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 <david@gibson.dropbear.id.au>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
This commit is contained in:
David Gibson 2014-12-19 14:57:26 +11:00 committed by Amit Shah
parent ab0302ee76
commit f2f6e00b2e

View File

@ -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);