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27ba7b02 VK |
1 | /* |
2 | * Vhost-user GPIO virtio device | |
3 | * | |
4 | * Copyright (c) 2022 Viresh Kumar <viresh.kumar@linaro.org> | |
5 | * | |
6 | * SPDX-License-Identifier: GPL-2.0-or-later | |
7 | */ | |
8 | ||
9 | #include "qemu/osdep.h" | |
10 | #include "qapi/error.h" | |
11 | #include "hw/qdev-properties.h" | |
12 | #include "hw/virtio/virtio-bus.h" | |
13 | #include "hw/virtio/vhost-user-gpio.h" | |
14 | #include "qemu/error-report.h" | |
15 | #include "standard-headers/linux/virtio_ids.h" | |
16 | #include "trace.h" | |
17 | ||
18 | #define REALIZE_CONNECTION_RETRIES 3 | |
19 | ||
20 | /* Features required from VirtIO */ | |
21 | static const int feature_bits[] = { | |
22 | VIRTIO_F_VERSION_1, | |
23 | VIRTIO_F_NOTIFY_ON_EMPTY, | |
24 | VIRTIO_RING_F_INDIRECT_DESC, | |
25 | VIRTIO_RING_F_EVENT_IDX, | |
26 | VIRTIO_GPIO_F_IRQ, | |
27 | VHOST_INVALID_FEATURE_BIT | |
28 | }; | |
29 | ||
30 | static void vu_gpio_get_config(VirtIODevice *vdev, uint8_t *config) | |
31 | { | |
32 | VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev); | |
33 | ||
34 | memcpy(config, &gpio->config, sizeof(gpio->config)); | |
35 | } | |
36 | ||
37 | static int vu_gpio_config_notifier(struct vhost_dev *dev) | |
38 | { | |
39 | VHostUserGPIO *gpio = VHOST_USER_GPIO(dev->vdev); | |
40 | ||
41 | memcpy(dev->vdev->config, &gpio->config, sizeof(gpio->config)); | |
42 | virtio_notify_config(dev->vdev); | |
43 | ||
44 | return 0; | |
45 | } | |
46 | ||
47 | const VhostDevConfigOps gpio_ops = { | |
48 | .vhost_dev_config_notifier = vu_gpio_config_notifier, | |
49 | }; | |
50 | ||
51 | static int vu_gpio_start(VirtIODevice *vdev) | |
52 | { | |
53 | BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); | |
54 | VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); | |
55 | VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev); | |
56 | struct vhost_dev *vhost_dev = &gpio->vhost_dev; | |
57 | int ret, i; | |
58 | ||
59 | if (!k->set_guest_notifiers) { | |
60 | error_report("binding does not support guest notifiers"); | |
61 | return -ENOSYS; | |
62 | } | |
63 | ||
64 | ret = vhost_dev_enable_notifiers(vhost_dev, vdev); | |
65 | if (ret < 0) { | |
66 | error_report("Error enabling host notifiers: %d", ret); | |
67 | return ret; | |
68 | } | |
69 | ||
70 | ret = k->set_guest_notifiers(qbus->parent, vhost_dev->nvqs, true); | |
71 | if (ret < 0) { | |
72 | error_report("Error binding guest notifier: %d", ret); | |
73 | goto err_host_notifiers; | |
74 | } | |
75 | ||
76 | /* | |
77 | * Before we start up we need to ensure we have the final feature | |
78 | * set needed for the vhost configuration. The backend may also | |
79 | * apply backend_features when the feature set is sent. | |
80 | */ | |
81 | vhost_ack_features(&gpio->vhost_dev, feature_bits, vdev->guest_features); | |
82 | ||
83 | ret = vhost_dev_start(&gpio->vhost_dev, vdev); | |
84 | if (ret < 0) { | |
85 | error_report("Error starting vhost-user-gpio: %d", ret); | |
86 | goto err_guest_notifiers; | |
87 | } | |
88 | ||
89 | /* | |
90 | * guest_notifier_mask/pending not used yet, so just unmask | |
91 | * everything here. virtio-pci will do the right thing by | |
92 | * enabling/disabling irqfd. | |
93 | */ | |
94 | for (i = 0; i < gpio->vhost_dev.nvqs; i++) { | |
95 | vhost_virtqueue_mask(&gpio->vhost_dev, vdev, i, false); | |
96 | } | |
97 | ||
98 | /* | |
99 | * As we must have VHOST_USER_F_PROTOCOL_FEATURES (because | |
100 | * VHOST_USER_GET_CONFIG requires it) we need to explicitly enable | |
101 | * the vrings. | |
102 | */ | |
103 | g_assert(vhost_dev->vhost_ops && | |
104 | vhost_dev->vhost_ops->vhost_set_vring_enable); | |
105 | ret = vhost_dev->vhost_ops->vhost_set_vring_enable(vhost_dev, true); | |
106 | if (ret == 0) { | |
107 | return 0; | |
108 | } | |
109 | ||
110 | error_report("Failed to start vrings for vhost-user-gpio: %d", ret); | |
111 | ||
112 | err_guest_notifiers: | |
113 | k->set_guest_notifiers(qbus->parent, gpio->vhost_dev.nvqs, false); | |
114 | err_host_notifiers: | |
115 | vhost_dev_disable_notifiers(&gpio->vhost_dev, vdev); | |
116 | ||
117 | return ret; | |
118 | } | |
119 | ||
120 | static void vu_gpio_stop(VirtIODevice *vdev) | |
121 | { | |
122 | VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev); | |
123 | BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); | |
124 | VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); | |
125 | struct vhost_dev *vhost_dev = &gpio->vhost_dev; | |
126 | int ret; | |
127 | ||
128 | if (!k->set_guest_notifiers) { | |
129 | return; | |
130 | } | |
131 | ||
132 | /* | |
133 | * We can call vu_gpio_stop multiple times, for example from | |
134 | * vm_state_notify and the final object finalisation. Check we | |
135 | * aren't already stopped before doing so. | |
136 | */ | |
137 | if (!vhost_dev_is_started(vhost_dev)) { | |
138 | return; | |
139 | } | |
140 | ||
141 | vhost_dev_stop(vhost_dev, vdev); | |
142 | ||
143 | ret = k->set_guest_notifiers(qbus->parent, vhost_dev->nvqs, false); | |
144 | if (ret < 0) { | |
145 | error_report("vhost guest notifier cleanup failed: %d", ret); | |
146 | return; | |
147 | } | |
148 | ||
149 | vhost_dev_disable_notifiers(vhost_dev, vdev); | |
150 | } | |
151 | ||
152 | static void vu_gpio_set_status(VirtIODevice *vdev, uint8_t status) | |
153 | { | |
154 | VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev); | |
259d69c0 | 155 | bool should_start = virtio_device_should_start(vdev, status); |
27ba7b02 VK |
156 | |
157 | trace_virtio_gpio_set_status(status); | |
158 | ||
159 | if (!gpio->connected) { | |
160 | return; | |
161 | } | |
162 | ||
163 | if (vhost_dev_is_started(&gpio->vhost_dev) == should_start) { | |
164 | return; | |
165 | } | |
166 | ||
167 | if (should_start) { | |
168 | if (vu_gpio_start(vdev)) { | |
169 | qemu_chr_fe_disconnect(&gpio->chardev); | |
170 | } | |
171 | } else { | |
172 | vu_gpio_stop(vdev); | |
173 | } | |
174 | } | |
175 | ||
176 | static uint64_t vu_gpio_get_features(VirtIODevice *vdev, uint64_t features, | |
177 | Error **errp) | |
178 | { | |
179 | VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev); | |
180 | ||
181 | return vhost_get_features(&gpio->vhost_dev, feature_bits, features); | |
182 | } | |
183 | ||
184 | static void vu_gpio_handle_output(VirtIODevice *vdev, VirtQueue *vq) | |
185 | { | |
186 | /* | |
187 | * Not normally called; it's the daemon that handles the queue; | |
188 | * however virtio's cleanup path can call this. | |
189 | */ | |
190 | } | |
191 | ||
192 | static void vu_gpio_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask) | |
193 | { | |
194 | VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev); | |
195 | ||
196 | vhost_virtqueue_mask(&gpio->vhost_dev, vdev, idx, mask); | |
197 | } | |
198 | ||
199 | static void do_vhost_user_cleanup(VirtIODevice *vdev, VHostUserGPIO *gpio) | |
200 | { | |
201 | virtio_delete_queue(gpio->command_vq); | |
202 | virtio_delete_queue(gpio->interrupt_vq); | |
203 | g_free(gpio->vhost_dev.vqs); | |
204 | gpio->vhost_dev.vqs = NULL; | |
205 | virtio_cleanup(vdev); | |
206 | vhost_user_cleanup(&gpio->vhost_user); | |
207 | } | |
208 | ||
209 | static int vu_gpio_connect(DeviceState *dev, Error **errp) | |
210 | { | |
211 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); | |
212 | VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev); | |
213 | struct vhost_dev *vhost_dev = &gpio->vhost_dev; | |
214 | int ret; | |
215 | ||
216 | if (gpio->connected) { | |
217 | return 0; | |
218 | } | |
219 | gpio->connected = true; | |
220 | ||
221 | vhost_dev_set_config_notifier(vhost_dev, &gpio_ops); | |
222 | gpio->vhost_user.supports_config = true; | |
223 | ||
224 | ret = vhost_dev_init(vhost_dev, &gpio->vhost_user, | |
225 | VHOST_BACKEND_TYPE_USER, 0, errp); | |
226 | if (ret < 0) { | |
227 | return ret; | |
228 | } | |
229 | ||
230 | /* restore vhost state */ | |
231 | if (virtio_device_started(vdev, vdev->status)) { | |
232 | vu_gpio_start(vdev); | |
233 | } | |
234 | ||
235 | return 0; | |
236 | } | |
237 | ||
238 | static void vu_gpio_disconnect(DeviceState *dev) | |
239 | { | |
240 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); | |
241 | VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev); | |
242 | ||
243 | if (!gpio->connected) { | |
244 | return; | |
245 | } | |
246 | gpio->connected = false; | |
247 | ||
248 | vu_gpio_stop(vdev); | |
249 | vhost_dev_cleanup(&gpio->vhost_dev); | |
250 | } | |
251 | ||
252 | static void vu_gpio_event(void *opaque, QEMUChrEvent event) | |
253 | { | |
254 | DeviceState *dev = opaque; | |
255 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); | |
256 | VHostUserGPIO *gpio = VHOST_USER_GPIO(vdev); | |
257 | Error *local_err = NULL; | |
258 | ||
259 | switch (event) { | |
260 | case CHR_EVENT_OPENED: | |
261 | if (vu_gpio_connect(dev, &local_err) < 0) { | |
262 | qemu_chr_fe_disconnect(&gpio->chardev); | |
263 | return; | |
264 | } | |
265 | break; | |
266 | case CHR_EVENT_CLOSED: | |
267 | vu_gpio_disconnect(dev); | |
268 | break; | |
269 | case CHR_EVENT_BREAK: | |
270 | case CHR_EVENT_MUX_IN: | |
271 | case CHR_EVENT_MUX_OUT: | |
272 | /* Ignore */ | |
273 | break; | |
274 | } | |
275 | } | |
276 | ||
277 | static int vu_gpio_realize_connect(VHostUserGPIO *gpio, Error **errp) | |
278 | { | |
279 | VirtIODevice *vdev = &gpio->parent_obj; | |
280 | DeviceState *dev = &vdev->parent_obj; | |
281 | struct vhost_dev *vhost_dev = &gpio->vhost_dev; | |
282 | int ret; | |
283 | ||
284 | ret = qemu_chr_fe_wait_connected(&gpio->chardev, errp); | |
285 | if (ret < 0) { | |
286 | return ret; | |
287 | } | |
288 | ||
289 | /* | |
290 | * vu_gpio_connect() may have already connected (via the event | |
291 | * callback) in which case it will just report success. | |
292 | */ | |
293 | ret = vu_gpio_connect(dev, errp); | |
294 | if (ret < 0) { | |
295 | qemu_chr_fe_disconnect(&gpio->chardev); | |
296 | return ret; | |
297 | } | |
298 | g_assert(gpio->connected); | |
299 | ||
300 | ret = vhost_dev_get_config(vhost_dev, (uint8_t *)&gpio->config, | |
301 | sizeof(gpio->config), errp); | |
302 | ||
303 | if (ret < 0) { | |
304 | error_report("vhost-user-gpio: get config failed"); | |
305 | ||
306 | qemu_chr_fe_disconnect(&gpio->chardev); | |
307 | vhost_dev_cleanup(vhost_dev); | |
308 | return ret; | |
309 | } | |
310 | ||
311 | return 0; | |
312 | } | |
313 | ||
314 | static void vu_gpio_device_realize(DeviceState *dev, Error **errp) | |
315 | { | |
316 | ERRP_GUARD(); | |
317 | ||
318 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); | |
319 | VHostUserGPIO *gpio = VHOST_USER_GPIO(dev); | |
320 | int retries, ret; | |
321 | ||
322 | if (!gpio->chardev.chr) { | |
323 | error_setg(errp, "vhost-user-gpio: chardev is mandatory"); | |
324 | return; | |
325 | } | |
326 | ||
327 | if (!vhost_user_init(&gpio->vhost_user, &gpio->chardev, errp)) { | |
328 | return; | |
329 | } | |
330 | ||
331 | virtio_init(vdev, VIRTIO_ID_GPIO, sizeof(gpio->config)); | |
332 | ||
333 | gpio->vhost_dev.nvqs = 2; | |
334 | gpio->command_vq = virtio_add_queue(vdev, 256, vu_gpio_handle_output); | |
335 | gpio->interrupt_vq = virtio_add_queue(vdev, 256, vu_gpio_handle_output); | |
336 | gpio->vhost_dev.vqs = g_new0(struct vhost_virtqueue, gpio->vhost_dev.nvqs); | |
337 | ||
338 | gpio->connected = false; | |
339 | ||
340 | qemu_chr_fe_set_handlers(&gpio->chardev, NULL, NULL, vu_gpio_event, NULL, | |
341 | dev, NULL, true); | |
342 | ||
343 | retries = REALIZE_CONNECTION_RETRIES; | |
344 | g_assert(!*errp); | |
345 | do { | |
346 | if (*errp) { | |
347 | error_prepend(errp, "Reconnecting after error: "); | |
348 | error_report_err(*errp); | |
349 | *errp = NULL; | |
350 | } | |
351 | ret = vu_gpio_realize_connect(gpio, errp); | |
352 | } while (ret < 0 && retries--); | |
353 | ||
354 | if (ret < 0) { | |
355 | do_vhost_user_cleanup(vdev, gpio); | |
356 | } | |
357 | ||
358 | return; | |
359 | } | |
360 | ||
361 | static void vu_gpio_device_unrealize(DeviceState *dev) | |
362 | { | |
363 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); | |
364 | VHostUserGPIO *gpio = VHOST_USER_GPIO(dev); | |
365 | ||
366 | vu_gpio_set_status(vdev, 0); | |
367 | qemu_chr_fe_set_handlers(&gpio->chardev, NULL, NULL, NULL, NULL, NULL, NULL, | |
368 | false); | |
369 | vhost_dev_cleanup(&gpio->vhost_dev); | |
370 | do_vhost_user_cleanup(vdev, gpio); | |
371 | } | |
372 | ||
373 | static const VMStateDescription vu_gpio_vmstate = { | |
374 | .name = "vhost-user-gpio", | |
375 | .unmigratable = 1, | |
376 | }; | |
377 | ||
378 | static Property vu_gpio_properties[] = { | |
379 | DEFINE_PROP_CHR("chardev", VHostUserGPIO, chardev), | |
380 | DEFINE_PROP_END_OF_LIST(), | |
381 | }; | |
382 | ||
383 | static void vu_gpio_class_init(ObjectClass *klass, void *data) | |
384 | { | |
385 | DeviceClass *dc = DEVICE_CLASS(klass); | |
386 | VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); | |
387 | ||
388 | device_class_set_props(dc, vu_gpio_properties); | |
389 | dc->vmsd = &vu_gpio_vmstate; | |
390 | set_bit(DEVICE_CATEGORY_INPUT, dc->categories); | |
391 | vdc->realize = vu_gpio_device_realize; | |
392 | vdc->unrealize = vu_gpio_device_unrealize; | |
393 | vdc->get_features = vu_gpio_get_features; | |
394 | vdc->get_config = vu_gpio_get_config; | |
395 | vdc->set_status = vu_gpio_set_status; | |
396 | vdc->guest_notifier_mask = vu_gpio_guest_notifier_mask; | |
397 | } | |
398 | ||
399 | static const TypeInfo vu_gpio_info = { | |
400 | .name = TYPE_VHOST_USER_GPIO, | |
401 | .parent = TYPE_VIRTIO_DEVICE, | |
402 | .instance_size = sizeof(VHostUserGPIO), | |
403 | .class_init = vu_gpio_class_init, | |
404 | }; | |
405 | ||
406 | static void vu_gpio_register_types(void) | |
407 | { | |
408 | type_register_static(&vu_gpio_info); | |
409 | } | |
410 | ||
411 | type_init(vu_gpio_register_types) |