49 50 ret = vhost_dev_init(&b->dev, &b->vhost_user, VHOST_BACKEND_TYPE_USER, 0, 51 errp); 52 if (ret < 0) { 53 return -1; 54 } 55 56 return 0; 57 } 58 59 void 60 vhost_user_backend_start(VhostUserBackend *b) 61 { 62 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev))); 63 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 64 int ret, i ; 65 66 if (b->started) { 67 return; 68 } 69 70 if (!k->set_guest_notifiers) { 71 error_report("binding does not support guest notifiers"); 72 return; 73 } 74 75 ret = vhost_dev_enable_notifiers(&b->dev, b->vdev); 76 if (ret < 0) { 77 return; 78 } 79 80 ret = k->set_guest_notifiers(qbus->parent, b->dev.nvqs, true); 81 if (ret < 0) { 82 error_report("Error binding guest notifier"); 83 goto err_host_notifiers; 84 } 85 86 b->dev.acked_features = b->vdev->guest_features; 87 ret = vhost_dev_start(&b->dev, b->vdev, true); 88 if (ret < 0) { 89 error_report("Error start vhost dev"); 90 goto err_guest_notifiers; 91 } 92 93 /* guest_notifier_mask/pending not used yet, so just unmask 94 * everything here. virtio-pci will do the right thing by 95 * enabling/disabling irqfd. 96 */ 97 for (i = 0; i < b->dev.nvqs; i++) { 98 vhost_virtqueue_mask(&b->dev, b->vdev, 99 b->dev.vq_index + i, false); 100 } 101 102 b->started = true; 103 return; 104 105 err_guest_notifiers: 106 k->set_guest_notifiers(qbus->parent, b->dev.nvqs, false); 107 err_host_notifiers: 108 vhost_dev_disable_notifiers(&b->dev, b->vdev); 109 } 110 111 void 112 vhost_user_backend_stop(VhostUserBackend *b) 113 { 114 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev))); 115 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 116 int ret = 0; 117 118 if (!b->started) { 119 return; 120 } 121 122 vhost_dev_stop(&b->dev, b->vdev, true); 123 124 if (k->set_guest_notifiers) { 125 ret = k->set_guest_notifiers(qbus->parent, 126 b->dev.nvqs, false); 127 if (ret < 0) { 128 error_report("vhost guest notifier cleanup failed: %d", ret); 129 } 130 } 131 assert(ret >= 0); 132 133 vhost_dev_disable_notifiers(&b->dev, b->vdev); 134 b->started = false; 135 } 136 137 static void set_chardev(Object *obj, const char *value, Error **errp) 138 { 139 VhostUserBackend *b = VHOST_USER_BACKEND(obj); 140 Chardev *chr; 141 142 if (b->completed) { 143 error_setg(errp, "Property 'chardev' can no longer be set"); 144 return; 145 } 146 147 g_free(b->chr_name); 148 b->chr_name = g_strdup(value); 149 150 chr = qemu_chr_find(b->chr_name); 151 if (chr == NULL) { 152 error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND, 153 "Chardev '%s' not found", b->chr_name); 154 return; 155 } 156 157 if (!qemu_chr_fe_init(&b->chr, chr, errp)) { 158 return; 159 } 160 161 b->completed = true; 162 /* could call vhost_dev_init() so early message can be exchanged */ 163 } 164 165 static char *get_chardev(Object *obj, Error **errp) 166 { 167 VhostUserBackend *b = VHOST_USER_BACKEND(obj); 168 Chardev *chr = qemu_chr_fe_get_driver(&b->chr); 169 170 if (chr && chr->label) { 171 return g_strdup(chr->label); 172 } 173 174 return NULL; 175 } 176 177 static void vhost_user_backend_class_init(ObjectClass *oc, void *data) 178 { 179 object_class_property_add_str(oc, "chardev", get_chardev, set_chardev); 180 } 181 182 static void vhost_user_backend_finalize(Object *obj) 183 { 184 VhostUserBackend *b = VHOST_USER_BACKEND(obj); 185 186 g_free(b->dev.vqs); 187 g_free(b->chr_name); 188 189 vhost_user_cleanup(&b->vhost_user); 190 qemu_chr_fe_deinit(&b->chr, true); 191 } 192 193 static const TypeInfo vhost_user_backend_info = { 194 .name = TYPE_VHOST_USER_BACKEND, 195 .parent = TYPE_OBJECT, 196 .instance_size = sizeof(VhostUserBackend), 197 .class_init = vhost_user_backend_class_init, 198 .instance_finalize = vhost_user_backend_finalize, 199 }; 200 201 static void register_types(void) 202 { 203 type_register_static(&vhost_user_backend_info); 204 } 205 206 type_init(register_types); 207