| /* |
| * A bus for connecting virtio serial and console ports |
| * |
| * Copyright (C) 2009 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. |
| */ |
| |
| #include "monitor.h" |
| #include "qemu-queue.h" |
| #include "sysbus.h" |
| #include "virtio-serial.h" |
| |
| /* The virtio-serial bus on top of which the ports will ride as devices */ |
| struct VirtIOSerialBus { |
| BusState qbus; |
| |
| /* This is the parent device that provides the bus for ports. */ |
| VirtIOSerial *vser; |
| |
| /* The maximum number of ports that can ride on top of this bus */ |
| uint32_t max_nr_ports; |
| }; |
| |
| struct VirtIOSerial { |
| VirtIODevice vdev; |
| |
| VirtQueue *c_ivq, *c_ovq; |
| /* Arrays of ivqs and ovqs: one per port */ |
| VirtQueue **ivqs, **ovqs; |
| |
| VirtIOSerialBus *bus; |
| |
| QTAILQ_HEAD(, VirtIOSerialPort) ports; |
| struct virtio_console_config config; |
| }; |
| |
| static VirtIOSerialPort *find_port_by_id(VirtIOSerial *vser, uint32_t id) |
| { |
| VirtIOSerialPort *port; |
| |
| 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 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) |
| { |
| VirtQueueElement elem; |
| VirtQueue *vq; |
| size_t offset = 0; |
| size_t len = 0; |
| |
| vq = port->ivq; |
| if (!virtio_queue_ready(vq)) { |
| return 0; |
| } |
| if (!size) { |
| return 0; |
| } |
| |
| while (offset < size) { |
| int i; |
| |
| if (!virtqueue_pop(vq, &elem)) { |
| break; |
| } |
| |
| for (i = 0; offset < size && i < elem.in_num; i++) { |
| len = MIN(elem.in_sg[i].iov_len, size - offset); |
| |
| memcpy(elem.in_sg[i].iov_base, buf + offset, len); |
| offset += len; |
| } |
| virtqueue_push(vq, &elem, len); |
| } |
| |
| virtio_notify(&port->vser->vdev, vq); |
| return offset; |
| } |
| |
| static size_t send_control_msg(VirtIOSerialPort *port, void *buf, size_t len) |
| { |
| VirtQueueElement elem; |
| VirtQueue *vq; |
| struct virtio_console_control *cpkt; |
| |
| vq = port->vser->c_ivq; |
| if (!virtio_queue_ready(vq)) { |
| return 0; |
| } |
| if (!virtqueue_pop(vq, &elem)) { |
| return 0; |
| } |
| |
| cpkt = (struct virtio_console_control *)buf; |
| stl_p(&cpkt->id, port->id); |
| memcpy(elem.in_sg[0].iov_base, buf, len); |
| |
| virtqueue_push(vq, &elem, len); |
| virtio_notify(&port->vser->vdev, vq); |
| return len; |
| } |
| |
| static size_t send_control_event(VirtIOSerialPort *port, uint16_t event, |
| uint16_t value) |
| { |
| struct virtio_console_control cpkt; |
| |
| stw_p(&cpkt.event, event); |
| stw_p(&cpkt.value, value); |
| |
| return send_control_msg(port, &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, 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; |
| } |
| |
| /* 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) |
| { |
| VirtQueue *vq = port->ivq; |
| |
| if (!virtio_queue_ready(vq) || |
| !(port->vser->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) || |
| 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; |
| } |
| if (virtqueue_avail_bytes(vq, 1, 0)) { |
| return 1; |
| } |
| return 0; |
| } |
| |
| /* Guest wants to notify us of some event */ |
| static void handle_control_message(VirtIOSerial *vser, void *buf) |
| { |
| struct VirtIOSerialPort *port; |
| struct virtio_console_control cpkt, *gcpkt; |
| uint8_t *buffer; |
| size_t buffer_len; |
| |
| gcpkt = buf; |
| port = find_port_by_id(vser, ldl_p(&gcpkt->id)); |
| if (!port) |
| return; |
| |
| cpkt.event = lduw_p(&gcpkt->event); |
| cpkt.value = lduw_p(&gcpkt->value); |
| |
| switch(cpkt.event) { |
| case VIRTIO_CONSOLE_PORT_READY: |
| /* |
| * 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 (port->is_console) { |
| send_control_event(port, VIRTIO_CONSOLE_CONSOLE_PORT, 1); |
| } |
| |
| if (port->name) { |
| stw_p(&cpkt.event, VIRTIO_CONSOLE_PORT_NAME); |
| stw_p(&cpkt.value, 1); |
| |
| buffer_len = sizeof(cpkt) + strlen(port->name) + 1; |
| buffer = qemu_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(port, buffer, buffer_len); |
| qemu_free(buffer); |
| } |
| |
| 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 |
| * initialised. If some app is interested in knowing about |
| * this event, let it know. |
| */ |
| if (port->info->guest_ready) { |
| 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; |
| } |
| } |
| |
| static void control_in(VirtIODevice *vdev, VirtQueue *vq) |
| { |
| } |
| |
| static void control_out(VirtIODevice *vdev, VirtQueue *vq) |
| { |
| VirtQueueElement elem; |
| VirtIOSerial *vser; |
| |
| vser = DO_UPCAST(VirtIOSerial, vdev, vdev); |
| |
| while (virtqueue_pop(vq, &elem)) { |
| handle_control_message(vser, elem.out_sg[0].iov_base); |
| virtqueue_push(vq, &elem, elem.out_sg[0].iov_len); |
| } |
| virtio_notify(vdev, vq); |
| } |
| |
| /* Guest wrote something to some port. */ |
| static void handle_output(VirtIODevice *vdev, VirtQueue *vq) |
| { |
| VirtIOSerial *vser; |
| VirtQueueElement elem; |
| |
| vser = DO_UPCAST(VirtIOSerial, vdev, vdev); |
| |
| while (virtqueue_pop(vq, &elem)) { |
| VirtIOSerialPort *port; |
| size_t ret; |
| |
| port = find_port_by_vq(vser, vq); |
| if (!port) { |
| ret = 0; |
| goto next_buf; |
| } |
| |
| /* |
| * A port may not have any handler registered for consuming the |
| * data that the guest sends or it may not have a chardev associated |
| * with it. Just ignore the data in that case. |
| */ |
| if (!port->info->have_data) { |
| ret = 0; |
| goto next_buf; |
| } |
| |
| /* The guest always sends only one sg */ |
| ret = port->info->have_data(port, elem.out_sg[0].iov_base, |
| elem.out_sg[0].iov_len); |
| |
| next_buf: |
| virtqueue_push(vq, &elem, ret); |
| } |
| virtio_notify(vdev, vq); |
| } |
| |
| static void handle_input(VirtIODevice *vdev, VirtQueue *vq) |
| { |
| } |
| |
| static uint32_t get_features(VirtIODevice *vdev, uint32_t features) |
| { |
| features |= (1 << VIRTIO_CONSOLE_F_MULTIPORT); |
| |
| return features; |
| } |
| |
| /* Guest requested config info */ |
| static void get_config(VirtIODevice *vdev, uint8_t *config_data) |
| { |
| VirtIOSerial *vser; |
| |
| vser = DO_UPCAST(VirtIOSerial, vdev, vdev); |
| memcpy(config_data, &vser->config, sizeof(struct virtio_console_config)); |
| } |
| |
| static void set_config(VirtIODevice *vdev, const uint8_t *config_data) |
| { |
| struct virtio_console_config config; |
| |
| memcpy(&config, config_data, sizeof(config)); |
| } |
| |
| 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); |
| |
| /* The config space */ |
| 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); |
| |
| if (version_id < 2) { |
| return 0; |
| } |
| |
| /* The config space */ |
| qemu_get_be16s(f, &s->config.cols); |
| 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; |
| } |
| |
| static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent); |
| |
| static struct BusInfo virtser_bus_info = { |
| .name = "virtio-serial-bus", |
| .size = sizeof(VirtIOSerialBus), |
| .print_dev = virtser_bus_dev_print, |
| }; |
| |
| static VirtIOSerialBus *virtser_bus_new(DeviceState *dev) |
| { |
| VirtIOSerialBus *bus; |
| |
| bus = FROM_QBUS(VirtIOSerialBus, qbus_create(&virtser_bus_info, dev, NULL)); |
| bus->qbus.allow_hotplug = 1; |
| |
| return bus; |
| } |
| |
| static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent) |
| { |
| VirtIOSerialDevice *dev = DO_UPCAST(VirtIOSerialDevice, qdev, qdev); |
| VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev); |
| |
| 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) |
| { |
| VirtIOSerialDevice *dev = DO_UPCAST(VirtIOSerialDevice, qdev, qdev); |
| VirtIOSerialPortInfo *info = DO_UPCAST(VirtIOSerialPortInfo, qdev, base); |
| VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev); |
| VirtIOSerialBus *bus = DO_UPCAST(VirtIOSerialBus, qbus, qdev->parent_bus); |
| int ret; |
| bool plugging_port0; |
| |
| port->vser = bus->vser; |
| |
| /* |
| * 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 = port->is_console && !find_port_by_id(port->vser, 0); |
| |
| if (port->vser->config.nr_ports == bus->max_nr_ports && !plugging_port0) { |
| qemu_error("virtio-serial-bus: Maximum device limit reached\n"); |
| return -1; |
| } |
| dev->info = info; |
| |
| ret = info->init(dev); |
| if (ret) { |
| return ret; |
| } |
| |
| 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]; |
| |
| /* Send an update to the guest about this new port added */ |
| virtio_notify_config(&port->vser->vdev); |
| |
| return ret; |
| } |
| |
| static int virtser_port_qdev_exit(DeviceState *qdev) |
| { |
| VirtIOSerialDevice *dev = DO_UPCAST(VirtIOSerialDevice, qdev, qdev); |
| VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev); |
| VirtIOSerial *vser = port->vser; |
| |
| send_control_event(port, VIRTIO_CONSOLE_PORT_REMOVE, 1); |
| |
| /* |
| * Don't decrement nr_ports here; thus we keep a linearly |
| * increasing port id. Not utilising an id again saves us a couple |
| * of complications: |
| * |
| * - Not having to bother about sending the port id to the guest |
| * kernel on hotplug or on addition of new ports; the guest can |
| * also linearly increment the port number. This is preferable |
| * because the config space won't have the need to store a |
| * ports_map. |
| * |
| * - Extra state to be stored for all the "holes" that got created |
| * so that we keep filling in the ids from the least available |
| * index. |
| * |
| * When such a functionality is desired, a control message to add |
| * a port can be introduced. |
| */ |
| QTAILQ_REMOVE(&vser->ports, port, next); |
| |
| if (port->info->exit) |
| port->info->exit(dev); |
| |
| return 0; |
| } |
| |
| void virtio_serial_port_qdev_register(VirtIOSerialPortInfo *info) |
| { |
| info->qdev.init = virtser_port_qdev_init; |
| info->qdev.bus_info = &virtser_bus_info; |
| info->qdev.exit = virtser_port_qdev_exit; |
| info->qdev.unplug = qdev_simple_unplug_cb; |
| qdev_register(&info->qdev); |
| } |
| |
| VirtIODevice *virtio_serial_init(DeviceState *dev, uint32_t max_nr_ports) |
| { |
| VirtIOSerial *vser; |
| VirtIODevice *vdev; |
| uint32_t i; |
| |
| if (!max_nr_ports) |
| return NULL; |
| |
| vdev = virtio_common_init("virtio-serial", VIRTIO_ID_CONSOLE, |
| sizeof(struct virtio_console_config), |
| sizeof(VirtIOSerial)); |
| |
| vser = DO_UPCAST(VirtIOSerial, vdev, vdev); |
| |
| /* Spawn a new virtio-serial bus on which the ports will ride as devices */ |
| vser->bus = virtser_bus_new(dev); |
| vser->bus->vser = vser; |
| QTAILQ_INIT(&vser->ports); |
| |
| vser->bus->max_nr_ports = max_nr_ports; |
| vser->ivqs = qemu_malloc(max_nr_ports * sizeof(VirtQueue *)); |
| vser->ovqs = qemu_malloc(max_nr_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); |
| |
| /* control queue: host to guest */ |
| vser->c_ivq = virtio_add_queue(vdev, 16, control_in); |
| /* control queue: guest to host */ |
| vser->c_ovq = virtio_add_queue(vdev, 16, 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->config.max_nr_ports = max_nr_ports; |
| /* |
| * Reserve location 0 for a console port for backward compat |
| * (old kernel, new qemu) |
| */ |
| vser->config.nr_ports = 1; |
| |
| vser->vdev.get_features = get_features; |
| vser->vdev.get_config = get_config; |
| vser->vdev.set_config = set_config; |
| |
| /* |
| * Register for the savevm section with the virtio-console name |
| * to preserve backward compat |
| */ |
| register_savevm("virtio-console", -1, 2, virtio_serial_save, |
| virtio_serial_load, vser); |
| |
| return vdev; |
| } |