qemu

1
/*
2
 * vhost-user-scsi host device
3
 *
4
 * Copyright (c) 2016 Nutanix Inc. All rights reserved.
5
 *
6
 * Author:
7
 *  Felipe Franciosi <felipe@nutanix.com>
8
 *
9
 * This work is largely based on the "vhost-scsi" implementation by:
10
 *  Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>
11
 *  Nicholas Bellinger <nab@risingtidesystems.com>
12
 *
13
 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
14
 * See the COPYING.LIB file in the top-level directory.
15
 *
16
 */
17

18
#include "qemu/osdep.h"
19
#include "qapi/error.h"
20
#include "qemu/error-report.h"
21
#include "hw/fw-path-provider.h"
22
#include "hw/qdev-core.h"
23
#include "hw/qdev-properties.h"
24
#include "hw/qdev-properties-system.h"
25
#include "hw/virtio/vhost.h"
26
#include "hw/virtio/vhost-backend.h"
27
#include "hw/virtio/vhost-user-scsi.h"
28
#include "hw/virtio/virtio.h"
29
#include "chardev/char-fe.h"
30
#include "sysemu/sysemu.h"
31

32
/* Features supported by the host application */
33
static const int user_feature_bits[] = {
34
    VIRTIO_F_NOTIFY_ON_EMPTY,
35
    VIRTIO_RING_F_INDIRECT_DESC,
36
    VIRTIO_RING_F_EVENT_IDX,
37
    VIRTIO_SCSI_F_HOTPLUG,
38
    VIRTIO_F_RING_RESET,
39
    VIRTIO_F_IN_ORDER,
40
    VIRTIO_F_NOTIFICATION_DATA,
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    VHOST_INVALID_FEATURE_BIT
42
};
43

44
static int vhost_user_scsi_start(VHostUserSCSI *s, Error **errp)
45
{
46
    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
47
    int ret;
48

49
    ret = vhost_scsi_common_start(vsc, errp);
50
    s->started_vu = !(ret < 0);
51

52
    return ret;
53
}
54

55
static void vhost_user_scsi_stop(VHostUserSCSI *s)
56
{
57
    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
58

59
    if (!s->started_vu) {
60
        return;
61
    }
62
    s->started_vu = false;
63

64
    vhost_scsi_common_stop(vsc);
65
}
66

67
static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status)
68
{
69
    VHostUserSCSI *s = (VHostUserSCSI *)vdev;
70
    DeviceState *dev = DEVICE(vdev);
71
    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
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    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
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    bool should_start = virtio_device_should_start(vdev, status);
74
    Error *local_err = NULL;
75
    int ret;
76

77
    if (!s->connected) {
78
        return;
79
    }
80

81
    if (vhost_dev_is_started(&vsc->dev) == should_start) {
82
        return;
83
    }
84

85
    if (should_start) {
86
        ret = vhost_user_scsi_start(s, &local_err);
87
        if (ret < 0) {
88
            error_reportf_err(local_err,
89
                              "unable to start vhost-user-scsi: %s: ",
90
                              strerror(-ret));
91
            qemu_chr_fe_disconnect(&vs->conf.chardev);
92
        }
93
    } else {
94
        vhost_user_scsi_stop(s);
95
    }
96
}
97

98
static void vhost_user_scsi_handle_output(VirtIODevice *vdev, VirtQueue *vq)
99
{
100
    VHostUserSCSI *s = (VHostUserSCSI *)vdev;
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    DeviceState *dev = DEVICE(vdev);
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    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
103
    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
104

105
    Error *local_err = NULL;
106
    int i, ret;
107

108
    if (!vdev->start_on_kick) {
109
        return;
110
    }
111

112
    if (!s->connected) {
113
        return;
114
    }
115

116
    if (vhost_dev_is_started(&vsc->dev)) {
117
        return;
118
    }
119

120
    /*
121
     * Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
122
     * vhost here instead of waiting for .set_status().
123
     */
124
    ret = vhost_user_scsi_start(s, &local_err);
125
    if (ret < 0) {
126
        error_reportf_err(local_err, "vhost-user-scsi: vhost start failed: ");
127
        qemu_chr_fe_disconnect(&vs->conf.chardev);
128
        return;
129
    }
130

131
    /* Kick right away to begin processing requests already in vring */
132
    for (i = 0; i < vsc->dev.nvqs; i++) {
133
        VirtQueue *kick_vq = virtio_get_queue(vdev, i);
134

135
        if (!virtio_queue_get_desc_addr(vdev, i)) {
136
            continue;
137
        }
138
        event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
139
    }
140
}
141

142
static int vhost_user_scsi_connect(DeviceState *dev, Error **errp)
143
{
144
    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
145
    VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
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    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
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    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
148
    int ret = 0;
149

150
    if (s->connected) {
151
        return 0;
152
    }
153

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    vsc->dev.num_queues = vs->conf.num_queues;
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    vsc->dev.nvqs = VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
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    vsc->dev.vqs = s->vhost_vqs;
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    vsc->dev.vq_index = 0;
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    vsc->dev.backend_features = 0;
159

160
    ret = vhost_dev_init(&vsc->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0,
161
                         errp);
162
    if (ret < 0) {
163
        return ret;
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    }
165

166
    s->connected = true;
167

168
    /* restore vhost state */
169
    if (virtio_device_started(vdev, vdev->status)) {
170
        ret = vhost_user_scsi_start(s, errp);
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    }
172

173
    return ret;
174
}
175

176
static void vhost_user_scsi_event(void *opaque, QEMUChrEvent event);
177

178
static void vhost_user_scsi_disconnect(DeviceState *dev)
179
{
180
    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
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    VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
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    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
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    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
184

185
    if (!s->connected) {
186
        goto done;
187
    }
188
    s->connected = false;
189

190
    vhost_user_scsi_stop(s);
191

192
    vhost_dev_cleanup(&vsc->dev);
193

194
done:
195
    /* Re-instate the event handler for new connections */
196
    qemu_chr_fe_set_handlers(&vs->conf.chardev, NULL, NULL,
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                             vhost_user_scsi_event, NULL, dev, NULL, true);
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}
199

200
static void vhost_user_scsi_event(void *opaque, QEMUChrEvent event)
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{
202
    DeviceState *dev = opaque;
203
    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
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    VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
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    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
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    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
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    Error *local_err = NULL;
208

209
    switch (event) {
210
    case CHR_EVENT_OPENED:
211
        if (vhost_user_scsi_connect(dev, &local_err) < 0) {
212
            error_report_err(local_err);
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            qemu_chr_fe_disconnect(&vs->conf.chardev);
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            return;
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        }
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        break;
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    case CHR_EVENT_CLOSED:
218
        /* defer close until later to avoid circular close */
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        vhost_user_async_close(dev, &vs->conf.chardev, &vsc->dev,
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                               vhost_user_scsi_disconnect);
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        break;
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    case CHR_EVENT_BREAK:
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    case CHR_EVENT_MUX_IN:
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    case CHR_EVENT_MUX_OUT:
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        /* Ignore */
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        break;
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    }
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}
229

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static int vhost_user_scsi_realize_connect(VHostUserSCSI *s, Error **errp)
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{
232
    DeviceState *dev = DEVICE(s);
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    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
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    int ret;
235

236
    s->connected = false;
237

238
    ret = qemu_chr_fe_wait_connected(&vs->conf.chardev, errp);
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    if (ret < 0) {
240
        return ret;
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    }
242

243
    ret = vhost_user_scsi_connect(dev, errp);
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    if (ret < 0) {
245
        qemu_chr_fe_disconnect(&vs->conf.chardev);
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        return ret;
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    }
248
    assert(s->connected);
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    return 0;
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}
252

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static void vhost_user_scsi_realize(DeviceState *dev, Error **errp)
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{
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    ERRP_GUARD();
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    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
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    VHostUserSCSI *s = VHOST_USER_SCSI(dev);
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    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
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    Error *err = NULL;
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    int ret;
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    int retries = VU_REALIZE_CONN_RETRIES;
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263
    if (!vs->conf.chardev.chr) {
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        error_setg(errp, "vhost-user-scsi: missing chardev");
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        return;
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    }
267

268
    virtio_scsi_common_realize(dev, vhost_user_scsi_handle_output,
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                               vhost_user_scsi_handle_output,
270
                               vhost_user_scsi_handle_output, &err);
271
    if (err != NULL) {
272
        error_propagate(errp, err);
273
        return;
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    }
275

276
    if (!vhost_user_init(&s->vhost_user, &vs->conf.chardev, errp)) {
277
        goto free_virtio;
278
    }
279

280
    vsc->inflight = g_new0(struct vhost_inflight, 1);
281
    s->vhost_vqs = g_new0(struct vhost_virtqueue,
282
                          VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues);
283

284
    assert(!*errp);
285
    do {
286
        if (*errp) {
287
            error_prepend(errp, "Reconnecting after error: ");
288
            error_report_err(*errp);
289
            *errp = NULL;
290
        }
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        ret = vhost_user_scsi_realize_connect(s, errp);
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    } while (ret < 0 && retries--);
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294
    if (ret < 0) {
295
        goto free_vhost;
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    }
297

298
    /* we're fully initialized, now we can operate, so add the handler */
299
    qemu_chr_fe_set_handlers(&vs->conf.chardev,  NULL, NULL,
300
                             vhost_user_scsi_event, NULL, (void *)dev,
301
                             NULL, true);
302
    /* Channel and lun both are 0 for bootable vhost-user-scsi disk */
303
    vsc->channel = 0;
304
    vsc->lun = 0;
305
    vsc->target = vs->conf.boot_tpgt;
306

307
    return;
308

309
free_vhost:
310
    g_free(s->vhost_vqs);
311
    s->vhost_vqs = NULL;
312
    g_free(vsc->inflight);
313
    vsc->inflight = NULL;
314
    vhost_user_cleanup(&s->vhost_user);
315

316
free_virtio:
317
    virtio_scsi_common_unrealize(dev);
318
}
319

320
static void vhost_user_scsi_unrealize(DeviceState *dev)
321
{
322
    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
323
    VHostUserSCSI *s = VHOST_USER_SCSI(dev);
324
    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
325
    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
326

327
    /* This will stop the vhost backend. */
328
    vhost_user_scsi_set_status(vdev, 0);
329
    qemu_chr_fe_set_handlers(&vs->conf.chardev, NULL, NULL, NULL, NULL, NULL,
330
                             NULL, false);
331

332
    vhost_dev_cleanup(&vsc->dev);
333
    g_free(s->vhost_vqs);
334
    s->vhost_vqs = NULL;
335

336
    vhost_dev_free_inflight(vsc->inflight);
337
    g_free(vsc->inflight);
338
    vsc->inflight = NULL;
339

340
    vhost_user_cleanup(&s->vhost_user);
341
    virtio_scsi_common_unrealize(dev);
342
}
343

344
static Property vhost_user_scsi_properties[] = {
345
    DEFINE_PROP_CHR("chardev", VirtIOSCSICommon, conf.chardev),
346
    DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
347
    DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues,
348
                       VIRTIO_SCSI_AUTO_NUM_QUEUES),
349
    DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
350
                       128),
351
    DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
352
                       0xFFFF),
353
    DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
354
    DEFINE_PROP_BIT64("hotplug", VHostSCSICommon, host_features,
355
                                                  VIRTIO_SCSI_F_HOTPLUG,
356
                                                  true),
357
    DEFINE_PROP_BIT64("param_change", VHostSCSICommon, host_features,
358
                                                       VIRTIO_SCSI_F_CHANGE,
359
                                                       true),
360
    DEFINE_PROP_BIT64("t10_pi", VHostSCSICommon, host_features,
361
                                                 VIRTIO_SCSI_F_T10_PI,
362
                                                 false),
363
    DEFINE_PROP_END_OF_LIST(),
364
};
365

366
static void vhost_user_scsi_reset(VirtIODevice *vdev)
367
{
368
    VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
369
    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
370

371
    vhost_dev_free_inflight(vsc->inflight);
372
}
373

374
static struct vhost_dev *vhost_user_scsi_get_vhost(VirtIODevice *vdev)
375
{
376
    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(vdev);
377
    return &vsc->dev;
378
}
379

380
static const VMStateDescription vmstate_vhost_scsi = {
381
    .name = "virtio-scsi",
382
    .minimum_version_id = 1,
383
    .version_id = 1,
384
    .fields = (const VMStateField[]) {
385
        VMSTATE_VIRTIO_DEVICE,
386
        VMSTATE_END_OF_LIST()
387
    },
388
};
389

390
static void vhost_user_scsi_class_init(ObjectClass *klass, void *data)
391
{
392
    DeviceClass *dc = DEVICE_CLASS(klass);
393
    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
394
    FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
395

396
    device_class_set_props(dc, vhost_user_scsi_properties);
397
    dc->vmsd = &vmstate_vhost_scsi;
398
    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
399
    vdc->realize = vhost_user_scsi_realize;
400
    vdc->unrealize = vhost_user_scsi_unrealize;
401
    vdc->get_features = vhost_scsi_common_get_features;
402
    vdc->set_config = vhost_scsi_common_set_config;
403
    vdc->set_status = vhost_user_scsi_set_status;
404
    fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
405
    vdc->reset = vhost_user_scsi_reset;
406
    vdc->get_vhost = vhost_user_scsi_get_vhost;
407
}
408

409
static void vhost_user_scsi_instance_init(Object *obj)
410
{
411
    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
412

413
    vsc->feature_bits = user_feature_bits;
414

415
    /* Add the bootindex property for this object */
416
    device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
417
                                  DEVICE(vsc));
418
}
419

420
static const TypeInfo vhost_user_scsi_info = {
421
    .name = TYPE_VHOST_USER_SCSI,
422
    .parent = TYPE_VHOST_SCSI_COMMON,
423
    .instance_size = sizeof(VHostUserSCSI),
424
    .class_init = vhost_user_scsi_class_init,
425
    .instance_init = vhost_user_scsi_instance_init,
426
    .interfaces = (InterfaceInfo[]) {
427
        { TYPE_FW_PATH_PROVIDER },
428
        { }
429
    },
430
};
431

432
static void virtio_register_types(void)
433
{
434
    type_register_static(&vhost_user_scsi_info);
435
}
436

437
type_init(virtio_register_types)
438