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qemu-e2k/hw/char/virtio-serial-bus.c
Jason Wang 86044b24e8 virtio: basic packed virtqueue support 
This patch implements basic support for the packed virtqueue. Compare
the split virtqueue which has three rings, packed virtqueue only have
one which is supposed to have better cache utilization and more
hardware friendly.

Please refer virtio specification for more information.

Signed-off-by: Wei Xu <wexu@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20191025083527.30803-6-eperezma@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-10-25 07:46:22 -04:00

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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 "qemu/main-loop.h"
#include "qemu/module.h"
#include "migration/qemu-file-types.h"
#include "monitor/monitor.h"
#include "qemu/error-report.h"
#include "qemu/queue.h"
#include "hw/qdev-properties.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_be16(f, config.cols);
qemu_put_be16(f, config.rows);
qemu_put_be32(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(vdev, 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), OBJECT(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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