blob: ab456ea3964cf39fa2235bf8941b858890a572cf [file] [log] [blame]
/*
* A bus for connecting virtio serial and console ports
*
* Copyright (C) 2009 Red Hat, Inc.
*
* Author(s):
* Amit Shah <amit.shah@redhat.com>
*
* Some earlier parts are:
* Copyright IBM, Corp. 2008
* authored by
* Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*/
#include "monitor.h"
#include "qemu-queue.h"
#include "sysbus.h"
#include "virtio-serial.h"
/* The virtio-serial bus on top of which the ports will ride as devices */
struct VirtIOSerialBus {
BusState qbus;
/* This is the parent device that provides the bus for ports. */
VirtIOSerial *vser;
/* The maximum number of ports that can ride on top of this bus */
uint32_t max_nr_ports;
};
struct VirtIOSerial {
VirtIODevice vdev;
VirtQueue *c_ivq, *c_ovq;
/* Arrays of ivqs and ovqs: one per port */
VirtQueue **ivqs, **ovqs;
VirtIOSerialBus *bus;
QTAILQ_HEAD(, VirtIOSerialPort) ports;
struct virtio_console_config config;
};
static VirtIOSerialPort *find_port_by_id(VirtIOSerial *vser, uint32_t id)
{
VirtIOSerialPort *port;
QTAILQ_FOREACH(port, &vser->ports, next) {
if (port->id == id)
return port;
}
return NULL;
}
static VirtIOSerialPort *find_port_by_vq(VirtIOSerial *vser, VirtQueue *vq)
{
VirtIOSerialPort *port;
QTAILQ_FOREACH(port, &vser->ports, next) {
if (port->ivq == vq || port->ovq == vq)
return port;
}
return NULL;
}
static bool use_multiport(VirtIOSerial *vser)
{
return vser->vdev.guest_features & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
}
static size_t write_to_port(VirtIOSerialPort *port,
const uint8_t *buf, size_t size)
{
VirtQueueElement elem;
VirtQueue *vq;
size_t offset = 0;
size_t len = 0;
vq = port->ivq;
if (!virtio_queue_ready(vq)) {
return 0;
}
if (!size) {
return 0;
}
while (offset < size) {
int i;
if (!virtqueue_pop(vq, &elem)) {
break;
}
for (i = 0; offset < size && i < elem.in_num; i++) {
len = MIN(elem.in_sg[i].iov_len, size - offset);
memcpy(elem.in_sg[i].iov_base, buf + offset, len);
offset += len;
}
virtqueue_push(vq, &elem, len);
}
virtio_notify(&port->vser->vdev, vq);
return offset;
}
static size_t send_control_msg(VirtIOSerialPort *port, void *buf, size_t len)
{
VirtQueueElement elem;
VirtQueue *vq;
struct virtio_console_control *cpkt;
vq = port->vser->c_ivq;
if (!virtio_queue_ready(vq)) {
return 0;
}
if (!virtqueue_pop(vq, &elem)) {
return 0;
}
cpkt = (struct virtio_console_control *)buf;
stl_p(&cpkt->id, port->id);
memcpy(elem.in_sg[0].iov_base, buf, len);
virtqueue_push(vq, &elem, len);
virtio_notify(&port->vser->vdev, vq);
return len;
}
static size_t send_control_event(VirtIOSerialPort *port, uint16_t event,
uint16_t value)
{
struct virtio_console_control cpkt;
stw_p(&cpkt.event, event);
stw_p(&cpkt.value, value);
return send_control_msg(port, &cpkt, sizeof(cpkt));
}
/* Functions for use inside qemu to open and read from/write to ports */
int virtio_serial_open(VirtIOSerialPort *port)
{
/* Don't allow opening an already-open port */
if (port->host_connected) {
return 0;
}
/* Send port open notification to the guest */
port->host_connected = true;
send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
return 0;
}
int virtio_serial_close(VirtIOSerialPort *port)
{
port->host_connected = false;
send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
return 0;
}
/* Individual ports/apps call this function to write to the guest. */
ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
size_t size)
{
if (!port || !port->host_connected || !port->guest_connected) {
return 0;
}
return write_to_port(port, buf, size);
}
/*
* Readiness of the guest to accept data on a port.
* Returns max. data the guest can receive
*/
size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
{
VirtQueue *vq = port->ivq;
if (!virtio_queue_ready(vq) ||
!(port->vser->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) ||
virtio_queue_empty(vq)) {
return 0;
}
if (use_multiport(port->vser) && !port->guest_connected) {
return 0;
}
if (virtqueue_avail_bytes(vq, 4096, 0)) {
return 4096;
}
if (virtqueue_avail_bytes(vq, 1, 0)) {
return 1;
}
return 0;
}
/* Guest wants to notify us of some event */
static void handle_control_message(VirtIOSerial *vser, void *buf)
{
struct VirtIOSerialPort *port;
struct virtio_console_control cpkt, *gcpkt;
uint8_t *buffer;
size_t buffer_len;
gcpkt = buf;
port = find_port_by_id(vser, ldl_p(&gcpkt->id));
if (!port)
return;
cpkt.event = lduw_p(&gcpkt->event);
cpkt.value = lduw_p(&gcpkt->value);
switch(cpkt.event) {
case VIRTIO_CONSOLE_PORT_READY:
/*
* Now that we know the guest asked for the port name, we're
* sure the guest has initialised whatever state is necessary
* for this port. Now's a good time to let the guest know if
* this port is a console port so that the guest can hook it
* up to hvc.
*/
if (port->is_console) {
send_control_event(port, VIRTIO_CONSOLE_CONSOLE_PORT, 1);
}
if (port->name) {
stw_p(&cpkt.event, VIRTIO_CONSOLE_PORT_NAME);
stw_p(&cpkt.value, 1);
buffer_len = sizeof(cpkt) + strlen(port->name) + 1;
buffer = qemu_malloc(buffer_len);
memcpy(buffer, &cpkt, sizeof(cpkt));
memcpy(buffer + sizeof(cpkt), port->name, strlen(port->name));
buffer[buffer_len - 1] = 0;
send_control_msg(port, buffer, buffer_len);
qemu_free(buffer);
}
if (port->host_connected) {
send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
}
/*
* When the guest has asked us for this information it means
* the guest is all setup and has its virtqueues
* initialised. If some app is interested in knowing about
* this event, let it know.
*/
if (port->info->guest_ready) {
port->info->guest_ready(port);
}
break;
case VIRTIO_CONSOLE_PORT_OPEN:
port->guest_connected = cpkt.value;
if (cpkt.value && port->info->guest_open) {
/* Send the guest opened notification if an app is interested */
port->info->guest_open(port);
}
if (!cpkt.value && port->info->guest_close) {
/* Send the guest closed notification if an app is interested */
port->info->guest_close(port);
}
break;
}
}
static void control_in(VirtIODevice *vdev, VirtQueue *vq)
{
}
static void control_out(VirtIODevice *vdev, VirtQueue *vq)
{
VirtQueueElement elem;
VirtIOSerial *vser;
vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
while (virtqueue_pop(vq, &elem)) {
handle_control_message(vser, elem.out_sg[0].iov_base);
virtqueue_push(vq, &elem, elem.out_sg[0].iov_len);
}
virtio_notify(vdev, vq);
}
/* Guest wrote something to some port. */
static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOSerial *vser;
VirtQueueElement elem;
vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
while (virtqueue_pop(vq, &elem)) {
VirtIOSerialPort *port;
size_t ret;
port = find_port_by_vq(vser, vq);
if (!port) {
ret = 0;
goto next_buf;
}
/*
* A port may not have any handler registered for consuming the
* data that the guest sends or it may not have a chardev associated
* with it. Just ignore the data in that case.
*/
if (!port->info->have_data) {
ret = 0;
goto next_buf;
}
/* The guest always sends only one sg */
ret = port->info->have_data(port, elem.out_sg[0].iov_base,
elem.out_sg[0].iov_len);
next_buf:
virtqueue_push(vq, &elem, ret);
}
virtio_notify(vdev, vq);
}
static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
{
}
static uint32_t get_features(VirtIODevice *vdev, uint32_t features)
{
features |= (1 << VIRTIO_CONSOLE_F_MULTIPORT);
return features;
}
/* Guest requested config info */
static void get_config(VirtIODevice *vdev, uint8_t *config_data)
{
VirtIOSerial *vser;
vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
memcpy(config_data, &vser->config, sizeof(struct virtio_console_config));
}
static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
{
struct virtio_console_config config;
memcpy(&config, config_data, sizeof(config));
}
static void virtio_serial_save(QEMUFile *f, void *opaque)
{
VirtIOSerial *s = opaque;
VirtIOSerialPort *port;
uint32_t nr_active_ports;
/* The virtio device */
virtio_save(&s->vdev, f);
/* The config space */
qemu_put_be16s(f, &s->config.cols);
qemu_put_be16s(f, &s->config.rows);
qemu_put_be32s(f, &s->config.nr_ports);
/* Items in struct VirtIOSerial */
/* Do this because we might have hot-unplugged some ports */
nr_active_ports = 0;
QTAILQ_FOREACH(port, &s->ports, next)
nr_active_ports++;
qemu_put_be32s(f, &nr_active_ports);
/*
* Items in struct VirtIOSerialPort.
*/
QTAILQ_FOREACH(port, &s->ports, next) {
/*
* We put the port number because we may not have an active
* port at id 0 that's reserved for a console port, or in case
* of ports that might have gotten unplugged
*/
qemu_put_be32s(f, &port->id);
qemu_put_byte(f, port->guest_connected);
}
}
static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
{
VirtIOSerial *s = opaque;
VirtIOSerialPort *port;
uint32_t nr_active_ports;
unsigned int i;
if (version_id > 2) {
return -EINVAL;
}
/* The virtio device */
virtio_load(&s->vdev, f);
if (version_id < 2) {
return 0;
}
/* The config space */
qemu_get_be16s(f, &s->config.cols);
qemu_get_be16s(f, &s->config.rows);
s->config.nr_ports = qemu_get_be32(f);
/* Items in struct VirtIOSerial */
qemu_get_be32s(f, &nr_active_ports);
/* Items in struct VirtIOSerialPort */
for (i = 0; i < nr_active_ports; i++) {
uint32_t id;
id = qemu_get_be32(f);
port = find_port_by_id(s, id);
port->guest_connected = qemu_get_byte(f);
}
return 0;
}
static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
static struct BusInfo virtser_bus_info = {
.name = "virtio-serial-bus",
.size = sizeof(VirtIOSerialBus),
.print_dev = virtser_bus_dev_print,
};
static VirtIOSerialBus *virtser_bus_new(DeviceState *dev)
{
VirtIOSerialBus *bus;
bus = FROM_QBUS(VirtIOSerialBus, qbus_create(&virtser_bus_info, dev, NULL));
bus->qbus.allow_hotplug = 1;
return bus;
}
static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
{
VirtIOSerialDevice *dev = DO_UPCAST(VirtIOSerialDevice, qdev, qdev);
VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev);
monitor_printf(mon, "%*s dev-prop-int: id: %u\n",
indent, "", port->id);
monitor_printf(mon, "%*s dev-prop-int: guest_connected: %d\n",
indent, "", port->guest_connected);
monitor_printf(mon, "%*s dev-prop-int: host_connected: %d\n",
indent, "", port->host_connected);
}
static int virtser_port_qdev_init(DeviceState *qdev, DeviceInfo *base)
{
VirtIOSerialDevice *dev = DO_UPCAST(VirtIOSerialDevice, qdev, qdev);
VirtIOSerialPortInfo *info = DO_UPCAST(VirtIOSerialPortInfo, qdev, base);
VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev);
VirtIOSerialBus *bus = DO_UPCAST(VirtIOSerialBus, qbus, qdev->parent_bus);
int ret;
bool plugging_port0;
port->vser = bus->vser;
/*
* Is the first console port we're seeing? If so, put it up at
* location 0. This is done for backward compatibility (old
* kernel, new qemu).
*/
plugging_port0 = port->is_console && !find_port_by_id(port->vser, 0);
if (port->vser->config.nr_ports == bus->max_nr_ports && !plugging_port0) {
qemu_error("virtio-serial-bus: Maximum device limit reached\n");
return -1;
}
dev->info = info;
ret = info->init(dev);
if (ret) {
return ret;
}
port->id = plugging_port0 ? 0 : port->vser->config.nr_ports++;
if (!use_multiport(port->vser)) {
/*
* Allow writes to guest in this case; we have no way of
* knowing if a guest port is connected.
*/
port->guest_connected = true;
}
QTAILQ_INSERT_TAIL(&port->vser->ports, port, next);
port->ivq = port->vser->ivqs[port->id];
port->ovq = port->vser->ovqs[port->id];
/* Send an update to the guest about this new port added */
virtio_notify_config(&port->vser->vdev);
return ret;
}
static int virtser_port_qdev_exit(DeviceState *qdev)
{
VirtIOSerialDevice *dev = DO_UPCAST(VirtIOSerialDevice, qdev, qdev);
VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev);
VirtIOSerial *vser = port->vser;
send_control_event(port, VIRTIO_CONSOLE_PORT_REMOVE, 1);
/*
* Don't decrement nr_ports here; thus we keep a linearly
* increasing port id. Not utilising an id again saves us a couple
* of complications:
*
* - Not having to bother about sending the port id to the guest
* kernel on hotplug or on addition of new ports; the guest can
* also linearly increment the port number. This is preferable
* because the config space won't have the need to store a
* ports_map.
*
* - Extra state to be stored for all the "holes" that got created
* so that we keep filling in the ids from the least available
* index.
*
* When such a functionality is desired, a control message to add
* a port can be introduced.
*/
QTAILQ_REMOVE(&vser->ports, port, next);
if (port->info->exit)
port->info->exit(dev);
return 0;
}
void virtio_serial_port_qdev_register(VirtIOSerialPortInfo *info)
{
info->qdev.init = virtser_port_qdev_init;
info->qdev.bus_info = &virtser_bus_info;
info->qdev.exit = virtser_port_qdev_exit;
info->qdev.unplug = qdev_simple_unplug_cb;
qdev_register(&info->qdev);
}
VirtIODevice *virtio_serial_init(DeviceState *dev, uint32_t max_nr_ports)
{
VirtIOSerial *vser;
VirtIODevice *vdev;
uint32_t i;
if (!max_nr_ports)
return NULL;
vdev = virtio_common_init("virtio-serial", VIRTIO_ID_CONSOLE,
sizeof(struct virtio_console_config),
sizeof(VirtIOSerial));
vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
/* Spawn a new virtio-serial bus on which the ports will ride as devices */
vser->bus = virtser_bus_new(dev);
vser->bus->vser = vser;
QTAILQ_INIT(&vser->ports);
vser->bus->max_nr_ports = max_nr_ports;
vser->ivqs = qemu_malloc(max_nr_ports * sizeof(VirtQueue *));
vser->ovqs = qemu_malloc(max_nr_ports * sizeof(VirtQueue *));
/* Add a queue for host to guest transfers for port 0 (backward compat) */
vser->ivqs[0] = virtio_add_queue(vdev, 128, handle_input);
/* Add a queue for guest to host transfers for port 0 (backward compat) */
vser->ovqs[0] = virtio_add_queue(vdev, 128, handle_output);
/* control queue: host to guest */
vser->c_ivq = virtio_add_queue(vdev, 16, control_in);
/* control queue: guest to host */
vser->c_ovq = virtio_add_queue(vdev, 16, control_out);
for (i = 1; i < vser->bus->max_nr_ports; i++) {
/* Add a per-port queue for host to guest transfers */
vser->ivqs[i] = virtio_add_queue(vdev, 128, handle_input);
/* Add a per-per queue for guest to host transfers */
vser->ovqs[i] = virtio_add_queue(vdev, 128, handle_output);
}
vser->config.max_nr_ports = max_nr_ports;
/*
* Reserve location 0 for a console port for backward compat
* (old kernel, new qemu)
*/
vser->config.nr_ports = 1;
vser->vdev.get_features = get_features;
vser->vdev.get_config = get_config;
vser->vdev.set_config = set_config;
/*
* Register for the savevm section with the virtio-console name
* to preserve backward compat
*/
register_savevm("virtio-console", -1, 2, virtio_serial_save,
virtio_serial_load, vser);
return vdev;
}