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From 4945aee74f494cc8a17ce1634b5200eb9ee227d2 Mon Sep 17 00:00:00 2001
From: Amit Shah <amit.shah@redhat.com>
Date: Wed, 20 Jan 2010 00:36:53 +0530
Subject: [PATCH 3/9] 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>
---
hw/virtio-serial-bus.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++
hw/virtio-serial.h | 6 +++
2 files changed, 100 insertions(+), 0 deletions(-)
diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
index 5132c9c..9af21df 100644
--- a/hw/virtio-serial-bus.c
+++ b/hw/virtio-serial-bus.c
@@ -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.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;
}
}
@@ -300,6 +340,8 @@ 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);
@@ -308,15 +350,41 @@ 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);
@@ -329,6 +397,20 @@ 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;
}
@@ -357,6 +439,10 @@ 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)
@@ -390,6 +476,14 @@ 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];
diff --git a/hw/virtio-serial.h b/hw/virtio-serial.h
index fe8e357..d9c7acb 100644
--- a/hw/virtio-serial.h
+++ b/hw/virtio-serial.h
@@ -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 {
--
1.6.2.5
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