xref: /openbmc/qemu/hw/s390x/css-bridge.c (revision 59a3a1c0)
1 /*
2  * css bridge implementation
3  *
4  * Copyright 2012,2016 IBM Corp.
5  * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
6  *            Pierre Morel <pmorel@linux.vnet.ibm.com>
7  *
8  * This work is licensed under the terms of the GNU GPL, version 2 or (at
9  * your option) any later version. See the COPYING file in the top-level
10  * directory.
11  */
12 
13 #include "qemu/osdep.h"
14 #include "qapi/error.h"
15 #include "hw/hotplug.h"
16 #include "hw/qdev-properties.h"
17 #include "hw/sysbus.h"
18 #include "qemu/bitops.h"
19 #include "qemu/module.h"
20 #include "hw/s390x/css.h"
21 #include "ccw-device.h"
22 #include "hw/s390x/css-bridge.h"
23 #include "cpu.h"
24 
25 /*
26  * Invoke device-specific unplug handler, disable the subchannel
27  * (including sending a channel report to the guest) and remove the
28  * device from the virtual css bus.
29  */
30 static void ccw_device_unplug(HotplugHandler *hotplug_dev,
31                               DeviceState *dev, Error **errp)
32 {
33     CcwDevice *ccw_dev = CCW_DEVICE(dev);
34     CCWDeviceClass *k = CCW_DEVICE_GET_CLASS(ccw_dev);
35     SubchDev *sch = ccw_dev->sch;
36     Error *err = NULL;
37 
38     if (k->unplug) {
39         k->unplug(hotplug_dev, dev, &err);
40         if (err) {
41             error_propagate(errp, err);
42             return;
43         }
44     }
45 
46     /*
47      * We should arrive here only for device_del, since we don't support
48      * direct hot(un)plug of channels.
49      */
50     assert(sch != NULL);
51     /* Subchannel is now disabled and no longer valid. */
52     sch->curr_status.pmcw.flags &= ~(PMCW_FLAGS_MASK_ENA |
53                                      PMCW_FLAGS_MASK_DNV);
54 
55     css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid, 1, 0);
56 
57     object_property_set_bool(OBJECT(dev), false, "realized", NULL);
58 }
59 
60 static void virtual_css_bus_reset(BusState *qbus)
61 {
62     /* This should actually be modelled via the generic css */
63     css_reset();
64 }
65 
66 static char *virtual_css_bus_get_dev_path(DeviceState *dev)
67 {
68     CcwDevice *ccw_dev = CCW_DEVICE(dev);
69     SubchDev *sch = ccw_dev->sch;
70     VirtualCssBridge *bridge =
71         VIRTUAL_CSS_BRIDGE(qdev_get_parent_bus(dev)->parent);
72 
73     /*
74      * We can't provide a dev path for backward compatibility on
75      * older machines, as it is visible in the migration stream.
76      */
77     return bridge->css_dev_path ?
78         g_strdup_printf("/%02x.%1x.%04x", sch->cssid, sch->ssid, sch->devno) :
79         NULL;
80 }
81 
82 static void virtual_css_bus_class_init(ObjectClass *klass, void *data)
83 {
84     BusClass *k = BUS_CLASS(klass);
85 
86     k->reset = virtual_css_bus_reset;
87     k->get_dev_path = virtual_css_bus_get_dev_path;
88 }
89 
90 static const TypeInfo virtual_css_bus_info = {
91     .name = TYPE_VIRTUAL_CSS_BUS,
92     .parent = TYPE_BUS,
93     .instance_size = sizeof(VirtualCssBus),
94     .class_init = virtual_css_bus_class_init,
95 };
96 
97 VirtualCssBus *virtual_css_bus_init(void)
98 {
99     VirtualCssBus *cbus;
100     BusState *bus;
101     DeviceState *dev;
102 
103     /* Create bridge device */
104     dev = qdev_create(NULL, TYPE_VIRTUAL_CSS_BRIDGE);
105     object_property_add_child(qdev_get_machine(), TYPE_VIRTUAL_CSS_BRIDGE,
106                               OBJECT(dev), NULL);
107     qdev_init_nofail(dev);
108 
109     /* Create bus on bridge device */
110     bus = qbus_create(TYPE_VIRTUAL_CSS_BUS, dev, "virtual-css");
111     cbus = VIRTUAL_CSS_BUS(bus);
112 
113     /* Enable hotplugging */
114     qbus_set_hotplug_handler(bus, OBJECT(dev), &error_abort);
115 
116     css_register_io_adapters(CSS_IO_ADAPTER_VIRTIO, true, false,
117                              0, &error_abort);
118 
119     return cbus;
120  }
121 
122 /***************** Virtual-css Bus Bridge Device ********************/
123 
124 static Property virtual_css_bridge_properties[] = {
125     DEFINE_PROP_BOOL("css_dev_path", VirtualCssBridge, css_dev_path,
126                      true),
127     DEFINE_PROP_END_OF_LIST(),
128 };
129 
130 static bool prop_get_true(Object *obj, Error **errp)
131 {
132     return true;
133 }
134 
135 static void virtual_css_bridge_class_init(ObjectClass *klass, void *data)
136 {
137     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
138     DeviceClass *dc = DEVICE_CLASS(klass);
139 
140     hc->unplug = ccw_device_unplug;
141     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
142     dc->props = virtual_css_bridge_properties;
143     object_class_property_add_bool(klass, "cssid-unrestricted",
144                                    prop_get_true, NULL, NULL);
145     object_class_property_set_description(klass, "cssid-unrestricted",
146             "A css device can use any cssid, regardless whether virtual"
147             " or not (read only, always true)",
148             NULL);
149 }
150 
151 static const TypeInfo virtual_css_bridge_info = {
152     .name          = TYPE_VIRTUAL_CSS_BRIDGE,
153     .parent        = TYPE_SYS_BUS_DEVICE,
154     .instance_size = sizeof(VirtualCssBridge),
155     .class_init    = virtual_css_bridge_class_init,
156     .interfaces = (InterfaceInfo[]) {
157         { TYPE_HOTPLUG_HANDLER },
158         { }
159     }
160 };
161 
162 static void virtual_css_register(void)
163 {
164     type_register_static(&virtual_css_bridge_info);
165     type_register_static(&virtual_css_bus_info);
166 }
167 
168 type_init(virtual_css_register)
169