xref: /openbmc/qemu/hw/s390x/css-bridge.c (revision 520e210c)
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 #include "qemu/osdep.h"
13 #include "qapi/error.h"
14 #include "hw/hotplug.h"
15 #include "hw/sysbus.h"
16 #include "qemu/bitops.h"
17 #include "hw/s390x/css.h"
18 #include "ccw-device.h"
19 #include "hw/s390x/css-bridge.h"
20 #include "cpu.h"
21 
22 /*
23  * Invoke device-specific unplug handler, disable the subchannel
24  * (including sending a channel report to the guest) and remove the
25  * device from the virtual css bus.
26  */
27 static void ccw_device_unplug(HotplugHandler *hotplug_dev,
28                               DeviceState *dev, Error **errp)
29 {
30     CcwDevice *ccw_dev = CCW_DEVICE(dev);
31     CCWDeviceClass *k = CCW_DEVICE_GET_CLASS(ccw_dev);
32     SubchDev *sch = ccw_dev->sch;
33     Error *err = NULL;
34 
35     if (k->unplug) {
36         k->unplug(hotplug_dev, dev, &err);
37         if (err) {
38             error_propagate(errp, err);
39             return;
40         }
41     }
42 
43     /*
44      * We should arrive here only for device_del, since we don't support
45      * direct hot(un)plug of channels.
46      */
47     assert(sch != NULL);
48     /* Subchannel is now disabled and no longer valid. */
49     sch->curr_status.pmcw.flags &= ~(PMCW_FLAGS_MASK_ENA |
50                                      PMCW_FLAGS_MASK_DNV);
51 
52     css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid, 1, 0);
53 
54     object_unparent(OBJECT(dev));
55 }
56 
57 static void virtual_css_bus_reset(BusState *qbus)
58 {
59     /* This should actually be modelled via the generic css */
60     css_reset();
61 }
62 
63 static char *virtual_css_bus_get_dev_path(DeviceState *dev)
64 {
65     CcwDevice *ccw_dev = CCW_DEVICE(dev);
66     SubchDev *sch = ccw_dev->sch;
67     VirtualCssBridge *bridge =
68         VIRTUAL_CSS_BRIDGE(qdev_get_parent_bus(dev)->parent);
69 
70     /*
71      * We can't provide a dev path for backward compatibility on
72      * older machines, as it is visible in the migration stream.
73      */
74     return bridge->css_dev_path ?
75         g_strdup_printf("/%02x.%1x.%04x", sch->cssid, sch->ssid, sch->devno) :
76         NULL;
77 }
78 
79 static void virtual_css_bus_class_init(ObjectClass *klass, void *data)
80 {
81     BusClass *k = BUS_CLASS(klass);
82 
83     k->reset = virtual_css_bus_reset;
84     k->get_dev_path = virtual_css_bus_get_dev_path;
85 }
86 
87 static const TypeInfo virtual_css_bus_info = {
88     .name = TYPE_VIRTUAL_CSS_BUS,
89     .parent = TYPE_BUS,
90     .instance_size = sizeof(VirtualCssBus),
91     .class_init = virtual_css_bus_class_init,
92 };
93 
94 VirtualCssBus *virtual_css_bus_init(void)
95 {
96     VirtualCssBus *cbus;
97     BusState *bus;
98     DeviceState *dev;
99 
100     /* Create bridge device */
101     dev = qdev_create(NULL, TYPE_VIRTUAL_CSS_BRIDGE);
102     object_property_add_child(qdev_get_machine(), TYPE_VIRTUAL_CSS_BRIDGE,
103                               OBJECT(dev), NULL);
104     qdev_init_nofail(dev);
105 
106     /* Create bus on bridge device */
107     bus = qbus_create(TYPE_VIRTUAL_CSS_BUS, dev, "virtual-css");
108     cbus = VIRTUAL_CSS_BUS(bus);
109 
110     /* Enable hotplugging */
111     qbus_set_hotplug_handler(bus, OBJECT(dev), &error_abort);
112 
113     css_register_io_adapters(CSS_IO_ADAPTER_VIRTIO, true, false,
114                              0, &error_abort);
115 
116     return cbus;
117  }
118 
119 /***************** Virtual-css Bus Bridge Device ********************/
120 
121 static Property virtual_css_bridge_properties[] = {
122     DEFINE_PROP_BOOL("css_dev_path", VirtualCssBridge, css_dev_path,
123                      true),
124     DEFINE_PROP_END_OF_LIST(),
125 };
126 
127 static bool prop_get_true(Object *obj, Error **errp)
128 {
129     return true;
130 }
131 
132 static void virtual_css_bridge_class_init(ObjectClass *klass, void *data)
133 {
134     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
135     DeviceClass *dc = DEVICE_CLASS(klass);
136 
137     hc->unplug = ccw_device_unplug;
138     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
139     dc->props = virtual_css_bridge_properties;
140     object_class_property_add_bool(klass, "cssid-unrestricted",
141                                    prop_get_true, NULL, NULL);
142     object_class_property_set_description(klass, "cssid-unrestricted",
143             "A css device can use any cssid, regardless whether virtual"
144             " or not (read only, always true)",
145             NULL);
146 }
147 
148 static const TypeInfo virtual_css_bridge_info = {
149     .name          = TYPE_VIRTUAL_CSS_BRIDGE,
150     .parent        = TYPE_SYS_BUS_DEVICE,
151     .instance_size = sizeof(VirtualCssBridge),
152     .class_init    = virtual_css_bridge_class_init,
153     .interfaces = (InterfaceInfo[]) {
154         { TYPE_HOTPLUG_HANDLER },
155         { }
156     }
157 };
158 
159 static void virtual_css_register(void)
160 {
161     type_register_static(&virtual_css_bridge_info);
162     type_register_static(&virtual_css_bus_info);
163 }
164 
165 type_init(virtual_css_register)
166