Merge remote-tracking branch 'remotes/philmd-gitlab/tags/renesas-20201027' into staging
[qemu.git] / hw / char / virtio-serial-bus.c
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 "qemu/osdep.h"
22 #include "qapi/error.h"
23 #include "qemu/iov.h"
24 #include "qemu/main-loop.h"
25 #include "qemu/module.h"
26 #include "migration/qemu-file-types.h"
27 #include "monitor/monitor.h"
28 #include "qemu/error-report.h"
29 #include "qemu/queue.h"
30 #include "hw/qdev-properties.h"
31 #include "hw/sysbus.h"
32 #include "trace.h"
33 #include "hw/virtio/virtio-serial.h"
34 #include "hw/virtio/virtio-access.h"
35
36 static struct VirtIOSerialDevices {
37 QLIST_HEAD(, VirtIOSerial) devices;
38 } vserdevices;
39
40 static VirtIOSerialPort *find_port_by_id(VirtIOSerial *vser, uint32_t id)
41 {
42 VirtIOSerialPort *port;
43
44 if (id == VIRTIO_CONSOLE_BAD_ID) {
45 return NULL;
46 }
47
48 QTAILQ_FOREACH(port, &vser->ports, next) {
49 if (port->id == id)
50 return port;
51 }
52 return NULL;
53 }
54
55 static VirtIOSerialPort *find_port_by_vq(VirtIOSerial *vser, VirtQueue *vq)
56 {
57 VirtIOSerialPort *port;
58
59 QTAILQ_FOREACH(port, &vser->ports, next) {
60 if (port->ivq == vq || port->ovq == vq)
61 return port;
62 }
63 return NULL;
64 }
65
66 static VirtIOSerialPort *find_port_by_name(char *name)
67 {
68 VirtIOSerial *vser;
69
70 QLIST_FOREACH(vser, &vserdevices.devices, next) {
71 VirtIOSerialPort *port;
72
73 QTAILQ_FOREACH(port, &vser->ports, next) {
74 if (port->name && !strcmp(port->name, name)) {
75 return port;
76 }
77 }
78 }
79 return NULL;
80 }
81
82 static VirtIOSerialPort *find_first_connected_console(VirtIOSerial *vser)
83 {
84 VirtIOSerialPort *port;
85
86 QTAILQ_FOREACH(port, &vser->ports, next) {
87 VirtIOSerialPortClass const *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
88 if (vsc->is_console && port->host_connected) {
89 return port;
90 }
91 }
92 return NULL;
93 }
94
95 static bool use_multiport(VirtIOSerial *vser)
96 {
97 VirtIODevice *vdev = VIRTIO_DEVICE(vser);
98 return virtio_vdev_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT);
99 }
100
101 static size_t write_to_port(VirtIOSerialPort *port,
102 const uint8_t *buf, size_t size)
103 {
104 VirtQueueElement *elem;
105 VirtQueue *vq;
106 size_t offset;
107
108 vq = port->ivq;
109 if (!virtio_queue_ready(vq)) {
110 return 0;
111 }
112
113 offset = 0;
114 while (offset < size) {
115 size_t len;
116
117 elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
118 if (!elem) {
119 break;
120 }
121
122 len = iov_from_buf(elem->in_sg, elem->in_num, 0,
123 buf + offset, size - offset);
124 offset += len;
125
126 virtqueue_push(vq, elem, len);
127 g_free(elem);
128 }
129
130 virtio_notify(VIRTIO_DEVICE(port->vser), vq);
131 return offset;
132 }
133
134 static void discard_vq_data(VirtQueue *vq, VirtIODevice *vdev)
135 {
136 VirtQueueElement *elem;
137
138 if (!virtio_queue_ready(vq)) {
139 return;
140 }
141 for (;;) {
142 elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
143 if (!elem) {
144 break;
145 }
146 virtqueue_push(vq, elem, 0);
147 g_free(elem);
148 }
149 virtio_notify(vdev, vq);
150 }
151
152 static void discard_throttle_data(VirtIOSerialPort *port)
153 {
154 if (port->elem) {
155 virtqueue_detach_element(port->ovq, port->elem, 0);
156 g_free(port->elem);
157 port->elem = NULL;
158 }
159 }
160
161 static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
162 VirtIODevice *vdev)
163 {
164 VirtIOSerialPortClass *vsc;
165
166 assert(port);
167 assert(virtio_queue_ready(vq));
168
169 vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
170
171 while (!port->throttled) {
172 unsigned int i;
173
174 /* Pop an elem only if we haven't left off a previous one mid-way */
175 if (!port->elem) {
176 port->elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
177 if (!port->elem) {
178 break;
179 }
180 port->iov_idx = 0;
181 port->iov_offset = 0;
182 }
183
184 for (i = port->iov_idx; i < port->elem->out_num; i++) {
185 size_t buf_size;
186 ssize_t ret;
187
188 buf_size = port->elem->out_sg[i].iov_len - port->iov_offset;
189 ret = vsc->have_data(port,
190 port->elem->out_sg[i].iov_base
191 + port->iov_offset,
192 buf_size);
193 if (!port->elem) { /* bail if we got disconnected */
194 return;
195 }
196 if (port->throttled) {
197 port->iov_idx = i;
198 if (ret > 0) {
199 port->iov_offset += ret;
200 }
201 break;
202 }
203 port->iov_offset = 0;
204 }
205 if (port->throttled) {
206 break;
207 }
208 virtqueue_push(vq, port->elem, 0);
209 g_free(port->elem);
210 port->elem = NULL;
211 }
212 virtio_notify(vdev, vq);
213 }
214
215 static void flush_queued_data(VirtIOSerialPort *port)
216 {
217 assert(port);
218
219 if (!virtio_queue_ready(port->ovq)) {
220 return;
221 }
222 do_flush_queued_data(port, port->ovq, VIRTIO_DEVICE(port->vser));
223 }
224
225 static size_t send_control_msg(VirtIOSerial *vser, void *buf, size_t len)
226 {
227 VirtQueueElement *elem;
228 VirtQueue *vq;
229
230 vq = vser->c_ivq;
231 if (!virtio_queue_ready(vq)) {
232 return 0;
233 }
234
235 elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
236 if (!elem) {
237 return 0;
238 }
239
240 /* TODO: detect a buffer that's too short, set NEEDS_RESET */
241 iov_from_buf(elem->in_sg, elem->in_num, 0, buf, len);
242
243 virtqueue_push(vq, elem, len);
244 virtio_notify(VIRTIO_DEVICE(vser), vq);
245 g_free(elem);
246
247 return len;
248 }
249
250 static size_t send_control_event(VirtIOSerial *vser, uint32_t port_id,
251 uint16_t event, uint16_t value)
252 {
253 VirtIODevice *vdev = VIRTIO_DEVICE(vser);
254 struct virtio_console_control cpkt;
255
256 virtio_stl_p(vdev, &cpkt.id, port_id);
257 virtio_stw_p(vdev, &cpkt.event, event);
258 virtio_stw_p(vdev, &cpkt.value, value);
259
260 trace_virtio_serial_send_control_event(port_id, event, value);
261 return send_control_msg(vser, &cpkt, sizeof(cpkt));
262 }
263
264 /* Functions for use inside qemu to open and read from/write to ports */
265 int virtio_serial_open(VirtIOSerialPort *port)
266 {
267 /* Don't allow opening an already-open port */
268 if (port->host_connected) {
269 return 0;
270 }
271 /* Send port open notification to the guest */
272 port->host_connected = true;
273 send_control_event(port->vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 1);
274
275 return 0;
276 }
277
278 int virtio_serial_close(VirtIOSerialPort *port)
279 {
280 port->host_connected = false;
281 /*
282 * If there's any data the guest sent which the app didn't
283 * consume, reset the throttling flag and discard the data.
284 */
285 port->throttled = false;
286 discard_throttle_data(port);
287 discard_vq_data(port->ovq, VIRTIO_DEVICE(port->vser));
288
289 send_control_event(port->vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 0);
290
291 return 0;
292 }
293
294 /* Individual ports/apps call this function to write to the guest. */
295 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
296 size_t size)
297 {
298 if (!port || !port->host_connected || !port->guest_connected) {
299 return 0;
300 }
301 return write_to_port(port, buf, size);
302 }
303
304 /*
305 * Readiness of the guest to accept data on a port.
306 * Returns max. data the guest can receive
307 */
308 size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
309 {
310 VirtIODevice *vdev = VIRTIO_DEVICE(port->vser);
311 VirtQueue *vq = port->ivq;
312 unsigned int bytes;
313
314 if (!virtio_queue_ready(vq) ||
315 !(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) ||
316 virtio_queue_empty(vq)) {
317 return 0;
318 }
319 if (use_multiport(port->vser) && !port->guest_connected) {
320 return 0;
321 }
322 virtqueue_get_avail_bytes(vq, &bytes, NULL, 4096, 0);
323 return bytes;
324 }
325
326 static void flush_queued_data_bh(void *opaque)
327 {
328 VirtIOSerialPort *port = opaque;
329
330 flush_queued_data(port);
331 }
332
333 void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
334 {
335 if (!port) {
336 return;
337 }
338
339 trace_virtio_serial_throttle_port(port->id, throttle);
340 port->throttled = throttle;
341 if (throttle) {
342 return;
343 }
344 qemu_bh_schedule(port->bh);
345 }
346
347 /* Guest wants to notify us of some event */
348 static void handle_control_message(VirtIOSerial *vser, void *buf, size_t len)
349 {
350 VirtIODevice *vdev = VIRTIO_DEVICE(vser);
351 struct VirtIOSerialPort *port;
352 VirtIOSerialPortClass *vsc;
353 struct virtio_console_control cpkt, *gcpkt;
354 uint8_t *buffer;
355 size_t buffer_len;
356
357 gcpkt = buf;
358
359 if (len < sizeof(cpkt)) {
360 /* The guest sent an invalid control packet */
361 return;
362 }
363
364 cpkt.event = virtio_lduw_p(vdev, &gcpkt->event);
365 cpkt.value = virtio_lduw_p(vdev, &gcpkt->value);
366
367 trace_virtio_serial_handle_control_message(cpkt.event, cpkt.value);
368
369 if (cpkt.event == VIRTIO_CONSOLE_DEVICE_READY) {
370 if (!cpkt.value) {
371 error_report("virtio-serial-bus: Guest failure in adding device %s",
372 vser->bus.qbus.name);
373 return;
374 }
375 /*
376 * The device is up, we can now tell the device about all the
377 * ports we have here.
378 */
379 QTAILQ_FOREACH(port, &vser->ports, next) {
380 send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_ADD, 1);
381 }
382 return;
383 }
384
385 port = find_port_by_id(vser, virtio_ldl_p(vdev, &gcpkt->id));
386 if (!port) {
387 error_report("virtio-serial-bus: Unexpected port id %u for device %s",
388 virtio_ldl_p(vdev, &gcpkt->id), vser->bus.qbus.name);
389 return;
390 }
391
392 trace_virtio_serial_handle_control_message_port(port->id);
393
394 vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
395
396 switch(cpkt.event) {
397 case VIRTIO_CONSOLE_PORT_READY:
398 if (!cpkt.value) {
399 error_report("virtio-serial-bus: Guest failure in adding port %u for device %s",
400 port->id, vser->bus.qbus.name);
401 break;
402 }
403 /*
404 * Now that we know the guest asked for the port name, we're
405 * sure the guest has initialised whatever state is necessary
406 * for this port. Now's a good time to let the guest know if
407 * this port is a console port so that the guest can hook it
408 * up to hvc.
409 */
410 if (vsc->is_console) {
411 send_control_event(vser, port->id, VIRTIO_CONSOLE_CONSOLE_PORT, 1);
412 }
413
414 if (port->name) {
415 virtio_stl_p(vdev, &cpkt.id, port->id);
416 virtio_stw_p(vdev, &cpkt.event, VIRTIO_CONSOLE_PORT_NAME);
417 virtio_stw_p(vdev, &cpkt.value, 1);
418
419 buffer_len = sizeof(cpkt) + strlen(port->name) + 1;
420 buffer = g_malloc(buffer_len);
421
422 memcpy(buffer, &cpkt, sizeof(cpkt));
423 memcpy(buffer + sizeof(cpkt), port->name, strlen(port->name));
424 buffer[buffer_len - 1] = 0;
425
426 send_control_msg(vser, buffer, buffer_len);
427 g_free(buffer);
428 }
429
430 if (port->host_connected) {
431 send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 1);
432 }
433
434 /*
435 * When the guest has asked us for this information it means
436 * the guest is all setup and has its virtqueues
437 * initialised. If some app is interested in knowing about
438 * this event, let it know.
439 */
440 if (vsc->guest_ready) {
441 vsc->guest_ready(port);
442 }
443 break;
444
445 case VIRTIO_CONSOLE_PORT_OPEN:
446 port->guest_connected = cpkt.value;
447 if (vsc->set_guest_connected) {
448 /* Send the guest opened notification if an app is interested */
449 vsc->set_guest_connected(port, cpkt.value);
450 }
451 break;
452 }
453 }
454
455 static void control_in(VirtIODevice *vdev, VirtQueue *vq)
456 {
457 }
458
459 static void control_out(VirtIODevice *vdev, VirtQueue *vq)
460 {
461 VirtQueueElement *elem;
462 VirtIOSerial *vser;
463 uint8_t *buf;
464 size_t len;
465
466 vser = VIRTIO_SERIAL(vdev);
467
468 len = 0;
469 buf = NULL;
470 for (;;) {
471 size_t cur_len;
472
473 elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
474 if (!elem) {
475 break;
476 }
477
478 cur_len = iov_size(elem->out_sg, elem->out_num);
479 /*
480 * Allocate a new buf only if we didn't have one previously or
481 * if the size of the buf differs
482 */
483 if (cur_len > len) {
484 g_free(buf);
485
486 buf = g_malloc(cur_len);
487 len = cur_len;
488 }
489 iov_to_buf(elem->out_sg, elem->out_num, 0, buf, cur_len);
490
491 handle_control_message(vser, buf, cur_len);
492 virtqueue_push(vq, elem, 0);
493 g_free(elem);
494 }
495 g_free(buf);
496 virtio_notify(vdev, vq);
497 }
498
499 /* Guest wrote something to some port. */
500 static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
501 {
502 VirtIOSerial *vser;
503 VirtIOSerialPort *port;
504
505 vser = VIRTIO_SERIAL(vdev);
506 port = find_port_by_vq(vser, vq);
507
508 if (!port || !port->host_connected) {
509 discard_vq_data(vq, vdev);
510 return;
511 }
512
513 if (!port->throttled) {
514 do_flush_queued_data(port, vq, vdev);
515 return;
516 }
517 }
518
519 static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
520 {
521 /*
522 * Users of virtio-serial would like to know when guest becomes
523 * writable again -- i.e. if a vq had stuff queued up and the
524 * guest wasn't reading at all, the host would not be able to
525 * write to the vq anymore. Once the guest reads off something,
526 * we can start queueing things up again. However, this call is
527 * made for each buffer addition by the guest -- even though free
528 * buffers existed prior to the current buffer addition. This is
529 * done so as not to maintain previous state, which will need
530 * additional live-migration-related changes.
531 */
532 VirtIOSerial *vser;
533 VirtIOSerialPort *port;
534 VirtIOSerialPortClass *vsc;
535
536 vser = VIRTIO_SERIAL(vdev);
537 port = find_port_by_vq(vser, vq);
538
539 if (!port) {
540 return;
541 }
542 vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
543
544 /*
545 * If guest_connected is false, this call is being made by the
546 * early-boot queueing up of descriptors, which is just noise for
547 * the host apps -- don't disturb them in that case.
548 */
549 if (port->guest_connected && port->host_connected && vsc->guest_writable) {
550 vsc->guest_writable(port);
551 }
552 }
553
554 static uint64_t get_features(VirtIODevice *vdev, uint64_t features,
555 Error **errp)
556 {
557 VirtIOSerial *vser;
558
559 vser = VIRTIO_SERIAL(vdev);
560
561 features |= vser->host_features;
562 if (vser->bus.max_nr_ports > 1) {
563 virtio_add_feature(&features, VIRTIO_CONSOLE_F_MULTIPORT);
564 }
565 return features;
566 }
567
568 /* Guest requested config info */
569 static void get_config(VirtIODevice *vdev, uint8_t *config_data)
570 {
571 VirtIOSerial *vser = VIRTIO_SERIAL(vdev);
572 struct virtio_console_config *config =
573 (struct virtio_console_config *)config_data;
574
575 config->cols = 0;
576 config->rows = 0;
577 config->max_nr_ports = virtio_tswap32(vdev,
578 vser->serial.max_virtserial_ports);
579 }
580
581 /* Guest sent new config info */
582 static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
583 {
584 VirtIOSerial *vser = VIRTIO_SERIAL(vdev);
585 struct virtio_console_config *config =
586 (struct virtio_console_config *)config_data;
587 VirtIOSerialPort *port = find_first_connected_console(vser);
588 VirtIOSerialPortClass *vsc;
589 uint8_t emerg_wr_lo;
590
591 if (!virtio_has_feature(vser->host_features,
592 VIRTIO_CONSOLE_F_EMERG_WRITE) || !config->emerg_wr) {
593 return;
594 }
595
596 emerg_wr_lo = le32_to_cpu(config->emerg_wr);
597 /* Make sure we don't misdetect an emergency write when the guest
598 * does a short config write after an emergency write. */
599 config->emerg_wr = 0;
600 if (!port) {
601 return;
602 }
603 vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
604 (void)vsc->have_data(port, &emerg_wr_lo, 1);
605 }
606
607 static void guest_reset(VirtIOSerial *vser)
608 {
609 VirtIOSerialPort *port;
610 VirtIOSerialPortClass *vsc;
611
612 QTAILQ_FOREACH(port, &vser->ports, next) {
613 vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
614
615 discard_throttle_data(port);
616
617 if (port->guest_connected) {
618 port->guest_connected = false;
619 if (vsc->set_guest_connected) {
620 vsc->set_guest_connected(port, false);
621 }
622 }
623 }
624 }
625
626 static void set_status(VirtIODevice *vdev, uint8_t status)
627 {
628 VirtIOSerial *vser;
629 VirtIOSerialPort *port;
630
631 vser = VIRTIO_SERIAL(vdev);
632 port = find_port_by_id(vser, 0);
633
634 if (port && !use_multiport(port->vser)
635 && (status & VIRTIO_CONFIG_S_DRIVER_OK)) {
636 /*
637 * Non-multiport guests won't be able to tell us guest
638 * open/close status. Such guests can only have a port at id
639 * 0, so set guest_connected for such ports as soon as guest
640 * is up.
641 */
642 port->guest_connected = true;
643 }
644 if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
645 guest_reset(vser);
646 }
647
648 QTAILQ_FOREACH(port, &vser->ports, next) {
649 VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
650 if (vsc->enable_backend) {
651 vsc->enable_backend(port, vdev->vm_running);
652 }
653 }
654 }
655
656 static void vser_reset(VirtIODevice *vdev)
657 {
658 VirtIOSerial *vser;
659
660 vser = VIRTIO_SERIAL(vdev);
661 guest_reset(vser);
662 }
663
664 static void virtio_serial_save_device(VirtIODevice *vdev, QEMUFile *f)
665 {
666 VirtIOSerial *s = VIRTIO_SERIAL(vdev);
667 VirtIOSerialPort *port;
668 uint32_t nr_active_ports;
669 unsigned int i, max_nr_ports;
670 struct virtio_console_config config;
671
672 /* The config space (ignored on the far end in current versions) */
673 get_config(vdev, (uint8_t *)&config);
674 qemu_put_be16(f, config.cols);
675 qemu_put_be16(f, config.rows);
676 qemu_put_be32(f, config.max_nr_ports);
677
678 /* The ports map */
679 max_nr_ports = s->serial.max_virtserial_ports;
680 for (i = 0; i < DIV_ROUND_UP(max_nr_ports, 32); i++) {
681 qemu_put_be32s(f, &s->ports_map[i]);
682 }
683
684 /* Ports */
685
686 nr_active_ports = 0;
687 QTAILQ_FOREACH(port, &s->ports, next) {
688 nr_active_ports++;
689 }
690
691 qemu_put_be32s(f, &nr_active_ports);
692
693 /*
694 * Items in struct VirtIOSerialPort.
695 */
696 QTAILQ_FOREACH(port, &s->ports, next) {
697 uint32_t elem_popped;
698
699 qemu_put_be32s(f, &port->id);
700 qemu_put_byte(f, port->guest_connected);
701 qemu_put_byte(f, port->host_connected);
702
703 elem_popped = 0;
704 if (port->elem) {
705 elem_popped = 1;
706 }
707 qemu_put_be32s(f, &elem_popped);
708 if (elem_popped) {
709 qemu_put_be32s(f, &port->iov_idx);
710 qemu_put_be64s(f, &port->iov_offset);
711 qemu_put_virtqueue_element(vdev, f, port->elem);
712 }
713 }
714 }
715
716 static void virtio_serial_post_load_timer_cb(void *opaque)
717 {
718 uint32_t i;
719 VirtIOSerial *s = VIRTIO_SERIAL(opaque);
720 VirtIOSerialPort *port;
721 uint8_t host_connected;
722 VirtIOSerialPortClass *vsc;
723
724 if (!s->post_load) {
725 return;
726 }
727 for (i = 0 ; i < s->post_load->nr_active_ports; ++i) {
728 port = s->post_load->connected[i].port;
729 host_connected = s->post_load->connected[i].host_connected;
730 if (host_connected != port->host_connected) {
731 /*
732 * We have to let the guest know of the host connection
733 * status change
734 */
735 send_control_event(s, port->id, VIRTIO_CONSOLE_PORT_OPEN,
736 port->host_connected);
737 }
738 vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
739 if (vsc->set_guest_connected) {
740 vsc->set_guest_connected(port, port->guest_connected);
741 }
742 }
743 g_free(s->post_load->connected);
744 timer_del(s->post_load->timer);
745 timer_free(s->post_load->timer);
746 g_free(s->post_load);
747 s->post_load = NULL;
748 }
749
750 static int fetch_active_ports_list(QEMUFile *f,
751 VirtIOSerial *s, uint32_t nr_active_ports)
752 {
753 VirtIODevice *vdev = VIRTIO_DEVICE(s);
754 uint32_t i;
755
756 s->post_load = g_malloc0(sizeof(*s->post_load));
757 s->post_load->nr_active_ports = nr_active_ports;
758 s->post_load->connected =
759 g_malloc0(sizeof(*s->post_load->connected) * nr_active_ports);
760
761 s->post_load->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
762 virtio_serial_post_load_timer_cb,
763 s);
764
765 /* Items in struct VirtIOSerialPort */
766 for (i = 0; i < nr_active_ports; i++) {
767 VirtIOSerialPort *port;
768 uint32_t elem_popped;
769 uint32_t id;
770
771 id = qemu_get_be32(f);
772 port = find_port_by_id(s, id);
773 if (!port) {
774 return -EINVAL;
775 }
776
777 port->guest_connected = qemu_get_byte(f);
778 s->post_load->connected[i].port = port;
779 s->post_load->connected[i].host_connected = qemu_get_byte(f);
780
781 qemu_get_be32s(f, &elem_popped);
782 if (elem_popped) {
783 qemu_get_be32s(f, &port->iov_idx);
784 qemu_get_be64s(f, &port->iov_offset);
785
786 port->elem =
787 qemu_get_virtqueue_element(vdev, f, sizeof(VirtQueueElement));
788
789 /*
790 * Port was throttled on source machine. Let's
791 * unthrottle it here so data starts flowing again.
792 */
793 virtio_serial_throttle_port(port, false);
794 }
795 }
796 timer_mod(s->post_load->timer, 1);
797 return 0;
798 }
799
800 static int virtio_serial_load_device(VirtIODevice *vdev, QEMUFile *f,
801 int version_id)
802 {
803 VirtIOSerial *s = VIRTIO_SERIAL(vdev);
804 uint32_t max_nr_ports, nr_active_ports, ports_map;
805 unsigned int i;
806 int ret;
807 uint32_t tmp;
808
809 /* Unused */
810 qemu_get_be16s(f, (uint16_t *) &tmp);
811 qemu_get_be16s(f, (uint16_t *) &tmp);
812 qemu_get_be32s(f, &tmp);
813
814 max_nr_ports = s->serial.max_virtserial_ports;
815 for (i = 0; i < DIV_ROUND_UP(max_nr_ports, 32); i++) {
816 qemu_get_be32s(f, &ports_map);
817
818 if (ports_map != s->ports_map[i]) {
819 /*
820 * Ports active on source and destination don't
821 * match. Fail migration.
822 */
823 return -EINVAL;
824 }
825 }
826
827 qemu_get_be32s(f, &nr_active_ports);
828
829 if (nr_active_ports) {
830 ret = fetch_active_ports_list(f, s, nr_active_ports);
831 if (ret) {
832 return ret;
833 }
834 }
835 return 0;
836 }
837
838 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
839
840 static Property virtser_props[] = {
841 DEFINE_PROP_UINT32("nr", VirtIOSerialPort, id, VIRTIO_CONSOLE_BAD_ID),
842 DEFINE_PROP_STRING("name", VirtIOSerialPort, name),
843 DEFINE_PROP_END_OF_LIST()
844 };
845
846 static void virtser_bus_class_init(ObjectClass *klass, void *data)
847 {
848 BusClass *k = BUS_CLASS(klass);
849 k->print_dev = virtser_bus_dev_print;
850 }
851
852 static const TypeInfo virtser_bus_info = {
853 .name = TYPE_VIRTIO_SERIAL_BUS,
854 .parent = TYPE_BUS,
855 .instance_size = sizeof(VirtIOSerialBus),
856 .class_init = virtser_bus_class_init,
857 };
858
859 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
860 {
861 VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(qdev);
862
863 monitor_printf(mon, "%*sport %d, guest %s, host %s, throttle %s\n",
864 indent, "", port->id,
865 port->guest_connected ? "on" : "off",
866 port->host_connected ? "on" : "off",
867 port->throttled ? "on" : "off");
868 }
869
870 /* This function is only used if a port id is not provided by the user */
871 static uint32_t find_free_port_id(VirtIOSerial *vser)
872 {
873 unsigned int i, max_nr_ports;
874
875 max_nr_ports = vser->serial.max_virtserial_ports;
876 for (i = 0; i < DIV_ROUND_UP(max_nr_ports, 32); i++) {
877 uint32_t map, zeroes;
878
879 map = vser->ports_map[i];
880 zeroes = ctz32(~map);
881 if (zeroes != 32) {
882 return zeroes + i * 32;
883 }
884 }
885 return VIRTIO_CONSOLE_BAD_ID;
886 }
887
888 static void mark_port_added(VirtIOSerial *vser, uint32_t port_id)
889 {
890 unsigned int i;
891
892 i = port_id / 32;
893 vser->ports_map[i] |= 1U << (port_id % 32);
894 }
895
896 static void add_port(VirtIOSerial *vser, uint32_t port_id)
897 {
898 mark_port_added(vser, port_id);
899 send_control_event(vser, port_id, VIRTIO_CONSOLE_PORT_ADD, 1);
900 }
901
902 static void remove_port(VirtIOSerial *vser, uint32_t port_id)
903 {
904 VirtIOSerialPort *port;
905
906 /*
907 * Don't mark port 0 removed -- we explicitly reserve it for
908 * backward compat with older guests, ensure a virtconsole device
909 * unplug retains the reservation.
910 */
911 if (port_id) {
912 unsigned int i;
913
914 i = port_id / 32;
915 vser->ports_map[i] &= ~(1U << (port_id % 32));
916 }
917
918 port = find_port_by_id(vser, port_id);
919 /*
920 * This function is only called from qdev's unplug callback; if we
921 * get a NULL port here, we're in trouble.
922 */
923 assert(port);
924
925 /* Flush out any unconsumed buffers first */
926 discard_throttle_data(port);
927 discard_vq_data(port->ovq, VIRTIO_DEVICE(port->vser));
928
929 send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_REMOVE, 1);
930 }
931
932 static void virtser_port_device_realize(DeviceState *dev, Error **errp)
933 {
934 VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
935 VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
936 VirtIOSerialBus *bus = VIRTIO_SERIAL_BUS(qdev_get_parent_bus(dev));
937 int max_nr_ports;
938 bool plugging_port0;
939 Error *err = NULL;
940
941 port->vser = bus->vser;
942
943 assert(vsc->have_data);
944
945 /*
946 * Is the first console port we're seeing? If so, put it up at
947 * location 0. This is done for backward compatibility (old
948 * kernel, new qemu).
949 */
950 plugging_port0 = vsc->is_console && !find_port_by_id(port->vser, 0);
951
952 if (find_port_by_id(port->vser, port->id)) {
953 error_setg(errp, "virtio-serial-bus: A port already exists at id %u",
954 port->id);
955 return;
956 }
957
958 if (port->name != NULL && find_port_by_name(port->name)) {
959 error_setg(errp, "virtio-serial-bus: A port already exists by name %s",
960 port->name);
961 return;
962 }
963
964 if (port->id == VIRTIO_CONSOLE_BAD_ID) {
965 if (plugging_port0) {
966 port->id = 0;
967 } else {
968 port->id = find_free_port_id(port->vser);
969 if (port->id == VIRTIO_CONSOLE_BAD_ID) {
970 error_setg(errp, "virtio-serial-bus: Maximum port limit for "
971 "this device reached");
972 return;
973 }
974 }
975 }
976
977 max_nr_ports = port->vser->serial.max_virtserial_ports;
978 if (port->id >= max_nr_ports) {
979 error_setg(errp, "virtio-serial-bus: Out-of-range port id specified, "
980 "max. allowed: %u", max_nr_ports - 1);
981 return;
982 }
983
984 vsc->realize(dev, &err);
985 if (err != NULL) {
986 error_propagate(errp, err);
987 return;
988 }
989
990 port->bh = qemu_bh_new(flush_queued_data_bh, port);
991 port->elem = NULL;
992 }
993
994 static void virtser_port_device_plug(HotplugHandler *hotplug_dev,
995 DeviceState *dev, Error **errp)
996 {
997 VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
998
999 QTAILQ_INSERT_TAIL(&port->vser->ports, port, next);
1000 port->ivq = port->vser->ivqs[port->id];
1001 port->ovq = port->vser->ovqs[port->id];
1002
1003 add_port(port->vser, port->id);
1004
1005 /* Send an update to the guest about this new port added */
1006 virtio_notify_config(VIRTIO_DEVICE(hotplug_dev));
1007 }
1008
1009 static void virtser_port_device_unrealize(DeviceState *dev)
1010 {
1011 VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
1012 VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(dev);
1013 VirtIOSerial *vser = port->vser;
1014
1015 qemu_bh_delete(port->bh);
1016 remove_port(port->vser, port->id);
1017
1018 QTAILQ_REMOVE(&vser->ports, port, next);
1019
1020 if (vsc->unrealize) {
1021 vsc->unrealize(dev);
1022 }
1023 }
1024
1025 static void virtio_serial_device_realize(DeviceState *dev, Error **errp)
1026 {
1027 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1028 VirtIOSerial *vser = VIRTIO_SERIAL(dev);
1029 uint32_t i, max_supported_ports;
1030 size_t config_size = sizeof(struct virtio_console_config);
1031
1032 if (!vser->serial.max_virtserial_ports) {
1033 error_setg(errp, "Maximum number of serial ports not specified");
1034 return;
1035 }
1036
1037 /* Each port takes 2 queues, and one pair is for the control queue */
1038 max_supported_ports = VIRTIO_QUEUE_MAX / 2 - 1;
1039
1040 if (vser->serial.max_virtserial_ports > max_supported_ports) {
1041 error_setg(errp, "maximum ports supported: %u", max_supported_ports);
1042 return;
1043 }
1044
1045 if (!virtio_has_feature(vser->host_features,
1046 VIRTIO_CONSOLE_F_EMERG_WRITE)) {
1047 config_size = offsetof(struct virtio_console_config, emerg_wr);
1048 }
1049 virtio_init(vdev, "virtio-serial", VIRTIO_ID_CONSOLE,
1050 config_size);
1051
1052 /* Spawn a new virtio-serial bus on which the ports will ride as devices */
1053 qbus_create_inplace(&vser->bus, sizeof(vser->bus), TYPE_VIRTIO_SERIAL_BUS,
1054 dev, vdev->bus_name);
1055 qbus_set_hotplug_handler(BUS(&vser->bus), OBJECT(vser));
1056 vser->bus.vser = vser;
1057 QTAILQ_INIT(&vser->ports);
1058
1059 vser->bus.max_nr_ports = vser->serial.max_virtserial_ports;
1060 vser->ivqs = g_malloc(vser->serial.max_virtserial_ports
1061 * sizeof(VirtQueue *));
1062 vser->ovqs = g_malloc(vser->serial.max_virtserial_ports
1063 * sizeof(VirtQueue *));
1064
1065 /* Add a queue for host to guest transfers for port 0 (backward compat) */
1066 vser->ivqs[0] = virtio_add_queue(vdev, 128, handle_input);
1067 /* Add a queue for guest to host transfers for port 0 (backward compat) */
1068 vser->ovqs[0] = virtio_add_queue(vdev, 128, handle_output);
1069
1070 /* TODO: host to guest notifications can get dropped
1071 * if the queue fills up. Implement queueing in host,
1072 * this might also make it possible to reduce the control
1073 * queue size: as guest preposts buffers there,
1074 * this will save 4Kbyte of guest memory per entry. */
1075
1076 /* control queue: host to guest */
1077 vser->c_ivq = virtio_add_queue(vdev, 32, control_in);
1078 /* control queue: guest to host */
1079 vser->c_ovq = virtio_add_queue(vdev, 32, control_out);
1080
1081 for (i = 1; i < vser->bus.max_nr_ports; i++) {
1082 /* Add a per-port queue for host to guest transfers */
1083 vser->ivqs[i] = virtio_add_queue(vdev, 128, handle_input);
1084 /* Add a per-per queue for guest to host transfers */
1085 vser->ovqs[i] = virtio_add_queue(vdev, 128, handle_output);
1086 }
1087
1088 vser->ports_map = g_malloc0((DIV_ROUND_UP(vser->serial.max_virtserial_ports, 32))
1089 * sizeof(vser->ports_map[0]));
1090 /*
1091 * Reserve location 0 for a console port for backward compat
1092 * (old kernel, new qemu)
1093 */
1094 mark_port_added(vser, 0);
1095
1096 vser->post_load = NULL;
1097
1098 QLIST_INSERT_HEAD(&vserdevices.devices, vser, next);
1099 }
1100
1101 static void virtio_serial_port_class_init(ObjectClass *klass, void *data)
1102 {
1103 DeviceClass *k = DEVICE_CLASS(klass);
1104
1105 set_bit(DEVICE_CATEGORY_INPUT, k->categories);
1106 k->bus_type = TYPE_VIRTIO_SERIAL_BUS;
1107 k->realize = virtser_port_device_realize;
1108 k->unrealize = virtser_port_device_unrealize;
1109 device_class_set_props(k, virtser_props);
1110 }
1111
1112 static const TypeInfo virtio_serial_port_type_info = {
1113 .name = TYPE_VIRTIO_SERIAL_PORT,
1114 .parent = TYPE_DEVICE,
1115 .instance_size = sizeof(VirtIOSerialPort),
1116 .abstract = true,
1117 .class_size = sizeof(VirtIOSerialPortClass),
1118 .class_init = virtio_serial_port_class_init,
1119 };
1120
1121 static void virtio_serial_device_unrealize(DeviceState *dev)
1122 {
1123 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1124 VirtIOSerial *vser = VIRTIO_SERIAL(dev);
1125 int i;
1126
1127 QLIST_REMOVE(vser, next);
1128
1129 virtio_delete_queue(vser->c_ivq);
1130 virtio_delete_queue(vser->c_ovq);
1131 for (i = 0; i < vser->bus.max_nr_ports; i++) {
1132 virtio_delete_queue(vser->ivqs[i]);
1133 virtio_delete_queue(vser->ovqs[i]);
1134 }
1135
1136 g_free(vser->ivqs);
1137 g_free(vser->ovqs);
1138 g_free(vser->ports_map);
1139 if (vser->post_load) {
1140 g_free(vser->post_load->connected);
1141 timer_del(vser->post_load->timer);
1142 timer_free(vser->post_load->timer);
1143 g_free(vser->post_load);
1144 }
1145
1146 qbus_set_hotplug_handler(BUS(&vser->bus), NULL);
1147
1148 virtio_cleanup(vdev);
1149 }
1150
1151 /* Note: 'console' is used for backwards compatibility */
1152 static const VMStateDescription vmstate_virtio_console = {
1153 .name = "virtio-console",
1154 .minimum_version_id = 3,
1155 .version_id = 3,
1156 .fields = (VMStateField[]) {
1157 VMSTATE_VIRTIO_DEVICE,
1158 VMSTATE_END_OF_LIST()
1159 },
1160 };
1161
1162 static Property virtio_serial_properties[] = {
1163 DEFINE_PROP_UINT32("max_ports", VirtIOSerial, serial.max_virtserial_ports,
1164 31),
1165 DEFINE_PROP_BIT64("emergency-write", VirtIOSerial, host_features,
1166 VIRTIO_CONSOLE_F_EMERG_WRITE, true),
1167 DEFINE_PROP_END_OF_LIST(),
1168 };
1169
1170 static void virtio_serial_class_init(ObjectClass *klass, void *data)
1171 {
1172 DeviceClass *dc = DEVICE_CLASS(klass);
1173 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1174 HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1175
1176 QLIST_INIT(&vserdevices.devices);
1177
1178 device_class_set_props(dc, virtio_serial_properties);
1179 dc->vmsd = &vmstate_virtio_console;
1180 set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
1181 vdc->realize = virtio_serial_device_realize;
1182 vdc->unrealize = virtio_serial_device_unrealize;
1183 vdc->get_features = get_features;
1184 vdc->get_config = get_config;
1185 vdc->set_config = set_config;
1186 vdc->set_status = set_status;
1187 vdc->reset = vser_reset;
1188 vdc->save = virtio_serial_save_device;
1189 vdc->load = virtio_serial_load_device;
1190 hc->plug = virtser_port_device_plug;
1191 hc->unplug = qdev_simple_device_unplug_cb;
1192 }
1193
1194 static const TypeInfo virtio_device_info = {
1195 .name = TYPE_VIRTIO_SERIAL,
1196 .parent = TYPE_VIRTIO_DEVICE,
1197 .instance_size = sizeof(VirtIOSerial),
1198 .class_init = virtio_serial_class_init,
1199 .interfaces = (InterfaceInfo[]) {
1200 { TYPE_HOTPLUG_HANDLER },
1201 { }
1202 }
1203 };
1204
1205 static void virtio_serial_register_types(void)
1206 {
1207 type_register_static(&virtser_bus_info);
1208 type_register_static(&virtio_serial_port_type_info);
1209 type_register_static(&virtio_device_info);
1210 }
1211
1212 type_init(virtio_serial_register_types)