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virtio-serial-bus: Maintain guest and host port open/close state 

Via control channel messages, the guest can tell us whether a port got
opened or closed. Similarly, we can also indicate to the guest of host
port open/close events.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Amit Shah 2010-01-20 00:36:53 +05:30 committed by Anthony Liguori
parent 98b19252cf
commit 6663a1956e
2 changed files with 100 additions and 0 deletions
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94
hw/virtio-serial-bus.c
View File

@ -66,6 +66,11 @@ static VirtIOSerialPort *find_port_by_vq(VirtIOSerial *vser, VirtQueue *vq)
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)
{
@ -139,11 +144,22 @@ static size_t send_control_event(VirtIOSerialPort *port, uint16_t event,
/* 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;
}
@ -151,6 +167,9 @@ int virtio_serial_close(VirtIOSerialPort *port)
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);
}
@ -167,6 +186,9 @@ size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
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;
@ -203,6 +225,11 @@ static void handle_control_message(VirtIOSerial *vser, void *buf)
if (port->is_console) {
send_control_event(port, VIRTIO_CONSOLE_CONSOLE_PORT, 1);
}
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
@ -213,6 +240,19 @@ static void handle_control_message(VirtIOSerial *vser, void *buf)
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;
}
}
@ -302,6 +342,8 @@ static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
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);
@ -310,15 +352,41 @@ static void virtio_serial_save(QEMUFile *f, void *opaque)
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);
@ -331,6 +399,20 @@ static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
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;
}
@ -360,6 +442,10 @@ static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
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)
@ -393,6 +479,14 @@ static int virtser_port_qdev_init(DeviceState *qdev, DeviceInfo *base)
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];

6
hw/virtio-serial.h
View File

@ -49,6 +49,7 @@ struct virtio_console_control {
#define VIRTIO_CONSOLE_PORT_READY 0
#define VIRTIO_CONSOLE_CONSOLE_PORT 1
#define VIRTIO_CONSOLE_RESIZE 2
#define VIRTIO_CONSOLE_PORT_OPEN 3
/* == In-qemu interface == */
@ -92,6 +93,11 @@ struct VirtIOSerialPort {
/* Identify if this is a port that binds with hvc in the guest */
uint8_t is_console;
/* Is the corresponding guest device open? */
bool guest_connected;
/* Is this device open for IO on the host? */
bool host_connected;
};
struct VirtIOSerialPortInfo {