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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.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

    
58
static VirtIOSerialPort *find_port_by_id(VirtIOSerial *vser, uint32_t id)
59
{
60
    VirtIOSerialPort *port;
61

    
62
    if (id == VIRTIO_CONSOLE_BAD_ID) {
63
        return NULL;
64
    }
65

    
66
    QTAILQ_FOREACH(port, &vser->ports, next) {
67
        if (port->id == id)
68
            return port;
69
    }
70
    return NULL;
71
}
72

    
73
static VirtIOSerialPort *find_port_by_vq(VirtIOSerial *vser, VirtQueue *vq)
74
{
75
    VirtIOSerialPort *port;
76

    
77
    QTAILQ_FOREACH(port, &vser->ports, next) {
78
        if (port->ivq == vq || port->ovq == vq)
79
            return port;
80
    }
81
    return NULL;
82
}
83

    
84
static bool use_multiport(VirtIOSerial *vser)
85
{
86
    return vser->vdev.guest_features & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
87
}
88

    
89
static size_t write_to_port(VirtIOSerialPort *port,
90
                            const uint8_t *buf, size_t size)
91
{
92
    VirtQueueElement elem;
93
    VirtQueue *vq;
94
    size_t offset;
95

    
96
    vq = port->ivq;
97
    if (!virtio_queue_ready(vq)) {
98
        return 0;
99
    }
100

    
101
    offset = 0;
102
    while (offset < size) {
103
        size_t len;
104

    
105
        if (!virtqueue_pop(vq, &elem)) {
106
            break;
107
        }
108

    
109
        len = iov_from_buf(elem.in_sg, elem.in_num,
110
                           buf + offset, 0, size - offset);
111
        offset += len;
112

    
113
        virtqueue_push(vq, &elem, len);
114
    }
115

    
116
    virtio_notify(&port->vser->vdev, vq);
117
    return offset;
118
}
119

    
120
static void discard_vq_data(VirtQueue *vq, VirtIODevice *vdev)
121
{
122
    VirtQueueElement elem;
123

    
124
    if (!virtio_queue_ready(vq)) {
125
        return;
126
    }
127
    while (virtqueue_pop(vq, &elem)) {
128
        virtqueue_push(vq, &elem, 0);
129
    }
130
    virtio_notify(vdev, vq);
131
}
132

    
133
static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
134
                                 VirtIODevice *vdev)
135
{
136
    VirtIOSerialPortClass *vsc;
137

    
138
    assert(port);
139
    assert(virtio_queue_ready(vq));
140

    
141
    vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
142

    
143
    while (!port->throttled) {
144
        unsigned int i;
145

    
146
        /* Pop an elem only if we haven't left off a previous one mid-way */
147
        if (!port->elem.out_num) {
148
            if (!virtqueue_pop(vq, &port->elem)) {
149
                break;
150
            }
151
            port->iov_idx = 0;
152
            port->iov_offset = 0;
153
        }
154

    
155
        for (i = port->iov_idx; i < port->elem.out_num; i++) {
156
            size_t buf_size;
157
            ssize_t ret;
158

    
159
            buf_size = port->elem.out_sg[i].iov_len - port->iov_offset;
160
            ret = vsc->have_data(port,
161
                                  port->elem.out_sg[i].iov_base
162
                                  + port->iov_offset,
163
                                  buf_size);
164
            if (ret < 0 && ret != -EAGAIN) {
165
                /* We don't handle any other type of errors here */
166
                abort();
167
            }
168
            if (ret == -EAGAIN || (ret >= 0 && ret < buf_size)) {
169
                /*
170
                 * this is a temporary check until chardevs can signal to
171
                 * frontends that they are writable again. This prevents
172
                 * the console from going into throttled mode (forever)
173
                 * if virtio-console is connected to a pty without a
174
                 * listener. Otherwise the guest spins forever.
175
                 * We can revert this if
176
                 * 1: chardevs can notify frondends
177
                 * 2: the guest driver does not spin in these cases
178
                 */
179
                if (!vsc->is_console) {
180
                    virtio_serial_throttle_port(port, true);
181
                }
182
                port->iov_idx = i;
183
                if (ret > 0) {
184
                    port->iov_offset += ret;
185
                }
186
                break;
187
            }
188
            port->iov_offset = 0;
189
        }
190
        if (port->throttled) {
191
            break;
192
        }
193
        virtqueue_push(vq, &port->elem, 0);
194
        port->elem.out_num = 0;
195
    }
196
    virtio_notify(vdev, vq);
197
}
198

    
199
static void flush_queued_data(VirtIOSerialPort *port)
200
{
201
    assert(port);
202

    
203
    if (!virtio_queue_ready(port->ovq)) {
204
        return;
205
    }
206
    do_flush_queued_data(port, port->ovq, &port->vser->vdev);
207
}
208

    
209
static size_t send_control_msg(VirtIOSerialPort *port, void *buf, size_t len)
210
{
211
    VirtQueueElement elem;
212
    VirtQueue *vq;
213
    struct virtio_console_control *cpkt;
214

    
215
    vq = port->vser->c_ivq;
216
    if (!virtio_queue_ready(vq)) {
217
        return 0;
218
    }
219
    if (!virtqueue_pop(vq, &elem)) {
220
        return 0;
221
    }
222

    
223
    cpkt = (struct virtio_console_control *)buf;
224
    stl_p(&cpkt->id, port->id);
225
    memcpy(elem.in_sg[0].iov_base, buf, len);
226

    
227
    virtqueue_push(vq, &elem, len);
228
    virtio_notify(&port->vser->vdev, vq);
229
    return len;
230
}
231

    
232
static size_t send_control_event(VirtIOSerialPort *port, uint16_t event,
233
                                 uint16_t value)
234
{
235
    struct virtio_console_control cpkt;
236

    
237
    stw_p(&cpkt.event, event);
238
    stw_p(&cpkt.value, value);
239

    
240
    trace_virtio_serial_send_control_event(port->id, event, value);
241
    return send_control_msg(port, &cpkt, sizeof(cpkt));
242
}
243

    
244
/* Functions for use inside qemu to open and read from/write to ports */
245
int virtio_serial_open(VirtIOSerialPort *port)
246
{
247
    /* Don't allow opening an already-open port */
248
    if (port->host_connected) {
249
        return 0;
250
    }
251
    /* Send port open notification to the guest */
252
    port->host_connected = true;
253
    send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
254

    
255
    return 0;
256
}
257

    
258
int virtio_serial_close(VirtIOSerialPort *port)
259
{
260
    port->host_connected = false;
261
    /*
262
     * If there's any data the guest sent which the app didn't
263
     * consume, reset the throttling flag and discard the data.
264
     */
265
    port->throttled = false;
266
    discard_vq_data(port->ovq, &port->vser->vdev);
267

    
268
    send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
269

    
270
    return 0;
271
}
272

    
273
/* Individual ports/apps call this function to write to the guest. */
274
ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
275
                            size_t size)
276
{
277
    if (!port || !port->host_connected || !port->guest_connected) {
278
        return 0;
279
    }
280
    return write_to_port(port, buf, size);
281
}
282

    
283
/*
284
 * Readiness of the guest to accept data on a port.
285
 * Returns max. data the guest can receive
286
 */
287
size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
288
{
289
    VirtQueue *vq = port->ivq;
290

    
291
    if (!virtio_queue_ready(vq) ||
292
        !(port->vser->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) ||
293
        virtio_queue_empty(vq)) {
294
        return 0;
295
    }
296
    if (use_multiport(port->vser) && !port->guest_connected) {
297
        return 0;
298
    }
299

    
300
    if (virtqueue_avail_bytes(vq, 4096, 0)) {
301
        return 4096;
302
    }
303
    if (virtqueue_avail_bytes(vq, 1, 0)) {
304
        return 1;
305
    }
306
    return 0;
307
}
308

    
309
static void flush_queued_data_bh(void *opaque)
310
{
311
    VirtIOSerialPort *port = opaque;
312

    
313
    flush_queued_data(port);
314
}
315

    
316
void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
317
{
318
    if (!port) {
319
        return;
320
    }
321

    
322
    trace_virtio_serial_throttle_port(port->id, throttle);
323
    port->throttled = throttle;
324
    if (throttle) {
325
        return;
326
    }
327
    qemu_bh_schedule(port->bh);
328
}
329

    
330
/* Guest wants to notify us of some event */
331
static void handle_control_message(VirtIOSerial *vser, void *buf, size_t len)
332
{
333
    struct VirtIOSerialPort *port;
334
    VirtIOSerialPortClass *vsc;
335
    struct virtio_console_control cpkt, *gcpkt;
336
    uint8_t *buffer;
337
    size_t buffer_len;
338

    
339
    gcpkt = buf;
340

    
341
    if (len < sizeof(cpkt)) {
342
        /* The guest sent an invalid control packet */
343
        return;
344
    }
345

    
346
    cpkt.event = lduw_p(&gcpkt->event);
347
    cpkt.value = lduw_p(&gcpkt->value);
348

    
349
    trace_virtio_serial_handle_control_message(cpkt.event, cpkt.value);
350

    
351
    if (cpkt.event == VIRTIO_CONSOLE_DEVICE_READY) {
352
        if (!cpkt.value) {
353
            error_report("virtio-serial-bus: Guest failure in adding device %s",
354
                         vser->bus.qbus.name);
355
            return;
356
        }
357
        /*
358
         * The device is up, we can now tell the device about all the
359
         * ports we have here.
360
         */
361
        QTAILQ_FOREACH(port, &vser->ports, next) {
362
            send_control_event(port, VIRTIO_CONSOLE_PORT_ADD, 1);
363
        }
364
        return;
365
    }
366

    
367
    port = find_port_by_id(vser, ldl_p(&gcpkt->id));
368
    if (!port) {
369
        error_report("virtio-serial-bus: Unexpected port id %u for device %s",
370
                     ldl_p(&gcpkt->id), vser->bus.qbus.name);
371
        return;
372
    }
373

    
374
    trace_virtio_serial_handle_control_message_port(port->id);
375

    
376
    vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
377

    
378
    switch(cpkt.event) {
379
    case VIRTIO_CONSOLE_PORT_READY:
380
        if (!cpkt.value) {
381
            error_report("virtio-serial-bus: Guest failure in adding port %u for device %s",
382
                         port->id, vser->bus.qbus.name);
383
            break;
384
        }
385
        /*
386
         * Now that we know the guest asked for the port name, we're
387
         * sure the guest has initialised whatever state is necessary
388
         * for this port. Now's a good time to let the guest know if
389
         * this port is a console port so that the guest can hook it
390
         * up to hvc.
391
         */
392
        if (vsc->is_console) {
393
            send_control_event(port, VIRTIO_CONSOLE_CONSOLE_PORT, 1);
394
        }
395

    
396
        if (port->name) {
397
            stw_p(&cpkt.event, VIRTIO_CONSOLE_PORT_NAME);
398
            stw_p(&cpkt.value, 1);
399

    
400
            buffer_len = sizeof(cpkt) + strlen(port->name) + 1;
401
            buffer = g_malloc(buffer_len);
402

    
403
            memcpy(buffer, &cpkt, sizeof(cpkt));
404
            memcpy(buffer + sizeof(cpkt), port->name, strlen(port->name));
405
            buffer[buffer_len - 1] = 0;
406

    
407
            send_control_msg(port, buffer, buffer_len);
408
            g_free(buffer);
409
        }
410

    
411
        if (port->host_connected) {
412
            send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
413
        }
414

    
415
        /*
416
         * When the guest has asked us for this information it means
417
         * the guest is all setup and has its virtqueues
418
         * initialised. If some app is interested in knowing about
419
         * this event, let it know.
420
         */
421
        if (vsc->guest_ready) {
422
            vsc->guest_ready(port);
423
        }
424
        break;
425

    
426
    case VIRTIO_CONSOLE_PORT_OPEN:
427
        port->guest_connected = cpkt.value;
428
        if (cpkt.value && vsc->guest_open) {
429
            /* Send the guest opened notification if an app is interested */
430
            vsc->guest_open(port);
431
        }
432

    
433
        if (!cpkt.value && vsc->guest_close) {
434
            /* Send the guest closed notification if an app is interested */
435
            vsc->guest_close(port);
436
        }
437
        break;
438
    }
439
}
440

    
441
static void control_in(VirtIODevice *vdev, VirtQueue *vq)
442
{
443
}
444

    
445
static void control_out(VirtIODevice *vdev, VirtQueue *vq)
446
{
447
    VirtQueueElement elem;
448
    VirtIOSerial *vser;
449
    uint8_t *buf;
450
    size_t len;
451

    
452
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
453

    
454
    len = 0;
455
    buf = NULL;
456
    while (virtqueue_pop(vq, &elem)) {
457
        size_t cur_len, copied;
458

    
459
        cur_len = iov_size(elem.out_sg, elem.out_num);
460
        /*
461
         * Allocate a new buf only if we didn't have one previously or
462
         * if the size of the buf differs
463
         */
464
        if (cur_len > len) {
465
            g_free(buf);
466

    
467
            buf = g_malloc(cur_len);
468
            len = cur_len;
469
        }
470
        copied = iov_to_buf(elem.out_sg, elem.out_num, buf, 0, len);
471

    
472
        handle_control_message(vser, buf, copied);
473
        virtqueue_push(vq, &elem, 0);
474
    }
475
    g_free(buf);
476
    virtio_notify(vdev, vq);
477
}
478

    
479
/* Guest wrote something to some port. */
480
static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
481
{
482
    VirtIOSerial *vser;
483
    VirtIOSerialPort *port;
484

    
485
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
486
    port = find_port_by_vq(vser, vq);
487

    
488
    if (!port || !port->host_connected) {
489
        discard_vq_data(vq, vdev);
490
        return;
491
    }
492

    
493
    if (!port->throttled) {
494
        do_flush_queued_data(port, vq, vdev);
495
        return;
496
    }
497
}
498

    
499
static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
500
{
501
}
502

    
503
static uint32_t get_features(VirtIODevice *vdev, uint32_t features)
504
{
505
    VirtIOSerial *vser;
506

    
507
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
508

    
509
    if (vser->bus.max_nr_ports > 1) {
510
        features |= (1 << VIRTIO_CONSOLE_F_MULTIPORT);
511
    }
512
    return features;
513
}
514

    
515
/* Guest requested config info */
516
static void get_config(VirtIODevice *vdev, uint8_t *config_data)
517
{
518
    VirtIOSerial *vser;
519

    
520
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
521
    memcpy(config_data, &vser->config, sizeof(struct virtio_console_config));
522
}
523

    
524
static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
525
{
526
    struct virtio_console_config config;
527

    
528
    memcpy(&config, config_data, sizeof(config));
529
}
530

    
531
static void guest_reset(VirtIOSerial *vser)
532
{
533
    VirtIOSerialPort *port;
534
    VirtIOSerialPortClass *vsc;
535

    
536
    QTAILQ_FOREACH(port, &vser->ports, next) {
537
        vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
538
        if (port->guest_connected) {
539
            port->guest_connected = false;
540

    
541
            if (vsc->guest_close)
542
                vsc->guest_close(port);
543
        }
544
    }
545
}
546

    
547
static void set_status(VirtIODevice *vdev, uint8_t status)
548
{
549
    VirtIOSerial *vser;
550
    VirtIOSerialPort *port;
551

    
552
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
553
    port = find_port_by_id(vser, 0);
554

    
555
    if (port && !use_multiport(port->vser)
556
        && (status & VIRTIO_CONFIG_S_DRIVER_OK)) {
557
        /*
558
         * Non-multiport guests won't be able to tell us guest
559
         * open/close status.  Such guests can only have a port at id
560
         * 0, so set guest_connected for such ports as soon as guest
561
         * is up.
562
         */
563
        port->guest_connected = true;
564
    }
565
    if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
566
        guest_reset(vser);
567
    }
568
}
569

    
570
static void vser_reset(VirtIODevice *vdev)
571
{
572
    VirtIOSerial *vser;
573

    
574
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
575
    guest_reset(vser);
576
}
577

    
578
static void virtio_serial_save(QEMUFile *f, void *opaque)
579
{
580
    VirtIOSerial *s = opaque;
581
    VirtIOSerialPort *port;
582
    uint32_t nr_active_ports;
583
    unsigned int i, max_nr_ports;
584

    
585
    /* The virtio device */
586
    virtio_save(&s->vdev, f);
587

    
588
    /* The config space */
589
    qemu_put_be16s(f, &s->config.cols);
590
    qemu_put_be16s(f, &s->config.rows);
591

    
592
    qemu_put_be32s(f, &s->config.max_nr_ports);
593

    
594
    /* The ports map */
595
    max_nr_ports = tswap32(s->config.max_nr_ports);
596
    for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
597
        qemu_put_be32s(f, &s->ports_map[i]);
598
    }
599

    
600
    /* Ports */
601

    
602
    nr_active_ports = 0;
603
    QTAILQ_FOREACH(port, &s->ports, next) {
604
        nr_active_ports++;
605
    }
606

    
607
    qemu_put_be32s(f, &nr_active_ports);
608

    
609
    /*
610
     * Items in struct VirtIOSerialPort.
611
     */
612
    QTAILQ_FOREACH(port, &s->ports, next) {
613
        uint32_t elem_popped;
614

    
615
        qemu_put_be32s(f, &port->id);
616
        qemu_put_byte(f, port->guest_connected);
617
        qemu_put_byte(f, port->host_connected);
618

    
619
        elem_popped = 0;
620
        if (port->elem.out_num) {
621
            elem_popped = 1;
622
        }
623
        qemu_put_be32s(f, &elem_popped);
624
        if (elem_popped) {
625
            qemu_put_be32s(f, &port->iov_idx);
626
            qemu_put_be64s(f, &port->iov_offset);
627

    
628
            qemu_put_buffer(f, (unsigned char *)&port->elem,
629
                            sizeof(port->elem));
630
        }
631
    }
632
}
633

    
634
static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
635
{
636
    VirtIOSerial *s = opaque;
637
    VirtIOSerialPort *port;
638
    uint32_t max_nr_ports, nr_active_ports, ports_map;
639
    unsigned int i;
640

    
641
    if (version_id > 3) {
642
        return -EINVAL;
643
    }
644

    
645
    /* The virtio device */
646
    virtio_load(&s->vdev, f);
647

    
648
    if (version_id < 2) {
649
        return 0;
650
    }
651

    
652
    /* The config space */
653
    qemu_get_be16s(f, &s->config.cols);
654
    qemu_get_be16s(f, &s->config.rows);
655

    
656
    qemu_get_be32s(f, &max_nr_ports);
657
    tswap32s(&max_nr_ports);
658
    if (max_nr_ports > tswap32(s->config.max_nr_ports)) {
659
        /* Source could have had more ports than us. Fail migration. */
660
        return -EINVAL;
661
    }
662

    
663
    for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
664
        qemu_get_be32s(f, &ports_map);
665

    
666
        if (ports_map != s->ports_map[i]) {
667
            /*
668
             * Ports active on source and destination don't
669
             * match. Fail migration.
670
             */
671
            return -EINVAL;
672
        }
673
    }
674

    
675
    qemu_get_be32s(f, &nr_active_ports);
676

    
677
    /* Items in struct VirtIOSerialPort */
678
    for (i = 0; i < nr_active_ports; i++) {
679
        uint32_t id;
680
        bool host_connected;
681

    
682
        id = qemu_get_be32(f);
683
        port = find_port_by_id(s, id);
684
        if (!port) {
685
            return -EINVAL;
686
        }
687

    
688
        port->guest_connected = qemu_get_byte(f);
689
        host_connected = qemu_get_byte(f);
690
        if (host_connected != port->host_connected) {
691
            /*
692
             * We have to let the guest know of the host connection
693
             * status change
694
             */
695
            send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN,
696
                               port->host_connected);
697
        }
698

    
699
        if (version_id > 2) {
700
            uint32_t elem_popped;
701

    
702
            qemu_get_be32s(f, &elem_popped);
703
            if (elem_popped) {
704
                qemu_get_be32s(f, &port->iov_idx);
705
                qemu_get_be64s(f, &port->iov_offset);
706

    
707
                qemu_get_buffer(f, (unsigned char *)&port->elem,
708
                                sizeof(port->elem));
709
                virtqueue_map_sg(port->elem.in_sg, port->elem.in_addr,
710
                                 port->elem.in_num, 1);
711
                virtqueue_map_sg(port->elem.out_sg, port->elem.out_addr,
712
                                 port->elem.out_num, 1);
713

    
714
                /*
715
                 *  Port was throttled on source machine.  Let's
716
                 *  unthrottle it here so data starts flowing again.
717
                 */
718
                virtio_serial_throttle_port(port, false);
719
            }
720
        }
721
    }
722
    return 0;
723
}
724

    
725
static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
726

    
727
static struct BusInfo virtser_bus_info = {
728
    .name      = "virtio-serial-bus",
729
    .size      = sizeof(VirtIOSerialBus),
730
    .print_dev = virtser_bus_dev_print,
731
    .props      = (Property[]) {
732
        DEFINE_PROP_UINT32("nr", VirtIOSerialPort, id, VIRTIO_CONSOLE_BAD_ID),
733
        DEFINE_PROP_STRING("name", VirtIOSerialPort, name),
734
        DEFINE_PROP_END_OF_LIST()
735
    }
736
};
737

    
738
static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
739
{
740
    VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
741

    
742
    monitor_printf(mon, "%*sport %d, guest %s, host %s, throttle %s\n",
743
                   indent, "", port->id,
744
                   port->guest_connected ? "on" : "off",
745
                   port->host_connected ? "on" : "off",
746
                   port->throttled ? "on" : "off");
747
}
748

    
749
/* This function is only used if a port id is not provided by the user */
750
static uint32_t find_free_port_id(VirtIOSerial *vser)
751
{
752
    unsigned int i, max_nr_ports;
753

    
754
    max_nr_ports = tswap32(vser->config.max_nr_ports);
755
    for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
756
        uint32_t map, bit;
757

    
758
        map = vser->ports_map[i];
759
        bit = ffs(~map);
760
        if (bit) {
761
            return (bit - 1) + i * 32;
762
        }
763
    }
764
    return VIRTIO_CONSOLE_BAD_ID;
765
}
766

    
767
static void mark_port_added(VirtIOSerial *vser, uint32_t port_id)
768
{
769
    unsigned int i;
770

    
771
    i = port_id / 32;
772
    vser->ports_map[i] |= 1U << (port_id % 32);
773
}
774

    
775
static void add_port(VirtIOSerial *vser, uint32_t port_id)
776
{
777
    mark_port_added(vser, port_id);
778

    
779
    send_control_event(find_port_by_id(vser, port_id),
780
                       VIRTIO_CONSOLE_PORT_ADD, 1);
781
}
782

    
783
static void remove_port(VirtIOSerial *vser, uint32_t port_id)
784
{
785
    VirtIOSerialPort *port;
786
    unsigned int i;
787

    
788
    i = port_id / 32;
789
    vser->ports_map[i] &= ~(1U << (port_id % 32));
790

    
791
    port = find_port_by_id(vser, port_id);
792
    /* Flush out any unconsumed buffers first */
793
    discard_vq_data(port->ovq, &port->vser->vdev);
794

    
795
    send_control_event(port, VIRTIO_CONSOLE_PORT_REMOVE, 1);
796
}
797

    
798
static int virtser_port_qdev_init(DeviceState *qdev)
799
{
800
    VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
801
    VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
802
    VirtIOSerialBus *bus = DO_UPCAST(VirtIOSerialBus, qbus, qdev->parent_bus);
803
    int ret, max_nr_ports;
804
    bool plugging_port0;
805

    
806
    port->vser = bus->vser;
807
    port->bh = qemu_bh_new(flush_queued_data_bh, port);
808

    
809
    assert(vsc->have_data);
810

    
811
    /*
812
     * Is the first console port we're seeing? If so, put it up at
813
     * location 0. This is done for backward compatibility (old
814
     * kernel, new qemu).
815
     */
816
    plugging_port0 = vsc->is_console && !find_port_by_id(port->vser, 0);
817

    
818
    if (find_port_by_id(port->vser, port->id)) {
819
        error_report("virtio-serial-bus: A port already exists at id %u",
820
                     port->id);
821
        return -1;
822
    }
823

    
824
    if (port->id == VIRTIO_CONSOLE_BAD_ID) {
825
        if (plugging_port0) {
826
            port->id = 0;
827
        } else {
828
            port->id = find_free_port_id(port->vser);
829
            if (port->id == VIRTIO_CONSOLE_BAD_ID) {
830
                error_report("virtio-serial-bus: Maximum port limit for this device reached");
831
                return -1;
832
            }
833
        }
834
    }
835

    
836
    max_nr_ports = tswap32(port->vser->config.max_nr_ports);
837
    if (port->id >= max_nr_ports) {
838
        error_report("virtio-serial-bus: Out-of-range port id specified, max. allowed: %u",
839
                     max_nr_ports - 1);
840
        return -1;
841
    }
842

    
843
    ret = vsc->init(port);
844
    if (ret) {
845
        return ret;
846
    }
847

    
848
    port->elem.out_num = 0;
849

    
850
    QTAILQ_INSERT_TAIL(&port->vser->ports, port, next);
851
    port->ivq = port->vser->ivqs[port->id];
852
    port->ovq = port->vser->ovqs[port->id];
853

    
854
    add_port(port->vser, port->id);
855

    
856
    /* Send an update to the guest about this new port added */
857
    virtio_notify_config(&port->vser->vdev);
858

    
859
    return ret;
860
}
861

    
862
static int virtser_port_qdev_exit(DeviceState *qdev)
863
{
864
    VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
865
    VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
866
    VirtIOSerial *vser = port->vser;
867

    
868
    qemu_bh_delete(port->bh);
869
    remove_port(port->vser, port->id);
870

    
871
    QTAILQ_REMOVE(&vser->ports, port, next);
872

    
873
    if (vsc->exit) {
874
        vsc->exit(port);
875
    }
876
    return 0;
877
}
878

    
879
VirtIODevice *virtio_serial_init(DeviceState *dev, virtio_serial_conf *conf)
880
{
881
    VirtIOSerial *vser;
882
    VirtIODevice *vdev;
883
    uint32_t i, max_supported_ports;
884

    
885
    if (!conf->max_virtserial_ports)
886
        return NULL;
887

    
888
    /* Each port takes 2 queues, and one pair is for the control queue */
889
    max_supported_ports = VIRTIO_PCI_QUEUE_MAX / 2 - 1;
890

    
891
    if (conf->max_virtserial_ports > max_supported_ports) {
892
        error_report("maximum ports supported: %u", max_supported_ports);
893
        return NULL;
894
    }
895

    
896
    vdev = virtio_common_init("virtio-serial", VIRTIO_ID_CONSOLE,
897
                              sizeof(struct virtio_console_config),
898
                              sizeof(VirtIOSerial));
899

    
900
    vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
901

    
902
    /* Spawn a new virtio-serial bus on which the ports will ride as devices */
903
    qbus_create_inplace(&vser->bus.qbus, &virtser_bus_info, dev, NULL);
904
    vser->bus.qbus.allow_hotplug = 1;
905
    vser->bus.vser = vser;
906
    QTAILQ_INIT(&vser->ports);
907

    
908
    vser->bus.max_nr_ports = conf->max_virtserial_ports;
909
    vser->ivqs = g_malloc(conf->max_virtserial_ports * sizeof(VirtQueue *));
910
    vser->ovqs = g_malloc(conf->max_virtserial_ports * sizeof(VirtQueue *));
911

    
912
    /* Add a queue for host to guest transfers for port 0 (backward compat) */
913
    vser->ivqs[0] = virtio_add_queue(vdev, 128, handle_input);
914
    /* Add a queue for guest to host transfers for port 0 (backward compat) */
915
    vser->ovqs[0] = virtio_add_queue(vdev, 128, handle_output);
916

    
917
    /* TODO: host to guest notifications can get dropped
918
     * if the queue fills up. Implement queueing in host,
919
     * this might also make it possible to reduce the control
920
     * queue size: as guest preposts buffers there,
921
     * this will save 4Kbyte of guest memory per entry. */
922

    
923
    /* control queue: host to guest */
924
    vser->c_ivq = virtio_add_queue(vdev, 32, control_in);
925
    /* control queue: guest to host */
926
    vser->c_ovq = virtio_add_queue(vdev, 32, control_out);
927

    
928
    for (i = 1; i < vser->bus.max_nr_ports; i++) {
929
        /* Add a per-port queue for host to guest transfers */
930
        vser->ivqs[i] = virtio_add_queue(vdev, 128, handle_input);
931
        /* Add a per-per queue for guest to host transfers */
932
        vser->ovqs[i] = virtio_add_queue(vdev, 128, handle_output);
933
    }
934

    
935
    vser->config.max_nr_ports = tswap32(conf->max_virtserial_ports);
936
    vser->ports_map = g_malloc0(((conf->max_virtserial_ports + 31) / 32)
937
        * sizeof(vser->ports_map[0]));
938
    /*
939
     * Reserve location 0 for a console port for backward compat
940
     * (old kernel, new qemu)
941
     */
942
    mark_port_added(vser, 0);
943

    
944
    vser->vdev.get_features = get_features;
945
    vser->vdev.get_config = get_config;
946
    vser->vdev.set_config = set_config;
947
    vser->vdev.set_status = set_status;
948
    vser->vdev.reset = vser_reset;
949

    
950
    vser->qdev = dev;
951

    
952
    /*
953
     * Register for the savevm section with the virtio-console name
954
     * to preserve backward compat
955
     */
956
    register_savevm(dev, "virtio-console", -1, 3, virtio_serial_save,
957
                    virtio_serial_load, vser);
958

    
959
    return vdev;
960
}
961

    
962
void virtio_serial_exit(VirtIODevice *vdev)
963
{
964
    VirtIOSerial *vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
965

    
966
    unregister_savevm(vser->qdev, "virtio-console", vser);
967

    
968
    g_free(vser->ivqs);
969
    g_free(vser->ovqs);
970
    g_free(vser->ports_map);
971

    
972
    virtio_cleanup(vdev);
973
}
974

    
975
static void virtio_serial_port_class_init(ObjectClass *klass, void *data)
976
{
977
    DeviceClass *k = DEVICE_CLASS(klass);
978
    k->init = virtser_port_qdev_init;
979
    k->bus_info = &virtser_bus_info;
980
    k->exit = virtser_port_qdev_exit;
981
    k->unplug = qdev_simple_unplug_cb;
982
}
983

    
984
static TypeInfo virtio_serial_port_type_info = {
985
    .name = TYPE_VIRTIO_SERIAL_PORT,
986
    .parent = TYPE_DEVICE,
987
    .instance_size = sizeof(VirtIOSerialPort),
988
    .abstract = true,
989
    .class_size = sizeof(VirtIOSerialPortClass),
990
    .class_init = virtio_serial_port_class_init,
991
};
992

    
993
static void virtio_serial_register_types(void)
994
{
995
    type_register_static(&virtio_serial_port_type_info);
996
}
997

    
998
type_init(virtio_serial_register_types)