From f2f6e00b2e27b65edaa6ce5cb01770c973cbf8fb Mon Sep 17 00:00:00 2001 From: David Gibson Date: Fri, 19 Dec 2014 14:57:26 +1100 Subject: virtio_serial: Don't use vser->config.max_nr_ports internally A number of places in the virtio_serial driver retrieve the number of ports from vser->config.max_nr_ports, which is guest-endian. But for internal users, we already have a host-endian copy of the number of ports in vser->serial.max_virtserial_ports. Using that instead of the config field removes the need for easy-to-forget byteswapping. In particular this fixes a bug on incoming migration, where we don't adjust the endianness vser->config correctly, because it hasn't yet been loaded from the migration stream when virtio_serial_load_device() is called. Signed-off-by: David Gibson Reviewed-by: Alexander Graf Signed-off-by: Amit Shah --- hw/char/virtio-serial-bus.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) (limited to 'hw/char') diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c index a7b1b68..e013504 100644 --- a/hw/char/virtio-serial-bus.c +++ b/hw/char/virtio-serial-bus.c @@ -559,7 +559,7 @@ static void virtio_serial_save_device(VirtIODevice *vdev, QEMUFile *f) qemu_put_be32s(f, &s->config.max_nr_ports); /* The ports map */ - max_nr_ports = virtio_tswap32(vdev, s->config.max_nr_ports); + max_nr_ports = s->serial.max_virtserial_ports; for (i = 0; i < (max_nr_ports + 31) / 32; i++) { qemu_put_be32s(f, &s->ports_map[i]); } @@ -715,13 +715,7 @@ static int virtio_serial_load_device(VirtIODevice *vdev, QEMUFile *f, qemu_get_be16s(f, (uint16_t *) &tmp); qemu_get_be32s(f, &tmp); - /* Note: this is the only location where we use tswap32() instead of - * virtio_tswap32() because: - * - virtio_tswap32() only makes sense when the device is fully restored - * - the target endianness that was used to populate s->config is - * necessarly the default one - */ - max_nr_ports = tswap32(s->config.max_nr_ports); + max_nr_ports = s->serial.max_virtserial_ports; for (i = 0; i < (max_nr_ports + 31) / 32; i++) { qemu_get_be32s(f, &ports_map); @@ -784,10 +778,9 @@ static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent) /* This function is only used if a port id is not provided by the user */ static uint32_t find_free_port_id(VirtIOSerial *vser) { - VirtIODevice *vdev = VIRTIO_DEVICE(vser); unsigned int i, max_nr_ports; - max_nr_ports = virtio_tswap32(vdev, vser->config.max_nr_ports); + max_nr_ports = vser->serial.max_virtserial_ports; for (i = 0; i < (max_nr_ports + 31) / 32; i++) { uint32_t map, bit; @@ -848,7 +841,6 @@ 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)); - VirtIODevice *vdev = VIRTIO_DEVICE(bus->vser); int max_nr_ports; bool plugging_port0; Error *err = NULL; @@ -890,7 +882,7 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp) } } - max_nr_ports = virtio_tswap32(vdev, port->vser->config.max_nr_ports); + 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); -- cgit v1.1 From 08f432aa3eb62d6d781eaa085e161e8628a9a538 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Fri, 19 Dec 2014 14:57:27 +1100 Subject: virtio-serial: Don't keep a persistent copy of config space The 'config' field in the VirtIOSerial structure keeps a copy of the virtio console's config space as visible to the guest, that is to say, in guest endianness. This is fiddly to maintain, because on some targets, such as powerpc, the "guest endianness" can change when a new guest OS boots. In fact, there's no need to maintain such a guest view of config space - instead we can reconstruct it from host-format data when it is accessed with get_config. Signed-off-by: David Gibson Reviewed-by: Alexander Graf Signed-off-by: Amit Shah --- hw/char/virtio-serial-bus.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) (limited to 'hw/char') diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c index e013504..37a6f44 100644 --- a/hw/char/virtio-serial-bus.c +++ b/hw/char/virtio-serial-bus.c @@ -482,10 +482,14 @@ static uint32_t get_features(VirtIODevice *vdev, uint32_t features) /* Guest requested config info */ static void get_config(VirtIODevice *vdev, uint8_t *config_data) { - VirtIOSerial *vser; - - vser = VIRTIO_SERIAL(vdev); - memcpy(config_data, &vser->config, sizeof(struct virtio_console_config)); + 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); } static void guest_reset(VirtIOSerial *vser) @@ -533,10 +537,6 @@ static void vser_reset(VirtIODevice *vdev) vser = VIRTIO_SERIAL(vdev); guest_reset(vser); - - /* In case we have switched endianness */ - vser->config.max_nr_ports = - virtio_tswap32(vdev, vser->serial.max_virtserial_ports); } static void virtio_serial_save(QEMUFile *f, void *opaque) @@ -551,12 +551,13 @@ static void virtio_serial_save_device(VirtIODevice *vdev, QEMUFile *f) VirtIOSerialPort *port; uint32_t nr_active_ports; unsigned int i, max_nr_ports; + struct virtio_console_config config; - /* The config space */ - qemu_put_be16s(f, &s->config.cols); - qemu_put_be16s(f, &s->config.rows); - - qemu_put_be32s(f, &s->config.max_nr_ports); + /* The config space (ignored on the far end in current versions) */ + get_config(vdev, (uint8_t *)&config); + qemu_put_be16s(f, &config.cols); + qemu_put_be16s(f, &config.rows); + qemu_put_be32s(f, &config.max_nr_ports); /* The ports map */ max_nr_ports = s->serial.max_virtserial_ports; @@ -987,8 +988,6 @@ static void virtio_serial_device_realize(DeviceState *dev, Error **errp) vser->ovqs[i] = virtio_add_queue(vdev, 128, handle_output); } - vser->config.max_nr_ports = - virtio_tswap32(vdev, vser->serial.max_virtserial_ports); vser->ports_map = g_malloc0(((vser->serial.max_virtserial_ports + 31) / 32) * sizeof(vser->ports_map[0])); /* -- cgit v1.1