1 | /* |
2 | * Virtio vsock device |
3 | * |
4 | * Copyright 2015 Red Hat, Inc. |
5 | * |
6 | * Authors: |
7 | * Stefan Hajnoczi <stefanha@redhat.com> |
8 | * |
9 | * This work is licensed under the terms of the GNU GPL, version 2 or |
10 | * (at your option) any later version. See the COPYING file in the |
11 | * top-level directory. |
12 | */ |
13 | |
14 | #include "qemu/osdep.h" |
15 | #include <sys/ioctl.h> |
16 | #include "standard-headers/linux/virtio_vsock.h" |
17 | #include "qapi/error.h" |
18 | #include "hw/virtio/virtio-bus.h" |
19 | #include "hw/virtio/virtio-access.h" |
20 | #include "qemu/error-report.h" |
21 | #include "hw/qdev-properties.h" |
22 | #include "hw/virtio/vhost-vsock.h" |
23 | #include "qemu/iov.h" |
24 | #include "qemu/module.h" |
25 | #include "monitor/monitor.h" |
26 | |
27 | enum { |
28 | VHOST_VSOCK_SAVEVM_VERSION = 0, |
29 | |
30 | VHOST_VSOCK_QUEUE_SIZE = 128, |
31 | }; |
32 | |
33 | static void vhost_vsock_get_config(VirtIODevice *vdev, uint8_t *config) |
34 | { |
35 | VHostVSock *vsock = VHOST_VSOCK(vdev); |
36 | struct virtio_vsock_config vsockcfg = {}; |
37 | |
38 | virtio_stq_p(vdev, &vsockcfg.guest_cid, vsock->conf.guest_cid); |
39 | memcpy(config, &vsockcfg, sizeof(vsockcfg)); |
40 | } |
41 | |
42 | static int vhost_vsock_set_guest_cid(VHostVSock *vsock) |
43 | { |
44 | const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops; |
45 | int ret; |
46 | |
47 | if (!vhost_ops->vhost_vsock_set_guest_cid) { |
48 | return -ENOSYS; |
49 | } |
50 | |
51 | ret = vhost_ops->vhost_vsock_set_guest_cid(&vsock->vhost_dev, |
52 | vsock->conf.guest_cid); |
53 | if (ret < 0) { |
54 | return -errno; |
55 | } |
56 | return 0; |
57 | } |
58 | |
59 | static int vhost_vsock_set_running(VHostVSock *vsock, int start) |
60 | { |
61 | const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops; |
62 | int ret; |
63 | |
64 | if (!vhost_ops->vhost_vsock_set_running) { |
65 | return -ENOSYS; |
66 | } |
67 | |
68 | ret = vhost_ops->vhost_vsock_set_running(&vsock->vhost_dev, start); |
69 | if (ret < 0) { |
70 | return -errno; |
71 | } |
72 | return 0; |
73 | } |
74 | |
75 | static void vhost_vsock_start(VirtIODevice *vdev) |
76 | { |
77 | VHostVSock *vsock = VHOST_VSOCK(vdev); |
78 | BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); |
79 | VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); |
80 | int ret; |
81 | int i; |
82 | |
83 | if (!k->set_guest_notifiers) { |
84 | error_report("binding does not support guest notifiers" ); |
85 | return; |
86 | } |
87 | |
88 | ret = vhost_dev_enable_notifiers(&vsock->vhost_dev, vdev); |
89 | if (ret < 0) { |
90 | error_report("Error enabling host notifiers: %d" , -ret); |
91 | return; |
92 | } |
93 | |
94 | ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, true); |
95 | if (ret < 0) { |
96 | error_report("Error binding guest notifier: %d" , -ret); |
97 | goto err_host_notifiers; |
98 | } |
99 | |
100 | vsock->vhost_dev.acked_features = vdev->guest_features; |
101 | ret = vhost_dev_start(&vsock->vhost_dev, vdev); |
102 | if (ret < 0) { |
103 | error_report("Error starting vhost: %d" , -ret); |
104 | goto err_guest_notifiers; |
105 | } |
106 | |
107 | ret = vhost_vsock_set_running(vsock, 1); |
108 | if (ret < 0) { |
109 | error_report("Error starting vhost vsock: %d" , -ret); |
110 | goto err_dev_start; |
111 | } |
112 | |
113 | /* guest_notifier_mask/pending not used yet, so just unmask |
114 | * everything here. virtio-pci will do the right thing by |
115 | * enabling/disabling irqfd. |
116 | */ |
117 | for (i = 0; i < vsock->vhost_dev.nvqs; i++) { |
118 | vhost_virtqueue_mask(&vsock->vhost_dev, vdev, i, false); |
119 | } |
120 | |
121 | return; |
122 | |
123 | err_dev_start: |
124 | vhost_dev_stop(&vsock->vhost_dev, vdev); |
125 | err_guest_notifiers: |
126 | k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false); |
127 | err_host_notifiers: |
128 | vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev); |
129 | } |
130 | |
131 | static void vhost_vsock_stop(VirtIODevice *vdev) |
132 | { |
133 | VHostVSock *vsock = VHOST_VSOCK(vdev); |
134 | BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); |
135 | VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); |
136 | int ret; |
137 | |
138 | if (!k->set_guest_notifiers) { |
139 | return; |
140 | } |
141 | |
142 | ret = vhost_vsock_set_running(vsock, 0); |
143 | if (ret < 0) { |
144 | error_report("vhost vsock set running failed: %d" , ret); |
145 | return; |
146 | } |
147 | |
148 | vhost_dev_stop(&vsock->vhost_dev, vdev); |
149 | |
150 | ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false); |
151 | if (ret < 0) { |
152 | error_report("vhost guest notifier cleanup failed: %d" , ret); |
153 | return; |
154 | } |
155 | |
156 | vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev); |
157 | } |
158 | |
159 | static void vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status) |
160 | { |
161 | VHostVSock *vsock = VHOST_VSOCK(vdev); |
162 | bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK; |
163 | |
164 | if (!vdev->vm_running) { |
165 | should_start = false; |
166 | } |
167 | |
168 | if (vsock->vhost_dev.started == should_start) { |
169 | return; |
170 | } |
171 | |
172 | if (should_start) { |
173 | vhost_vsock_start(vdev); |
174 | } else { |
175 | vhost_vsock_stop(vdev); |
176 | } |
177 | } |
178 | |
179 | static uint64_t vhost_vsock_get_features(VirtIODevice *vdev, |
180 | uint64_t requested_features, |
181 | Error **errp) |
182 | { |
183 | /* No feature bits used yet */ |
184 | return requested_features; |
185 | } |
186 | |
187 | static void vhost_vsock_handle_output(VirtIODevice *vdev, VirtQueue *vq) |
188 | { |
189 | /* Do nothing */ |
190 | } |
191 | |
192 | static void vhost_vsock_guest_notifier_mask(VirtIODevice *vdev, int idx, |
193 | bool mask) |
194 | { |
195 | VHostVSock *vsock = VHOST_VSOCK(vdev); |
196 | |
197 | vhost_virtqueue_mask(&vsock->vhost_dev, vdev, idx, mask); |
198 | } |
199 | |
200 | static bool vhost_vsock_guest_notifier_pending(VirtIODevice *vdev, int idx) |
201 | { |
202 | VHostVSock *vsock = VHOST_VSOCK(vdev); |
203 | |
204 | return vhost_virtqueue_pending(&vsock->vhost_dev, idx); |
205 | } |
206 | |
207 | static void vhost_vsock_send_transport_reset(VHostVSock *vsock) |
208 | { |
209 | VirtQueueElement *elem; |
210 | VirtQueue *vq = vsock->event_vq; |
211 | struct virtio_vsock_event event = { |
212 | .id = cpu_to_le32(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET), |
213 | }; |
214 | |
215 | elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); |
216 | if (!elem) { |
217 | error_report("vhost-vsock missed transport reset event" ); |
218 | return; |
219 | } |
220 | |
221 | if (elem->out_num) { |
222 | error_report("invalid vhost-vsock event virtqueue element with " |
223 | "out buffers" ); |
224 | goto out; |
225 | } |
226 | |
227 | if (iov_from_buf(elem->in_sg, elem->in_num, 0, |
228 | &event, sizeof(event)) != sizeof(event)) { |
229 | error_report("vhost-vsock event virtqueue element is too short" ); |
230 | goto out; |
231 | } |
232 | |
233 | virtqueue_push(vq, elem, sizeof(event)); |
234 | virtio_notify(VIRTIO_DEVICE(vsock), vq); |
235 | |
236 | out: |
237 | g_free(elem); |
238 | } |
239 | |
240 | static void vhost_vsock_post_load_timer_cleanup(VHostVSock *vsock) |
241 | { |
242 | if (!vsock->post_load_timer) { |
243 | return; |
244 | } |
245 | |
246 | timer_del(vsock->post_load_timer); |
247 | timer_free(vsock->post_load_timer); |
248 | vsock->post_load_timer = NULL; |
249 | } |
250 | |
251 | static void vhost_vsock_post_load_timer_cb(void *opaque) |
252 | { |
253 | VHostVSock *vsock = opaque; |
254 | |
255 | vhost_vsock_post_load_timer_cleanup(vsock); |
256 | vhost_vsock_send_transport_reset(vsock); |
257 | } |
258 | |
259 | static int vhost_vsock_pre_save(void *opaque) |
260 | { |
261 | VHostVSock *vsock = opaque; |
262 | |
263 | /* At this point, backend must be stopped, otherwise |
264 | * it might keep writing to memory. */ |
265 | assert(!vsock->vhost_dev.started); |
266 | |
267 | return 0; |
268 | } |
269 | |
270 | static int vhost_vsock_post_load(void *opaque, int version_id) |
271 | { |
272 | VHostVSock *vsock = opaque; |
273 | VirtIODevice *vdev = VIRTIO_DEVICE(vsock); |
274 | |
275 | if (virtio_queue_get_addr(vdev, 2)) { |
276 | /* Defer transport reset event to a vm clock timer so that virtqueue |
277 | * changes happen after migration has completed. |
278 | */ |
279 | assert(!vsock->post_load_timer); |
280 | vsock->post_load_timer = |
281 | timer_new_ns(QEMU_CLOCK_VIRTUAL, |
282 | vhost_vsock_post_load_timer_cb, |
283 | vsock); |
284 | timer_mod(vsock->post_load_timer, 1); |
285 | } |
286 | return 0; |
287 | } |
288 | |
289 | static const VMStateDescription vmstate_virtio_vhost_vsock = { |
290 | .name = "virtio-vhost_vsock" , |
291 | .minimum_version_id = VHOST_VSOCK_SAVEVM_VERSION, |
292 | .version_id = VHOST_VSOCK_SAVEVM_VERSION, |
293 | .fields = (VMStateField[]) { |
294 | VMSTATE_VIRTIO_DEVICE, |
295 | VMSTATE_END_OF_LIST() |
296 | }, |
297 | .pre_save = vhost_vsock_pre_save, |
298 | .post_load = vhost_vsock_post_load, |
299 | }; |
300 | |
301 | static void vhost_vsock_device_realize(DeviceState *dev, Error **errp) |
302 | { |
303 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
304 | VHostVSock *vsock = VHOST_VSOCK(dev); |
305 | int vhostfd; |
306 | int ret; |
307 | |
308 | /* Refuse to use reserved CID numbers */ |
309 | if (vsock->conf.guest_cid <= 2) { |
310 | error_setg(errp, "guest-cid property must be greater than 2" ); |
311 | return; |
312 | } |
313 | |
314 | if (vsock->conf.guest_cid > UINT32_MAX) { |
315 | error_setg(errp, "guest-cid property must be a 32-bit number" ); |
316 | return; |
317 | } |
318 | |
319 | if (vsock->conf.vhostfd) { |
320 | vhostfd = monitor_fd_param(cur_mon, vsock->conf.vhostfd, errp); |
321 | if (vhostfd == -1) { |
322 | error_prepend(errp, "vhost-vsock: unable to parse vhostfd: " ); |
323 | return; |
324 | } |
325 | } else { |
326 | vhostfd = open("/dev/vhost-vsock" , O_RDWR); |
327 | if (vhostfd < 0) { |
328 | error_setg_errno(errp, -errno, |
329 | "vhost-vsock: failed to open vhost device" ); |
330 | return; |
331 | } |
332 | } |
333 | |
334 | virtio_init(vdev, "vhost-vsock" , VIRTIO_ID_VSOCK, |
335 | sizeof(struct virtio_vsock_config)); |
336 | |
337 | /* Receive and transmit queues belong to vhost */ |
338 | virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output); |
339 | virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output); |
340 | |
341 | /* The event queue belongs to QEMU */ |
342 | vsock->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, |
343 | vhost_vsock_handle_output); |
344 | |
345 | vsock->vhost_dev.nvqs = ARRAY_SIZE(vsock->vhost_vqs); |
346 | vsock->vhost_dev.vqs = vsock->vhost_vqs; |
347 | ret = vhost_dev_init(&vsock->vhost_dev, (void *)(uintptr_t)vhostfd, |
348 | VHOST_BACKEND_TYPE_KERNEL, 0); |
349 | if (ret < 0) { |
350 | error_setg_errno(errp, -ret, "vhost-vsock: vhost_dev_init failed" ); |
351 | goto err_virtio; |
352 | } |
353 | |
354 | ret = vhost_vsock_set_guest_cid(vsock); |
355 | if (ret < 0) { |
356 | error_setg_errno(errp, -ret, "vhost-vsock: unable to set guest cid" ); |
357 | goto err_vhost_dev; |
358 | } |
359 | |
360 | vsock->post_load_timer = NULL; |
361 | return; |
362 | |
363 | err_vhost_dev: |
364 | vhost_dev_cleanup(&vsock->vhost_dev); |
365 | err_virtio: |
366 | virtio_cleanup(vdev); |
367 | close(vhostfd); |
368 | return; |
369 | } |
370 | |
371 | static void vhost_vsock_device_unrealize(DeviceState *dev, Error **errp) |
372 | { |
373 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
374 | VHostVSock *vsock = VHOST_VSOCK(dev); |
375 | |
376 | vhost_vsock_post_load_timer_cleanup(vsock); |
377 | |
378 | /* This will stop vhost backend if appropriate. */ |
379 | vhost_vsock_set_status(vdev, 0); |
380 | |
381 | vhost_dev_cleanup(&vsock->vhost_dev); |
382 | virtio_cleanup(vdev); |
383 | } |
384 | |
385 | static Property vhost_vsock_properties[] = { |
386 | DEFINE_PROP_UINT64("guest-cid" , VHostVSock, conf.guest_cid, 0), |
387 | DEFINE_PROP_STRING("vhostfd" , VHostVSock, conf.vhostfd), |
388 | DEFINE_PROP_END_OF_LIST(), |
389 | }; |
390 | |
391 | static void vhost_vsock_class_init(ObjectClass *klass, void *data) |
392 | { |
393 | DeviceClass *dc = DEVICE_CLASS(klass); |
394 | VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); |
395 | |
396 | dc->props = vhost_vsock_properties; |
397 | dc->vmsd = &vmstate_virtio_vhost_vsock; |
398 | set_bit(DEVICE_CATEGORY_MISC, dc->categories); |
399 | vdc->realize = vhost_vsock_device_realize; |
400 | vdc->unrealize = vhost_vsock_device_unrealize; |
401 | vdc->get_features = vhost_vsock_get_features; |
402 | vdc->get_config = vhost_vsock_get_config; |
403 | vdc->set_status = vhost_vsock_set_status; |
404 | vdc->guest_notifier_mask = vhost_vsock_guest_notifier_mask; |
405 | vdc->guest_notifier_pending = vhost_vsock_guest_notifier_pending; |
406 | } |
407 | |
408 | static const TypeInfo vhost_vsock_info = { |
409 | .name = TYPE_VHOST_VSOCK, |
410 | .parent = TYPE_VIRTIO_DEVICE, |
411 | .instance_size = sizeof(VHostVSock), |
412 | .class_init = vhost_vsock_class_init, |
413 | }; |
414 | |
415 | static void vhost_vsock_register_types(void) |
416 | { |
417 | type_register_static(&vhost_vsock_info); |
418 | } |
419 | |
420 | type_init(vhost_vsock_register_types) |
421 | |