From 9d1ea8d22ea5798e7cecc717facc74fb1eabc17e Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Tue, 27 Apr 2010 09:07:32 -0300 Subject: [PATCH 05/20] virtio-serial: Use control messages to notify guest of new ports RH-Author: Amit Shah Message-id: <1272359264-8464-6-git-send-email-amit.shah@redhat.com> Patchwork-id: 8851 O-Subject: [RHEL6 PATCH v4 05/17] virtio-serial: Use control messages to notify guest of new ports Bugzilla: 574296 RH-Acked-by: Gerd Hoffmann RH-Acked-by: Juan Quintela RH-Acked-by: Alon Levy Allow the port 'id's to be set by a user on the command line. This is needed by management apps that will want a stable port numbering scheme for hot-plug/unplug and migration. Since the port numbers are shared with the guest (to identify ports in control messages), we just send a control message to the guest indicating addition of new ports (hot-plug) or notifying the guest of the available ports when the guest sends us a DEVICE_READY control message. Bugzilla: 574296 Upstream: Signed-off-by: Amit Shah --- hw/virtio-console.c | 2 + hw/virtio-serial-bus.c | 184 +++++++++++++++++++++++++++++++---------------- hw/virtio-serial.h | 17 +++-- 3 files changed, 133 insertions(+), 70 deletions(-) Signed-off-by: Eduardo Habkost --- hw/virtio-console.c | 2 + hw/virtio-serial-bus.c | 184 +++++++++++++++++++++++++++++++---------------- hw/virtio-serial.h | 17 +++-- 3 files changed, 133 insertions(+), 70 deletions(-) diff --git a/hw/virtio-console.c b/hw/virtio-console.c index bd44ec6..17b221d 100644 --- a/hw/virtio-console.c +++ b/hw/virtio-console.c @@ -99,6 +99,7 @@ static VirtIOSerialPortInfo virtconsole_info = { .exit = virtconsole_exitfn, .qdev.props = (Property[]) { DEFINE_PROP_UINT8("is_console", VirtConsole, port.is_console, 1), + DEFINE_PROP_UINT32("nr", VirtConsole, port.id, VIRTIO_CONSOLE_BAD_ID), DEFINE_PROP_CHR("chardev", VirtConsole, chr), DEFINE_PROP_STRING("name", VirtConsole, port.name), DEFINE_PROP_END_OF_LIST(), @@ -133,6 +134,7 @@ static VirtIOSerialPortInfo virtserialport_info = { .init = virtserialport_initfn, .exit = virtconsole_exitfn, .qdev.props = (Property[]) { + DEFINE_PROP_UINT32("nr", VirtConsole, port.id, VIRTIO_CONSOLE_BAD_ID), DEFINE_PROP_CHR("chardev", VirtConsole, chr), DEFINE_PROP_STRING("name", VirtConsole, port.name), DEFINE_PROP_END_OF_LIST(), diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c index 484dc94..bb11a9b 100644 --- a/hw/virtio-serial-bus.c +++ b/hw/virtio-serial-bus.c @@ -41,6 +41,10 @@ struct VirtIOSerial { VirtIOSerialBus *bus; QTAILQ_HEAD(, VirtIOSerialPort) ports; + + /* bitmap for identifying active ports */ + uint32_t *ports_map; + struct virtio_console_config config; }; @@ -48,6 +52,10 @@ 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; @@ -208,14 +216,25 @@ static void handle_control_message(VirtIOSerial *vser, void *buf) 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); + port = find_port_by_id(vser, ldl_p(&gcpkt->id)); + if (!port && cpkt.event != VIRTIO_CONSOLE_DEVICE_READY) + return; + switch(cpkt.event) { + case VIRTIO_CONSOLE_DEVICE_READY: + /* + * 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(port, VIRTIO_CONSOLE_PORT_ADD, 1); + } + break; + case VIRTIO_CONSOLE_PORT_READY: /* * Now that we know the guest asked for the port name, we're @@ -363,6 +382,7 @@ static void virtio_serial_save(QEMUFile *f, void *opaque) VirtIOSerial *s = opaque; VirtIOSerialPort *port; uint32_t nr_active_ports; + unsigned int i; /* The virtio device */ virtio_save(&s->vdev, f); @@ -370,13 +390,17 @@ static void virtio_serial_save(QEMUFile *f, void *opaque) /* 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 */ + qemu_put_be32s(f, &s->config.max_nr_ports); + + /* The ports map */ + + for (i = 0; i < (s->config.max_nr_ports + 31) / 32; i++) { + qemu_put_be32s(f, &s->ports_map[i]); + } - qemu_put_be32s(f, &s->bus->max_nr_ports); + /* Ports */ - /* Do this because we might have hot-unplugged some ports */ nr_active_ports = 0; QTAILQ_FOREACH(port, &s->ports, next) { nr_active_ports++; @@ -388,11 +412,6 @@ static void virtio_serial_save(QEMUFile *f, void *opaque) * 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); qemu_put_byte(f, port->host_connected); @@ -403,7 +422,8 @@ static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id) { VirtIOSerial *s = opaque; VirtIOSerialPort *port; - uint32_t max_nr_ports, nr_active_ports, nr_ports; + size_t ports_map_size; + uint32_t max_nr_ports, nr_active_ports, *ports_map; unsigned int i; if (version_id > 2) { @@ -420,29 +440,29 @@ static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id) /* The config space */ qemu_get_be16s(f, &s->config.cols); qemu_get_be16s(f, &s->config.rows); - nr_ports = qemu_get_be32(f); - if (nr_ports != s->config.nr_ports) { - /* - * Source hot-plugged/unplugged ports and we don't have all of - * them here. - * - * Note: This condition cannot check for all hotplug/unplug - * events: eg, if one port was hot-plugged and one was - * unplugged, the nr_ports remains the same but the port id's - * would have changed and we won't catch it here. A later - * check for !find_port_by_id() will confirm if this happened. - */ + qemu_get_be32s(f, &max_nr_ports); + if (max_nr_ports > s->config.max_nr_ports) { + /* Source could have had more ports than us. Fail migration. */ return -EINVAL; } - /* Items in struct VirtIOSerial */ + ports_map_size = sizeof(uint32_t) * (max_nr_ports + 31) / 32; + ports_map = qemu_malloc(ports_map_size); - qemu_get_be32s(f, &max_nr_ports); - if (max_nr_ports > s->bus->max_nr_ports) { - /* Source could have more ports than us. Fail migration. */ - return -EINVAL; + for (i = 0; i < (max_nr_ports + 31) / 32; i++) { + qemu_get_be32s(f, &ports_map[i]); + + if (ports_map[i] != s->ports_map[i]) { + /* + * Ports active on source and destination don't + * match. Fail migration. + */ + qemu_free(ports_map); + return -EINVAL; + } } + qemu_free(ports_map); qemu_get_be32s(f, &nr_active_ports); @@ -453,13 +473,6 @@ static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id) id = qemu_get_be32(f); port = find_port_by_id(s, id); - if (!port) { - /* - * The requested port was hot-plugged on the source but we - * don't have it - */ - return -EINVAL; - } port->guest_connected = qemu_get_byte(f); host_connected = qemu_get_byte(f); @@ -472,7 +485,6 @@ static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id) port->host_connected); } } - return 0; } @@ -507,6 +519,50 @@ static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent) indent, "", port->host_connected); } +/* 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; + + for (i = 0; i < (vser->config.max_nr_ports + 31) / 32; i++) { + uint32_t map, bit; + + map = vser->ports_map[i]; + bit = ffs(~map); + if (bit) { + return (bit - 1) + 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(find_port_by_id(vser, port_id), + VIRTIO_CONSOLE_PORT_ADD, 1); +} + +static void remove_port(VirtIOSerial *vser, uint32_t port_id) +{ + unsigned int i; + + i = port_id / 32; + vser->ports_map[i] &= ~(1U << (port_id % 32)); + + send_control_event(find_port_by_id(vser, port_id), + VIRTIO_CONSOLE_PORT_REMOVE, 1); +} + static int virtser_port_qdev_init(DeviceState *qdev, DeviceInfo *base) { VirtIOSerialDevice *dev = DO_UPCAST(VirtIOSerialDevice, qdev, qdev); @@ -525,19 +581,36 @@ static int virtser_port_qdev_init(DeviceState *qdev, DeviceInfo *base) */ plugging_port0 = port->is_console && !find_port_by_id(port->vser, 0); - if (port->vser->config.nr_ports == bus->max_nr_ports && !plugging_port0) { - error_report("virtio-serial-bus: Maximum device limit reached"); + if (find_port_by_id(port->vser, port->id)) { + error_report("virtio-serial-bus: A port already exists at id %u\n", + port->id); return -1; } - dev->info = info; + 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_report("virtio-serial-bus: Maximum port limit for this device reached\n"); + return -1; + } + } + } + + if (port->id >= port->vser->config.max_nr_ports) { + error_report("virtio-serial-bus: Out-of-range port id specified, max. allowed: %u\n", + port->vser->config.max_nr_ports - 1); + 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 @@ -550,6 +623,8 @@ static int virtser_port_qdev_init(DeviceState *qdev, DeviceInfo *base) 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(&port->vser->vdev); @@ -562,26 +637,8 @@ static int virtser_port_qdev_exit(DeviceState *qdev) VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev); VirtIOSerial *vser = port->vser; - send_control_event(port, VIRTIO_CONSOLE_PORT_REMOVE, 1); + remove_port(port->vser, port->id); - /* - * 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) @@ -641,11 +698,12 @@ VirtIODevice *virtio_serial_init(DeviceState *dev, uint32_t max_nr_ports) } vser->config.max_nr_ports = max_nr_ports; + vser->ports_map = qemu_mallocz((max_nr_ports + 31) / 32); /* * Reserve location 0 for a console port for backward compat * (old kernel, new qemu) */ - vser->config.nr_ports = 1; + mark_port_added(vser, 0); vser->vdev.get_features = get_features; vser->vdev.get_config = get_config; diff --git a/hw/virtio-serial.h b/hw/virtio-serial.h index f297b00..0548689 100644 --- a/hw/virtio-serial.h +++ b/hw/virtio-serial.h @@ -27,6 +27,8 @@ /* Features supported */ #define VIRTIO_CONSOLE_F_MULTIPORT 1 +#define VIRTIO_CONSOLE_BAD_ID (~(uint32_t)0) + struct virtio_console_config { /* * These two fields are used by VIRTIO_CONSOLE_F_SIZE which @@ -36,7 +38,6 @@ struct virtio_console_config { uint16_t rows; uint32_t max_nr_ports; - uint32_t nr_ports; } __attribute__((packed)); struct virtio_console_control { @@ -46,12 +47,14 @@ struct virtio_console_control { }; /* Some events for the internal messages (control packets) */ -#define VIRTIO_CONSOLE_PORT_READY 0 -#define VIRTIO_CONSOLE_CONSOLE_PORT 1 -#define VIRTIO_CONSOLE_RESIZE 2 -#define VIRTIO_CONSOLE_PORT_OPEN 3 -#define VIRTIO_CONSOLE_PORT_NAME 4 -#define VIRTIO_CONSOLE_PORT_REMOVE 5 +#define VIRTIO_CONSOLE_DEVICE_READY 0 +#define VIRTIO_CONSOLE_PORT_ADD 1 +#define VIRTIO_CONSOLE_PORT_REMOVE 2 +#define VIRTIO_CONSOLE_PORT_READY 3 +#define VIRTIO_CONSOLE_CONSOLE_PORT 4 +#define VIRTIO_CONSOLE_RESIZE 5 +#define VIRTIO_CONSOLE_PORT_OPEN 6 +#define VIRTIO_CONSOLE_PORT_NAME 7 /* == In-qemu interface == */ -- 1.7.0.3