2 * A bus for connecting virtio serial and console ports
4 * Copyright (C) 2009, 2010 Red Hat, Inc.
7 * Amit Shah <amit.shah@redhat.com>
9 * Some earlier parts are:
10 * Copyright IBM, Corp. 2008
12 * Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
14 * This work is licensed under the terms of the GNU GPL, version 2. See
15 * the COPYING file in the top-level directory.
20 #include "qemu-queue.h"
22 #include "virtio-serial.h"
24 /* The virtio-serial bus on top of which the ports will ride as devices */
25 struct VirtIOSerialBus
{
28 /* This is the parent device that provides the bus for ports. */
31 /* The maximum number of ports that can ride on top of this bus */
32 uint32_t max_nr_ports
;
38 VirtQueue
*c_ivq
, *c_ovq
;
39 /* Arrays of ivqs and ovqs: one per port */
40 VirtQueue
**ivqs
, **ovqs
;
44 QTAILQ_HEAD(, VirtIOSerialPort
) ports
;
46 /* bitmap for identifying active ports */
49 struct virtio_console_config config
;
52 static VirtIOSerialPort
*find_port_by_id(VirtIOSerial
*vser
, uint32_t id
)
54 VirtIOSerialPort
*port
;
56 if (id
== VIRTIO_CONSOLE_BAD_ID
) {
60 QTAILQ_FOREACH(port
, &vser
->ports
, next
) {
67 static VirtIOSerialPort
*find_port_by_vq(VirtIOSerial
*vser
, VirtQueue
*vq
)
69 VirtIOSerialPort
*port
;
71 QTAILQ_FOREACH(port
, &vser
->ports
, next
) {
72 if (port
->ivq
== vq
|| port
->ovq
== vq
)
78 static bool use_multiport(VirtIOSerial
*vser
)
80 return vser
->vdev
.guest_features
& (1 << VIRTIO_CONSOLE_F_MULTIPORT
);
83 static size_t write_to_port(VirtIOSerialPort
*port
,
84 const uint8_t *buf
, size_t size
)
86 VirtQueueElement elem
;
91 if (!virtio_queue_ready(vq
)) {
96 while (offset
< size
) {
99 if (!virtqueue_pop(vq
, &elem
)) {
103 len
= iov_from_buf(elem
.in_sg
, elem
.in_num
,
104 buf
+ offset
, size
- offset
);
107 virtqueue_push(vq
, &elem
, len
);
110 virtio_notify(&port
->vser
->vdev
, vq
);
114 static size_t send_control_msg(VirtIOSerialPort
*port
, void *buf
, size_t len
)
116 VirtQueueElement elem
;
118 struct virtio_console_control
*cpkt
;
120 vq
= port
->vser
->c_ivq
;
121 if (!virtio_queue_ready(vq
)) {
124 if (!virtqueue_pop(vq
, &elem
)) {
128 cpkt
= (struct virtio_console_control
*)buf
;
129 stl_p(&cpkt
->id
, port
->id
);
130 memcpy(elem
.in_sg
[0].iov_base
, buf
, len
);
132 virtqueue_push(vq
, &elem
, len
);
133 virtio_notify(&port
->vser
->vdev
, vq
);
137 static size_t send_control_event(VirtIOSerialPort
*port
, uint16_t event
,
140 struct virtio_console_control cpkt
;
142 stw_p(&cpkt
.event
, event
);
143 stw_p(&cpkt
.value
, value
);
145 return send_control_msg(port
, &cpkt
, sizeof(cpkt
));
148 /* Functions for use inside qemu to open and read from/write to ports */
149 int virtio_serial_open(VirtIOSerialPort
*port
)
151 /* Don't allow opening an already-open port */
152 if (port
->host_connected
) {
155 /* Send port open notification to the guest */
156 port
->host_connected
= true;
157 send_control_event(port
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
162 int virtio_serial_close(VirtIOSerialPort
*port
)
164 port
->host_connected
= false;
165 send_control_event(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
170 /* Individual ports/apps call this function to write to the guest. */
171 ssize_t
virtio_serial_write(VirtIOSerialPort
*port
, const uint8_t *buf
,
174 if (!port
|| !port
->host_connected
|| !port
->guest_connected
) {
177 return write_to_port(port
, buf
, size
);
181 * Readiness of the guest to accept data on a port.
182 * Returns max. data the guest can receive
184 size_t virtio_serial_guest_ready(VirtIOSerialPort
*port
)
186 VirtQueue
*vq
= port
->ivq
;
188 if (!virtio_queue_ready(vq
) ||
189 !(port
->vser
->vdev
.status
& VIRTIO_CONFIG_S_DRIVER_OK
) ||
190 virtio_queue_empty(vq
)) {
193 if (use_multiport(port
->vser
) && !port
->guest_connected
) {
197 if (virtqueue_avail_bytes(vq
, 4096, 0)) {
200 if (virtqueue_avail_bytes(vq
, 1, 0)) {
206 /* Guest wants to notify us of some event */
207 static void handle_control_message(VirtIOSerial
*vser
, void *buf
)
209 struct VirtIOSerialPort
*port
;
210 struct virtio_console_control cpkt
, *gcpkt
;
216 cpkt
.event
= lduw_p(&gcpkt
->event
);
217 cpkt
.value
= lduw_p(&gcpkt
->value
);
219 port
= find_port_by_id(vser
, ldl_p(&gcpkt
->id
));
220 if (!port
&& cpkt
.event
!= VIRTIO_CONSOLE_DEVICE_READY
)
224 case VIRTIO_CONSOLE_DEVICE_READY
:
226 error_report("virtio-serial-bus: Guest failure in adding device %s\n",
227 vser
->bus
->qbus
.name
);
231 * The device is up, we can now tell the device about all the
232 * ports we have here.
234 QTAILQ_FOREACH(port
, &vser
->ports
, next
) {
235 send_control_event(port
, VIRTIO_CONSOLE_PORT_ADD
, 1);
239 case VIRTIO_CONSOLE_PORT_READY
:
241 error_report("virtio-serial-bus: Guest failure in adding port %u for device %s\n",
242 port
->id
, vser
->bus
->qbus
.name
);
246 * Now that we know the guest asked for the port name, we're
247 * sure the guest has initialised whatever state is necessary
248 * for this port. Now's a good time to let the guest know if
249 * this port is a console port so that the guest can hook it
252 if (port
->is_console
) {
253 send_control_event(port
, VIRTIO_CONSOLE_CONSOLE_PORT
, 1);
257 stw_p(&cpkt
.event
, VIRTIO_CONSOLE_PORT_NAME
);
258 stw_p(&cpkt
.value
, 1);
260 buffer_len
= sizeof(cpkt
) + strlen(port
->name
) + 1;
261 buffer
= qemu_malloc(buffer_len
);
263 memcpy(buffer
, &cpkt
, sizeof(cpkt
));
264 memcpy(buffer
+ sizeof(cpkt
), port
->name
, strlen(port
->name
));
265 buffer
[buffer_len
- 1] = 0;
267 send_control_msg(port
, buffer
, buffer_len
);
271 if (port
->host_connected
) {
272 send_control_event(port
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
276 * When the guest has asked us for this information it means
277 * the guest is all setup and has its virtqueues
278 * initialised. If some app is interested in knowing about
279 * this event, let it know.
281 if (port
->info
->guest_ready
) {
282 port
->info
->guest_ready(port
);
286 case VIRTIO_CONSOLE_PORT_OPEN
:
287 port
->guest_connected
= cpkt
.value
;
288 if (cpkt
.value
&& port
->info
->guest_open
) {
289 /* Send the guest opened notification if an app is interested */
290 port
->info
->guest_open(port
);
293 if (!cpkt
.value
&& port
->info
->guest_close
) {
294 /* Send the guest closed notification if an app is interested */
295 port
->info
->guest_close(port
);
301 static void control_in(VirtIODevice
*vdev
, VirtQueue
*vq
)
305 static void control_out(VirtIODevice
*vdev
, VirtQueue
*vq
)
307 VirtQueueElement elem
;
310 vser
= DO_UPCAST(VirtIOSerial
, vdev
, vdev
);
312 while (virtqueue_pop(vq
, &elem
)) {
313 handle_control_message(vser
, elem
.out_sg
[0].iov_base
);
314 virtqueue_push(vq
, &elem
, elem
.out_sg
[0].iov_len
);
316 virtio_notify(vdev
, vq
);
319 /* Guest wrote something to some port. */
320 static void handle_output(VirtIODevice
*vdev
, VirtQueue
*vq
)
323 VirtQueueElement elem
;
325 vser
= DO_UPCAST(VirtIOSerial
, vdev
, vdev
);
327 while (virtqueue_pop(vq
, &elem
)) {
328 VirtIOSerialPort
*port
;
331 port
= find_port_by_vq(vser
, vq
);
337 if (!port
->host_connected
) {
343 * A port may not have any handler registered for consuming the
344 * data that the guest sends or it may not have a chardev associated
345 * with it. Just ignore the data in that case.
347 if (!port
->info
->have_data
) {
352 /* The guest always sends only one sg */
353 ret
= port
->info
->have_data(port
, elem
.out_sg
[0].iov_base
,
354 elem
.out_sg
[0].iov_len
);
357 virtqueue_push(vq
, &elem
, ret
);
359 virtio_notify(vdev
, vq
);
362 static void handle_input(VirtIODevice
*vdev
, VirtQueue
*vq
)
366 static uint32_t get_features(VirtIODevice
*vdev
, uint32_t features
)
370 vser
= DO_UPCAST(VirtIOSerial
, vdev
, vdev
);
372 if (vser
->bus
->max_nr_ports
> 1) {
373 features
|= (1 << VIRTIO_CONSOLE_F_MULTIPORT
);
378 /* Guest requested config info */
379 static void get_config(VirtIODevice
*vdev
, uint8_t *config_data
)
383 vser
= DO_UPCAST(VirtIOSerial
, vdev
, vdev
);
384 memcpy(config_data
, &vser
->config
, sizeof(struct virtio_console_config
));
387 static void set_config(VirtIODevice
*vdev
, const uint8_t *config_data
)
389 struct virtio_console_config config
;
391 memcpy(&config
, config_data
, sizeof(config
));
394 static void virtio_serial_save(QEMUFile
*f
, void *opaque
)
396 VirtIOSerial
*s
= opaque
;
397 VirtIOSerialPort
*port
;
398 uint32_t nr_active_ports
;
401 /* The virtio device */
402 virtio_save(&s
->vdev
, f
);
404 /* The config space */
405 qemu_put_be16s(f
, &s
->config
.cols
);
406 qemu_put_be16s(f
, &s
->config
.rows
);
408 qemu_put_be32s(f
, &s
->config
.max_nr_ports
);
412 for (i
= 0; i
< (s
->config
.max_nr_ports
+ 31) / 32; i
++) {
413 qemu_put_be32s(f
, &s
->ports_map
[i
]);
419 QTAILQ_FOREACH(port
, &s
->ports
, next
) {
423 qemu_put_be32s(f
, &nr_active_ports
);
426 * Items in struct VirtIOSerialPort.
428 QTAILQ_FOREACH(port
, &s
->ports
, next
) {
429 qemu_put_be32s(f
, &port
->id
);
430 qemu_put_byte(f
, port
->guest_connected
);
431 qemu_put_byte(f
, port
->host_connected
);
435 static int virtio_serial_load(QEMUFile
*f
, void *opaque
, int version_id
)
437 VirtIOSerial
*s
= opaque
;
438 VirtIOSerialPort
*port
;
439 size_t ports_map_size
;
440 uint32_t max_nr_ports
, nr_active_ports
, *ports_map
;
443 if (version_id
> 2) {
447 /* The virtio device */
448 virtio_load(&s
->vdev
, f
);
450 if (version_id
< 2) {
454 /* The config space */
455 qemu_get_be16s(f
, &s
->config
.cols
);
456 qemu_get_be16s(f
, &s
->config
.rows
);
458 qemu_get_be32s(f
, &max_nr_ports
);
459 if (max_nr_ports
> s
->config
.max_nr_ports
) {
460 /* Source could have had more ports than us. Fail migration. */
464 ports_map_size
= sizeof(uint32_t) * (max_nr_ports
+ 31) / 32;
465 ports_map
= qemu_malloc(ports_map_size
);
467 for (i
= 0; i
< (max_nr_ports
+ 31) / 32; i
++) {
468 qemu_get_be32s(f
, &ports_map
[i
]);
470 if (ports_map
[i
] != s
->ports_map
[i
]) {
472 * Ports active on source and destination don't
473 * match. Fail migration.
475 qemu_free(ports_map
);
479 qemu_free(ports_map
);
481 qemu_get_be32s(f
, &nr_active_ports
);
483 /* Items in struct VirtIOSerialPort */
484 for (i
= 0; i
< nr_active_ports
; i
++) {
488 id
= qemu_get_be32(f
);
489 port
= find_port_by_id(s
, id
);
491 port
->guest_connected
= qemu_get_byte(f
);
492 host_connected
= qemu_get_byte(f
);
493 if (host_connected
!= port
->host_connected
) {
495 * We have to let the guest know of the host connection
498 send_control_event(port
, VIRTIO_CONSOLE_PORT_OPEN
,
499 port
->host_connected
);
505 static void virtser_bus_dev_print(Monitor
*mon
, DeviceState
*qdev
, int indent
);
507 static struct BusInfo virtser_bus_info
= {
508 .name
= "virtio-serial-bus",
509 .size
= sizeof(VirtIOSerialBus
),
510 .print_dev
= virtser_bus_dev_print
,
513 static VirtIOSerialBus
*virtser_bus_new(DeviceState
*dev
)
515 VirtIOSerialBus
*bus
;
517 bus
= FROM_QBUS(VirtIOSerialBus
, qbus_create(&virtser_bus_info
, dev
, NULL
));
518 bus
->qbus
.allow_hotplug
= 1;
523 static void virtser_bus_dev_print(Monitor
*mon
, DeviceState
*qdev
, int indent
)
525 VirtIOSerialDevice
*dev
= DO_UPCAST(VirtIOSerialDevice
, qdev
, qdev
);
526 VirtIOSerialPort
*port
= DO_UPCAST(VirtIOSerialPort
, dev
, &dev
->qdev
);
528 monitor_printf(mon
, "%*s dev-prop-int: id: %u\n",
529 indent
, "", port
->id
);
530 monitor_printf(mon
, "%*s dev-prop-int: guest_connected: %d\n",
531 indent
, "", port
->guest_connected
);
532 monitor_printf(mon
, "%*s dev-prop-int: host_connected: %d\n",
533 indent
, "", port
->host_connected
);
536 /* This function is only used if a port id is not provided by the user */
537 static uint32_t find_free_port_id(VirtIOSerial
*vser
)
541 for (i
= 0; i
< (vser
->config
.max_nr_ports
+ 31) / 32; i
++) {
544 map
= vser
->ports_map
[i
];
547 return (bit
- 1) + i
* 32;
550 return VIRTIO_CONSOLE_BAD_ID
;
553 static void mark_port_added(VirtIOSerial
*vser
, uint32_t port_id
)
558 vser
->ports_map
[i
] |= 1U << (port_id
% 32);
561 static void add_port(VirtIOSerial
*vser
, uint32_t port_id
)
563 mark_port_added(vser
, port_id
);
565 send_control_event(find_port_by_id(vser
, port_id
),
566 VIRTIO_CONSOLE_PORT_ADD
, 1);
569 static void remove_port(VirtIOSerial
*vser
, uint32_t port_id
)
574 vser
->ports_map
[i
] &= ~(1U << (port_id
% 32));
576 send_control_event(find_port_by_id(vser
, port_id
),
577 VIRTIO_CONSOLE_PORT_REMOVE
, 1);
580 static int virtser_port_qdev_init(DeviceState
*qdev
, DeviceInfo
*base
)
582 VirtIOSerialDevice
*dev
= DO_UPCAST(VirtIOSerialDevice
, qdev
, qdev
);
583 VirtIOSerialPortInfo
*info
= DO_UPCAST(VirtIOSerialPortInfo
, qdev
, base
);
584 VirtIOSerialPort
*port
= DO_UPCAST(VirtIOSerialPort
, dev
, &dev
->qdev
);
585 VirtIOSerialBus
*bus
= DO_UPCAST(VirtIOSerialBus
, qbus
, qdev
->parent_bus
);
589 port
->vser
= bus
->vser
;
592 * Is the first console port we're seeing? If so, put it up at
593 * location 0. This is done for backward compatibility (old
596 plugging_port0
= port
->is_console
&& !find_port_by_id(port
->vser
, 0);
598 if (find_port_by_id(port
->vser
, port
->id
)) {
599 error_report("virtio-serial-bus: A port already exists at id %u\n",
604 if (port
->id
== VIRTIO_CONSOLE_BAD_ID
) {
605 if (plugging_port0
) {
608 port
->id
= find_free_port_id(port
->vser
);
609 if (port
->id
== VIRTIO_CONSOLE_BAD_ID
) {
610 error_report("virtio-serial-bus: Maximum port limit for this device reached\n");
616 if (port
->id
>= port
->vser
->config
.max_nr_ports
) {
617 error_report("virtio-serial-bus: Out-of-range port id specified, max. allowed: %u\n",
618 port
->vser
->config
.max_nr_ports
- 1);
623 ret
= info
->init(dev
);
628 if (!use_multiport(port
->vser
)) {
630 * Allow writes to guest in this case; we have no way of
631 * knowing if a guest port is connected.
633 port
->guest_connected
= true;
636 QTAILQ_INSERT_TAIL(&port
->vser
->ports
, port
, next
);
637 port
->ivq
= port
->vser
->ivqs
[port
->id
];
638 port
->ovq
= port
->vser
->ovqs
[port
->id
];
640 add_port(port
->vser
, port
->id
);
642 /* Send an update to the guest about this new port added */
643 virtio_notify_config(&port
->vser
->vdev
);
648 static int virtser_port_qdev_exit(DeviceState
*qdev
)
650 VirtIOSerialDevice
*dev
= DO_UPCAST(VirtIOSerialDevice
, qdev
, qdev
);
651 VirtIOSerialPort
*port
= DO_UPCAST(VirtIOSerialPort
, dev
, &dev
->qdev
);
652 VirtIOSerial
*vser
= port
->vser
;
654 remove_port(port
->vser
, port
->id
);
656 QTAILQ_REMOVE(&vser
->ports
, port
, next
);
658 if (port
->info
->exit
)
659 port
->info
->exit(dev
);
664 void virtio_serial_port_qdev_register(VirtIOSerialPortInfo
*info
)
666 info
->qdev
.init
= virtser_port_qdev_init
;
667 info
->qdev
.bus_info
= &virtser_bus_info
;
668 info
->qdev
.exit
= virtser_port_qdev_exit
;
669 info
->qdev
.unplug
= qdev_simple_unplug_cb
;
670 qdev_register(&info
->qdev
);
673 VirtIODevice
*virtio_serial_init(DeviceState
*dev
, uint32_t max_nr_ports
)
682 vdev
= virtio_common_init("virtio-serial", VIRTIO_ID_CONSOLE
,
683 sizeof(struct virtio_console_config
),
684 sizeof(VirtIOSerial
));
686 vser
= DO_UPCAST(VirtIOSerial
, vdev
, vdev
);
688 /* Spawn a new virtio-serial bus on which the ports will ride as devices */
689 vser
->bus
= virtser_bus_new(dev
);
690 vser
->bus
->vser
= vser
;
691 QTAILQ_INIT(&vser
->ports
);
693 vser
->bus
->max_nr_ports
= max_nr_ports
;
694 vser
->ivqs
= qemu_malloc(max_nr_ports
* sizeof(VirtQueue
*));
695 vser
->ovqs
= qemu_malloc(max_nr_ports
* sizeof(VirtQueue
*));
697 /* Add a queue for host to guest transfers for port 0 (backward compat) */
698 vser
->ivqs
[0] = virtio_add_queue(vdev
, 128, handle_input
);
699 /* Add a queue for guest to host transfers for port 0 (backward compat) */
700 vser
->ovqs
[0] = virtio_add_queue(vdev
, 128, handle_output
);
702 /* control queue: host to guest */
703 vser
->c_ivq
= virtio_add_queue(vdev
, 16, control_in
);
704 /* control queue: guest to host */
705 vser
->c_ovq
= virtio_add_queue(vdev
, 16, control_out
);
707 for (i
= 1; i
< vser
->bus
->max_nr_ports
; i
++) {
708 /* Add a per-port queue for host to guest transfers */
709 vser
->ivqs
[i
] = virtio_add_queue(vdev
, 128, handle_input
);
710 /* Add a per-per queue for guest to host transfers */
711 vser
->ovqs
[i
] = virtio_add_queue(vdev
, 128, handle_output
);
714 vser
->config
.max_nr_ports
= max_nr_ports
;
715 vser
->ports_map
= qemu_mallocz((max_nr_ports
+ 31) / 32);
717 * Reserve location 0 for a console port for backward compat
718 * (old kernel, new qemu)
720 mark_port_added(vser
, 0);
722 vser
->vdev
.get_features
= get_features
;
723 vser
->vdev
.get_config
= get_config
;
724 vser
->vdev
.set_config
= set_config
;
727 * Register for the savevm section with the virtio-console name
728 * to preserve backward compat
730 register_savevm("virtio-console", -1, 2, virtio_serial_save
,
731 virtio_serial_load
, vser
);