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>
stable-2.7
Cornelia Huck 2016-07-11 12:55:44 +02:00
parent 727a0424dd
commit 2a79eb1a61
3 changed files with 36 additions and 1 deletions

View File

@ -59,11 +59,28 @@ static void virtual_css_bus_reset(BusState *qbus)
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 = {
@ -95,6 +112,12 @@ VirtualCssBus *virtual_css_bus_init(void)
/***************** 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);
@ -102,12 +125,13 @@ static void virtual_css_bridge_class_init(ObjectClass *klass, void *data)
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(SysBusDevice),
.instance_size = sizeof(VirtualCssBridge),
.class_init = virtual_css_bridge_class_init,
.interfaces = (InterfaceInfo[]) {
{ TYPE_HOTPLUG_HANDLER },

View File

@ -322,6 +322,10 @@ static const TypeInfo ccw_machine_info = {
.driver = TYPE_S390_IPL,\
.property = "iplbext_migration",\
.value = "off",\
}, {\
.driver = TYPE_VIRTUAL_CSS_BRIDGE,\
.property = "css_dev_path",\
.value = "off",\
},
#define CCW_COMPAT_2_5 \

View File

@ -16,7 +16,14 @@
#include "hw/qdev-core.h"
/* virtual css bridge */
typedef struct VirtualCssBridge {
SysBusDevice sysbus_dev;
bool css_dev_path;
} VirtualCssBridge;
#define TYPE_VIRTUAL_CSS_BRIDGE "virtual-css-bridge"
#define VIRTUAL_CSS_BRIDGE(obj) \
OBJECT_CHECK(VirtualCssBridge, (obj), TYPE_VIRTUAL_CSS_BRIDGE)
/* virtual css bus type */
typedef struct VirtualCssBus {