1 /* 2 * Parent class for vhost-vsock devices 3 * 4 * Copyright 2015-2020 Red Hat, Inc. 5 * 6 * This work is licensed under the terms of the GNU GPL, version 2 or 7 * (at your option) any later version. See the COPYING file in the 8 * top-level directory. 9 */ 10 11 #include "qemu/osdep.h" 12 #include "standard-headers/linux/virtio_vsock.h" 13 #include "qapi/error.h" 14 #include "hw/virtio/virtio-access.h" 15 #include "qemu/error-report.h" 16 #include "hw/qdev-properties.h" 17 #include "hw/virtio/vhost.h" 18 #include "hw/virtio/vhost-vsock.h" 19 #include "qemu/iov.h" 20 #include "monitor/monitor.h" 21 22 const int feature_bits[] = { 23 VIRTIO_VSOCK_F_SEQPACKET, 24 VIRTIO_F_RING_RESET, 25 VHOST_INVALID_FEATURE_BIT 26 }; 27 28 uint64_t vhost_vsock_common_get_features(VirtIODevice *vdev, uint64_t features, 29 Error **errp) 30 { 31 VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev); 32 33 if (vvc->seqpacket != ON_OFF_AUTO_OFF) { 34 virtio_add_feature(&features, VIRTIO_VSOCK_F_SEQPACKET); 35 } 36 37 features = vhost_get_features(&vvc->vhost_dev, feature_bits, features); 38 39 if (vvc->seqpacket == ON_OFF_AUTO_ON && 40 !virtio_has_feature(features, VIRTIO_VSOCK_F_SEQPACKET)) { 41 error_setg(errp, "vhost-vsock backend doesn't support seqpacket"); 42 } 43 44 return features; 45 } 46 47 int vhost_vsock_common_start(VirtIODevice *vdev) 48 { 49 VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev); 50 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 51 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 52 int ret; 53 int i; 54 55 if (!k->set_guest_notifiers) { 56 error_report("binding does not support guest notifiers"); 57 return -ENOSYS; 58 } 59 60 ret = vhost_dev_enable_notifiers(&vvc->vhost_dev, vdev); 61 if (ret < 0) { 62 error_report("Error enabling host notifiers: %d", -ret); 63 return ret; 64 } 65 66 ret = k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, true); 67 if (ret < 0) { 68 error_report("Error binding guest notifier: %d", -ret); 69 goto err_host_notifiers; 70 } 71 72 vvc->vhost_dev.acked_features = vdev->guest_features; 73 ret = vhost_dev_start(&vvc->vhost_dev, vdev); 74 if (ret < 0) { 75 error_report("Error starting vhost: %d", -ret); 76 goto err_guest_notifiers; 77 } 78 79 /* 80 * guest_notifier_mask/pending not used yet, so just unmask 81 * everything here. virtio-pci will do the right thing by 82 * enabling/disabling irqfd. 83 */ 84 for (i = 0; i < vvc->vhost_dev.nvqs; i++) { 85 vhost_virtqueue_mask(&vvc->vhost_dev, vdev, i, false); 86 } 87 88 return 0; 89 90 err_guest_notifiers: 91 k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, false); 92 err_host_notifiers: 93 vhost_dev_disable_notifiers(&vvc->vhost_dev, vdev); 94 return ret; 95 } 96 97 void vhost_vsock_common_stop(VirtIODevice *vdev) 98 { 99 VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev); 100 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); 101 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); 102 int ret; 103 104 if (!k->set_guest_notifiers) { 105 return; 106 } 107 108 vhost_dev_stop(&vvc->vhost_dev, vdev); 109 110 ret = k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, false); 111 if (ret < 0) { 112 error_report("vhost guest notifier cleanup failed: %d", ret); 113 return; 114 } 115 116 vhost_dev_disable_notifiers(&vvc->vhost_dev, vdev); 117 } 118 119 120 static void vhost_vsock_common_handle_output(VirtIODevice *vdev, VirtQueue *vq) 121 { 122 /* Do nothing */ 123 } 124 125 static void vhost_vsock_common_guest_notifier_mask(VirtIODevice *vdev, int idx, 126 bool mask) 127 { 128 VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev); 129 130 vhost_virtqueue_mask(&vvc->vhost_dev, vdev, idx, mask); 131 } 132 133 static bool vhost_vsock_common_guest_notifier_pending(VirtIODevice *vdev, 134 int idx) 135 { 136 VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev); 137 138 return vhost_virtqueue_pending(&vvc->vhost_dev, idx); 139 } 140 141 static void vhost_vsock_common_send_transport_reset(VHostVSockCommon *vvc) 142 { 143 VirtQueueElement *elem; 144 VirtQueue *vq = vvc->event_vq; 145 struct virtio_vsock_event event = { 146 .id = cpu_to_le32(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET), 147 }; 148 149 elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); 150 if (!elem) { 151 error_report("vhost-vsock missed transport reset event"); 152 return; 153 } 154 155 if (elem->out_num) { 156 error_report("invalid vhost-vsock event virtqueue element with " 157 "out buffers"); 158 goto err; 159 } 160 161 if (iov_from_buf(elem->in_sg, elem->in_num, 0, 162 &event, sizeof(event)) != sizeof(event)) { 163 error_report("vhost-vsock event virtqueue element is too short"); 164 goto err; 165 } 166 167 virtqueue_push(vq, elem, sizeof(event)); 168 virtio_notify(VIRTIO_DEVICE(vvc), vq); 169 170 g_free(elem); 171 return; 172 173 err: 174 virtqueue_detach_element(vq, elem, 0); 175 g_free(elem); 176 } 177 178 static void vhost_vsock_common_post_load_timer_cleanup(VHostVSockCommon *vvc) 179 { 180 if (!vvc->post_load_timer) { 181 return; 182 } 183 184 timer_free(vvc->post_load_timer); 185 vvc->post_load_timer = NULL; 186 } 187 188 static void vhost_vsock_common_post_load_timer_cb(void *opaque) 189 { 190 VHostVSockCommon *vvc = opaque; 191 192 vhost_vsock_common_post_load_timer_cleanup(vvc); 193 vhost_vsock_common_send_transport_reset(vvc); 194 } 195 196 int vhost_vsock_common_pre_save(void *opaque) 197 { 198 VHostVSockCommon *vvc = opaque; 199 200 /* 201 * At this point, backend must be stopped, otherwise 202 * it might keep writing to memory. 203 */ 204 assert(!vhost_dev_is_started(&vvc->vhost_dev)); 205 206 return 0; 207 } 208 209 int vhost_vsock_common_post_load(void *opaque, int version_id) 210 { 211 VHostVSockCommon *vvc = opaque; 212 VirtIODevice *vdev = VIRTIO_DEVICE(vvc); 213 214 if (virtio_queue_get_addr(vdev, 2)) { 215 /* 216 * Defer transport reset event to a vm clock timer so that virtqueue 217 * changes happen after migration has completed. 218 */ 219 assert(!vvc->post_load_timer); 220 vvc->post_load_timer = 221 timer_new_ns(QEMU_CLOCK_VIRTUAL, 222 vhost_vsock_common_post_load_timer_cb, 223 vvc); 224 timer_mod(vvc->post_load_timer, 1); 225 } 226 return 0; 227 } 228 229 void vhost_vsock_common_realize(VirtIODevice *vdev) 230 { 231 VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev); 232 233 virtio_init(vdev, VIRTIO_ID_VSOCK, sizeof(struct virtio_vsock_config)); 234 235 /* Receive and transmit queues belong to vhost */ 236 vvc->recv_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, 237 vhost_vsock_common_handle_output); 238 vvc->trans_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, 239 vhost_vsock_common_handle_output); 240 241 /* The event queue belongs to QEMU */ 242 vvc->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, 243 vhost_vsock_common_handle_output); 244 245 vvc->vhost_dev.nvqs = ARRAY_SIZE(vvc->vhost_vqs); 246 vvc->vhost_dev.vqs = vvc->vhost_vqs; 247 248 vvc->post_load_timer = NULL; 249 } 250 251 void vhost_vsock_common_unrealize(VirtIODevice *vdev) 252 { 253 VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev); 254 255 vhost_vsock_common_post_load_timer_cleanup(vvc); 256 257 virtio_delete_queue(vvc->recv_vq); 258 virtio_delete_queue(vvc->trans_vq); 259 virtio_delete_queue(vvc->event_vq); 260 virtio_cleanup(vdev); 261 } 262 263 static struct vhost_dev *vhost_vsock_common_get_vhost(VirtIODevice *vdev) 264 { 265 VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev); 266 return &vvc->vhost_dev; 267 } 268 269 static Property vhost_vsock_common_properties[] = { 270 DEFINE_PROP_ON_OFF_AUTO("seqpacket", VHostVSockCommon, seqpacket, 271 ON_OFF_AUTO_AUTO), 272 DEFINE_PROP_END_OF_LIST(), 273 }; 274 275 static void vhost_vsock_common_class_init(ObjectClass *klass, void *data) 276 { 277 DeviceClass *dc = DEVICE_CLASS(klass); 278 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 279 280 device_class_set_props(dc, vhost_vsock_common_properties); 281 set_bit(DEVICE_CATEGORY_MISC, dc->categories); 282 vdc->guest_notifier_mask = vhost_vsock_common_guest_notifier_mask; 283 vdc->guest_notifier_pending = vhost_vsock_common_guest_notifier_pending; 284 vdc->get_vhost = vhost_vsock_common_get_vhost; 285 } 286 287 static const TypeInfo vhost_vsock_common_info = { 288 .name = TYPE_VHOST_VSOCK_COMMON, 289 .parent = TYPE_VIRTIO_DEVICE, 290 .instance_size = sizeof(VHostVSockCommon), 291 .class_init = vhost_vsock_common_class_init, 292 .abstract = true, 293 }; 294 295 static void vhost_vsock_common_register_types(void) 296 { 297 type_register_static(&vhost_vsock_common_info); 298 } 299 300 type_init(vhost_vsock_common_register_types) 301