xref: /openbmc/qemu/hw/s390x/css-bridge.c (revision fc8c745d)
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 
24 /*
25  * Invoke device-specific unplug handler, disable the subchannel
26  * (including sending a channel report to the guest) and remove the
27  * device from the virtual css bus.
28  */
29 static void ccw_device_unplug(HotplugHandler *hotplug_dev,
30                               DeviceState *dev, Error **errp)
31 {
32     CcwDevice *ccw_dev = CCW_DEVICE(dev);
33     CCWDeviceClass *k = CCW_DEVICE_GET_CLASS(ccw_dev);
34     SubchDev *sch = ccw_dev->sch;
35     Error *err = NULL;
36 
37     if (k->unplug) {
38         k->unplug(hotplug_dev, dev, &err);
39         if (err) {
40             error_propagate(errp, err);
41             return;
42         }
43     }
44 
45     /*
46      * We should arrive here only for device_del, since we don't support
47      * direct hot(un)plug of channels.
48      */
49     assert(sch != NULL);
50     /* Subchannel is now disabled and no longer valid. */
51     sch->curr_status.pmcw.flags &= ~(PMCW_FLAGS_MASK_ENA |
52                                      PMCW_FLAGS_MASK_DNV);
53 
54     css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid, 1, 0);
55 
56     qdev_unrealize(dev);
57 }
58 
59 static void virtual_css_bus_reset(BusState *qbus)
60 {
61     /* This should actually be modelled via the generic css */
62     css_reset();
63 }
64 
65 static char *virtual_css_bus_get_dev_path(DeviceState *dev)
66 {
67     CcwDevice *ccw_dev = CCW_DEVICE(dev);
68     SubchDev *sch = ccw_dev->sch;
69     VirtualCssBridge *bridge =
70         VIRTUAL_CSS_BRIDGE(qdev_get_parent_bus(dev)->parent);
71 
72     /*
73      * We can't provide a dev path for backward compatibility on
74      * older machines, as it is visible in the migration stream.
75      */
76     return bridge->css_dev_path ?
77         g_strdup_printf("/%02x.%1x.%04x", sch->cssid, sch->ssid, sch->devno) :
78         NULL;
79 }
80 
81 static void virtual_css_bus_class_init(ObjectClass *klass, void *data)
82 {
83     BusClass *k = BUS_CLASS(klass);
84 
85     k->reset = virtual_css_bus_reset;
86     k->get_dev_path = virtual_css_bus_get_dev_path;
87 }
88 
89 static const TypeInfo virtual_css_bus_info = {
90     .name = TYPE_VIRTUAL_CSS_BUS,
91     .parent = TYPE_BUS,
92     .instance_size = sizeof(VirtualCssBus),
93     .class_init = virtual_css_bus_class_init,
94 };
95 
96 VirtualCssBus *virtual_css_bus_init(void)
97 {
98     VirtualCssBus *cbus;
99     BusState *bus;
100     DeviceState *dev;
101 
102     /* Create bridge device */
103     dev = qdev_new(TYPE_VIRTUAL_CSS_BRIDGE);
104     object_property_add_child(qdev_get_machine(), TYPE_VIRTUAL_CSS_BRIDGE,
105                               OBJECT(dev));
106     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
107 
108     /* Create bus on bridge device */
109     bus = qbus_create(TYPE_VIRTUAL_CSS_BUS, dev, "virtual-css");
110     cbus = VIRTUAL_CSS_BUS(bus);
111 
112     /* Enable hotplugging */
113     qbus_set_hotplug_handler(bus, OBJECT(dev));
114 
115     css_register_io_adapters(CSS_IO_ADAPTER_VIRTIO, true, false,
116                              0, &error_abort);
117 
118     return cbus;
119  }
120 
121 /***************** Virtual-css Bus Bridge Device ********************/
122 
123 static Property virtual_css_bridge_properties[] = {
124     DEFINE_PROP_BOOL("css_dev_path", VirtualCssBridge, css_dev_path,
125                      true),
126     DEFINE_PROP_END_OF_LIST(),
127 };
128 
129 static bool prop_get_true(Object *obj, Error **errp)
130 {
131     return true;
132 }
133 
134 static void virtual_css_bridge_class_init(ObjectClass *klass, void *data)
135 {
136     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
137     DeviceClass *dc = DEVICE_CLASS(klass);
138 
139     hc->unplug = ccw_device_unplug;
140     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
141     device_class_set_props(dc, virtual_css_bridge_properties);
142     object_class_property_add_bool(klass, "cssid-unrestricted",
143                                    prop_get_true, NULL);
144     object_class_property_set_description(klass, "cssid-unrestricted",
145             "A css device can use any cssid, regardless whether virtual"
146             " or not (read only, always true)");
147 }
148 
149 static const TypeInfo virtual_css_bridge_info = {
150     .name          = TYPE_VIRTUAL_CSS_BRIDGE,
151     .parent        = TYPE_SYS_BUS_DEVICE,
152     .instance_size = sizeof(VirtualCssBridge),
153     .class_init    = virtual_css_bridge_class_init,
154     .interfaces = (InterfaceInfo[]) {
155         { TYPE_HOTPLUG_HANDLER },
156         { }
157     }
158 };
159 
160 static void virtual_css_register(void)
161 {
162     type_register_static(&virtual_css_bridge_info);
163     type_register_static(&virtual_css_bus_info);
164 }
165 
166 type_init(virtual_css_register)
167