xref: /openbmc/qemu/hw/virtio/vhost-vsock-common.c (revision bf616ce4)
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-bus.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, true);
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, true);
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     /*
131      * Add the check for configure interrupt, Use VIRTIO_CONFIG_IRQ_IDX -1
132      * as the macro of configure interrupt's IDX, If this driver does not
133      * support, the function will return
134      */
135 
136     if (idx == VIRTIO_CONFIG_IRQ_IDX) {
137         return;
138     }
139     vhost_virtqueue_mask(&vvc->vhost_dev, vdev, idx, mask);
140 }
141 
142 static bool vhost_vsock_common_guest_notifier_pending(VirtIODevice *vdev,
143                                                int idx)
144 {
145     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
146 
147     /*
148      * Add the check for configure interrupt, Use VIRTIO_CONFIG_IRQ_IDX -1
149      * as the macro of configure interrupt's IDX, If this driver does not
150      * support, the function will return
151      */
152 
153     if (idx == VIRTIO_CONFIG_IRQ_IDX) {
154         return false;
155     }
156     return vhost_virtqueue_pending(&vvc->vhost_dev, idx);
157 }
158 
159 static void vhost_vsock_common_send_transport_reset(VHostVSockCommon *vvc)
160 {
161     VirtQueueElement *elem;
162     VirtQueue *vq = vvc->event_vq;
163     struct virtio_vsock_event event = {
164         .id = cpu_to_le32(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET),
165     };
166 
167     elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
168     if (!elem) {
169         error_report("vhost-vsock missed transport reset event");
170         return;
171     }
172 
173     if (elem->out_num) {
174         error_report("invalid vhost-vsock event virtqueue element with "
175                      "out buffers");
176         goto err;
177     }
178 
179     if (iov_from_buf(elem->in_sg, elem->in_num, 0,
180                      &event, sizeof(event)) != sizeof(event)) {
181         error_report("vhost-vsock event virtqueue element is too short");
182         goto err;
183     }
184 
185     virtqueue_push(vq, elem, sizeof(event));
186     virtio_notify(VIRTIO_DEVICE(vvc), vq);
187 
188     g_free(elem);
189     return;
190 
191 err:
192     virtqueue_detach_element(vq, elem, 0);
193     g_free(elem);
194 }
195 
196 static void vhost_vsock_common_post_load_timer_cleanup(VHostVSockCommon *vvc)
197 {
198     if (!vvc->post_load_timer) {
199         return;
200     }
201 
202     timer_free(vvc->post_load_timer);
203     vvc->post_load_timer = NULL;
204 }
205 
206 static void vhost_vsock_common_post_load_timer_cb(void *opaque)
207 {
208     VHostVSockCommon *vvc = opaque;
209 
210     vhost_vsock_common_post_load_timer_cleanup(vvc);
211     vhost_vsock_common_send_transport_reset(vvc);
212 }
213 
214 int vhost_vsock_common_pre_save(void *opaque)
215 {
216     VHostVSockCommon *vvc = opaque;
217 
218     /*
219      * At this point, backend must be stopped, otherwise
220      * it might keep writing to memory.
221      */
222     assert(!vhost_dev_is_started(&vvc->vhost_dev));
223 
224     return 0;
225 }
226 
227 int vhost_vsock_common_post_load(void *opaque, int version_id)
228 {
229     VHostVSockCommon *vvc = opaque;
230     VirtIODevice *vdev = VIRTIO_DEVICE(vvc);
231 
232     if (virtio_queue_get_addr(vdev, 2)) {
233         /*
234          * Defer transport reset event to a vm clock timer so that virtqueue
235          * changes happen after migration has completed.
236          */
237         assert(!vvc->post_load_timer);
238         vvc->post_load_timer =
239             timer_new_ns(QEMU_CLOCK_VIRTUAL,
240                          vhost_vsock_common_post_load_timer_cb,
241                          vvc);
242         timer_mod(vvc->post_load_timer, 1);
243     }
244     return 0;
245 }
246 
247 void vhost_vsock_common_realize(VirtIODevice *vdev)
248 {
249     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
250 
251     virtio_init(vdev, VIRTIO_ID_VSOCK, sizeof(struct virtio_vsock_config));
252 
253     /* Receive and transmit queues belong to vhost */
254     vvc->recv_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
255                                       vhost_vsock_common_handle_output);
256     vvc->trans_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
257                                        vhost_vsock_common_handle_output);
258 
259     /* The event queue belongs to QEMU */
260     vvc->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
261                                        vhost_vsock_common_handle_output);
262 
263     vvc->vhost_dev.nvqs = ARRAY_SIZE(vvc->vhost_vqs);
264     vvc->vhost_dev.vqs = vvc->vhost_vqs;
265 
266     vvc->post_load_timer = NULL;
267 }
268 
269 void vhost_vsock_common_unrealize(VirtIODevice *vdev)
270 {
271     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
272 
273     vhost_vsock_common_post_load_timer_cleanup(vvc);
274 
275     virtio_delete_queue(vvc->recv_vq);
276     virtio_delete_queue(vvc->trans_vq);
277     virtio_delete_queue(vvc->event_vq);
278     virtio_cleanup(vdev);
279 }
280 
281 static struct vhost_dev *vhost_vsock_common_get_vhost(VirtIODevice *vdev)
282 {
283     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
284     return &vvc->vhost_dev;
285 }
286 
287 static Property vhost_vsock_common_properties[] = {
288     DEFINE_PROP_ON_OFF_AUTO("seqpacket", VHostVSockCommon, seqpacket,
289                             ON_OFF_AUTO_AUTO),
290     DEFINE_PROP_END_OF_LIST(),
291 };
292 
293 static void vhost_vsock_common_class_init(ObjectClass *klass, void *data)
294 {
295     DeviceClass *dc = DEVICE_CLASS(klass);
296     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
297 
298     device_class_set_props(dc, vhost_vsock_common_properties);
299     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
300     vdc->guest_notifier_mask = vhost_vsock_common_guest_notifier_mask;
301     vdc->guest_notifier_pending = vhost_vsock_common_guest_notifier_pending;
302     vdc->get_vhost = vhost_vsock_common_get_vhost;
303 }
304 
305 static const TypeInfo vhost_vsock_common_info = {
306     .name = TYPE_VHOST_VSOCK_COMMON,
307     .parent = TYPE_VIRTIO_DEVICE,
308     .instance_size = sizeof(VHostVSockCommon),
309     .class_init = vhost_vsock_common_class_init,
310     .abstract = true,
311 };
312 
313 static void vhost_vsock_common_register_types(void)
314 {
315     type_register_static(&vhost_vsock_common_info);
316 }
317 
318 type_init(vhost_vsock_common_register_types)
319