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