diff options
Diffstat (limited to 'hw/char/virtio-serial-bus.c')
| -rw-r--r-- | hw/char/virtio-serial-bus.c | 1209 |
1 files changed, 1209 insertions, 0 deletions
diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c new file mode 100644 index 000000000..f01ec2137 --- /dev/null +++ b/hw/char/virtio-serial-bus.c @@ -0,0 +1,1209 @@ +/* + * 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 "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_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() +}; + +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; + + 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->bh = qemu_bh_new(flush_queued_data_bh, port); + 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) +{ + 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); + } +} + +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_init(&vser->bus, sizeof(vser->bus), TYPE_VIRTIO_SERIAL_BUS, + dev, vdev->bus_name); + qbus_set_hotplug_handler(BUS(&vser->bus), OBJECT(vser)); + 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; + device_class_set_props(k, 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) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(dev); + VirtIOSerial *vser = VIRTIO_SERIAL(dev); + int i; + + QLIST_REMOVE(vser, next); + + virtio_delete_queue(vser->c_ivq); + virtio_delete_queue(vser->c_ovq); + for (i = 0; i < vser->bus.max_nr_ports; i++) { + virtio_delete_queue(vser->ivqs[i]); + virtio_delete_queue(vser->ovqs[i]); + } + + g_free(vser->ivqs); + g_free(vser->ovqs); + g_free(vser->ports_map); + if (vser->post_load) { + g_free(vser->post_load->connected); + timer_free(vser->post_load->timer); + g_free(vser->post_load); + } + + qbus_set_hotplug_handler(BUS(&vser->bus), NULL); + + 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); + + device_class_set_props(dc, 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) |