aboutsummaryrefslogtreecommitdiff
path: root/hw/virtio/vhost-vsock.c
blob: 0371493197fd529a086b9ceaf2e182c95dd463df (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
/*
 * Virtio vsock device
 *
 * Copyright 2015 Red Hat, Inc.
 *
 * Authors:
 *  Stefan Hajnoczi <stefanha@redhat.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or
 * (at your option) any later version.  See the COPYING file in the
 * top-level directory.
 */

#include "qemu/osdep.h"
#include <sys/ioctl.h>
#include "standard-headers/linux/virtio_vsock.h"
#include "qapi/error.h"
#include "hw/virtio/virtio-bus.h"
#include "hw/virtio/virtio-access.h"
#include "qemu/error-report.h"
#include "hw/virtio/vhost-vsock.h"
#include "qemu/iov.h"
#include "qemu/module.h"
#include "monitor/monitor.h"

enum {
    VHOST_VSOCK_SAVEVM_VERSION = 0,

    VHOST_VSOCK_QUEUE_SIZE = 128,
};

static void vhost_vsock_get_config(VirtIODevice *vdev, uint8_t *config)
{
    VHostVSock *vsock = VHOST_VSOCK(vdev);
    struct virtio_vsock_config vsockcfg = {};

    virtio_stq_p(vdev, &vsockcfg.guest_cid, vsock->conf.guest_cid);
    memcpy(config, &vsockcfg, sizeof(vsockcfg));
}

static int vhost_vsock_set_guest_cid(VHostVSock *vsock)
{
    const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops;
    int ret;

    if (!vhost_ops->vhost_vsock_set_guest_cid) {
        return -ENOSYS;
    }

    ret = vhost_ops->vhost_vsock_set_guest_cid(&vsock->vhost_dev,
                                               vsock->conf.guest_cid);
    if (ret < 0) {
        return -errno;
    }
    return 0;
}

static int vhost_vsock_set_running(VHostVSock *vsock, int start)
{
    const VhostOps *vhost_ops = vsock->vhost_dev.vhost_ops;
    int ret;

    if (!vhost_ops->vhost_vsock_set_running) {
        return -ENOSYS;
    }

    ret = vhost_ops->vhost_vsock_set_running(&vsock->vhost_dev, start);
    if (ret < 0) {
        return -errno;
    }
    return 0;
}

static void vhost_vsock_start(VirtIODevice *vdev)
{
    VHostVSock *vsock = VHOST_VSOCK(vdev);
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
    int ret;
    int i;

    if (!k->set_guest_notifiers) {
        error_report("binding does not support guest notifiers");
        return;
    }

    ret = vhost_dev_enable_notifiers(&vsock->vhost_dev, vdev);
    if (ret < 0) {
        error_report("Error enabling host notifiers: %d", -ret);
        return;
    }

    ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, true);
    if (ret < 0) {
        error_report("Error binding guest notifier: %d", -ret);
        goto err_host_notifiers;
    }

    vsock->vhost_dev.acked_features = vdev->guest_features;
    ret = vhost_dev_start(&vsock->vhost_dev, vdev);
    if (ret < 0) {
        error_report("Error starting vhost: %d", -ret);
        goto err_guest_notifiers;
    }

    ret = vhost_vsock_set_running(vsock, 1);
    if (ret < 0) {
        error_report("Error starting vhost vsock: %d", -ret);
        goto err_dev_start;
    }

    /* guest_notifier_mask/pending not used yet, so just unmask
     * everything here.  virtio-pci will do the right thing by
     * enabling/disabling irqfd.
     */
    for (i = 0; i < vsock->vhost_dev.nvqs; i++) {
        vhost_virtqueue_mask(&vsock->vhost_dev, vdev, i, false);
    }

    return;

err_dev_start:
    vhost_dev_stop(&vsock->vhost_dev, vdev);
err_guest_notifiers:
    k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false);
err_host_notifiers:
    vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
}

static void vhost_vsock_stop(VirtIODevice *vdev)
{
    VHostVSock *vsock = VHOST_VSOCK(vdev);
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
    int ret;

    if (!k->set_guest_notifiers) {
        return;
    }

    ret = vhost_vsock_set_running(vsock, 0);
    if (ret < 0) {
        error_report("vhost vsock set running failed: %d", ret);
        return;
    }

    vhost_dev_stop(&vsock->vhost_dev, vdev);

    ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false);
    if (ret < 0) {
        error_report("vhost guest notifier cleanup failed: %d", ret);
        return;
    }

    vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
}

static void vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status)
{
    VHostVSock *vsock = VHOST_VSOCK(vdev);
    bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;

    if (!vdev->vm_running) {
        should_start = false;
    }

    if (vsock->vhost_dev.started == should_start) {
        return;
    }

    if (should_start) {
        vhost_vsock_start(vdev);
    } else {
        vhost_vsock_stop(vdev);
    }
}

static uint64_t vhost_vsock_get_features(VirtIODevice *vdev,
                                         uint64_t requested_features,
                                         Error **errp)
{
    /* No feature bits used yet */
    return requested_features;
}

static void vhost_vsock_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
    /* Do nothing */
}

static void vhost_vsock_guest_notifier_mask(VirtIODevice *vdev, int idx,
                                            bool mask)
{
    VHostVSock *vsock = VHOST_VSOCK(vdev);

    vhost_virtqueue_mask(&vsock->vhost_dev, vdev, idx, mask);
}

static bool vhost_vsock_guest_notifier_pending(VirtIODevice *vdev, int idx)
{
    VHostVSock *vsock = VHOST_VSOCK(vdev);

    return vhost_virtqueue_pending(&vsock->vhost_dev, idx);
}

static void vhost_vsock_send_transport_reset(VHostVSock *vsock)
{
    VirtQueueElement *elem;
    VirtQueue *vq = vsock->event_vq;
    struct virtio_vsock_event event = {
        .id = cpu_to_le32(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET),
    };

    elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
    if (!elem) {
        error_report("vhost-vsock missed transport reset event");
        return;
    }

    if (elem->out_num) {
        error_report("invalid vhost-vsock event virtqueue element with "
                     "out buffers");
        goto out;
    }

    if (iov_from_buf(elem->in_sg, elem->in_num, 0,
                     &event, sizeof(event)) != sizeof(event)) {
        error_report("vhost-vsock event virtqueue element is too short");
        goto out;
    }

    virtqueue_push(vq, elem, sizeof(event));
    virtio_notify(VIRTIO_DEVICE(vsock), vq);

out:
    g_free(elem);
}

static void vhost_vsock_post_load_timer_cleanup(VHostVSock *vsock)
{
    if (!vsock->post_load_timer) {
        return;
    }

    timer_del(vsock->post_load_timer);
    timer_free(vsock->post_load_timer);
    vsock->post_load_timer = NULL;
}

static void vhost_vsock_post_load_timer_cb(void *opaque)
{
    VHostVSock *vsock = opaque;

    vhost_vsock_post_load_timer_cleanup(vsock);
    vhost_vsock_send_transport_reset(vsock);
}

static int vhost_vsock_pre_save(void *opaque)
{
    VHostVSock *vsock = opaque;

    /* At this point, backend must be stopped, otherwise
     * it might keep writing to memory. */
    assert(!vsock->vhost_dev.started);

    return 0;
}

static int vhost_vsock_post_load(void *opaque, int version_id)
{
    VHostVSock *vsock = opaque;
    VirtIODevice *vdev = VIRTIO_DEVICE(vsock);

    if (virtio_queue_get_addr(vdev, 2)) {
        /* Defer transport reset event to a vm clock timer so that virtqueue
         * changes happen after migration has completed.
         */
        assert(!vsock->post_load_timer);
        vsock->post_load_timer =
            timer_new_ns(QEMU_CLOCK_VIRTUAL,
                         vhost_vsock_post_load_timer_cb,
                         vsock);
        timer_mod(vsock->post_load_timer, 1);
    }
    return 0;
}

static const VMStateDescription vmstate_virtio_vhost_vsock = {
    .name = "virtio-vhost_vsock",
    .minimum_version_id = VHOST_VSOCK_SAVEVM_VERSION,
    .version_id = VHOST_VSOCK_SAVEVM_VERSION,
    .fields = (VMStateField[]) {
        VMSTATE_VIRTIO_DEVICE,
        VMSTATE_END_OF_LIST()
    },
    .pre_save = vhost_vsock_pre_save,
    .post_load = vhost_vsock_post_load,
};

static void vhost_vsock_device_realize(DeviceState *dev, Error **errp)
{
    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
    VHostVSock *vsock = VHOST_VSOCK(dev);
    int vhostfd;
    int ret;

    /* Refuse to use reserved CID numbers */
    if (vsock->conf.guest_cid <= 2) {
        error_setg(errp, "guest-cid property must be greater than 2");
        return;
    }

    if (vsock->conf.guest_cid > UINT32_MAX) {
        error_setg(errp, "guest-cid property must be a 32-bit number");
        return;
    }

    if (vsock->conf.vhostfd) {
        vhostfd = monitor_fd_param(cur_mon, vsock->conf.vhostfd, errp);
        if (vhostfd == -1) {
            error_prepend(errp, "vhost-vsock: unable to parse vhostfd: ");
            return;
        }
    } else {
        vhostfd = open("/dev/vhost-vsock", O_RDWR);
        if (vhostfd < 0) {
            error_setg_errno(errp, -errno,
                             "vhost-vsock: failed to open vhost device");
            return;
        }
    }

    virtio_init(vdev, "vhost-vsock", VIRTIO_ID_VSOCK,
                sizeof(struct virtio_vsock_config));

    /* Receive and transmit queues belong to vhost */
    virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output);
    virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output);

    /* The event queue belongs to QEMU */
    vsock->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
                                       vhost_vsock_handle_output);

    vsock->vhost_dev.nvqs = ARRAY_SIZE(vsock->vhost_vqs);
    vsock->vhost_dev.vqs = vsock->vhost_vqs;
    ret = vhost_dev_init(&vsock->vhost_dev, (void *)(uintptr_t)vhostfd,
                         VHOST_BACKEND_TYPE_KERNEL, 0);
    if (ret < 0) {
        error_setg_errno(errp, -ret, "vhost-vsock: vhost_dev_init failed");
        goto err_virtio;
    }

    ret = vhost_vsock_set_guest_cid(vsock);
    if (ret < 0) {
        error_setg_errno(errp, -ret, "vhost-vsock: unable to set guest cid");
        goto err_vhost_dev;
    }

    vsock->post_load_timer = NULL;
    return;

err_vhost_dev:
    vhost_dev_cleanup(&vsock->vhost_dev);
err_virtio:
    virtio_cleanup(vdev);
    close(vhostfd);
    return;
}

static void vhost_vsock_device_unrealize(DeviceState *dev, Error **errp)
{
    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
    VHostVSock *vsock = VHOST_VSOCK(dev);

    vhost_vsock_post_load_timer_cleanup(vsock);

    /* This will stop vhost backend if appropriate. */
    vhost_vsock_set_status(vdev, 0);

    vhost_dev_cleanup(&vsock->vhost_dev);
    virtio_cleanup(vdev);
}

static Property vhost_vsock_properties[] = {
    DEFINE_PROP_UINT64("guest-cid", VHostVSock, conf.guest_cid, 0),
    DEFINE_PROP_STRING("vhostfd", VHostVSock, conf.vhostfd),
    DEFINE_PROP_END_OF_LIST(),
};

static void vhost_vsock_class_init(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);
    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);

    dc->props = vhost_vsock_properties;
    dc->vmsd = &vmstate_virtio_vhost_vsock;
    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
    vdc->realize = vhost_vsock_device_realize;
    vdc->unrealize = vhost_vsock_device_unrealize;
    vdc->get_features = vhost_vsock_get_features;
    vdc->get_config = vhost_vsock_get_config;
    vdc->set_status = vhost_vsock_set_status;
    vdc->guest_notifier_mask = vhost_vsock_guest_notifier_mask;
    vdc->guest_notifier_pending = vhost_vsock_guest_notifier_pending;
}

static const TypeInfo vhost_vsock_info = {
    .name = TYPE_VHOST_VSOCK,
    .parent = TYPE_VIRTIO_DEVICE,
    .instance_size = sizeof(VHostVSock),
    .class_init = vhost_vsock_class_init,
};

static void vhost_vsock_register_types(void)
{
    type_register_static(&vhost_vsock_info);
}

type_init(vhost_vsock_register_types)