From 4945aee74f494cc8a17ce1634b5200eb9ee227d2 Mon Sep 17 00:00:00 2001 From: Amit Shah 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 Signed-off-by: Anthony Liguori --- 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