Merge tag 'edgar/xilinx-next-2022-09-21.for-upstream' of https://github.com/edgarigl...
[qemu.git] / hw / virtio / vhost-user-rng.c
1 /*
2 * Vhost-user RNG virtio device
3 *
4 * Copyright (c) 2021 Mathieu Poirier <mathieu.poirier@linaro.org>
5 *
6 * Implementation seriously tailored on vhost-user-i2c.c
7 *
8 * SPDX-License-Identifier: GPL-2.0-or-later
9 */
10
11 #include "qemu/osdep.h"
12 #include "qapi/error.h"
13 #include "hw/qdev-properties.h"
14 #include "hw/virtio/virtio-bus.h"
15 #include "hw/virtio/vhost-user-rng.h"
16 #include "qemu/error-report.h"
17 #include "standard-headers/linux/virtio_ids.h"
18
19 static void vu_rng_start(VirtIODevice *vdev)
20 {
21 VHostUserRNG *rng = VHOST_USER_RNG(vdev);
22 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
23 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
24 int ret;
25 int i;
26
27 if (!k->set_guest_notifiers) {
28 error_report("binding does not support guest notifiers");
29 return;
30 }
31
32 ret = vhost_dev_enable_notifiers(&rng->vhost_dev, vdev);
33 if (ret < 0) {
34 error_report("Error enabling host notifiers: %d", -ret);
35 return;
36 }
37
38 ret = k->set_guest_notifiers(qbus->parent, rng->vhost_dev.nvqs, true);
39 if (ret < 0) {
40 error_report("Error binding guest notifier: %d", -ret);
41 goto err_host_notifiers;
42 }
43
44 rng->vhost_dev.acked_features = vdev->guest_features;
45 ret = vhost_dev_start(&rng->vhost_dev, vdev);
46 if (ret < 0) {
47 error_report("Error starting vhost-user-rng: %d", -ret);
48 goto err_guest_notifiers;
49 }
50
51 /*
52 * guest_notifier_mask/pending not used yet, so just unmask
53 * everything here. virtio-pci will do the right thing by
54 * enabling/disabling irqfd.
55 */
56 for (i = 0; i < rng->vhost_dev.nvqs; i++) {
57 vhost_virtqueue_mask(&rng->vhost_dev, vdev, i, false);
58 }
59
60 return;
61
62 err_guest_notifiers:
63 k->set_guest_notifiers(qbus->parent, rng->vhost_dev.nvqs, false);
64 err_host_notifiers:
65 vhost_dev_disable_notifiers(&rng->vhost_dev, vdev);
66 }
67
68 static void vu_rng_stop(VirtIODevice *vdev)
69 {
70 VHostUserRNG *rng = VHOST_USER_RNG(vdev);
71 BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
72 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
73 int ret;
74
75 if (!k->set_guest_notifiers) {
76 return;
77 }
78
79 vhost_dev_stop(&rng->vhost_dev, vdev);
80
81 ret = k->set_guest_notifiers(qbus->parent, rng->vhost_dev.nvqs, false);
82 if (ret < 0) {
83 error_report("vhost guest notifier cleanup failed: %d", ret);
84 return;
85 }
86
87 vhost_dev_disable_notifiers(&rng->vhost_dev, vdev);
88 }
89
90 static void vu_rng_set_status(VirtIODevice *vdev, uint8_t status)
91 {
92 VHostUserRNG *rng = VHOST_USER_RNG(vdev);
93 bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
94
95 if (!vdev->vm_running) {
96 should_start = false;
97 }
98
99 if (rng->vhost_dev.started == should_start) {
100 return;
101 }
102
103 if (should_start) {
104 vu_rng_start(vdev);
105 } else {
106 vu_rng_stop(vdev);
107 }
108 }
109
110 static uint64_t vu_rng_get_features(VirtIODevice *vdev,
111 uint64_t requested_features, Error **errp)
112 {
113 /* No feature bits used yet */
114 return requested_features;
115 }
116
117 static void vu_rng_handle_output(VirtIODevice *vdev, VirtQueue *vq)
118 {
119 /*
120 * Not normally called; it's the daemon that handles the queue;
121 * however virtio's cleanup path can call this.
122 */
123 }
124
125 static void vu_rng_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask)
126 {
127 VHostUserRNG *rng = VHOST_USER_RNG(vdev);
128
129 vhost_virtqueue_mask(&rng->vhost_dev, vdev, idx, mask);
130 }
131
132 static bool vu_rng_guest_notifier_pending(VirtIODevice *vdev, int idx)
133 {
134 VHostUserRNG *rng = VHOST_USER_RNG(vdev);
135
136 return vhost_virtqueue_pending(&rng->vhost_dev, idx);
137 }
138
139 static void vu_rng_connect(DeviceState *dev)
140 {
141 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
142 VHostUserRNG *rng = VHOST_USER_RNG(vdev);
143
144 if (rng->connected) {
145 return;
146 }
147
148 rng->connected = true;
149
150 /* restore vhost state */
151 if (virtio_device_started(vdev, vdev->status)) {
152 vu_rng_start(vdev);
153 }
154 }
155
156 static void vu_rng_disconnect(DeviceState *dev)
157 {
158 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
159 VHostUserRNG *rng = VHOST_USER_RNG(vdev);
160
161 if (!rng->connected) {
162 return;
163 }
164
165 rng->connected = false;
166
167 if (rng->vhost_dev.started) {
168 vu_rng_stop(vdev);
169 }
170 }
171
172 static void vu_rng_event(void *opaque, QEMUChrEvent event)
173 {
174 DeviceState *dev = opaque;
175
176 switch (event) {
177 case CHR_EVENT_OPENED:
178 vu_rng_connect(dev);
179 break;
180 case CHR_EVENT_CLOSED:
181 vu_rng_disconnect(dev);
182 break;
183 case CHR_EVENT_BREAK:
184 case CHR_EVENT_MUX_IN:
185 case CHR_EVENT_MUX_OUT:
186 /* Ignore */
187 break;
188 }
189 }
190
191 static void vu_rng_device_realize(DeviceState *dev, Error **errp)
192 {
193 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
194 VHostUserRNG *rng = VHOST_USER_RNG(dev);
195 int ret;
196
197 if (!rng->chardev.chr) {
198 error_setg(errp, "missing chardev");
199 return;
200 }
201
202 if (!vhost_user_init(&rng->vhost_user, &rng->chardev, errp)) {
203 return;
204 }
205
206 virtio_init(vdev, "vhost-user-rng", VIRTIO_ID_RNG, 0);
207
208 rng->req_vq = virtio_add_queue(vdev, 4, vu_rng_handle_output);
209 if (!rng->req_vq) {
210 error_setg_errno(errp, -1, "virtio_add_queue() failed");
211 goto virtio_add_queue_failed;
212 }
213
214 rng->vhost_dev.nvqs = 1;
215 rng->vhost_dev.vqs = g_new0(struct vhost_virtqueue, rng->vhost_dev.nvqs);
216 ret = vhost_dev_init(&rng->vhost_dev, &rng->vhost_user,
217 VHOST_BACKEND_TYPE_USER, 0, errp);
218 if (ret < 0) {
219 error_setg_errno(errp, -ret, "vhost_dev_init() failed");
220 goto vhost_dev_init_failed;
221 }
222
223 qemu_chr_fe_set_handlers(&rng->chardev, NULL, NULL, vu_rng_event, NULL,
224 dev, NULL, true);
225
226 return;
227
228 vhost_dev_init_failed:
229 virtio_delete_queue(rng->req_vq);
230 virtio_add_queue_failed:
231 virtio_cleanup(vdev);
232 vhost_user_cleanup(&rng->vhost_user);
233 }
234
235 static void vu_rng_device_unrealize(DeviceState *dev)
236 {
237 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
238 VHostUserRNG *rng = VHOST_USER_RNG(dev);
239
240 vu_rng_set_status(vdev, 0);
241
242 vhost_dev_cleanup(&rng->vhost_dev);
243 g_free(rng->vhost_dev.vqs);
244 rng->vhost_dev.vqs = NULL;
245 virtio_delete_queue(rng->req_vq);
246 virtio_cleanup(vdev);
247 vhost_user_cleanup(&rng->vhost_user);
248 }
249
250 static const VMStateDescription vu_rng_vmstate = {
251 .name = "vhost-user-rng",
252 .unmigratable = 1,
253 };
254
255 static Property vu_rng_properties[] = {
256 DEFINE_PROP_CHR("chardev", VHostUserRNG, chardev),
257 DEFINE_PROP_END_OF_LIST(),
258 };
259
260 static void vu_rng_class_init(ObjectClass *klass, void *data)
261 {
262 DeviceClass *dc = DEVICE_CLASS(klass);
263 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
264
265 device_class_set_props(dc, vu_rng_properties);
266 dc->vmsd = &vu_rng_vmstate;
267 set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
268
269 vdc->realize = vu_rng_device_realize;
270 vdc->unrealize = vu_rng_device_unrealize;
271 vdc->get_features = vu_rng_get_features;
272 vdc->set_status = vu_rng_set_status;
273 vdc->guest_notifier_mask = vu_rng_guest_notifier_mask;
274 vdc->guest_notifier_pending = vu_rng_guest_notifier_pending;
275 }
276
277 static const TypeInfo vu_rng_info = {
278 .name = TYPE_VHOST_USER_RNG,
279 .parent = TYPE_VIRTIO_DEVICE,
280 .instance_size = sizeof(VHostUserRNG),
281 .class_init = vu_rng_class_init,
282 };
283
284 static void vu_rng_register_types(void)
285 {
286 type_register_static(&vu_rng_info);
287 }
288
289 type_init(vu_rng_register_types)