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1
/*
2
 * A bus for connecting virtio serial and console ports
3
 *
4
 * Copyright (C) 2009, 2010 Red Hat, Inc.
5
 *
6
 * Author(s):
7
 *  Amit Shah <amit.shah@redhat.com>
8
 *
9
 * Some earlier parts are:
10
 *  Copyright IBM, Corp. 2008
11
 * authored by
12
 *  Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
13
 *
14
 * This work is licensed under the terms of the GNU GPL, version 2.  See
15
 * the COPYING file in the top-level directory.
16
 *
17
 * Contributions after 2012-01-13 are licensed under the terms of the
18
 * GNU GPL, version 2 or (at your option) any later version.
19
 */
20

    
21
#include "iov.h"
22
#include "monitor/monitor.h"
23
#include "qemu-queue.h"
24
#include "sysbus.h"
25
#include "trace.h"
26
#include "virtio-serial.h"
27

    
28
/* The virtio-serial bus on top of which the ports will ride as devices */
29
struct VirtIOSerialBus {
30
    BusState qbus;
31

    
32
    /* This is the parent device that provides the bus for ports. */
33
    VirtIOSerial *vser;
34

    
35
    /* The maximum number of ports that can ride on top of this bus */
36
    uint32_t max_nr_ports;
37
};
38

    
39
struct VirtIOSerial {
40
    VirtIODevice vdev;
41

    
42
    VirtQueue *c_ivq, *c_ovq;
43
    /* Arrays of ivqs and ovqs: one per port */
44
    VirtQueue **ivqs, **ovqs;
45

    
46
    VirtIOSerialBus bus;
47

    
48
    DeviceState *qdev;
49

    
50
    QTAILQ_HEAD(, VirtIOSerialPort) ports;
51

    
52
    /* bitmap for identifying active ports */
53
    uint32_t *ports_map;
54

    
55
    struct virtio_console_config config;
56

    
57
    struct {
58
        QEMUTimer *timer;
59
        int nr_active_ports;
60
        struct {
61
            VirtIOSerialPort *port;
62
            uint8_t host_connected;
63
        } *connected;
64
    } post_load;
65
};
66

    
67
static VirtIOSerialPort *find_port_by_id(VirtIOSerial *vser, uint32_t id)
68
{
69
    VirtIOSerialPort *port;
70

    
71
    if (id == VIRTIO_CONSOLE_BAD_ID) {
72
        return NULL;
73
    }
74

    
75
    QTAILQ_FOREACH(port, &vser->ports, next) {
76
        if (port->id == id)
77
            return port;
78
    }
79
    return NULL;
80
}
81

    
82
static VirtIOSerialPort *find_port_by_vq(VirtIOSerial *vser, VirtQueue *vq)
83
{
84
    VirtIOSerialPort *port;
85

    
86
    QTAILQ_FOREACH(port, &vser->ports, next) {
87
        if (port->ivq == vq || port->ovq == vq)
88
            return port;
89
    }
90
    return NULL;
91
}
92

    
93
static bool use_multiport(VirtIOSerial *vser)
94
{
95
    return vser->vdev.guest_features & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
96
}
97

    
98
static size_t write_to_port(VirtIOSerialPort *port,
99
                            const uint8_t *buf, size_t size)
100
{
101
    VirtQueueElement elem;
102
    VirtQueue *vq;
103
    size_t offset;
104

    
105
    vq = port->ivq;
106
    if (!virtio_queue_ready(vq)) {
107
        return 0;
108
    }
109

    
110
    offset = 0;
111
    while (offset < size) {
112
        size_t len;
113

    
114
        if (!virtqueue_pop(vq, &elem)) {
115
            break;
116
        }
117

    
118
        len = iov_from_buf(elem.in_sg, elem.in_num, 0,
119
                           buf + offset, size - offset);
120
        offset += len;
121

    
122
        virtqueue_push(vq, &elem, len);
123
    }
124

    
125
    virtio_notify(&port->vser->vdev, vq);
126
    return offset;
127
}
128

    
129
static void discard_vq_data(VirtQueue *vq, VirtIODevice *vdev)
130
{
131
    VirtQueueElement elem;
132

    
133
    if (!virtio_queue_ready(vq)) {
134
        return;
135
    }
136
    while (virtqueue_pop(vq, &elem)) {
137
        virtqueue_push(vq, &elem, 0);
138
    }
139
    virtio_notify(vdev, vq);
140
}
141

    
142
static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
143
                                 VirtIODevice *vdev)
144
{
145
    VirtIOSerialPortClass *vsc;
146

    
147
    assert(port);
148
    assert(virtio_queue_ready(vq));
149

    
150
    vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
151

    
152
    while (!port->throttled) {
153
        unsigned int i;
154

    
155
        /* Pop an elem only if we haven't left off a previous one mid-way */
156
        if (!port->elem.out_num) {
157
            if (!virtqueue_pop(vq, &port->elem)) {
158
                break;
159
            }
160
            port->iov_idx = 0;
161
            port->iov_offset = 0;
162
        }
163

    
164
        for (i = port->iov_idx; i < port->elem.out_num; i++) {
165
            size_t buf_size;
166
            ssize_t ret;
167

    
168
            buf_size = port->elem.out_sg[i].iov_len - port->iov_offset;
169
            ret = vsc->have_data(port,
170
                                  port->elem.out_sg[i].iov_base
171
                                  + port->iov_offset,
172
                                  buf_size);
173
            if (ret < 0 && ret != -EAGAIN) {
174
                /* We don't handle any other type of errors here */
175
                abort();
176
            }
177
            if (ret == -EAGAIN || (ret >= 0 && ret < buf_size)) {
178
                /*
179
                 * this is a temporary check until chardevs can signal to
180
                 * frontends that they are writable again. This prevents
181
                 * the console from going into throttled mode (forever)
182
                 * if virtio-console is connected to a pty without a
183
                 * listener. Otherwise the guest spins forever.
184
                 * We can revert this if
185
                 * 1: chardevs can notify frondends
186
                 * 2: the guest driver does not spin in these cases
187
                 */
188
                if (!vsc->is_console) {
189
                    virtio_serial_throttle_port(port, true);
190
                }
191
                port->iov_idx = i;
192
                if (ret > 0) {
193
                    port->iov_offset += ret;
194
                }
195
                break;
196
            }
197
            port->iov_offset = 0;
198
        }
199
        if (port->throttled) {
200
            break;
201
        }
202
        virtqueue_push(vq, &port->elem, 0);
203
        port->elem.out_num = 0;
204
    }
205
    virtio_notify(vdev, vq);
206
}
207

    
208
static void flush_queued_data(VirtIOSerialPort *port)
209
{
210
    assert(port);
211

    
212
    if (!virtio_queue_ready(port->ovq)) {
213
        return;
214
    }
215
    do_flush_queued_data(port, port->ovq, &port->vser->vdev);
216
}
217

    
218
static size_t send_control_msg(VirtIOSerialPort *port, void *buf, size_t len)
219
{
220
    VirtQueueElement elem;
221
    VirtQueue *vq;
222
    struct virtio_console_control *cpkt;
223

    
224
    vq = port->vser->c_ivq;
225
    if (!virtio_queue_ready(vq)) {
226
        return 0;
227
    }
228
    if (!virtqueue_pop(vq, &elem)) {
229
        return 0;
230
    }
231

    
232
    cpkt = (struct virtio_console_control *)buf;
233
    stl_p(&cpkt->id, port->id);
234
    memcpy(elem.in_sg[0].iov_base, buf, len);
235

    
236
    virtqueue_push(vq, &elem, len);
237
    virtio_notify(&port->vser->vdev, vq);
238
    return len;
239
}
240

    
241
static size_t send_control_event(VirtIOSerialPort *port, uint16_t event,
242
                                 uint16_t value)
243
{
244
    struct virtio_console_control cpkt;
245

    
246
    stw_p(&cpkt.event, event);
247
    stw_p(&cpkt.value, value);
248

    
249
    trace_virtio_serial_send_control_event(port->id, event, value);
250
    return send_control_msg(port, &cpkt, sizeof(cpkt));
251
}
252

    
253
/* Functions for use inside qemu to open and read from/write to ports */
254
int virtio_serial_open(VirtIOSerialPort *port)
255
{
256
    /* Don't allow opening an already-open port */
257
    if (port->host_connected) {
258
        return 0;
259
    }
260
    /* Send port open notification to the guest */
261
    port->host_connected = true;
262
    send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
263

    
264
    return 0;
265
}
266

    
267
int virtio_serial_close(VirtIOSerialPort *port)
268
{
269
    port->host_connected = false;
270
    /*
271
     * If there's any data the guest sent which the app didn't
272
     * consume, reset the throttling flag and discard the data.
273
     */
274
    port->throttled = false;
275
    discard_vq_data(port->ovq, &port->vser->vdev);
276

    
277
    send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
278

    
279
    return 0;
280
}
281

    
282
/* Individual ports/apps call this function to write to the guest. */
283
ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
284
                            size_t size)
285
{
286
    if (!port || !port->host_connected || !port->guest_connected) {
287
        return 0;
288
    }
289
    return write_to_port(port, buf, size);
290
}
291

    
292
/*
293
 * Readiness of the guest to accept data on a port.
294
 * Returns max. data the guest can receive
295
 */
296
size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
297
{
298
    VirtQueue *vq = port->ivq;
299
    unsigned int bytes;
300

    
301
    if (!virtio_queue_ready(vq) ||
302
        !(port->vser->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) ||
303
        virtio_queue_empty(vq)) {
304
        return 0;
305
    }
306
    if (use_multiport(port->vser) && !port->guest_connected) {
307
        return 0;
308
    }
309
    virtqueue_get_avail_bytes(vq, &bytes, NULL, 4096, 0);
310
    return bytes;
311
}
312

    
313
static void flush_queued_data_bh(void *opaque)
314
{
315
    VirtIOSerialPort *port = opaque;
316

    
317
    flush_queued_data(port);
318
}
319

    
320
void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
321
{
322
    if (!port) {
323
        return;
324
    }
325

    
326
    trace_virtio_serial_throttle_port(port->id, throttle);
327
    port->throttled = throttle;
328
    if (throttle) {
329
        return;
330
    }
331
    qemu_bh_schedule(port->bh);
332
}
333

    
334
/* Guest wants to notify us of some event */
335
static void handle_control_message(VirtIOSerial *vser, void *buf, size_t len)
336
{
337
    struct VirtIOSerialPort *port;
338
    VirtIOSerialPortClass *vsc;
339
    struct virtio_console_control cpkt, *gcpkt;
340
    uint8_t *buffer;
341
    size_t buffer_len;
342

    
343
    gcpkt = buf;
344

    
345
    if (len < sizeof(cpkt)) {
346
        /* The guest sent an invalid control packet */
347
        return;
348
    }
349

    
350
    cpkt.event = lduw_p(&gcpkt->event);
351
    cpkt.value = lduw_p(&gcpkt->value);
352

    
353
    trace_virtio_serial_handle_control_message(cpkt.event, cpkt.value);
354

    
355
    if (cpkt.event == VIRTIO_CONSOLE_DEVICE_READY) {
356
        if (!cpkt.value) {
357
            error_report("virtio-serial-bus: Guest failure in adding device %s",
358
                         vser->bus.qbus.name);
359
            return;
360
        }
361
        /*
362
         * The device is up, we can now tell the device about all the
363
         * ports we have here.
364
         */
365
        QTAILQ_FOREACH(port, &vser->ports, next) {
366
            send_control_event(port, VIRTIO_CONSOLE_PORT_ADD, 1);
367
        }
368
        return;
369
    }
370

    
371
    port = find_port_by_id(vser, ldl_p(&gcpkt->id));
372
    if (!port) {
373
        error_report("virtio-serial-bus: Unexpected port id %u for device %s",
374
                     ldl_p(&gcpkt->id), vser->bus.qbus.name);
375
        return;
376
    }
377

    
378
    trace_virtio_serial_handle_control_message_port(port->id);
379

    
380
    vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
381

    
382
    switch(cpkt.event) {
383
    case VIRTIO_CONSOLE_PORT_READY:
384
        if (!cpkt.value) {
385
            error_report("virtio-serial-bus: Guest failure in adding port %u for device %s",
386
                         port->id, vser->bus.qbus.name);
387
            break;
388
        }
389
        /*
390
         * Now that we know the guest asked for the port name, we're
391
         * sure the guest has initialised whatever state is necessary
392
         * for this port. Now's a good time to let the guest know if
393
         * this port is a console port so that the guest can hook it
394
         * up to hvc.
395
         */
396
        if (vsc->is_console) {
397
            send_control_event(port, VIRTIO_CONSOLE_CONSOLE_PORT, 1);
398
        }
399

    
400
        if (port->name) {
401
            stw_p(&cpkt.event, VIRTIO_CONSOLE_PORT_NAME);
402
            stw_p(&cpkt.value, 1);
403

    
404
            buffer_len = sizeof(cpkt) + strlen(port->name) + 1;
405
            buffer = g_malloc(buffer_len);
406

    
407
            memcpy(buffer, &cpkt, sizeof(cpkt));
408
            memcpy(buffer + sizeof(cpkt), port->name, strlen(port->name));
409
            buffer[buffer_len - 1] = 0;
410

    
411
            send_control_msg(port, buffer, buffer_len);
412
            g_free(buffer);
413
        }
414

    
415
        if (port->host_connected) {
416
            send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
417
        }
418

    
419
        /*
420
         * When the guest has asked us for this information it means
421
         * the guest is all setup and has its virtqueues
422
         * initialised. If some app is interested in knowing about
423
         * this event, let it know.
424
         */
425
        if (vsc->guest_ready) {
426
            vsc->guest_ready(port);
427
        }
428
        break;
429

    
430
    case VIRTIO_CONSOLE_PORT_OPEN:
431
        port->guest_connected = cpkt.value;
432
        if (cpkt.value && vsc->guest_open) {
433
            /* Send the guest opened notification if an app is interested */
434
            vsc->guest_open(port);
435
        }
436

    
437
        if (!cpkt.value && vsc->guest_close) {
438
            /* Send the guest closed notification if an app is interested */
439
            vsc->guest_close(port);
440
        }
441
        break;
442
    }
443
}
444

    
445
static void control_in(VirtIODevice *vdev, VirtQueue *vq)
446
{
447
}
448

    
449
static void control_out(VirtIODevice *vdev, VirtQueue *vq)
450
{
451
    VirtQueueElement elem;
452
    VirtIOSerial *vser;
453
    uint8_t *buf;
454
    size_t len;
455

    
456
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
457

    
458
    len = 0;
459
    buf = NULL;
460
    while (virtqueue_pop(vq, &elem)) {
461
        size_t cur_len;
462

    
463
        cur_len = iov_size(elem.out_sg, elem.out_num);
464
        /*
465
         * Allocate a new buf only if we didn't have one previously or
466
         * if the size of the buf differs
467
         */
468
        if (cur_len > len) {
469
            g_free(buf);
470

    
471
            buf = g_malloc(cur_len);
472
            len = cur_len;
473
        }
474
        iov_to_buf(elem.out_sg, elem.out_num, 0, buf, cur_len);
475

    
476
        handle_control_message(vser, buf, cur_len);
477
        virtqueue_push(vq, &elem, 0);
478
    }
479
    g_free(buf);
480
    virtio_notify(vdev, vq);
481
}
482

    
483
/* Guest wrote something to some port. */
484
static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
485
{
486
    VirtIOSerial *vser;
487
    VirtIOSerialPort *port;
488

    
489
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
490
    port = find_port_by_vq(vser, vq);
491

    
492
    if (!port || !port->host_connected) {
493
        discard_vq_data(vq, vdev);
494
        return;
495
    }
496

    
497
    if (!port->throttled) {
498
        do_flush_queued_data(port, vq, vdev);
499
        return;
500
    }
501
}
502

    
503
static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
504
{
505
}
506

    
507
static uint32_t get_features(VirtIODevice *vdev, uint32_t features)
508
{
509
    VirtIOSerial *vser;
510

    
511
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
512

    
513
    if (vser->bus.max_nr_ports > 1) {
514
        features |= (1 << VIRTIO_CONSOLE_F_MULTIPORT);
515
    }
516
    return features;
517
}
518

    
519
/* Guest requested config info */
520
static void get_config(VirtIODevice *vdev, uint8_t *config_data)
521
{
522
    VirtIOSerial *vser;
523

    
524
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
525
    memcpy(config_data, &vser->config, sizeof(struct virtio_console_config));
526
}
527

    
528
static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
529
{
530
    struct virtio_console_config config;
531

    
532
    memcpy(&config, config_data, sizeof(config));
533
}
534

    
535
static void guest_reset(VirtIOSerial *vser)
536
{
537
    VirtIOSerialPort *port;
538
    VirtIOSerialPortClass *vsc;
539

    
540
    QTAILQ_FOREACH(port, &vser->ports, next) {
541
        vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
542
        if (port->guest_connected) {
543
            port->guest_connected = false;
544

    
545
            if (vsc->guest_close)
546
                vsc->guest_close(port);
547
        }
548
    }
549
}
550

    
551
static void set_status(VirtIODevice *vdev, uint8_t status)
552
{
553
    VirtIOSerial *vser;
554
    VirtIOSerialPort *port;
555

    
556
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
557
    port = find_port_by_id(vser, 0);
558

    
559
    if (port && !use_multiport(port->vser)
560
        && (status & VIRTIO_CONFIG_S_DRIVER_OK)) {
561
        /*
562
         * Non-multiport guests won't be able to tell us guest
563
         * open/close status.  Such guests can only have a port at id
564
         * 0, so set guest_connected for such ports as soon as guest
565
         * is up.
566
         */
567
        port->guest_connected = true;
568
    }
569
    if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
570
        guest_reset(vser);
571
    }
572
}
573

    
574
static void vser_reset(VirtIODevice *vdev)
575
{
576
    VirtIOSerial *vser;
577

    
578
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
579
    guest_reset(vser);
580
}
581

    
582
static void virtio_serial_save(QEMUFile *f, void *opaque)
583
{
584
    VirtIOSerial *s = opaque;
585
    VirtIOSerialPort *port;
586
    uint32_t nr_active_ports;
587
    unsigned int i, max_nr_ports;
588

    
589
    /* The virtio device */
590
    virtio_save(&s->vdev, f);
591

    
592
    /* The config space */
593
    qemu_put_be16s(f, &s->config.cols);
594
    qemu_put_be16s(f, &s->config.rows);
595

    
596
    qemu_put_be32s(f, &s->config.max_nr_ports);
597

    
598
    /* The ports map */
599
    max_nr_ports = tswap32(s->config.max_nr_ports);
600
    for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
601
        qemu_put_be32s(f, &s->ports_map[i]);
602
    }
603

    
604
    /* Ports */
605

    
606
    nr_active_ports = 0;
607
    QTAILQ_FOREACH(port, &s->ports, next) {
608
        nr_active_ports++;
609
    }
610

    
611
    qemu_put_be32s(f, &nr_active_ports);
612

    
613
    /*
614
     * Items in struct VirtIOSerialPort.
615
     */
616
    QTAILQ_FOREACH(port, &s->ports, next) {
617
        uint32_t elem_popped;
618

    
619
        qemu_put_be32s(f, &port->id);
620
        qemu_put_byte(f, port->guest_connected);
621
        qemu_put_byte(f, port->host_connected);
622

    
623
        elem_popped = 0;
624
        if (port->elem.out_num) {
625
            elem_popped = 1;
626
        }
627
        qemu_put_be32s(f, &elem_popped);
628
        if (elem_popped) {
629
            qemu_put_be32s(f, &port->iov_idx);
630
            qemu_put_be64s(f, &port->iov_offset);
631

    
632
            qemu_put_buffer(f, (unsigned char *)&port->elem,
633
                            sizeof(port->elem));
634
        }
635
    }
636
}
637

    
638
static void virtio_serial_post_load_timer_cb(void *opaque)
639
{
640
    int i;
641
    VirtIOSerial *s = opaque;
642
    VirtIOSerialPort *port;
643
    uint8_t host_connected;
644

    
645
    for (i = 0 ; i < s->post_load.nr_active_ports; ++i) {
646
        port = s->post_load.connected[i].port;
647
        host_connected = s->post_load.connected[i].host_connected;
648
        if (host_connected != port->host_connected) {
649
            /*
650
             * We have to let the guest know of the host connection
651
             * status change
652
             */
653
            send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN,
654
                               port->host_connected);
655
        }
656
    }
657
    g_free(s->post_load.connected);
658
    s->post_load.connected = NULL;
659
}
660

    
661
static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
662
{
663
    VirtIOSerial *s = opaque;
664
    VirtIOSerialPort *port;
665
    uint32_t max_nr_ports, nr_active_ports, ports_map;
666
    unsigned int i;
667
    int ret;
668

    
669
    if (version_id > 3) {
670
        return -EINVAL;
671
    }
672

    
673
    /* The virtio device */
674
    ret = virtio_load(&s->vdev, f);
675
    if (ret) {
676
        return ret;
677
    }
678

    
679
    if (version_id < 2) {
680
        return 0;
681
    }
682

    
683
    /* The config space */
684
    qemu_get_be16s(f, &s->config.cols);
685
    qemu_get_be16s(f, &s->config.rows);
686

    
687
    qemu_get_be32s(f, &max_nr_ports);
688
    tswap32s(&max_nr_ports);
689
    if (max_nr_ports > tswap32(s->config.max_nr_ports)) {
690
        /* Source could have had more ports than us. Fail migration. */
691
        return -EINVAL;
692
    }
693

    
694
    for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
695
        qemu_get_be32s(f, &ports_map);
696

    
697
        if (ports_map != s->ports_map[i]) {
698
            /*
699
             * Ports active on source and destination don't
700
             * match. Fail migration.
701
             */
702
            return -EINVAL;
703
        }
704
    }
705

    
706
    qemu_get_be32s(f, &nr_active_ports);
707

    
708
    s->post_load.nr_active_ports = nr_active_ports;
709
    s->post_load.connected =
710
        g_malloc0(sizeof(*s->post_load.connected) * nr_active_ports);
711

    
712
    /* Items in struct VirtIOSerialPort */
713
    for (i = 0; i < nr_active_ports; i++) {
714
        uint32_t id;
715

    
716
        id = qemu_get_be32(f);
717
        port = find_port_by_id(s, id);
718
        if (!port) {
719
            return -EINVAL;
720
        }
721

    
722
        port->guest_connected = qemu_get_byte(f);
723
        s->post_load.connected[i].port = port;
724
        s->post_load.connected[i].host_connected = qemu_get_byte(f);
725

    
726
        if (version_id > 2) {
727
            uint32_t elem_popped;
728

    
729
            qemu_get_be32s(f, &elem_popped);
730
            if (elem_popped) {
731
                qemu_get_be32s(f, &port->iov_idx);
732
                qemu_get_be64s(f, &port->iov_offset);
733

    
734
                qemu_get_buffer(f, (unsigned char *)&port->elem,
735
                                sizeof(port->elem));
736
                virtqueue_map_sg(port->elem.in_sg, port->elem.in_addr,
737
                                 port->elem.in_num, 1);
738
                virtqueue_map_sg(port->elem.out_sg, port->elem.out_addr,
739
                                 port->elem.out_num, 1);
740

    
741
                /*
742
                 *  Port was throttled on source machine.  Let's
743
                 *  unthrottle it here so data starts flowing again.
744
                 */
745
                virtio_serial_throttle_port(port, false);
746
            }
747
        }
748
    }
749
    qemu_mod_timer(s->post_load.timer, 1);
750
    return 0;
751
}
752

    
753
static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
754

    
755
static Property virtser_props[] = {
756
    DEFINE_PROP_UINT32("nr", VirtIOSerialPort, id, VIRTIO_CONSOLE_BAD_ID),
757
    DEFINE_PROP_STRING("name", VirtIOSerialPort, name),
758
    DEFINE_PROP_END_OF_LIST()
759
};
760

    
761
#define TYPE_VIRTIO_SERIAL_BUS "virtio-serial-bus"
762
#define VIRTIO_SERIAL_BUS(obj) \
763
      OBJECT_CHECK(VirtIOSerialBus, (obj), TYPE_VIRTIO_SERIAL_BUS)
764

    
765
static void virtser_bus_class_init(ObjectClass *klass, void *data)
766
{
767
    BusClass *k = BUS_CLASS(klass);
768
    k->print_dev = virtser_bus_dev_print;
769
}
770

    
771
static const TypeInfo virtser_bus_info = {
772
    .name = TYPE_VIRTIO_SERIAL_BUS,
773
    .parent = TYPE_BUS,
774
    .instance_size = sizeof(VirtIOSerialBus),
775
    .class_init = virtser_bus_class_init,
776
};
777

    
778
static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
779
{
780
    VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
781

    
782
    monitor_printf(mon, "%*sport %d, guest %s, host %s, throttle %s\n",
783
                   indent, "", port->id,
784
                   port->guest_connected ? "on" : "off",
785
                   port->host_connected ? "on" : "off",
786
                   port->throttled ? "on" : "off");
787
}
788

    
789
/* This function is only used if a port id is not provided by the user */
790
static uint32_t find_free_port_id(VirtIOSerial *vser)
791
{
792
    unsigned int i, max_nr_ports;
793

    
794
    max_nr_ports = tswap32(vser->config.max_nr_ports);
795
    for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
796
        uint32_t map, bit;
797

    
798
        map = vser->ports_map[i];
799
        bit = ffs(~map);
800
        if (bit) {
801
            return (bit - 1) + i * 32;
802
        }
803
    }
804
    return VIRTIO_CONSOLE_BAD_ID;
805
}
806

    
807
static void mark_port_added(VirtIOSerial *vser, uint32_t port_id)
808
{
809
    unsigned int i;
810

    
811
    i = port_id / 32;
812
    vser->ports_map[i] |= 1U << (port_id % 32);
813
}
814

    
815
static void add_port(VirtIOSerial *vser, uint32_t port_id)
816
{
817
    mark_port_added(vser, port_id);
818

    
819
    send_control_event(find_port_by_id(vser, port_id),
820
                       VIRTIO_CONSOLE_PORT_ADD, 1);
821
}
822

    
823
static void remove_port(VirtIOSerial *vser, uint32_t port_id)
824
{
825
    VirtIOSerialPort *port;
826
    unsigned int i;
827

    
828
    i = port_id / 32;
829
    vser->ports_map[i] &= ~(1U << (port_id % 32));
830

    
831
    port = find_port_by_id(vser, port_id);
832
    /* Flush out any unconsumed buffers first */
833
    discard_vq_data(port->ovq, &port->vser->vdev);
834

    
835
    send_control_event(port, VIRTIO_CONSOLE_PORT_REMOVE, 1);
836
}
837

    
838
static int virtser_port_qdev_init(DeviceState *qdev)
839
{
840
    VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
841
    VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
842
    VirtIOSerialBus *bus = DO_UPCAST(VirtIOSerialBus, qbus, qdev->parent_bus);
843
    int ret, max_nr_ports;
844
    bool plugging_port0;
845

    
846
    port->vser = bus->vser;
847
    port->bh = qemu_bh_new(flush_queued_data_bh, port);
848

    
849
    assert(vsc->have_data);
850

    
851
    /*
852
     * Is the first console port we're seeing? If so, put it up at
853
     * location 0. This is done for backward compatibility (old
854
     * kernel, new qemu).
855
     */
856
    plugging_port0 = vsc->is_console && !find_port_by_id(port->vser, 0);
857

    
858
    if (find_port_by_id(port->vser, port->id)) {
859
        error_report("virtio-serial-bus: A port already exists at id %u",
860
                     port->id);
861
        return -1;
862
    }
863

    
864
    if (port->id == VIRTIO_CONSOLE_BAD_ID) {
865
        if (plugging_port0) {
866
            port->id = 0;
867
        } else {
868
            port->id = find_free_port_id(port->vser);
869
            if (port->id == VIRTIO_CONSOLE_BAD_ID) {
870
                error_report("virtio-serial-bus: Maximum port limit for this device reached");
871
                return -1;
872
            }
873
        }
874
    }
875

    
876
    max_nr_ports = tswap32(port->vser->config.max_nr_ports);
877
    if (port->id >= max_nr_ports) {
878
        error_report("virtio-serial-bus: Out-of-range port id specified, max. allowed: %u",
879
                     max_nr_ports - 1);
880
        return -1;
881
    }
882

    
883
    ret = vsc->init(port);
884
    if (ret) {
885
        return ret;
886
    }
887

    
888
    port->elem.out_num = 0;
889

    
890
    QTAILQ_INSERT_TAIL(&port->vser->ports, port, next);
891
    port->ivq = port->vser->ivqs[port->id];
892
    port->ovq = port->vser->ovqs[port->id];
893

    
894
    add_port(port->vser, port->id);
895

    
896
    /* Send an update to the guest about this new port added */
897
    virtio_notify_config(&port->vser->vdev);
898

    
899
    return ret;
900
}
901

    
902
static int virtser_port_qdev_exit(DeviceState *qdev)
903
{
904
    VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
905
    VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
906
    VirtIOSerial *vser = port->vser;
907

    
908
    qemu_bh_delete(port->bh);
909
    remove_port(port->vser, port->id);
910

    
911
    QTAILQ_REMOVE(&vser->ports, port, next);
912

    
913
    if (vsc->exit) {
914
        vsc->exit(port);
915
    }
916
    return 0;
917
}
918

    
919
VirtIODevice *virtio_serial_init(DeviceState *dev, virtio_serial_conf *conf)
920
{
921
    VirtIOSerial *vser;
922
    VirtIODevice *vdev;
923
    uint32_t i, max_supported_ports;
924

    
925
    if (!conf->max_virtserial_ports)
926
        return NULL;
927

    
928
    /* Each port takes 2 queues, and one pair is for the control queue */
929
    max_supported_ports = VIRTIO_PCI_QUEUE_MAX / 2 - 1;
930

    
931
    if (conf->max_virtserial_ports > max_supported_ports) {
932
        error_report("maximum ports supported: %u", max_supported_ports);
933
        return NULL;
934
    }
935

    
936
    vdev = virtio_common_init("virtio-serial", VIRTIO_ID_CONSOLE,
937
                              sizeof(struct virtio_console_config),
938
                              sizeof(VirtIOSerial));
939

    
940
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
941

    
942
    /* Spawn a new virtio-serial bus on which the ports will ride as devices */
943
    qbus_create_inplace(&vser->bus.qbus, TYPE_VIRTIO_SERIAL_BUS, dev, NULL);
944
    vser->bus.qbus.allow_hotplug = 1;
945
    vser->bus.vser = vser;
946
    QTAILQ_INIT(&vser->ports);
947

    
948
    vser->bus.max_nr_ports = conf->max_virtserial_ports;
949
    vser->ivqs = g_malloc(conf->max_virtserial_ports * sizeof(VirtQueue *));
950
    vser->ovqs = g_malloc(conf->max_virtserial_ports * sizeof(VirtQueue *));
951

    
952
    /* Add a queue for host to guest transfers for port 0 (backward compat) */
953
    vser->ivqs[0] = virtio_add_queue(vdev, 128, handle_input);
954
    /* Add a queue for guest to host transfers for port 0 (backward compat) */
955
    vser->ovqs[0] = virtio_add_queue(vdev, 128, handle_output);
956

    
957
    /* TODO: host to guest notifications can get dropped
958
     * if the queue fills up. Implement queueing in host,
959
     * this might also make it possible to reduce the control
960
     * queue size: as guest preposts buffers there,
961
     * this will save 4Kbyte of guest memory per entry. */
962

    
963
    /* control queue: host to guest */
964
    vser->c_ivq = virtio_add_queue(vdev, 32, control_in);
965
    /* control queue: guest to host */
966
    vser->c_ovq = virtio_add_queue(vdev, 32, control_out);
967

    
968
    for (i = 1; i < vser->bus.max_nr_ports; i++) {
969
        /* Add a per-port queue for host to guest transfers */
970
        vser->ivqs[i] = virtio_add_queue(vdev, 128, handle_input);
971
        /* Add a per-per queue for guest to host transfers */
972
        vser->ovqs[i] = virtio_add_queue(vdev, 128, handle_output);
973
    }
974

    
975
    vser->config.max_nr_ports = tswap32(conf->max_virtserial_ports);
976
    vser->ports_map = g_malloc0(((conf->max_virtserial_ports + 31) / 32)
977
        * sizeof(vser->ports_map[0]));
978
    /*
979
     * Reserve location 0 for a console port for backward compat
980
     * (old kernel, new qemu)
981
     */
982
    mark_port_added(vser, 0);
983

    
984
    vser->vdev.get_features = get_features;
985
    vser->vdev.get_config = get_config;
986
    vser->vdev.set_config = set_config;
987
    vser->vdev.set_status = set_status;
988
    vser->vdev.reset = vser_reset;
989

    
990
    vser->qdev = dev;
991

    
992
    /*
993
     * Register for the savevm section with the virtio-console name
994
     * to preserve backward compat
995
     */
996
    register_savevm(dev, "virtio-console", -1, 3, virtio_serial_save,
997
                    virtio_serial_load, vser);
998

    
999
    vser->post_load.timer = qemu_new_timer_ns(vm_clock,
1000
            virtio_serial_post_load_timer_cb, vser);
1001

    
1002
    return vdev;
1003
}
1004

    
1005
void virtio_serial_exit(VirtIODevice *vdev)
1006
{
1007
    VirtIOSerial *vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
1008

    
1009
    unregister_savevm(vser->qdev, "virtio-console", vser);
1010

    
1011
    g_free(vser->ivqs);
1012
    g_free(vser->ovqs);
1013
    g_free(vser->ports_map);
1014
    g_free(vser->post_load.connected);
1015
    qemu_free_timer(vser->post_load.timer);
1016

    
1017
    virtio_cleanup(vdev);
1018
}
1019

    
1020
static void virtio_serial_port_class_init(ObjectClass *klass, void *data)
1021
{
1022
    DeviceClass *k = DEVICE_CLASS(klass);
1023
    k->init = virtser_port_qdev_init;
1024
    k->bus_type = TYPE_VIRTIO_SERIAL_BUS;
1025
    k->exit = virtser_port_qdev_exit;
1026
    k->unplug = qdev_simple_unplug_cb;
1027
    k->props = virtser_props;
1028
}
1029

    
1030
static TypeInfo virtio_serial_port_type_info = {
1031
    .name = TYPE_VIRTIO_SERIAL_PORT,
1032
    .parent = TYPE_DEVICE,
1033
    .instance_size = sizeof(VirtIOSerialPort),
1034
    .abstract = true,
1035
    .class_size = sizeof(VirtIOSerialPortClass),
1036
    .class_init = virtio_serial_port_class_init,
1037
};
1038

    
1039
static void virtio_serial_register_types(void)
1040
{
1041
    type_register_static(&virtser_bus_info);
1042
    type_register_static(&virtio_serial_port_type_info);
1043
}
1044

    
1045
type_init(virtio_serial_register_types)