qemu/hw/s390x/css-bridge.c
Cornelia Huck 2a79eb1a61 s390x/css: provide a dev_path for css devices
We need to implement the get_dev_path method for the css bus, or
else we might end up with two different devices having the same
qdev_path.

This was noticed when adding two scsi_hd controllers: The SCSIBus
code will produce a non-unique dev_path for vmstate usage if the
parent bus does not provide the get_dev_path method.

We simply use the device's bus id, as this is unique and we won't
have any deeper hierarchy from a channel subsystem perspective
anyway.

Note that we need to disable this for older machine versions,
as this changes the migration format.

Reported-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-07-20 15:47:25 +02:00

149 lines
4.1 KiB
C

/*
* css bridge implementation
*
* Copyright 2012,2016 IBM Corp.
* Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
* Pierre Morel <pmorel@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or (at
* your option) any later version. See the COPYING file in the top-level
* directory.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "hw/hotplug.h"
#include "hw/sysbus.h"
#include "qemu/bitops.h"
#include "hw/s390x/css.h"
#include "ccw-device.h"
#include "hw/s390x/css-bridge.h"
/*
* Invoke device-specific unplug handler, disable the subchannel
* (including sending a channel report to the guest) and remove the
* device from the virtual css bus.
*/
static void ccw_device_unplug(HotplugHandler *hotplug_dev,
DeviceState *dev, Error **errp)
{
CcwDevice *ccw_dev = CCW_DEVICE(dev);
CCWDeviceClass *k = CCW_DEVICE_GET_CLASS(ccw_dev);
SubchDev *sch = ccw_dev->sch;
Error *err = NULL;
if (k->unplug) {
k->unplug(hotplug_dev, dev, &err);
if (err) {
error_propagate(errp, err);
return;
}
}
/*
* We should arrive here only for device_del, since we don't support
* direct hot(un)plug of channels.
*/
assert(sch != NULL);
/* Subchannel is now disabled and no longer valid. */
sch->curr_status.pmcw.flags &= ~(PMCW_FLAGS_MASK_ENA |
PMCW_FLAGS_MASK_DNV);
css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid, 1, 0);
object_unparent(OBJECT(dev));
}
static void virtual_css_bus_reset(BusState *qbus)
{
/* This should actually be modelled via the generic css */
css_reset();
}
static char *virtual_css_bus_get_dev_path(DeviceState *dev)
{
CcwDevice *ccw_dev = CCW_DEVICE(dev);
SubchDev *sch = ccw_dev->sch;
VirtualCssBridge *bridge =
VIRTUAL_CSS_BRIDGE(qdev_get_parent_bus(dev)->parent);
/*
* We can't provide a dev path for backward compatibility on
* older machines, as it is visible in the migration stream.
*/
return bridge->css_dev_path ?
g_strdup_printf("/%02x.%1x.%04x", sch->cssid, sch->ssid, sch->devno) :
NULL;
}
static void virtual_css_bus_class_init(ObjectClass *klass, void *data)
{
BusClass *k = BUS_CLASS(klass);
k->reset = virtual_css_bus_reset;
k->get_dev_path = virtual_css_bus_get_dev_path;
}
static const TypeInfo virtual_css_bus_info = {
.name = TYPE_VIRTUAL_CSS_BUS,
.parent = TYPE_BUS,
.instance_size = sizeof(VirtualCssBus),
.class_init = virtual_css_bus_class_init,
};
VirtualCssBus *virtual_css_bus_init(void)
{
VirtualCssBus *cbus;
BusState *bus;
DeviceState *dev;
/* Create bridge device */
dev = qdev_create(NULL, TYPE_VIRTUAL_CSS_BRIDGE);
qdev_init_nofail(dev);
/* Create bus on bridge device */
bus = qbus_create(TYPE_VIRTUAL_CSS_BUS, dev, "virtual-css");
cbus = VIRTUAL_CSS_BUS(bus);
/* Enable hotplugging */
qbus_set_hotplug_handler(bus, dev, &error_abort);
return cbus;
}
/***************** Virtual-css Bus Bridge Device ********************/
static Property virtual_css_bridge_properties[] = {
DEFINE_PROP_BOOL("css_dev_path", VirtualCssBridge, css_dev_path,
true),
DEFINE_PROP_END_OF_LIST(),
};
static void virtual_css_bridge_class_init(ObjectClass *klass, void *data)
{
HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
DeviceClass *dc = DEVICE_CLASS(klass);
hc->unplug = ccw_device_unplug;
set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
dc->props = virtual_css_bridge_properties;
}
static const TypeInfo virtual_css_bridge_info = {
.name = TYPE_VIRTUAL_CSS_BRIDGE,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(VirtualCssBridge),
.class_init = virtual_css_bridge_class_init,
.interfaces = (InterfaceInfo[]) {
{ TYPE_HOTPLUG_HANDLER },
{ }
}
};
static void virtual_css_register(void)
{
type_register_static(&virtual_css_bridge_info);
type_register_static(&virtual_css_bus_info);
}
type_init(virtual_css_register)