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qemu/hw/char/virtio-serial-bus.c

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/*
* A bus for connecting virtio serial and console ports
*
* Copyright (C) 2009, 2010 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.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/iov.h"
#include "monitor/monitor.h"
#include "qemu/error-report.h"
#include "qemu/queue.h"
#include "hw/sysbus.h"
#include "trace.h"
#include "hw/virtio/virtio-serial.h"
#include "hw/virtio/virtio-access.h"
static struct VirtIOSerialDevices {
QLIST_HEAD(, VirtIOSerial) devices;
} vserdevices;
static VirtIOSerialPort *find_port_by_id(VirtIOSerial *vser, uint32_t id)
{
VirtIOSerialPort *port;
if (id == VIRTIO_CONSOLE_BAD_ID) {
return NULL;
}
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 VirtIOSerialPort *find_port_by_name(char *name)
{
VirtIOSerial *vser;
QLIST_FOREACH(vser, &vserdevices.devices, next) {
VirtIOSerialPort *port;
QTAILQ_FOREACH(port, &vser->ports, next) {
if (port->name && !strcmp(port->name, name)) {
return port;
}
}
}
return NULL;
}
static VirtIOSerialPort *find_first_connected_console(VirtIOSerial *vser)
{
VirtIOSerialPort *port;
QTAILQ_FOREACH(port, &vser->ports, next) {
VirtIOSerialPortClass const *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
if (vsc->is_console && port->host_connected) {
return port;
}
}
return NULL;
}
static bool use_multiport(VirtIOSerial *vser)
{
VirtIODevice *vdev = VIRTIO_DEVICE(vser);
return virtio_vdev_has_feature(vdev, 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;
vq = port->ivq;
if (!virtio_queue_ready(vq)) {
return 0;
}
offset = 0;
while (offset < size) {
size_t len;
elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
if (!elem) {
break;
}
len = iov_from_buf(elem->in_sg, elem->in_num, 0,
buf + offset, size - offset);
offset += len;
virtqueue_push(vq, elem, len);
g_free(elem);
}
virtio_notify(VIRTIO_DEVICE(port->vser), vq);
return offset;
}
static void discard_vq_data(VirtQueue *vq, VirtIODevice *vdev)
{
VirtQueueElement *elem;
if (!virtio_queue_ready(vq)) {
return;
}
for (;;) {
elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
if (!elem) {
break;
}
virtqueue_push(vq, elem, 0);
g_free(elem);
}
virtio_notify(vdev, vq);
}
static void discard_throttle_data(VirtIOSerialPort *port)
{
if (port->elem) {
virtqueue_detach_element(port->ovq, port->elem, 0);
g_free(port->elem);
port->elem = NULL;
}
}
static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
VirtIODevice *vdev)
{
VirtIOSerialPortClass *vsc;
assert(port);
assert(virtio_queue_ready(vq));
vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
while (!port->throttled) {
unsigned int i;
/* Pop an elem only if we haven't left off a previous one mid-way */
if (!port->elem) {
port->elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
if (!port->elem) {
break;
}
port->iov_idx = 0;
port->iov_offset = 0;
}
for (i = port->iov_idx; i < port->elem->out_num; i++) {
size_t buf_size;
ssize_t ret;
buf_size = port->elem->out_sg[i].iov_len - port->iov_offset;
ret = vsc->have_data(port,
port->elem->out_sg[i].iov_base
+ port->iov_offset,
buf_size);
if (!port->elem) { /* bail if we got disconnected */
return;
}
if (port->throttled) {
port->iov_idx = i;
if (ret > 0) {
port->iov_offset += ret;
}
break;
}
port->iov_offset = 0;
}
if (port->throttled) {
break;
}
virtqueue_push(vq, port->elem, 0);
g_free(port->elem);
port->elem = NULL;
}
virtio_notify(vdev, vq);
}
static void flush_queued_data(VirtIOSerialPort *port)
{
assert(port);
if (!virtio_queue_ready(port->ovq)) {
return;
}
do_flush_queued_data(port, port->ovq, VIRTIO_DEVICE(port->vser));
}
static size_t send_control_msg(VirtIOSerial *vser, void *buf, size_t len)
{
VirtQueueElement *elem;
VirtQueue *vq;
vq = vser->c_ivq;
if (!virtio_queue_ready(vq)) {
return 0;
}
elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
if (!elem) {
return 0;
}
/* TODO: detect a buffer that's too short, set NEEDS_RESET */
iov_from_buf(elem->in_sg, elem->in_num, 0, buf, len);
virtqueue_push(vq, elem, len);
virtio_notify(VIRTIO_DEVICE(vser), vq);
g_free(elem);
return len;
}
static size_t send_control_event(VirtIOSerial *vser, uint32_t port_id,
uint16_t event, uint16_t value)
{
VirtIODevice *vdev = VIRTIO_DEVICE(vser);
struct virtio_console_control cpkt;
virtio_stl_p(vdev, &cpkt.id, port_id);
virtio_stw_p(vdev, &cpkt.event, event);
virtio_stw_p(vdev, &cpkt.value, value);
trace_virtio_serial_send_control_event(port_id, event, value);
return send_control_msg(vser, &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->vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 1);
return 0;
}
int virtio_serial_close(VirtIOSerialPort *port)
{
port->host_connected = false;
/*
* If there's any data the guest sent which the app didn't
* consume, reset the throttling flag and discard the data.
*/
port->throttled = false;
discard_throttle_data(port);
discard_vq_data(port->ovq, VIRTIO_DEVICE(port->vser));
send_control_event(port->vser, port->id, 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)
{
VirtIODevice *vdev = VIRTIO_DEVICE(port->vser);
VirtQueue *vq = port->ivq;
unsigned int bytes;
if (!virtio_queue_ready(vq) ||
!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) ||
virtio_queue_empty(vq)) {
return 0;
}
if (use_multiport(port->vser) && !port->guest_connected) {
return 0;
}
virtqueue_get_avail_bytes(vq, &bytes, NULL, 4096, 0);
return bytes;
}
static void flush_queued_data_bh(void *opaque)
{
VirtIOSerialPort *port = opaque;
flush_queued_data(port);
}
void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
{
if (!port) {
return;
}
trace_virtio_serial_throttle_port(port->id, throttle);
port->throttled = throttle;
if (throttle) {
return;
}
qemu_bh_schedule(port->bh);
}
/* Guest wants to notify us of some event */
static void handle_control_message(VirtIOSerial *vser, void *buf, size_t len)
{
VirtIODevice *vdev = VIRTIO_DEVICE(vser);
struct VirtIOSerialPort *port;
VirtIOSerialPortClass *vsc;
struct virtio_console_control cpkt, *gcpkt;
uint8_t *buffer;
size_t buffer_len;
gcpkt = buf;
if (len < sizeof(cpkt)) {
/* The guest sent an invalid control packet */
return;
}
cpkt.event = virtio_lduw_p(vdev, &gcpkt->event);
cpkt.value = virtio_lduw_p(vdev, &gcpkt->value);
trace_virtio_serial_handle_control_message(cpkt.event, cpkt.value);
if (cpkt.event == VIRTIO_CONSOLE_DEVICE_READY) {
if (!cpkt.value) {
error_report("virtio-serial-bus: Guest failure in adding device %s",
vser->bus.qbus.name);
return;
}
/*
* The device is up, we can now tell the device about all the
* ports we have here.
*/
QTAILQ_FOREACH(port, &vser->ports, next) {
send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_ADD, 1);
}
return;
}
port = find_port_by_id(vser, virtio_ldl_p(vdev, &gcpkt->id));
if (!port) {
error_report("virtio-serial-bus: Unexpected port id %u for device %s",
virtio_ldl_p(vdev, &gcpkt->id), vser->bus.qbus.name);
return;
}
trace_virtio_serial_handle_control_message_port(port->id);
vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
switch(cpkt.event) {
case VIRTIO_CONSOLE_PORT_READY:
if (!cpkt.value) {
error_report("virtio-serial-bus: Guest failure in adding port %u for device %s",
port->id, vser->bus.qbus.name);
break;
}
/*
* 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 (vsc->is_console) {
send_control_event(vser, port->id, VIRTIO_CONSOLE_CONSOLE_PORT, 1);
}
if (port->name) {
virtio_stl_p(vdev, &cpkt.id, port->id);
virtio_stw_p(vdev, &cpkt.event, VIRTIO_CONSOLE_PORT_NAME);
virtio_stw_p(vdev, &cpkt.value, 1);
buffer_len = sizeof(cpkt) + strlen(port->name) + 1;
buffer = g_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(vser, buffer, buffer_len);
g_free(buffer);
}
if (port->host_connected) {
send_control_event(vser, port->id, 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 (vsc->guest_ready) {
vsc->guest_ready(port);
}
break;
case VIRTIO_CONSOLE_PORT_OPEN:
port->guest_connected = cpkt.value;
if (vsc->set_guest_connected) {
/* Send the guest opened notification if an app is interested */
vsc->set_guest_connected(port, cpkt.value);
}
break;
}
}
static void control_in(VirtIODevice *vdev, VirtQueue *vq)
{
}
static void control_out(VirtIODevice *vdev, VirtQueue *vq)
{
VirtQueueElement *elem;
VirtIOSerial *vser;
uint8_t *buf;
size_t len;
vser = VIRTIO_SERIAL(vdev);
len = 0;
buf = NULL;
for (;;) {
size_t cur_len;
elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
if (!elem) {
break;
}
cur_len = iov_size(elem->out_sg, elem->out_num);
/*
* Allocate a new buf only if we didn't have one previously or
* if the size of the buf differs
*/
if (cur_len > len) {
g_free(buf);
buf = g_malloc(cur_len);
len = cur_len;
}
iov_to_buf(elem->out_sg, elem->out_num, 0, buf, cur_len);
handle_control_message(vser, buf, cur_len);
virtqueue_push(vq, elem, 0);
g_free(elem);
}
g_free(buf);
virtio_notify(vdev, vq);
}
/* Guest wrote something to some port. */
static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOSerial *vser;
VirtIOSerialPort *port;
vser = VIRTIO_SERIAL(vdev);
port = find_port_by_vq(vser, vq);
if (!port || !port->host_connected) {
discard_vq_data(vq, vdev);
return;
}
if (!port->throttled) {
do_flush_queued_data(port, vq, vdev);
return;
}
}
static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
{
/*
* Users of virtio-serial would like to know when guest becomes
* writable again -- i.e. if a vq had stuff queued up and the
* guest wasn't reading at all, the host would not be able to
* write to the vq anymore. Once the guest reads off something,
* we can start queueing things up again. However, this call is
* made for each buffer addition by the guest -- even though free
* buffers existed prior to the current buffer addition. This is
* done so as not to maintain previous state, which will need
* additional live-migration-related changes.
*/
VirtIOSerial *vser;
VirtIOSerialPort *port;
VirtIOSerialPortClass *vsc;
vser = VIRTIO_SERIAL(vdev);
port = find_port_by_vq(vser, vq);
if (!port) {
return;
}
vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
/*
* If guest_connected is false, this call is being made by the
* early-boot queueing up of descriptors, which is just noise for
* the host apps -- don't disturb them in that case.
*/
if (port->guest_connected && port->host_connected && vsc->guest_writable) {
vsc->guest_writable(port);
}
}
static uint64_t get_features(VirtIODevice *vdev, uint64_t features,
Error **errp)
{
VirtIOSerial *vser;
vser = VIRTIO_SERIAL(vdev);
features |= vser->host_features;
if (vser->bus.max_nr_ports > 1) {
virtio_add_feature(&features, VIRTIO_CONSOLE_F_MULTIPORT);
}
return features;
}
/* Guest requested config info */
static void get_config(VirtIODevice *vdev, uint8_t *config_data)
{
VirtIOSerial *vser = VIRTIO_SERIAL(vdev);
struct virtio_console_config *config =
(struct virtio_console_config *)config_data;
config->cols = 0;
config->rows = 0;
config->max_nr_ports = virtio_tswap32(vdev,
vser->serial.max_virtserial_ports);
}
/* Guest sent new config info */
static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
{
VirtIOSerial *vser = VIRTIO_SERIAL(vdev);
struct virtio_console_config *config =
(struct virtio_console_config *)config_data;
VirtIOSerialPort *port = find_first_connected_console(vser);
VirtIOSerialPortClass *vsc;
uint8_t emerg_wr_lo;
if (!virtio_has_feature(vser->host_features,
VIRTIO_CONSOLE_F_EMERG_WRITE) || !config->emerg_wr) {
return;
}
emerg_wr_lo = le32_to_cpu(config->emerg_wr);
/* Make sure we don't misdetect an emergency write when the guest
* does a short config write after an emergency write. */
config->emerg_wr = 0;
if (!port) {
return;
}
vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
(void)vsc->have_data(port, &emerg_wr_lo, 1);
}
static void guest_reset(VirtIOSerial *vser)
{
VirtIOSerialPort *port;
VirtIOSerialPortClass *vsc;
QTAILQ_FOREACH(port, &vser->ports, next) {
vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
discard_throttle_data(port);
if (port->guest_connected) {
port->guest_connected = false;
if (vsc->set_guest_connected) {
vsc->set_guest_connected(port, false);
}
}
}
}
static void set_status(VirtIODevice *vdev, uint8_t status)
{
VirtIOSerial *vser;
VirtIOSerialPort *port;
vser = VIRTIO_SERIAL(vdev);
port = find_port_by_id(vser, 0);
if (port && !use_multiport(port->vser)
&& (status & VIRTIO_CONFIG_S_DRIVER_OK)) {
/*
* Non-multiport guests won't be able to tell us guest
* open/close status. Such guests can only have a port at id
* 0, so set guest_connected for such ports as soon as guest
* is up.
*/
port->guest_connected = true;
}
if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
guest_reset(vser);
}
QTAILQ_FOREACH(port, &vser->ports, next) {
VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
if (vsc->enable_backend) {
vsc->enable_backend(port, vdev->vm_running);
}
}
}
static void vser_reset(VirtIODevice *vdev)
{
VirtIOSerial *vser;
vser = VIRTIO_SERIAL(vdev);
guest_reset(vser);
}
static void virtio_serial_save_device(VirtIODevice *vdev, QEMUFile *f)
{
VirtIOSerial *s = VIRTIO_SERIAL(vdev);
VirtIOSerialPort *port;
uint32_t nr_active_ports;
unsigned int i, max_nr_ports;
struct virtio_console_config config;
/* The config space (ignored on the far end in current versions) */
get_config(vdev, (uint8_t *)&config);
qemu_put_be16s(f, &config.cols);
qemu_put_be16s(f, &config.rows);
qemu_put_be32s(f, &config.max_nr_ports);
/* The ports map */
max_nr_ports = s->serial.max_virtserial_ports;
for (i = 0; i < DIV_ROUND_UP(max_nr_ports, 32); i++) {
qemu_put_be32s(f, &s->ports_map[i]);
}
/* 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) {
uint32_t elem_popped;
qemu_put_be32s(f, &port->id);
qemu_put_byte(f, port->guest_connected);
qemu_put_byte(f, port->host_connected);
elem_popped = 0;
if (port->elem) {
elem_popped = 1;
}
qemu_put_be32s(f, &elem_popped);
if (elem_popped) {
qemu_put_be32s(f, &port->iov_idx);
qemu_put_be64s(f, &port->iov_offset);
qemu_put_virtqueue_element(f, port->elem);
}
}
}
static void virtio_serial_post_load_timer_cb(void *opaque)
{
uint32_t i;
VirtIOSerial *s = VIRTIO_SERIAL(opaque);
VirtIOSerialPort *port;
uint8_t host_connected;
VirtIOSerialPortClass *vsc;
if (!s->post_load) {
return;
}
for (i = 0 ; i < s->post_load->nr_active_ports; ++i) {
port = s->post_load->connected[i].port;
host_connected = s->post_load->connected[i].host_connected;
if (host_connected != port->host_connected) {
/*
* We have to let the guest know of the host connection
* status change
*/
send_control_event(s, port->id, VIRTIO_CONSOLE_PORT_OPEN,
port->host_connected);
}
vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
if (vsc->set_guest_connected) {
vsc->set_guest_connected(port, port->guest_connected);
}
}
g_free(s->post_load->connected);
timer_del(s->post_load->timer);
timer_free(s->post_load->timer);
g_free(s->post_load);
s->post_load = NULL;
}
static int fetch_active_ports_list(QEMUFile *f,
VirtIOSerial *s, uint32_t nr_active_ports)
{
VirtIODevice *vdev = VIRTIO_DEVICE(s);
uint32_t i;
s->post_load = g_malloc0(sizeof(*s->post_load));
s->post_load->nr_active_ports = nr_active_ports;
s->post_load->connected =
g_malloc0(sizeof(*s->post_load->connected) * nr_active_ports);
s->post_load->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
virtio_serial_post_load_timer_cb,
s);
/* Items in struct VirtIOSerialPort */
for (i = 0; i < nr_active_ports; i++) {
VirtIOSerialPort *port;
uint32_t elem_popped;
uint32_t id;
id = qemu_get_be32(f);
port = find_port_by_id(s, id);
if (!port) {
return -EINVAL;
}
port->guest_connected = qemu_get_byte(f);
s->post_load->connected[i].port = port;
s->post_load->connected[i].host_connected = qemu_get_byte(f);
qemu_get_be32s(f, &elem_popped);
if (elem_popped) {
qemu_get_be32s(f, &port->iov_idx);
qemu_get_be64s(f, &port->iov_offset);
port->elem =
qemu_get_virtqueue_element(vdev, f, sizeof(VirtQueueElement));
/*
* Port was throttled on source machine. Let's
* unthrottle it here so data starts flowing again.
*/
virtio_serial_throttle_port(port, false);
}
}
timer_mod(s->post_load->timer, 1);
return 0;
}
static int virtio_serial_load_device(VirtIODevice *vdev, QEMUFile *f,
int version_id)
{
VirtIOSerial *s = VIRTIO_SERIAL(vdev);
uint32_t max_nr_ports, nr_active_ports, ports_map;
unsigned int i;
int ret;
uint32_t tmp;
/* Unused */
qemu_get_be16s(f, (uint16_t *) &tmp);
qemu_get_be16s(f, (uint16_t *) &tmp);
qemu_get_be32s(f, &tmp);
max_nr_ports = s->serial.max_virtserial_ports;
for (i = 0; i < DIV_ROUND_UP(max_nr_ports, 32); i++) {
qemu_get_be32s(f, &ports_map);
if (ports_map != s->ports_map[i]) {
/*
* Ports active on source and destination don't
* match. Fail migration.
*/
return -EINVAL;
}
}
qemu_get_be32s(f, &nr_active_ports);
if (nr_active_ports) {
ret = fetch_active_ports_list(f, s, nr_active_ports);
if (ret) {
return ret;
}
}
return 0;
}
static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
static Property virtser_props[] = {
DEFINE_PROP_UINT32("nr", VirtIOSerialPort, id, VIRTIO_CONSOLE_BAD_ID),
DEFINE_PROP_STRING("name", VirtIOSerialPort, name),
DEFINE_PROP_END_OF_LIST()
};
#define TYPE_VIRTIO_SERIAL_BUS "virtio-serial-bus"
#define VIRTIO_SERIAL_BUS(obj) \
OBJECT_CHECK(VirtIOSerialBus, (obj), TYPE_VIRTIO_SERIAL_BUS)
static void virtser_bus_class_init(ObjectClass *klass, void *data)
{
BusClass *k = BUS_CLASS(klass);
k->print_dev = virtser_bus_dev_print;
}
static const TypeInfo virtser_bus_info = {
.name = TYPE_VIRTIO_SERIAL_BUS,
.parent = TYPE_BUS,
.instance_size = sizeof(VirtIOSerialBus),
.class_init = virtser_bus_class_init,
};
static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
{
VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(qdev);
monitor_printf(mon, "%*sport %d, guest %s, host %s, throttle %s\n",
indent, "", port->id,
port->guest_connected ? "on" : "off",
port->host_connected ? "on" : "off",
port->throttled ? "on" : "off");
}
/* This function is only used if a port id is not provided by the user */
static uint32_t find_free_port_id(VirtIOSerial *vser)
{
unsigned int i, max_nr_ports;
max_nr_ports = vser->serial.max_virtserial_ports;
for (i = 0; i < DIV_ROUND_UP(max_nr_ports, 32); i++) {
uint32_t map, zeroes;
map = vser->ports_map[i];
zeroes = ctz32(~map);
if (zeroes != 32) {
return zeroes + i * 32;
}
}
return VIRTIO_CONSOLE_BAD_ID;
}
static void mark_port_added(VirtIOSerial *vser, uint32_t port_id)
{
unsigned int i;
i = port_id / 32;
vser->ports_map[i] |= 1U << (port_id % 32);
}
static void add_port(VirtIOSerial *vser, uint32_t port_id)
{
mark_port_added(vser, port_id);
send_control_event(vser, port_id, VIRTIO_CONSOLE_PORT_ADD, 1);
}
static void remove_port(VirtIOSerial *vser, uint32_t port_id)
{
VirtIOSerialPort *port;
/*
* Don't mark port 0 removed -- we explicitly reserve it for
* backward compat with older guests, ensure a virtconsole device
* unplug retains the reservation.
*/
if (port_id) {
unsigned int i;
i = port_id / 32;
vser->ports_map[i] &= ~(1U << (port_id % 32));
}
port = find_port_by_id(vser, port_id);
/*
* This function is only called from qdev's unplug callback; if we
* get a NULL port here, we're in trouble.
*/
assert(port);
/* Flush out any unconsumed buffers first */
discard_throttle_data(port);
discard_vq_data(port->ovq, VIRTIO_DEVICE(port->vser));
send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_REMOVE, 1);
}
static void virtser_port_device_realize(DeviceState *dev, Error **errp)
{
VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
VirtIOSerialBus *bus = VIRTIO_SERIAL_BUS(qdev_get_parent_bus(dev));
int max_nr_ports;
bool plugging_port0;
Error *err = NULL;
port->vser = bus->vser;
port->bh = qemu_bh_new(flush_queued_data_bh, port);
assert(vsc->have_data);
/*
* 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 = vsc->is_console && !find_port_by_id(port->vser, 0);
if (find_port_by_id(port->vser, port->id)) {
error_setg(errp, "virtio-serial-bus: A port already exists at id %u",
port->id);
return;
}
if (port->name != NULL && find_port_by_name(port->name)) {
error_setg(errp, "virtio-serial-bus: A port already exists by name %s",
port->name);
return;
}
if (port->id == VIRTIO_CONSOLE_BAD_ID) {
if (plugging_port0) {
port->id = 0;
} else {
port->id = find_free_port_id(port->vser);
if (port->id == VIRTIO_CONSOLE_BAD_ID) {
error_setg(errp, "virtio-serial-bus: Maximum port limit for "
"this device reached");
return;
}
}
}
max_nr_ports = port->vser->serial.max_virtserial_ports;
if (port->id >= max_nr_ports) {
error_setg(errp, "virtio-serial-bus: Out-of-range port id specified, "
"max. allowed: %u", max_nr_ports - 1);
return;
}
vsc->realize(dev, &err);
if (err != NULL) {
error_propagate(errp, err);
return;
}
port->elem = NULL;
}
static void virtser_port_device_plug(HotplugHandler *hotplug_dev,
DeviceState *dev, Error **errp)
{
VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
QTAILQ_INSERT_TAIL(&port->vser->ports, port, next);
port->ivq = port->vser->ivqs[port->id];
port->ovq = port->vser->ovqs[port->id];
add_port(port->vser, port->id);
/* Send an update to the guest about this new port added */
virtio_notify_config(VIRTIO_DEVICE(hotplug_dev));
}
static void virtser_port_device_unrealize(DeviceState *dev, Error **errp)
{
VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(dev);
VirtIOSerial *vser = port->vser;
qemu_bh_delete(port->bh);
remove_port(port->vser, port->id);
QTAILQ_REMOVE(&vser->ports, port, next);
if (vsc->unrealize) {
vsc->unrealize(dev, errp);
}
}
static void virtio_serial_device_realize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VirtIOSerial *vser = VIRTIO_SERIAL(dev);
uint32_t i, max_supported_ports;
size_t config_size = sizeof(struct virtio_console_config);
if (!vser->serial.max_virtserial_ports) {
error_setg(errp, "Maximum number of serial ports not specified");
return;
}
/* Each port takes 2 queues, and one pair is for the control queue */
max_supported_ports = VIRTIO_QUEUE_MAX / 2 - 1;
if (vser->serial.max_virtserial_ports > max_supported_ports) {
error_setg(errp, "maximum ports supported: %u", max_supported_ports);
return;
}
if (!virtio_has_feature(vser->host_features,
VIRTIO_CONSOLE_F_EMERG_WRITE)) {
config_size = offsetof(struct virtio_console_config, emerg_wr);
}
virtio_init(vdev, "virtio-serial", VIRTIO_ID_CONSOLE,
config_size);
/* Spawn a new virtio-serial bus on which the ports will ride as devices */
qbus_create_inplace(&vser->bus, sizeof(vser->bus), TYPE_VIRTIO_SERIAL_BUS,
dev, vdev->bus_name);
qbus_set_hotplug_handler(BUS(&vser->bus), DEVICE(vser), errp);
vser->bus.vser = vser;
QTAILQ_INIT(&vser->ports);
vser->bus.max_nr_ports = vser->serial.max_virtserial_ports;
vser->ivqs = g_malloc(vser->serial.max_virtserial_ports
* sizeof(VirtQueue *));
vser->ovqs = g_malloc(vser->serial.max_virtserial_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);
/* TODO: host to guest notifications can get dropped
* if the queue fills up. Implement queueing in host,
* this might also make it possible to reduce the control
* queue size: as guest preposts buffers there,
* this will save 4Kbyte of guest memory per entry. */
/* control queue: host to guest */
vser->c_ivq = virtio_add_queue(vdev, 32, control_in);
/* control queue: guest to host */
vser->c_ovq = virtio_add_queue(vdev, 32, 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->ports_map = g_malloc0((DIV_ROUND_UP(vser->serial.max_virtserial_ports, 32))
* sizeof(vser->ports_map[0]));
/*
* Reserve location 0 for a console port for backward compat
* (old kernel, new qemu)
*/
mark_port_added(vser, 0);
vser->post_load = NULL;
QLIST_INSERT_HEAD(&vserdevices.devices, vser, next);
}
static void virtio_serial_port_class_init(ObjectClass *klass, void *data)
{
DeviceClass *k = DEVICE_CLASS(klass);
set_bit(DEVICE_CATEGORY_INPUT, k->categories);
k->bus_type = TYPE_VIRTIO_SERIAL_BUS;
k->realize = virtser_port_device_realize;
k->unrealize = virtser_port_device_unrealize;
k->props = virtser_props;
}
static const TypeInfo virtio_serial_port_type_info = {
.name = TYPE_VIRTIO_SERIAL_PORT,
.parent = TYPE_DEVICE,
.instance_size = sizeof(VirtIOSerialPort),
.abstract = true,
.class_size = sizeof(VirtIOSerialPortClass),
.class_init = virtio_serial_port_class_init,
};
static void virtio_serial_device_unrealize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VirtIOSerial *vser = VIRTIO_SERIAL(dev);
QLIST_REMOVE(vser, next);
g_free(vser->ivqs);
g_free(vser->ovqs);
g_free(vser->ports_map);
if (vser->post_load) {
g_free(vser->post_load->connected);
timer_del(vser->post_load->timer);
timer_free(vser->post_load->timer);
g_free(vser->post_load);
}
qbus_set_hotplug_handler(BUS(&vser->bus), NULL, errp);
virtio_cleanup(vdev);
}
/* Note: 'console' is used for backwards compatibility */
static const VMStateDescription vmstate_virtio_console = {
.name = "virtio-console",
.minimum_version_id = 3,
.version_id = 3,
.fields = (VMStateField[]) {
VMSTATE_VIRTIO_DEVICE,
VMSTATE_END_OF_LIST()
},
};
static Property virtio_serial_properties[] = {
DEFINE_PROP_UINT32("max_ports", VirtIOSerial, serial.max_virtserial_ports,
31),
DEFINE_PROP_BIT64("emergency-write", VirtIOSerial, host_features,
VIRTIO_CONSOLE_F_EMERG_WRITE, true),
DEFINE_PROP_END_OF_LIST(),
};
static void virtio_serial_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
QLIST_INIT(&vserdevices.devices);
dc->props = virtio_serial_properties;
dc->vmsd = &vmstate_virtio_console;
set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
vdc->realize = virtio_serial_device_realize;
vdc->unrealize = virtio_serial_device_unrealize;
vdc->get_features = get_features;
vdc->get_config = get_config;
vdc->set_config = set_config;
vdc->set_status = set_status;
vdc->reset = vser_reset;
vdc->save = virtio_serial_save_device;
vdc->load = virtio_serial_load_device;
hc->plug = virtser_port_device_plug;
hc->unplug = qdev_simple_device_unplug_cb;
}
static const TypeInfo virtio_device_info = {
.name = TYPE_VIRTIO_SERIAL,
.parent = TYPE_VIRTIO_DEVICE,
.instance_size = sizeof(VirtIOSerial),
.class_init = virtio_serial_class_init,
.interfaces = (InterfaceInfo[]) {
{ TYPE_HOTPLUG_HANDLER },
{ }
}
};
static void virtio_serial_register_types(void)
{
type_register_static(&virtser_bus_info);
type_register_static(&virtio_serial_port_type_info);
type_register_static(&virtio_device_info);
}
type_init(virtio_serial_register_types)
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